Background/Objectives: Natural therapeutics for the treatment of diabetes mellitus represent a common challenge for many researchers. Thus, the aim of this study was to evaluate the antihyperglycemic and anti-inflammatory effects and the hepatic antioxidant activities of both diosmin and linagliptin on nicotinamide/streptozotocin-induced diabetes mellitus in rats. Methods: Induction of diabetes mellitus was produced by injecting an intraperitoneal dose of nicotinamide (60 mg/kg) to 16-hour-fasted rats, then after 15 min, an intraperitoneal dose of streptozotocin (60 mg/kg) was injected. The rats with diabetes were orally treated with linagliptin (1 mg/kg), diosmin (10 mg/kg), and both of them every other day for 4 weeks. Results: The elevated hepatic glucose-6-phosphatase and glycogen phosphorylase activities, the lowered concentrations of serum insulin, C-peptide, and hepatic glycogen, and the diminished hepatic antioxidant defense system of nicotinamide/streptozotocin-induced diabetic rats were all potentially improved by the therapies. The treatments also improved the deteriorated adiponectin and resistin mRNA expression in visceral adipose tissue of nicotinamide/streptozotocin-induced diabetic rats. In addition, the treatments induced a recovery of damaged islets of Langerhans and a regeneration of islet cells in association with the enhancement of the formation of insulin granules in β-cells and the improvement of kidney function; the combined effect was the most potent. Conclusions: Diosmin alone or in combination with linagliptin has potent antidiabetic effects, which were managed through their insulinotropic and insulin-improving actions. The diosmin in combination with linagliptin has the most potent antihyperglycemic effects.

Despite pharmacological and lifestyle changes, hyperglycemia management in type 2 diabetes mellitus patients, combined with a risk for cardio-renal problems, continues to present a significant challenge for doctors. Linagliptin has been found to have a renoprotective effect in diabetic nephropathy patients in recent studies. This systematic review and meta-analysis (SRMA) was conducted to synthesize available information so as to better understand if linagliptin has a renoprotective effect in type 2 diabetes mellitus patients with nephropathy. Three databases were searched from January 2013 to December 2022 to identify all published studies reporting "linagliptin's effect in patients with diabetic nephropathy". Owing to the heterogeneity of the included studies, the authors have employed a random-effects model to examine the data in this meta-analysis. Standardized mean differences (SMD) for continuous outcomes were used to compute effect sizes. The final analysis included five studies. The change in estimated glomerular filtration rate (eGFR) did not show a statistically significant difference between the group on linagliptin and the other group on placebo, at baseline (mean difference = 1.19, p = 0.28), after three months of intervention in the selected three studies (mean difference = 0.51, p = 0.85), and after six months of intervention in the selected two studies (mean difference = 0.72, p = 0.70). The study found that linagliptin did not have a significant renoprotective effect in patients with type 2 diabetes, indicating no substantial benefit in slowing kidney disease progression. For diabetes patients with chronic renal disease, linagliptin may be a helpful renoprotective treatment choice, but in the future, more robust and longer-duration research is warranted to establish the inference.

Bayesian borrowing analyses have an important role in the design and analysis of pediatric trials. This paper describes use of a prespecified Pharmacometrics Enhanced Bayesian Borrowing (PEBB) analysis that was conducted to overcome an expectation for reduced statistical power in the pediatric DINAMO trial due to a greater than expected variability in the primary endpoint. The DINAMO trial assessed the efficacy and safety of an empagliflozin dosing regimen versus placebo and linagliptin versus placebo on glycemic control (change in HbA1c over 26 weeks) in young people with type 2 diabetes (T2D). Previously fitted pharmacokinetic and exposure-response models for empagliflozin and linagliptin based on available historical data in adult and pediatric patients with T2D were used to simulate participant data and derive the informative component of a Bayesian robust mixture prior distribution. External experts and representatives from the U.S. Food and Drug Administration provided recommendations to determine the effective sample size of the prior and the weight of the informative prior component. Separate exposure response-based Bayesian borrowing analyses for empagliflozin and linagliptin showed posterior mean and 95% credible intervals that were consistent with the trial results. Sensitivity analyses with a full range of alternative weights were also performed. The use of PEBB in this analysis combined advantages of mechanistic modeling of pharmacometric differences between adults and young people with T2D, with advantages of partial extrapolation through Bayesian dynamic borrowing. Our findings suggest that the described PEBB approach is a promising option to optimize the power for future pediatric trials.

Sitagliptin functions similarly to GLP-1RAs by incretin and insulin secretion and has a renoprotective effect. Diabetic kidney disease (DKD) is a kidney complication that increases the mortality rate in type 2 diabetes mellitus (T2DM) patients. The important parameters that predict appropriate sitagliptin treatment are known as factors. This study aimed to assess factors that correlated with the renoprotective effect of sitagliptin in patients with T2DM.

This retrospective study collected data from a tertiary hospital in Thailand. All T2DM patients who were treated with sitagliptin and had complete data were recruited to analyze the outcome. The primary outcome was a correlation between demographics, laboratory data, and kidney outcome. The secondary outcome was the different laboratory results between pre- and posttreatment of patients treated with sitagliptin.

The number of patients who were treated for T2DM with sitagliptin was 191. Only 102 patients had complete laboratory parameters. Results showed a positive correlation between baseline FBS, HbA1c, and Scr change (p value = 0.042 and 0.005) at 6 months and baseline age, TG, and Scr change (p value = 0.010 and 0.022) at 18 months; while a negative correlation was observed between baseline FBS, HbA1c, and eGFR change (p value = 0.017 and 0.007) at 6 months and baseline age and eGFR change (p value = 0.010) and between HDL-cholesterol and Scr change at 18 months (p value = 0.044). The eGFR stage 1 subgroup showed a positive correlation between baseline HbA1c and Scr change (p value <0.001) and baseline DM duration and eGFR change (p value = 0.004). Moreover, sitagliptin showed statistically significant FBS, HbA1c, LDL-cholesterol, and TC reduction. Furthermore, HDL-cholesterol showed statistically significant elevation.

FBS, HbA1c, and age were factors that correlated with the renoprotective effect of sitagliptin. The eGFR ≥90.00 ml/min/1.73 m2 patients group showed a duration of DM in which factors correlated with renoprotective effect. Moreover, sitagliptin also can improve glucose levels and lipid profile.

Linagliptin is an oral dipeptidyl peptidase DPP-4 inhibitor, which is indicated for the treatment of Type 2 diabetes mellitus (T2DM) as monotherapy or add-on to therapy with other hypoglycemic drugs.

We aimed to summarize the evidence from randomized controlled trials (RCTs) to assess the safety of linagliptin focusing on cardiovascular risks among subjects with type 2 diabetes mellitus.

We conducted a systematic search across the following databases: Medline, Embase, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov from inception to November 2021. Randomized controlled trials (RCTs) of linagliptin compared to placebo in patients with Type 2 diabetes were included. The primary safety points were cardiovascular (CV) adverse events including non-fatal stroke, non-fatal myocardial infarction (MI), CV death, MI, stroke, and hospitalization for unstable angina. While, secondary safety points included 17 reported adverse events such as infections, hypoglycemia and abdominal pain. Three reviewers independently screened and reviewed each study to extract relevant information. Any discrepancies were resolved by consensus. We conducted a meta-analysis using the random effects model. Pooled risk ratios (RRs) of targeted adverse events with linagliptin compared to placebo were estimated using the Mantel-Haenszel test.

A total of 24 studies with 19,981 adult patients were included. There was no difference in the incidence of all CV adverse events or individual CV adverse events between linagliptin and the placebo arms. The pooled estimate of the risk of upper respiratory tract infection was reported in twelve trials with a 38% risk reduction among patients treated with the linagliptin group compared to the placebo group (RR = 0.62, 95% CI: 0.45-0.85, and I2 = 0%), while no difference was found in other infections. For gastrointestinal disorders, the risk of abdominal pain showed a 65% risk reduction among patients treated with the linagliptin group compared to the placebo group (RR = 0.35, 95% CI: 0.16-0.77, and I2 = 0%).

