Recent studies suggest that metabolic factors, such as fasting blood glucose (FBG), may significantly affect bone health, influencing the risk and severity of osteoporotic fractures (OPFs). This study examined the association between FBG levels and bone turnover markers (BTMs) in patients hospitalized for OPFs requiring surgical intervention.

A retrospective cross-sectional analysis was conducted on 888 patients treated for OPFs at Kunshan Hospital affiliated with Jiangsu University from November 2018 to August 2023. Serum levels of FBG, procollagen type 1 N-terminal propeptide (P1NP), and β-C-terminal telopeptide of type I collagen (β-CTX) were measured, with FBG serving as an independent variable, and P1NP and β-CTX as outcome variables. Patients were stratified into tertiles based on FBG levels, and multiple regression models were adjusted for confounding variables, including age, gender, BMI, and clinical parameters. Non-linear relationships and threshold effects were analyzed.

Adjusted regression models identified a negative association between FBG and BTMs. For each 1 mmol/L increase in FBG, β-CTX levels decreased by 0.02 ng/mL (95% CI: -0.04 to -0.01; p < 0.01), and P1NP levels decreased by 2.91 ng/mL (95% CI: -4.38 to -1.45; p < 0.01). Non-linear relationships were observed, with an inflection point at 7.93 mmol/L for both markers. Below this threshold, higher FBG levels were associated with a steeper decline in BTMs.

FBG levels exhibit a negative non-linear association with P1NP and β-CTX in patients with OPFs. Elevated FBG levels may adversely affect BTMs, potentially contributing to the progression of osteoporosis (OP). These findings underscore the importance of glycemic control in managing bone health among patients with OPFs.

A growing body of evidence emphasizes the role of glycemic variability (GV) in the development of conventional diabetes-related complications. Furthermore, advancements in diabetes management and increased life expectancy have led to the emergence of new complications, such as cancer, liver disease, fractures, infections, and cognitive dysfunction. GV is considered to exacerbate oxidative stress and inflammation, acting as a major mechanism underlying these complications. However, few reviews have synthesized the association between GV and these emerging complications or examined their underlying mechanisms. Hence, this narrative review provides a comprehensive discussion of the burden, risks, and mechanisms of GV in these complications, offering further evidence supporting GV as a potential therapeutic target for diabetes management.

The purpose of this review is to investigate the impacts of blood glucose fluctuations on diabetic osteoporosis, a complication of Type 2 diabetes mellitus (T2DM) that remains poorly understood. We reviewed the current evidence of the relationship between blood glucose fluctuations and diabetic osteoporosis in patients with T2DM. The findings indicate that blood glucose fluctuations may contribute to inhibiting the processes of bone formation and resorption, promoting diabetic osteoporosis and fractures in T2DM. Mechanistic studies, both in vitro and in vivo, reveal that these effects are largely mediated by oxidative stress, advanced glycation end products, inflammatory mediators, and multiple pathways inducing cell apoptosis or autophagy. Thus, maintaining the long-term stability of blood glucose levels emerges as a target to be pursued in clinical practice in order to safely reduce mean blood glucose and for its direct effects on osteoporosis and fractures in T2DM.

To study the association between femoral neck (FN) bone mineral density (BMD) T-score and fracture risk in individuals with and without type 2 diabetes (T2D).

We performed a single-centre retrospective cohort study using the Danish National Health Service. BMD of the FN was measured by dual-energy X-ray absorptiometry. Cox proportional hazards regression models were used to study the association between FN BMD T-score and fractures in individuals with and without T2D separately, adjusted for age, comorbidities and comedication. The results from this analysis were used to estimate the 10-year absolute fracture risk.

In total, there were 35,129 women (2362 with T2D) and 7069 men (758 with T2D). The FN BMD T-score was significantly associated with risk of any, hip and major osteoporotic fracture in men and women with [adjusted hazard risk ratios (aHR) women, hip: 1.57; 95% confidence interval (CI) 1.24-2.00, incidence rate (IR) 8.7; aHR men, hip: 1.55; 95% CI 1.01-2.36, IR 4.6] and without T2D (aHR women, hip: 1.75; 95% CI 1.64-1.87, IR 7.0; aHR men, hip: 1.97, 95% CI 1.73-2.25, IR 6.3), and its ability to predict fracture risk was similar. Fracture IRs were not significantly different for individuals with or without T2D, nor was the estimated cumulative 10-year fracture risk.

The FN BMD T-score was significantly associated with hip, non-spine and major osteoporotic fracture risk in men and women with and without T2D. Fracture risk for a given T-score and age was equal in individuals with and without T2D, as was the ability of the FN BMD T-score to predict fracture risk.

This meta-analysis aims to examine differences in biochemical markers of bone metabolism between individuals with type 2 diabetes (T2DM) and non-T2DM control groups.