Our study showed an overall acceptable safety profile of linagliptin in patients with T2DM. Moreover, our study showed a risk reduction of upper respiratory tract infection and abdominal pain when using linagliptin compared to placebo.

The linagliptin (LIN) and pioglitazone HCl (PIO) combination, currently undergoing phase III clinical trials for diabetes mellitus treatment, demonstrated significant improvements in glycemic control. However, the absence of an analytical method for simultaneous determination in biological fluids highlights a crucial gap. This underscores the pressing need for sensitive bioanalytical methods, emphasizing the paramount importance of developing such tools to advance diabetes management strategies and enhance patient care. Herein, a sensitive reverse-phase high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry method was developed for simultaneous determination of LIN and PIO in rat plasma using alogliptin as an internal standard. Chromatographic separation was performed on an Agilent Eclipse Plus C18 (4.6 × 100 mm, 3.5 μm) using an isocratic mobile phase system consisting of ammonium formate (pH 4.5) and methanol using an acetonitrile-induced protein precipitation technique for sample preparation. Multiple reaction monitoring in positive ion mode was used for quantitation of the precursor to production at m/z 473.2 → 419.9 for LIN, 357.1 → 134.2 for PIO, and 340.3 → 116.1 for ALO. The linearity range was 0.5 to 100 and 1 to 2000 ng/mL for LIN and PIO, respectively. The developed method was validated as per US-FDA guidelines and successfully applied to clinical pharmacokinetic and drug-drug interaction studies with a single oral administration of LIN and PIO in rat plasma. Pharmacokinetic parameters of LIN were significantly influenced by the concomitant administration of PIO and vice versa. Molecular modeling revealed the significant interaction of LIN and PIO with P-glycoprotein. Therefore, the drug-drug interaction between LIN and PIO deserves further study to improve drug therapy and prevent dangerous adverse effects.

Islet β-cell dysfunction is a basic pathophysiological characteristic of type 2 diabetes mellitus (T2DM). Appropriate assessment of islet β-cell function is beneficial to better management of T2DM. Protecting islet β-cell function is vital to delay the progress of type 2 diabetes mellitus. Therefore, the Pancreatic Islet β-cell Expert Panel of the Chinese Diabetes Society and Endocrinology Society of Jiangsu Medical Association organized experts to draft the "Clinical expert consensus on the assessment and protection of pancreatic islet β-cell function in type 2 diabetes mellitus." This consensus suggests that β-cell function can be clinically assessed using blood glucose-based methods or methods that combine blood glucose and endogenous insulin or C-peptide levels. Some measures, including weight loss and early and sustained euglycemia control, could effectively protect islet β-cell function, and some newly developed drugs, such as Sodium-glucose cotransporter-2 inhibitor and Glucagon-like peptide-1 receptor agonists, could improve islet β-cell function, independent of glycemic control.

There are multiple glucose-lowering drugs available as alternative initial monotherapy for type 2 diabetes patients with contraindications or intolerance to metformin. However, little comparative and systematic data are available for them as initial monotherapy. This study estimated and compared the treatment effects of glucose-lowering drugs as initial monotherapy for type 2 diabetes.

PubMed, Web of Science, Embase, CNKI, Chongqing VIP, and WanFang Data from 1 January 1990 until 31 December 2020 were searched for randomized controlled trials which compared a glucose-lowering drug with placebo/lifestyle-intervention for type 2 diabetes. Drug classes included metformin, sulfonylureas (SUs), thiazolidinediones (TZDs), glinides (NIDEs), α-glucosidase inhibitors (AGIs), dipeptidyl peptidase-4 inhibitors (DPP-4is), sodium-glucose cotransporter-2 inhibitors (SGLT2is), insulins (INSs), and glucagon-like peptide-1 receptor agonists (GLP-1RAs).

A total of 185 trials were included, identifying 38,376 patients from 56 countries across six continents. When choosing an initial drug monotherapy alternative to metformin, SUs were most efficacious in reducing HbA1c (-1.39%; 95% CI -1.63, -1.16) and FPG (-2.70 mmol/L; 95% CI -3.18, -2.23), but increased hypoglycemia risks (5.44; 95% CI 2.11, 14.02). GLP-1RAs were most efficacious in reducing BMI (-1.05 kg/m²; 95% CI -1.81, -0.29) and TC (-0.42 mmol/L; 95% CI -0.61, -0.22). TZDs were most efficacious in increasing HDL-C (0.12 mmol/L; 95% CI 0.07, 0.17). SGLT2is were most efficacious in lowering SBP (-4.18 mmHg; 95% CI -4.84, -3.53). While AGIs conferred higher risk of AE-induced discontinuations (2.57; 95% CI 1.64, 4.03). Overall, only GLP-1RAs showed an integrated beneficial effect on all outcomes. Our results also confirmed the intraclass differences in treatment effects across drugs. Most trials were short-term, and no significant differences in mortality, total vascular events, myocardial infarction, heart failure, stroke, or diabetic nephropathy were observed across drug classes.

Our results suggest a potential treatment hierarchy for decision-makers, with GLP-1RAs being the preferred alternative therapy to metformin regarding their favorable efficacy and safety profiles.

In contrast to Western population, glucagon-like peptide-1 (GLP-1) levels are preserved in some East Asian population with type 2 diabetes (T2D), explaining why dipeptidyl peptidase-IV (DPP-IV) inhibitors are more effective in East Asians. We assessed whether differences in endogenous GLP-1 levels resulted in different treatment responses to DPP-IV inhibitors in prediabetes and T2D.

A prospective 12-week study using linagliptin 5mg once daily in 50 subjects (28 prediabetes and 22 T2D) who were stratified into high versus low fasting GLP-1 groups. A 75-g oral glucose tolerance test (OGTT) was performed at week 0 and 12. Primary outcomes were changes in HbA1c, fasting and post-OGTT glucose after 12 weeks. Secondary outcomes included changes in insulin resistance and beta cell function indices.

There was a greater HbA1c reduction in subjects with high GLP-1 compared to low GLP-1 levels in both the prediabetes and T2D populations [least-squares mean (LS-mean) change of -0.33% vs. -0.11% and -1.48% vs. -0.90% respectively)]. Linagliptin significantly reduced glucose excursion by 18% in high GLP-1 compared with 8% in low GLP-1 prediabetes groups. The reduction in glucose excursion was greater in high GLP-1 compared to low GLP-1 T2D by 30% and 21% respectively. There were significant LS-mean between-group differences in fasting glucose (-0.95 mmol/L), 2-hour glucose post-OGTT (-2.4 mmol/L) in the high GLP-1 T2D group. Improvement in insulin resistance indices were seen in the high GLP-1 T2D group while high GLP-1 prediabetes group demonstrated improvement in beta cell function indices. No incidence of hypoglycemia was reported.

Linagliptin resulted in a greater HbA1c reduction in the high GLP-1 prediabetes and T2D compared to low GLP-1 groups. Endogenous GLP-1 level play an important role in determining the efficacy of DPP-IV inhibitors irrespective of the abnormal glucose tolerance states.

Impaired secretion of glucagon-like peptide-1 (GLP-1) among Caucasians contributes to reduced incretin effect in type 2 diabetes mellitus (T2DM) patients. However, studies emanating from East Asia suggested preserved GLP-1 levels in pre-diabetes (pre-DM) and T2DM. We aimed to resolve these conflicting findings by investigating GLP-1 levels during oral glucose tolerance test (OGTT) among Malay, Chinese, and Indian ethnicities with normal glucose tolerance (NGT), pre-DM, and T2DM. The association between total GLP-1 levels, insulin resistance, and insulin sensitivity, and GLP-1 predictors were also analyzed.

A total of 174 subjects were divided into NGT (n=58), pre-DM (n=54), and T2DM (n=62). Plasma total GLP-1 concentrations were measured at 0, 30, and 120 min during a 75-g OGTT. Homeostasis model assessment of insulin resistance (HOMA-IR), HOMA of insulin sensitivity (HOMA-IS), and triglyceride-glucose index (TyG) were calculated.

Total GLP-1 levels at fasting and 30 min were significantly higher in T2DM compared with pre-DM and NGT (27.18 ± 11.56 pmol/L vs. 21.99 ± 10.16 pmol/L vs. 16.24 ± 7.79 pmol/L, p=0.001; and 50.22 ± 18.03 pmol/L vs. 41.05 ± 17.68 pmol/L vs. 31.44 ± 22.59 pmol/L, p<0.001; respectively). Ethnicity was a significant determinant of AUCGLP-1, with the Indians exhibiting higher GLP-1 responses than Chinese and Malays. Indians were the most insulin resistant, whereas Chinese were the most insulin sensitive. The GLP-1 levels were positively correlated with HOMA-IR and TyG but negatively correlated with HOMA-IS. This relationship was evident among Indians who exhibited augmented GLP-1 responses proportionately to their high insulin-resistant states.

This is the first study that showed GLP-1 responses are augmented as IR states increase. Fasting and post-OGTT GLP-1 levels are raised in T2DM and pre-DM compared to that in NGT. This raises a possibility of an adaptive compensatory response that has not been reported before. Among the three ethnic groups, the Indians has the highest IR and GLP-1 levels supporting the notion of an adaptive compensatory secretion of GLP-1.

Safety and tolerability of glucose-lowering drugs is a key consideration for use in type 2 diabetes (T2D). We evaluated the safety and tolerability of the dipeptidyl peptidase-4 inhibitor linagliptin in Asian patients with T2D.

This was a post-hoc, descriptive pooled analysis of 21 randomized, double-blind, placebo-controlled clinical trials of linagliptin in T2D patients lasting ≤52 weeks. We evaluated adverse events (AEs) and laboratory parameters in Asian participants living in Asia, both overall and in the East Asian subgroup.

This analysis included 4457 Asian patients overall (2712 receiving linagliptin; 1745 receiving placebo) and 3057 (68.6%) East Asians. AEs were reported in 1510 (55.7%) Asian patients receiving linagliptin and 1032 (59.1%) receiving placebo but were considered drug-related in only 13.0% of each group. Serious AEs occurred in 109 (4.0%) linagliptin patients and 90 (5.2%) placebo patients. The most common AEs were nasopharyngitis (6.4% linagliptin, 7.3% placebo), upper respiratory tract infection (5.7% linagliptin, 6.5% placebo), and hypoglycemia (7.3% linagliptin, 6.3% placebo). One linagliptin patient had pancreatitis; none had bullous pemphigoid. No clinically relevant mean changes in laboratory parameters occurred. These findings were consistent in East Asians.

Linagliptin is well tolerated in Asian T2D patients, including East Asians, with low risk for AEs.

During the related substances testing method development for linagliptin tablet, an unknown peak was observed in HPLC chromatograms with a level exceeding the identification threshold. By using a strategy that combines LC-PDA/UV-MSⁿ with mechanism-based stress studies, the unknown peak was rapidly identified as linagliptin urea, a solution degradant that is caused by the reaction between the API and hydrocyanic acid with sonication treatment to accelerate dissolution of the drug substance in sample preparation of linagliptin tablets, and hydrocyanic acid is a known impurity in HPLC grade acetonitrile and acetonitrile is used as part of diluent. The mechanism of the solution degradation chemistry was verified by stressing linagliptin API with trimethylsilyl cyanide (TMSCN, which can give off HCN slowly in the presence of water) treated with sonication in the sample preparation. Further investigation found that when the sonication treatment was replaced by vortex vibration in the process of the sample preparation, the RRT 1.28 species was decreased to below the level of the detection limit (0.02%). The structure of this impurity was further confirmed through the synthesis of the impurity and subsequent structure characterization by 1D and 2D NMR. Due to the presence of trace amount of HCN in HPLC grade acetonitrile, these types of solution degradation would likely occur in analysis of pharmaceutical finished products containing APIs with primary and secondary amine moieties drug product during sample preparations, particularly when sonication treatment is used to accelerate dissolution of drug substance from the finished drug product. In the GMP quality control laboratories, such events may trigger undesirable out-of-specification (OOS) events. Hence, the results of this paper can help to prevent these events from happening in the first place or resolve these OOS events in GMP laboratories.

Hyperlipidemia due to a high-fat diet (HFD) is a risk factor for inducing insulin resistance (IR) and adverse effects on pancreatic β-cells in obesity and type 2 diabetes mellitus. This relationship may be due to activation of the hexosaminebiosynthesis pathway. Administration of exogenous glucosamine (GlcN) can increase the end product of this pathway (uridine-5'-diphosphate-N-acetyl-glucosamine), which can mediate IR and protein glycosylation. The objective of this study was to evaluate the effects of oral GlcN and HFD on IR and pancreatic histologic damage in a 22 wk study of 4 groups of male Wistar rats: control group with normal chow diet, HFD group (24%. g/g lard), GlcN group (500 mg/kg^-1 per day of glucosamine hydrochloride in drinking water) and HFD plus oral GlcN. Metabolic variables related to IR that were measured included triglycerides (TG), free fatty acids (FFAs) and malondialdehyde (MDA). Histopathologic evaluation of the pancreas was also performed. The results showed IR in the HFD group, which had increased pancreatic nuclear pyknosis and vacuolization, with fatty infiltration and structural alteration of the islets of Langerhans. TG, FFAs and MDA were higher in serum and pancreatic tissue as compared with the control group. The GlcN group did not develop IR and had only mild nuclear pyknosis with no significant change in the pancreatic content of TG, FFAs and MDA. However, the combined administration of GlcN and HFD attenuated IR and improved TG, FFAs and MDA levels in serum and pancreatic tissue and the pancreatic histopathologic changes, with no significant differences as compared with the control group. These findings suggest that the oral GlcN at a dose of 500 mg/kg^-1 is protective against IR and the pancreatic histologic damage caused by HFD.

We designed a postmarketing surveillance study of linagliptin for patients with type 2 diabetes (T2D) in Korea. This prospective, observational, multicentre study investigated the safety and glycaemic effectiveness of linagliptin as monotherapy or combination therapy with other antidiabetic drugs in routine clinical practice. Endpoints were the incidence of adverse drug reactions (ADRs) and the change in HbA1c. Overall, 3119 and 2171 patients were included in the safety and effectiveness analysis sets, respectively. A total of 56 patients (1.8%) experienced ADRs. The most common ADR was gastrointestinal disorders (0.7%), followed by metabolism and nutrition disorders (0.5%). ADRs of special interest, including pancreatic diseases, cardiac diseases and hypoglycaemia, occurred in 12 patients, 11 of whom had hypoglycaemia, while one had a skin lesion. Mean HbA1c change during the study period was -0.8%. Lower body mass index, shorter diabetes duration and higher baseline HbA1c were independently associated with a better effectiveness, while the presence of diabetic complications, dyslipidaemia and the use of sulphonylureas were associated with a poor response. In conclusion, linagliptin showed an excellent safety profile and glycaemic effectiveness in Korean patients with T2D.

South Asians constitute approximately 1.6 billion people from the Indian subcontinent, comprising Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka; and make up the largest diaspora globally. Compared to the White European population, this group is at a higher risk of developing type 2 diabetes along with cardiovascular, renal and eye complications. Over the recent years, a number of new therapies for type 2 diabetes have become available for which cardiovascular outcome trials (CVOTs) have been published. The recent ADA/EASD consensus guidelines on diabetes, pre-diabetes and cardiovascular diseases' offer a transitional shift in type 2 diabetes management. The new consensus recommendations are based on recent CVOTs, many of which had a representation of South Asian cohorts. In light of this new evidence, there is urgent need for an integrated, evidence-based, cost-effective and individualised approach specific for South Asians. This review takes into consideration the evidence from these CVOTs and provides best practice recommendations for optimal management of South Asian people with type 2 diabetes, alongside the previously published consensus report from South Asian Health Foundation in 2014 [1].

We investigated the long-term safety and effectiveness of linagliptin in Japanese type 2 diabetes (T2D) patients starting linagliptin add-on therapy in routine clinical practice.

This 3-year prospective, observational, post-marketing surveillance (PMS) was conducted in Japanese patients starting linagliptin add-on therapy. The primary outcome was the incidence of adverse drug reactions (ADRs). The secondary outcome was the change from baseline in HbA1c.