Two independent evaluators searched five databases: PubMed, EMBASE, EBSCOhost, Web of Science, and the Cochrane Library. We aimed to identify observational studies investigating the impact of T2DM on biochemical markers of bone metabolism. Literature retrieval covered the period from the establishment of the databases up to November 2022. Studies were included if they assessed differences in biochemical markers of bone metabolism between T2DM patients and non-T2DM control groups using cross-sectional, cohort, or case-control study designs.

Fourteen studies were included in the analysis, comprising 12 cross-sectional studies and 2 cohort studies. Compared to the non-T2DM control group, T2DM patients showed reduced levels of Osteocalcin and P1NP, which are markers of bone formation. Conversely, levels of Alkaline phosphatase and Bone-specific alkaline phosphatase, other bone formation markers, increased. The bone resorption marker CTX showed decreased levels, while TRACP showed no significant difference.

In individuals with T2DM, most bone turnover markers indicated a reduced rate of bone turnover. This reduction can lead to increased bone fragility despite higher bone mineral density, potentially increasing the risk of osteoporosis.

Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php? identifier CRD42022366430.

Patients with Type 2 diabetes mellitus (T2DM) have decreased bone health. We aimed to investigate serum levels of bone turnover markers (BTMs) (markers of bone formation and bone resorption) and bone mineral density (BMD) at three sites (lumber, neck femur, and total femur) in middle-aged men with type 2 diabetes and to analyze the relationship between them. Also to evaluate serum osteoglycin as a novel marker and its relation to BTMs, BMD, and diabetic status.

We recruited seventy-eight patients with T2DM and thirteen non-diabetic, male volunteers as a control group. BMD was measured using a DEXA scan. BTMs (carboxy-terminal crosslinking telopeptide of type 1 collagen [CTX] and procollagen type 1 N propeptide [P1NP]), osteoglycin, PTH, and vitamin D were estimated. Data was compared among subjects and statistical analysis was performed.

Most of the patients were having normal BMD with no significant difference between patients and the controls. BTMs and osteoglycin were significantly higher and vitamin D was significantly lower in the diabetic patients. Serum osteoglycin was positively correlated with DEXA Neck Femur (r = 0.233; p-value < 0.05).

Body mass index and Serum osteoglycin have a significant positive effect on BMD. Both markers of bone formation and bone resorption were increased indicating a state of increased bone turnover in T2DM.

In this study, the fracture behavior of ribosylated bovine cortical bone is investigated under loading conditions simulating a fall event. Single edge notched specimens, separated into a control group (n = 11) and a ribosylated group (n = 8), were extracted from the mid-diaphysis of a single bovine femur harvested from a mature cow. A seven-day ribosylation process results in the accumulation of Advanced-Glycation End Products (AGEs) cross-links and AGE adducts. Specimens were subjected to symmetric three point bending (opening mode) and an impact velocity of 1.6 m/s using a drop tower. Near-crack displacement fields up to fracture initiation are determined from high-speed images post-processed using digital image correlation. A constrained over-deterministic least squares regression and orthotropic material linear elastic fracture mechanics theory are used to extract the in-plane critical stress intensity factors at fracture initiation (i.e., fracture initiation toughness values). Statistically significant differences were not observed when comparing the in-plane fracture initiation toughness values (p≥0.96) or energy release rate (p=0.90) between the control and seven-day ribosylated groups. The intrinsic variability of bone may require high sample numbers in order to achieve an adequately powered experiment when assessing dynamic fracture behavior. While there are no detectable differences due to the ribosylation treatment investigated, this is likely due to the limited sample sizes utilized.