The safety analysis set comprised of 3,372 patients. Mean ± standard deviation (SD) age was 66.5 ± 12.4 years. Most patients (63.2%) received linagliptin in combination with another antidiabetic drug, most commonly a sulfonylurea (38.6%). The incidence of ADRs was 11.39%; the most common ADRs according to MedDRA preferred terms were diabetes mellitus (1.25%), hypertension (0.83%), and hypoglycemia (0.80%). In the effectiveness analysis set (n = 3,029), mean ± SD HbA1c was 7.76 ± 1.37% at baseline and 7.26 ± 1.19% at last observation; mean change from baseline to last observation was - 0.49 ± 1.33%; sustained reductions in HbA1c were observed. These results were consistent across patient subgroups.

In this PMS, linagliptin add-on therapy for Japanese T2D patients had a safety profile consistent with its known profile and HbA1c reductions over 3 years were observed.

NCT01904383.

A simple, rapid, and ultra sensitive dispersive solid phase extraction based on nano graphene oxide was developed for simultaneous measurement of trace amounts of metformin (MET) and linagliptin (LIN) in plasma samples by HPLC-UV-Vis. Affecting factors on the extraction of these drugs, including adsorbent weight, extraction time, organic solvent type, desorption situations, and composition of solvent were examined and optimized. In optimum conditions, the LOD (limit of detection) and LOQ (limit of quantification) of the suggested technique were 2.0 ngmL^-1 and 6.1 (ngmL^-1) for LIN and 3.0 ngmL^-1 and 9.2 ngmL^-1 for MET, respectively. Suitable linear behavior in the considered ranges of concentration (10-2000 ngmL^-1) and good correlation coefficient of 0.9901 and 0.9903 (r²) for LIN and MET were obtained, respectively. The RSD (relative standard deviations) according to three replicate measurements at 2, 20, 200 ngmL^-1 levels of these drugs was less than 8.0%. In the last step, applicability of the suggested technique was examined by analyzing the drugs in plasma samples and reasonable results were achieved.

The placebo response in patients with diabetes mellitus is very common. A systematic evaluation needs to be updated with the current evidence about the placebo response in diabetes mellitus and the associated factors in clinical trials of anti-diabetic medicine.

Literature research was conducted in Medline, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov for studies published between the date of inception and June 2019. Randomized placebo-controlled trials conducted in type 1and type 2 diabetes mellitus (T1DM/T2DM) were included. Random-effects model and meta-regression analysis were accordingly used. This meta-analysis was registered in PROSPERO as CRD42014009373.

Significantly weight elevation (effect size (ES) = 0.33 kg, 95% CI, 0.03 to 0.61 kg) was observed in patients with placebo treatments in T1DM subgroup while significantly HbA1c reduction (ES = - 0.12%, 95% CI, - 0.16 to - 0.07%) and weight reduction (ES = - 0.40 kg, 95% CI, - 0.50 to - 0.29 kg) were observed in patients with placebo treatments in T2DM subgroup. Greater HbA1c reduction was observed in patients with injectable placebo treatments (ES = - 0.22%, 95% CI, - 0.32 to - 0.11%) versus oral types (ES = - 0.09%, 95% CI, - 0.14 to - 0.04%) in T2DM (P = 0.03). Older age (β = - 0.01, 95% CI, - 0.02 to - 0.01, P < 0.01) and longer diabetes duration (β = - 0.02, 95% CI, - 0.03 to - 0.21 × 10^-2, P = 0.03) was significantly associated with more HbA1c reduction by placebo in T1DM. However, younger age (β = 0.02, 95% CI, 0.01 to 0.03, P = 0.01), lower male percentage (β = 0.01, 95% CI, 0.22 × 10^-2, 0.01, P < 0.01), higher baseline BMI (β = - 0.02, 95% CI, - 0.04 to - 0.26 × 10^-2, P = 0.02), and higher baseline HbA1c (β = - 0.09, 95% CI, - 0.16 to - 0.01, P = 0.02) were significantly associated with more HbA1c reduction by placebo in T2DM. Shorter diabetes duration (β = 0.06, 95% CI, 0.06 to 0.10, P < 0.01) was significantly associated with more weight reduction by placebo in T2DM. However, the associations between baseline BMI, baseline HbA1c, and placebo response were insignificant after the adjusted analyses.

The placebo response in diabetes mellitus was systematically outlined. Age, sex, disease severity (indirectly reflected by baseline BMI and baseline HbA1c), and disease duration were associated with placebo response in diabetes mellitus. The association between baseline BMI, baseline HbA1c, and placebo response may be the result of regression to the mean.

Linagliptin (LGP), a novel anti-diabetic drug, is a DPP-4 inhibitor used in the treatment of type II diabetes. One of the major disadvantages of LGP is its low oral bioavailability (29.5%) due to first-pass metabolism and P-gp efflux. In an attempt to increase the oral bioavailability, LGP solid lipid nanoparticles (LGP-SLNs) were developed with poloxamer 188 and Tween 80 as P-gp inhibitors. LGP-SLNs were formulated using palmitic acid, poloxamer 188 and Tween 80 as lipid, surfactant and co-surfactant, respectively, by hot homogenization ultrasonication method and optimized using 3² full factorial designs. Particle size, entrapment efficiency (%EE) and drug release at 24 h were evaluated as responses. An optimized batch of LGP-SLNs (L12) was evaluated for intestinal transport of LGP by conducting in situ single-pass intestinal perfusion (SPIP), everted gut sac and Caco-2 permeability study. The pharmacokinetic and pharmacodynamic evaluation of L12 was carried out in albino Wistar rats. The mean particle size, polydispersity index, zeta potential and %EE of L12 were found to be 225.96 ± 2.8 nm, 0.180 ± 0.034, - 5.4 ± 1.07 mV and 73.8 ± 1.73%, respectively. %CDR of 80.96 ± 3.13% was observed in 24 h. The permeability values of LGP-SLNs in the absorptive direction were 1.82-, 1.76- and 1.74-folds higher than LGP-solution (LGP-SOL) in SPIP, everted gut sac and Caco-2 permeability studies, respectively. LGP-SLNs exhibited relative bioavailability of 300% and better reduction in glucose levels in comparison with LGP-SOL in rats. The enhanced oral bioavailability exhibited by LGP-SLNs bioavailability may be due to P-gp efflux inhibition and lymphatic targeting. Improved bioabsorption can cause reduction in dose, dose-related side effects and frequency of administration. Thus, LGP-SLNs can be considered promising carriers for oral delivery but clinical studies are required to confirm the proof of concept.Graphical abstract.

Liver fibrosis is a common complication of diabetes mellitus, with a major global public health concern. Linagliptin, a dipeptidyl peptidase-4 inhibitor (DPP-4), is classically used to treat type 2 diabetes mellitus and improves insulin resistance. Additional potential influences of linagliptin on liver fibrosis are still unclear. The present study was undertaken to investigate the therapeutic credit of linagliptin in hepatic fibrosis induced by a high-fat diet (HFD) and streptozotocin (STZ) in rats. Moreover, the mechanisms underline its anti-fibrotic effect were explored. To induce liver fibrosis with T2DM; male Sprague-Dawley albino rats were fed on a high-fat high-sucrose diet for 28 days then exposed to a single dose of STZ (30 mg/kg, IP). After two days of STZ injection, a diabetes confirmation test was done and all diabetic rats were constantly fed on HFD for thirty days with or without treatment with linagliptin (6 mg/kg). Hepatotoxicity markers, lipid profile screening, insulin signaling, inflammatory cytokines (TNF-α, IL-6, NF-κB p65), fibrosis markers (Collagen, α-SMA, TGF-β1) and histopathological studies including hematoxylin and eosin (H&E) as well Masson's trichrome stains were performed. In our preliminary study, linagliptin at a dose of 6 mg/kg was chosen as the optimum anti-diabetic dose in rats challenged with STZ. Linagliptin significantly improved insulin sensitivity and lipid profile and reduced inflammatory mediators, and collagen depositions in rats with liver fibrosis and T2DM. In conclusion, above and beyond its anti-diabetic effect, this study introduced linagliptin as a promising option for preventing the pathological progression of liver fibrosis associated with T2DM.

To evaluate the effect of linagliptin on left ventricular systolic function beyond glycaemic control in type 2 diabetes mellitus.

A multicentre, randomised, double-blind, placebo controlled, parallel-group study, was performed (the DYDA 2 trial). Individuals with type 2 diabetes mellitus and asymptomatic impaired left ventricular systolic function were randomly allocated in a 1:1 ratio to receive for 48 weeks either linagliptin 5 mg daily or placebo, in addition to their diabetes therapy. Eligibility criteria were age 40 years and older, haemoglobin A1c 8.0% or less (≤64 mmol/mol), no history of cardiac disease, concentric left ventricular geometry (relative wall thickness ≥0.42), impaired left ventricular systolic function defined as midwall fractional shortening 15% or less at baseline echocardiography. The primary end point was the modification of midwall fractional shortening over time. The main secondary objectives were changes in diastolic and/or in longitudinal left ventricular systolic function as measured by tissue Doppler echocardiography. One hundred and eighty-eight patients were enrolled, predominantly men with typical insulin-resistance comorbidities. At baseline, mean midwall fractional shortening was 13.3%±2.5. At final evaluation, 88 linagliptin patients and 86 placebo patients were compared: midwall fractional shortening increased from 13.29 to 13.82 (+4.1%) in the linagliptin group, from 13.58 to 13.84 in the placebo group (+1.8%, analysis of covariance P = 0.86), corresponding to a 2.3-fold higher increase in linagliptin than the placebo group, although non-statistically significant. Also, changes in diastolic and longitudinal left ventricular systolic function did not differ between the groups. Serious adverse events or linagliptin/placebo permanent discontinuation occurred in very few cases and in the same percentage between the groups.

In the DYDA 2 patients the addition of linagliptin to stable diabetes therapy was safe and provided a modest non-significant increase in left ventricular systolic function measured as midwall fractional shortening.

ClinicalTrial.gov (ID NCT02851745).

The present meta-analysis evaluated the efficacy and safety of empagliflozin + linagliptin combination compared with either monotherapy [n=6 randomized controlled trials; 2857 adults with type 2 diabetes (T2DM) on diet + exercise ± metformin; 39.7% women; mean age: 54.6-59.9 years]. The combination of empagliflozin 10 mg + linagliptin 5 mg led to significantly greater reductions in glycated haemoglobin (HbA1c) compared with either drug alone over 24 weeks: weighted mean difference [WMD; -0.72%, 95% confidence interval (CI): -1.04, -0.40], and fasting plasma glucose (-1.60 mmol/L 95% CI: -2.21, -1.00). Similar results were observed when empagliflozin 25 mg + linagliptin 5 mg was compared with linagliptin 5 mg monotherapy or with empagliflozin 10 or 25 mg monotherapy. Patients with T2DM treated with the drug combination had more than three times higher likelihood of achieving HbA1c <7% than those on either monotherapy. Weight reduction was significantly greater in the combination group only when compared with linagliptin monotherapy. Safety profile was similar between combination treatment and monotherapies. Overall, the empagliflozin + linagliptin combination had superior efficacy and similar safety in achieving euglycaemia compared with either monotherapy. This combination, administered once daily, has the potential to reduce regimen complexity, enhance adherence and improve outcomes in clinical practice.

A multicentre, randomized, double-blind, placebo-controlled, parallel-group study aimed to define the potential positive effect of dipeptidyl peptidase-4 inhibition on left ventricular systolic function (LVSF) beyond glycemic control in type 2 diabetes mellitus (T2DM) (DYDA 2™ trial).

Individuals with fairly controlled T2DM and asymptomatic impaired LVSF were randomized in a 1:1 ratio to receive for 48 weeks either linagliptin 5 mg daily or placebo, in addition to their stable diabetes therapy. Eligibility criteria were age ≥ 40 years, history of T2DM with a duration of at least 6 months, HbA1c ≤ 8.0% (≤ 64 mmol/mol), no history or clinical signs/symptoms of cardiac disease, evidence at baseline echocardiography of concentric LV geometry (relative wall thickness ≥ 0.42), and impaired LVSF defined as midwall fractional shortening (MFS) ≤ 15%. The primary end-point was the modification from baseline to 48 weeks of MFS. As an exploratory analysis, significant changes in LV global longitudinal strain and global circumferential strain, measured by speckle tracking echocardiography, were also considered. Secondary objectives were changes in diastolic and/or in systolic longitudinal function as measured by tissue Doppler.

A total of 188 patients were enrolled. They were predominantly males, mildly obese, with typical insulin-resistance co-morbidities such as hypertension and dyslipidemia. Mean relative wall thickness was 0.51 ± 0.09 and mean MFS 13.3% ± 2.5.

DYDA 2 is the first randomized, double-blind, placebo-controlled trial to explore the effect of a dipeptidyl peptidase-4 inhibitor on LVSF in T2DM patients in primary prevention regardless of glycemic control. The main characteristics of the enrolled population are reported.

ClinicalTrial.gov Identifier: NCT02851745.

Today, excluding insulin, there are eight classes of anti-diabetic medicines that have been added to the pharmacy since the introduction of metformin in the mid-1950s; the sulfonylureas, biguanides, thiazolidinediones, α-glucosidase inhibitors, meglitinides, incretins, and sodium glucose transport 2 inhibitors. Does the fact that metformin is still first-line treatment suggest that our drug discovery efforts over the past 60 years have not been good enough? Or does it suggest that diabetes is such a complex disorder that no single treatment, other than gastric bypass surgery, can affect true normalization of not only blood sugar but also the underlying pathologies? Our understanding of the disease has most definitely improved which may bring hope for the future in terms of science, but for it to be beneficial, this science has to be translated into better drug treatments for the disease. In this review, I have examined the eight classes of anti-diabetes drugs from a drug discovery perspective.

For patients with type 2 diabetes, newer antihyperglycaemic agents (AHA), including the dipeptidyl peptidase IV inhibitors (DPP4i), glucagon-like peptide-1 receptor agonists (GLP1RA) and sodium glucose co-transporter 2 inhibitors (SGLT2i) offer a lower risk of hypoglycaemia relative to sulfonylurea or insulin. However, it is not clear how AHA compare to placebo on risk of any hypoglycaemia. This study evaluates the risk of any and severe hypoglycaemia with AHA and metformin relative to placebo.

A systematic review and meta-analysis was conducted of randomized, placebo-controlled trials ≥12 weeks in duration. MEDLINE, Embase and the Cochrane Library were searched up to April 16, 2019. Studies allowing use of other diabetes medications were excluded. Mantel-Haenszel risk ratio with 95% confidence intervals were used to pool estimates based on class of AHA and number of concomitant therapies used.

Eligible studies enrolled patients with type 2 diabetes ≥18 years of age.

144 studies met our inclusion criteria. Any hypoglycaemia was not increased with AHA when used as monotherapy (DPP4i (RR 1.12; 95% CI 0.81-1.56), GLP1RA (1.77; 0.91-3.46), SGLT2i (1.34; 0.83-2.15)), or as add-on to metformin (DPP4i (0.95; 0.67-1.35), GLP1RA (1.24; 0.80-1.91), SGLT2i (1.29; 0.91-1.83)) or as triple therapy (1.13; 0.67-1.91). However, metformin monotherapy (1.73; 1.02-2.94) and dual therapy initiation (3.56; 1.79-7.10) was associated with an increased risk of any hypoglycaemia. Severe hypoglycaemia was rare not increased for any comparisons.

Metformin and the simultaneous initiation of dual therapy, but not AHA used alone or as single add-on combination therapy, was associated with an increased risk of any hypoglycaemia relative to placebo.

The incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are released from enteroendocrine cells in response to the presence of nutrients in the small intestines. These homones facilitate glucose regulation by stimulating insulin secretion in a glucose dependent manner while suppressing glucagon secretion. In patients with type 2 diabetes (T2DM), an impaired insulin response to GLP-1 and GIP contributes to hyperglycemia. Dipeptidyl peptidase-4 (DPP-4) inhibitors block the breakdown of GLP-1 and GIP to increase levels of the active hormones. In clinical trials, DPP-4 inhibitors have a modest impact on glycemic control. They are generally well-tolerated, weight neutral and do not increase the risk of hypoglycemia. GLP-1 receptor agonists (GLP-1 RA) are peptide derivatives of either exendin-4 or human GLP-1 designed to resist the activity of DPP-4 and therefore, have a prolonged half-life. In clinical trials, they have demonstrated superior efficacy to many oral antihyperglycemic drugs, improved weight loss and a low risk of hypoglycemia. However, GI adverse events, particularly nausea, vomiting, and diarrhea are seen. Both DPP-4 inhibitors and GLP-1 RAs have demonstrated safety in robust cardiovascular outcome trials, while several GLP-1 RAs have been shown to significantly reduce the risk of major adverse cardiovascular events in persons with T2DM with pre-existing cardiovascular disease (CVD). Several clinical trials have directly compared the efficacy and safety of DPP-4 inhibitors and GLP-1 RAs. These studies have generally demonstrated that the GLP-1 RA provided superior glycemic control and weight loss relative to the DPP-4 inhibitor. Both treatments were associated with a low and comparable incidence of hypoglycemia, but treatment with GLP-1 RAs were invariably associated with a higher incidence of GI adverse events. A few studies have evaluated switching patients from DPP-4 inhibitors to a GLP-1RA and, as expected, improved glycemic control and weight loss are seen following the switch. According to current clinical guidelines, GLP-1RA and DPP-4 inhibitors are both indicated for the glycemic management of patients with T2DM across the spectrum of disease. GLP-1RA may be preferred over DPP- 4 inhibitors for many patients because of the greater reductions in hemoglobin A1c and weight loss observed in the clinical trials. Among patients with preexisting CVD, GLP-1 receptor agonists with a proven cardiovascular benefit are indicated as add-on to metformin therapy.

Clinical trials of linagliptin in Japanese patients conducted to date have had limited observational periods; therefore, there is a need for additional longer-term real-world data. The aim of this study was to investigate the long-term safety and effectiveness of linagliptin in routine clinical practice.

This was a prospective, observational, post-marketing surveillance study conducted over 156 weeks in patients with type 2 diabetes mellitus who started linagliptin monotherapy. The primary endpoint was the incidence of adverse drug reactions (ADRs). The secondary endpoint was the change in glycated hemoglobin (HbA1c) from baseline to last available observation. Other effectiveness endpoints included the change in HbA1c and change in fasting plasma glucose (FPG) from baseline to week 26 and over the course of the treatment period.

Overall, 2235 and 2054 patients were included in the safety and effectiveness analysis sets, respectively. Patients were mostly male (58.4%), and the mean age was 66.7 years. The incidence of ADRs was 10.7% (n = 240). The most frequent ADRs according to MedDRA preferred terms were diabetes mellitus (n = 35 patients, 1.6%), constipation (n = 21, 0.9%), diabetes mellitus inadequate control (n = 13, 0.6%) and hypertension (n = 13, 0.6%). The mean change in HbA1c from baseline to last observation was - 0.67% [standard deviation (SD) 1.27%, 95% confidence interval - 0.72, - 0.61]. At week 26, HbA1c and FPG showed mean ± SD changes from baseline of - 0.73 ± 1.20% and - 21.02 ± 44.33 mg/dL, respectively, that were sustained until week 156.

In Japanese patients with type 2 diabetes mellitus, linagliptin produced sustained reductions in HbA1c and had a safety profile consistent with the established safety profile of linagliptin.

ClinicalTrials.gov (NCT01650259).

To verify whether the treatment with linagliptin induces the browning of the subcutaneous WAT (sWAT) and thermogenesis in murine diet-induced obesity (DIO) model.

Forty animals were randomly assigned to receive a control diet (C, 10% lipids as energy) or a high-fat diet (HF, 50% lipids as energy) for 10 weeks. Each group was re-divided to begin the 5-week treatment, totalizing four experimental groups: C, C-L (C plus linagliptin, 30 mg/kg body mass; BM), HF, and HF-L (HF plus linagliptin, 30 mg/kg BM). The drug was mixed with diet.

HF animals showed overweight, glucose intolerance, and a greater cross-sectional area of adipocytes. The treatment with linagliptin was able to normalize the BM, restore the glucose tolerance and the cross-sectional area of adipocytes. These observations comply with the observation of UCP1-positive multilocular adipocytes in the sWAT of treated animals. Both treated groups (C-L and HF-L) showed high expression of thermogenic and type 2 cytokines genes, which agree with the enhanced body temperature and the lower respiratory exchange ratio, implying enhanced thermogenesis with the use of lipids as fuel.

The reduced BM, the enhanced body temperature, and the presence of positive UCP1 beige cells in the sWAT point to the activation of the browning cascade on the sWAT of linagliptin-treated mice, and hence, linagliptin could induce the thermogenic pathway as a pleiotropic effect that can have translational potential.

Diabetes mellitus, especially type 2 diabetes mellitus (T2DM), has become a significant public health burden. Rhizoma coptidis (RC), known as Huang Lian, is widely used for treating diabetes in China. The bioactive compounds of RC, especially alkaloids, have the potential to suppress T2DM-induced lesions, including diabetic vascular dysfunction, diabetic heart disease, diabetic hyperlipidemia, diabetic nephropathy, diabetic encephalopathy, diabetic osteopathy, diabetic enteropathy, and diabetic retinopathy. This review summarizes the effects of RC and its bioactive compounds on T2DM and T2DM complications. Less research has been conducted on non-alkaloid fractions of RC, which may exert synergistic action with alkaloids. Moreover, we summarized the pharmacokinetic properties and structure-activity relationships of RC on T2DM with reference to extant literature and showed clearly that RC has potential therapeutic effect on T2DM.

Cardiovascular (CV) disease (CVD) is a well-recognized complication of type 2 diabetes mellitus (T2DM) and there is a clinical need for glucose-lowering therapies that do not further increase CV risk in this population. Although sulfonylureas (SUs) may be used as second-line therapy for patients requiring additional therapy after first-line metformin to improve glycemic control, their long-term effects on CV outcomes remain uncertain, and a wide range of alternative agents exist including dipeptidyl peptidase-4 (DPP-4) inhibitors.

Literature searches in PubMed (2013-2018) were conducted with terms for DPP-4 inhibitors combined with CV terms, with preference given to cardiovascular outcomes trials (CVOTs). Reference lists from retrieved articles and diabetes guidelines were also considered.

This narrative review discusses current evidence for the CV safety of these agents, describes the long-term CV effects of DPP-4 inhibitors, including effects on CV events, mortality, the risk for heart failure hospitalization, and highlights the need for further research into the CV effects of SU therapy. Although SUs remain a treatment option for T2DM, the long-term effects of these agents on CV outcomes are unclear, and further long-term studies are required. For DPP-4 inhibitors, uncertainties have been raised about their long-term effect on hospitalization for heart failure in light of the results of SAVOR-TIMI 53, although the findings of other DPP-4 inhibitor CVOTs in T2DM and data analyses have suggested these agents do not increase the occurrence of adverse CV outcomes.

Based on recent CVOTs and guideline updates, the choice of add-on to metformin therapy for patients with T2DM and established CV disease should be a sodium-glucose co-transporter-2 inhibitor or a glucagon-like peptide-1 agonist with proven CV benefit. Additional treatment options for those individuals who require therapy intensification, as well as in patients with T2DM and without established CVD include DPP-4 inhibitors and SUs. Since few head-to-head trials have compared the effects of different oral glucose-lowering agents on CV outcomes in T2DM, with most CVOTs using placebo as a comparator, the CAROLINA trial will provide important information on the comparative CV safety of a commonly prescribed SU and a DPP-4 inhibitor.

The aim is to evaluate the efficacy and safety of dipeptidyl peptidase-4 inhibitors (DPP4-I: sitagliptin, saxagliptin, linagliptin, vildagliptin and alogliptin) in patients with type 2 diabetes.

We searched the Cochrane Library, PubMed, EMBASE, Chinese Biomedical Database (CBM), China National Knowledge Infrastructure (CNKI), and the Wanfang Database from inception to April, 2018. Randomized controlled trials were included if they compared the different versions of DPP4-I with each other or with placebo in treatment of type 2 diabetes. Bayesian network meta-analysis and pairwise meta-analysis were performed to evaluate the efficacy and safety of the different kinds of DPP4-I and placebo. The data were analyzed using STATA 12.0 and WinBUGS1.4 software.

We identified 58 eligible studies (with 31356 patients) involving 14 treatment arms. Indirect comparison results showed that except for alogliptin, a decrease was found for all DPP4-I versus the placebo for hemoglobin A1c (HbA1c) with vildagliptin50 twice daily (BID) showing the highest probability. Linagliptin5 once daily (QD) decreased the level of fasting plasma glucose (FPG) the most for all DPP4-I versus the placebo; when comparing them with each other, alogliptin25QD was more effective when compared with sitagliptin100QD and vildaglipti50BID; linagliptin5qd had the highest decrease impact on body mass index (BMI). Except for hypoglycemia and upper respiratory tract infection (URTI), there are no statistical significance on incidence of adverse events and the body weight when DPP4-I are compared with each other or with placebo.

Our network meta-analysis presents the associations of DPP4-I versus placebos on HbA1c, FPG, 2 h postprandial blood glucose (2HPPG), BMI, body weight and adverse events. DPP4-I have a lowering effect on the glycemic level (HbA1c, FPG), especially vildaglipti50BID and linagliptin10QD, respectively. Besides, linagliptin5QD has the greatest probabilities of reducing BMI. In addition, DPP4-I were associated with not increasing the incidence of adverse events. Among them, vildagliptin100QD and sitagliptin100QD have the lowest probability in reducing the incidence of hypoglycemia and URTI, respectively.

To investigate the effects of dipeptidyl peptidase-4 (DPP-4) inhibitors on renal outcomes in patients with type 2 diabetes.

MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched to identify randomized controlled trials (RCTs) of DPP-4 inhibitors from inception to September 2017. We selected eligible RCTs comparing DPP-4 inhibitors with placebo or other antidiabetic agents and reporting at least one renal outcome. A meta-analysis was conducted to calculate standardized mean differences, weighted mean differences (WMDs), relative risks (RRs), and 95% confidence intervals (CIs) for each renal outcome.

We included 23 RCTs with 19 publications involving 41,359 patients. Overall changes in urine albumin-to-creatinine ratio were comparable between DPP-4 inhibitors and controls (P=0.150). However, DPP-4 inhibitors were associated with significantly lower risk of incident microalbuminuria (RR, 0.89; 95% CI, 0.80 to 0.98; P=0.022) and macroalbuminuria (RR, 0.77; 95% CI, 0.61 to 0.97; P=0.027), as well as higher rates of regression of albuminuria (RR, 1.22; 95% CI, 1.10 to 1.35; P<0.001) compared with controls. Although DPP-4 inhibitors were associated with small but significantly lower estimated glomerular filtration rate (WMD, -1.11 mL/min/1.73 m²; 95% CI, -1.78 to -0.44; P=0.001), there was no difference in the risk of end-stage renal disease between two groups (RR, 0.93; 95% CI, 0.76 to 1.14; P=0.475).

DPP-4 inhibitors had beneficial renal effects mainly by reducing the risk of development or progression of albuminuria compared with placebo or other antidiabetic agents.

Chronic kidney disease (CKD) is a serious complication of hyperglycemia and treatment options to slow its progression are scarce. Dipeptidyl peptidase-4 (DPP-4) inhibitors are common glucose-lowering drugs in type 2 diabetes (T2D). Among these, linagliptin has been suggested to exert kidney protective effects. It is investigated whether an effect of linagliptin on kidney function could be unmasked by characterizing the urinary proteome profile (UPP) in albuminuric T2D individuals.

Participants of the MARLINA-T2D trial (NCT01792518) are randomized 1:1 to receive either linagliptin 5 mg or placebo for 24 weeks. A previously developed proteome-based classifier, CKD273, is assessed.

Results confirm a significant correlation between CKD273 and clinical kidney parameters as well as with eGFR decline. Patient stratification using CKD273 at baseline, show a trend toward attenuation of renal function loss in high CKD-risk patients treated with linagliptin. Moreover, characterized are linagliptin affected peptides of which the majority contained a DPP-4 target sequence.

CKD273 is a promising tool for identifying patients at high risk for CKD progression and may unmask a potential of linagliptin to slow progressive kidney function loss in high CKD-risk patients. UPP characterization reveals a significant impact of linagliptin on urinary peptides.

Despite advances in our understanding of metabolic syndrome (MetS) and the treatment of each of its components separately, currently there is no single therapy approved to manage it as a single condition. Since multi-drug treatment increases drug interactions, decreases patient compliance and increases health costs, it is important to introduce single therapies that improve all of the MetS components.

We conducted a PubMed, Scopus, Google Scholar, Web of Science, US FDA, utdo.ir and clinicaltrial.gov search, gathered the most relevant preclinical and clinical studies that have been published since 2010, and discussed the beneficial effects of dipeptidyl peptidase (DPP)-4 inhibitors to prevent and treat different constituent of the MetS as a single therapy. Furthermore, the pharmacology of DPP-4 inhibitors, focusing on pharmacodynamics, pharmacokinetics, drug interactions and their side effects are also reviewed.

DPP-4 inhibitors or gliptins are a new class of oral anti-diabetic drugs that seem safe drugs with no severe side effects, commonly GI disturbance, infection and inflammatory bowel disease. They increase mass and function of pancreatic β-cells, and insulin sensitivity in liver, muscle and adipose tissue. It has been noted that gliptin therapy decreases dyslipidemia. DPP-4 inhibitors increase fatty oxidation, and cholesterol efflux, and decrease hepatic triglyceride synthase and de novo lipogenesis. They delay gastric emptying time and lead to satiety. Besides, gliptin therapy has anti-inflammatory and anti-atherogenic impacts, and improves endothelial function and reduces vascular stiffness.

The gathered data prove the efficacy of DPP-4 inhibitors in managing MetS in some levels beyond anti-diabetic effects. This review could be a lead for designing new DPP-4 inhibitors with greatest effects on MetS in future. Introducing drugs with polypharmacologic effects could increase the patient's compliance and decrease the health cost that there is not in multi-drug therapy. Graphical abstract ᅟ.

In the 1990s it was discovered that the enzyme dipeptidyl peptidase-4 (DPP-4) inactivates the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). DPP-4 inhibition results in raised levels of the two incretin hormones which in turn result in lowering of circulating glucose through stimulation of insulin secretion and inhibition of glucagon secretion. Since then, several small orally available molecules have been developed with DPP-4 inhibitory action. Early studies in the 1990s showed that the DPP-4 inhibitors improve glycemia in animals. Subsequent clinical studies during the 2000s showed a glucose-lowering action of DPP-4 inhibitors also in human subjects with type 2 diabetes. This action was seen when DPP-4 inhibitors were used both as monotherapy and as add-on to other therapies, i.e., metformin, sulfonylureas, tiazolidinediones or exogenous insulin. The DPP-4 inhibitors were also found to have a low risk of adverse events, including hypoglycemia. Five of the DPP-4 inhibitors (sitagliptin, vildagliptin, alogliptin, saxagliptin and linagliptin) were approved by regulatory authorities and entered the market between 2006 and 2013. DPP-4 inhibitors have thereafter undergone long-term cardiovascular outcome trials, showing non-inferiority for risk of major acute cardiovascular endpoints. Also the risk of other potential adverse events is low in these long-term studies. DPP-4 inhibitors are at present included in guidelines as a glucose-lowering concept both as monotherapy and in combination therapies. This article summarizes the development of the DPP-4 inhibition concept from its early stages in the 1990s. The article underscores that the development has its basis in scientific studies on pathophysiology of type 2 diabetes and the importance of targeting the islet dysfunction, that the development has been made possible through academic science in collaboration with the research-oriented pharmaceutical industry, and that the development of a novel concept takes time and requires focused efforts, persistence and long-term perserverance.

Linagliptin (LNG) is a selective dipeptidyl peptidase-4 (DPP-4) inhibitor that ameliorates blood glucose control of patients with type 2 diabetes, without developing hypoglycemic risk and weight gain with a good clinical and biological tolerance profile. To the best of our knowledge, its cytotoxic, genotoxic and oxidative effects have never been studied on any cell line.

To evaluate the in vitro cytotoxic, genotoxic damage potential and antioxidant/oxidant activity of LNG in cultured peripheral blood mononuclear cells (PBMC).

After exposure to different doses (from 0.5 to 500 mg/L) of LNG, cell viability was measured by the MTT (3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and lactate dehydrogenase (LDH) leakage tests. The antioxidant activity was assessed by the total antioxidant capacity (TAC) and total oxidative stress (TOS) assays. To evaluate the genotoxic damage potential, chromosomal aberration (CA) frequencies and 8-oxo-2'-deoxyguanosine (8-oxo-dG) levels were determined.

Treatment with LNG did not cause statistically significant decreases of cell viability at lower concentrations than 100 mg/L as compared to untreated cultures. However, LNG exhibited cytotoxic action at 250 and 500 mg/L. Also, IC20 and IC50 values of LNG were determined as 8.827 and 70.307 mg/L, respectively. In addition, the oxidative analysis revealed that LNG supported antioxidant capacity at concentrations of 2.5, 5, 10, 25, 50 and 100 mg/L without generating oxidative stress. Besides, the results of CA and 8-oxo-dG assays showed in vitro non-genotoxic feature of LNG. As a conclusion, our findings clearly revealed that LNG had no cytotoxic and genotoxic actions, but exhibited antioxidative activity. In conclusion, therefore it is suggested that LNG use in diabetic patients is safe and provides protection against diabetic vascular and oxidative complications.

This two-part, double-blind, double-dummy, randomized, placebo-controlled trial (83 sites) evaluated the efficacy and safety of empagliflozin (Empa) 10 or 25 mg and linagliptin (Lina) 5 mg fixed-dose combinations (FDCs) in Japanese patients with type 2 diabetes mellitus (T2DM) who were poorly controlled with Empa.

Patients (previously drug-naive or using one oral antidiabetic drug for ≥ 12 weeks) entered an open-label stabilization period (16 weeks, Empa 10 mg [Part A] or Empa 25 mg [Part B]). Subsequently, they received Empa 10 mg plus placebo (Plc) for Empa/Lina10/5 (Empa/Plc 10/5; Part A) or Empa 25 mg plus Plc for Empa/Lina 25/5 (Empa/Plc 25/5; Part B) for 2 weeks. Patients with HbA1c 7.5-10.0% were randomized (1:1) to a 24-week regimen of once-daily Empa/Lina 10/5 (n = 107) or Empa/Plc 10/5 (n = 108) in Part A, or to Empa/Lina 25/5 (n = 116) or Empa/Plc 25/5 (n = 116) in Part B, with a 28-week extension period in Part B.

Change from baseline in HbA1c at Week 24 was greater (P < 0.0001) with Empa/Lina than with Empa/Plc (primary outcome, Empa/Lina 10/5: -0.94 vs -0.12%; adjusted mean difference, -0.82%; Empa/Lina 25/5: -0.91 vs -0.33%; adjusted mean difference, -0.59%). Over 24- and 52-week periods, higher proportions of patients achieved HbA1c < 7.0% and greater decreases in fasting plasma glucose were observed with Empa/Lina compared with Empa/Plc. Empa/Lina was well tolerated, with no unexpected adverse events or diabetic ketoacidosis. One case of confirmed hypoglycaemia with Empa/Plc 25/5 was reported.

These results support Empa/Lina FDC as a potential option for Japanese patients with T2DM who require combination therapy. ClinicalTrials.gov NCT02489968.

Evogliptin (EVO) is a potent and selective dipeptidyl peptidase-4 inhibitor (DPP4i) developed for the treatment of type 2 diabetes mellitus (T2DM). DPP4is are known to exhibit a better glucose-lowering effect in Asians compared to other ethnic groups. Once EVO's clinical development program was conducted in Asian patients, this bridging study was designed to validate for the Brazilian population the efficacy and safety of the approved dose regimen (once-daily 5.0 mg).

In this randomized, double-blind, double-dummy, parallel trial, 146 patients with T2DM with inadequate glycemic control on diet and exercise (7.5% ≤ HbA1c ≤ 10.5%) were randomly assigned to a 12-week once-daily treatment with EVO 2.5 mg (N = 35), EVO 5 mg (N = 36), EVO 10 mg (N = 36), or sitagliptin (SITA) 100 mg (N = 39). Absolute changes (Week 12-baseline) in HbA1c, fasting plasma glucose (FPG) and body weight (BW) were obtained. One-sided one sample t test was used to determine if mean HbA1c reduction in each group was < - 0.5% (beneficial metabolic response). An analysis of covariance estimated the change in HbA1c and FPG adjusted by baseline HbA1c, FPG, body mass index (BMI) and study site. Response rates to treatment were also established. No between-group statistical comparisons were planned.

HbA1c mean reductions were - 1.26% (90% CI - 1.7%, - 0.8%), - 1.12% (90% CI - 1.4%, - 0.8%), - 1.29% (90% CI - 1.6%, - 1.0%), and - 1.15% (90% CI - 1.5%, - 0.8%) in groups EVO 2.5 mg, EVO 5 mg, EVO 10 mg, and SITA 100 mg, respectively. FPG levels showed a mean increase of 10.89 mg/dL in group EVO 2.5 mg, with significant mean reductions of - 18.94 mg/dL, - 21.17 mg/dL, and - 39.90 mg/dL in those treated with EVO 5 mg, EVO 10 mg, and SITA 100 mg, respectively. BW showed significant reductions of approximately 1 kg in patients treated with EVO 5 mg, EVO 10 mg, and SITA 100 mg. Mean adjusted reductions of HbA1c and FPG levels confirmed the significant clinical benefit of all study treatments. The clinical benefit of EVO's "target" dose (5 mg) was confirmed. No safety concerns were identified.

These results validate for the Brazilian population the approved dose regimen of EVO (once-daily 5 mg).Trial registration ClinicalTrials.gov Identifier: NCT02689362 (first posted on 02/23/2016).

To investigate the risk of hypoglycaemia in people aged ≥65 years with type 2 diabetes mellitus (T2DM) treated with linagliptin, in the largest pooled analysis performed to date.

One thousand four hundred and eighty-nine patients aged ≥65 years with T2DM were pooled from 11 randomised, double-blind, parallel group, placebo-controlled trials evaluating linagliptin 5 mg alone, or in addition to various background therapies. The primary safety endpoint was the incidence of investigator-defined hypoglycaemia.

There was no significant difference in the risk of hypoglycaemia between linagliptin and placebo in the all-patient population at 24 weeks (hazard ratio [HR] 1.07; 95% confidence interval [CI]: 0.84, 1.36; P = 0.5943)-despite significant (P < 0.0001) improvements in glycaemic control-and 1 year (HR 1.02; 95% CI: 0.81, 1.27; P = 0.8803). Similar findings were observed for linagliptin vs placebo in subgroup analyses by background medication (eg, sulphonylureas (SUs) and/or insulin vs no such drugs), age, baseline glycated haemoglobin (HbA1c), ethnicity, and baseline estimated glomerular filtration rate. Patients with a baseline HbA1c ≥7.5% had significantly higher odds of achieving HbA1c <7.5% without hypoglycaemia in the linagliptin group compared with placebo at 24 weeks (34.1% vs 13.7%; 95% CI: 2.04, 4.12; P < 0.0001).

This pooled analysis indicates that linagliptin was effective in treating older people with T2DM towards their HbA1c targets with a favourable safety and tolerability profile and low risk of hypoglycaemia. The safety profile was maintained even on background therapies with known risk of hypoglycaemia, such as insulin and SU.