Preclinical studies demonstrated that bone plays a central role in energy metabolism. However, how bone metabolism is related to the risk of diabetes in humans is unknown. We investigated the association of bone health (bone mineral density [BMD] and bone turnover markers) with incident type-2 diabetes mellitus (T2DM) based on the Hong Kong Osteoporosis Study (HKOS). A total of 993 and 7160 participants from the HKOS were studied for the cross-sectional and prospective analyses, respectively. The cross-sectional study evaluated the association of BMD and bone biomarkers with fasting glucose and glycated hemoglobin (HbA1c ) levels, whereas the prospective study examined the associations between BMD at study sites and the risk of T2DM by following subjects a median of 16.8 years. Body mass index (BMI) was adjusted in all full models. Mendelian randomization (MR) was conducted for causal inference. In the cross-sectional analysis, lower levels of circulating bone turnover markers and higher BMD were significantly associated with increased fasting glucose and HbA1c levels. In the prospective analysis, higher BMD (0.1 g/cm2 ) at the femoral neck and total hip was associated with increased risk of T2DM with hazard ratios (HRs) of 1.10 (95% confidence interval [CI], 1.03 to 1.18) and 1.14 (95% CI, 1.08 to 1.21), respectively. The presence of osteoporosis was associated with a 30% reduction in risk of T2DM compared to those with normal BMD (HR = 0.70; 95% CI, 0.55 to 0.90). The MR results indicate a robust genetic causal association of estimated BMD (eBMD) with 2-h glucose level after an oral glucose challenge test (estimate = 0.043; 95% CI, 0.007 to 0.079) and T2DM (odds ratio = 1.064; 95% CI, 1.036 to 1.093). Higher BMD and lower levels of circulating bone biomarkers were cross-sectionally associated with poor glycemic control. Moreover, higher BMD was associated with a higher risk of incident T2DM and the association is probably causal. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Bone fragility is a complication of type 2 diabetes mellitus (T2DM) that has been identified in recent decades. Trabecular bone score (TBS) appears to be more accurate than bone mineral density (BMD) in diabetic bone disease, particularly in menopausal women with T2DM, to independently capture the fracture risk. Our purpose was to provide the most recent overview on TBS-associated clinical data in T2DM. The core of this narrative review is based on original studies (PubMed-indexed journals, full-length, English articles). The sample-based analysis (n = 11, N = 4653) confirmed the use of TBS in T2DM particularly in females (females/males ratio of 1.9), with ages varying between 35 and 91 (mean 65.34) years. With concern to the study design, apart from the transversal studies, two others were prospective, while another two were case-control. These early-post-pandemic data included studies of various sample sizes, such as: males and females (N of 245, 361, 511, and 2294), only women (N of 80, 96, 104, 243, 493, and 887), and only men (N = 169). Overall, this 21-month study on published data confirmed the prior profile of BMD-TBS in T2DM, while the issue of whether checking the fracture risk is mandatory in adults with uncontrolled T2DM remains to be proven or whether, on the other hand, a reduced TBS might function as a surrogate marker of complicated/uncontrolled T2DM. The interventional approach with bisphosphonates for treating T2DM-associated osteoporosis remains a standard one (n = 2). One control study on 4 mg zoledronic acid showed after 1 year a statistically significant increase of lumbar BMD in both diabetic and non-diabetic groups (+3.6%, p = 0.01 and +6.2%, p = 0.01, respectively). Further studies will pinpoint additive benefits on glucose status of anti-osteoporotic drugs or will confirm if certain glucose-lowering regimes are supplementarily beneficial for fracture risk reduction. The novelty of this literature research: these insights showed once again that the patients with T2DM often have a lower TBS than those without diabetes or with normal glucose levels. Therefore, the decline in TBS may reflect an early stage of bone health impairment in T2DM. The novelty of the TBS as a handy, non-invasive method that proved to be an index of bone microarchitecture confirms its practicality as an easily applicable tool for assessing bone fragility in T2DM.

The potential relationship between diffuse idiopathic skeletal hyperostosis (DISH) and bone microstructure has not been studied in women. We aimed to assess the association between the trabecular bone score (TBS) and DISH in postmenopausal women, as well as the role of other parameters related to bone metabolism, such as bone mineral density (BMD), calciotropic hormones, and bone remodeling markers.

Cross-sectional study, nested in a prospective population-based cohort (Camargo cohort). Clinical covariates, DISH, TBS, vitamin D, parathormone, BMD and serum bone turnover markers, were analyzed.

We have included 1545 postmenopausal women (mean age, 62±9 years). Those with DISH (n = 152; 8.2%) were older and had a significantly higher prevalence of obesity, metabolic syndrome, hypertension, and type 2 diabetes mellitus (p<0.05). Moreover, they had lower TBS values (p = 0.0001) despite having a higher lumbar spine BMD (p<0.0001) and a higher prevalence of vertebral fractures than women without DISH (28.6% vs. 15.1%; p = 0.002). When analyzing DISH through Schlapbach grades, women without DISH had a median TBS value consistent with a normal trabecular structure while the values for women with DISH from grades 1 to 3 were consistent with a partially degraded trabecular structure. Women with vertebral fractures and DISH had a mean TBS corresponding to a degraded trabecular structure (1.219±0.1). After adjusting for confounders, the estimated TBS means were 1.272 (1.253-1.290) in the DISH group, and 1.334 (1.328-1.339) in the NDISH group (p<0.0001).

An association between DISH and TBS has been shown in postmenopausal women, in which hyperostosis has been significantly and consistently related to trabecular degradation and, therefore, to deterioration in bone quality after adjusting for confounding variables.

Cerebral palsy (CP) is a broad range of diseases with permanent and nonprogressive motor impairments, carrying a high cost for both the individual and the society. The characteristics of low bone mineral density and high risk of fractures suggest that bone metabolism disorders are present in CP. This study aims to investigate the association between indicators of bone metabolism and children with CP. A total of 139 children (75 children with CP and 64 healthy controls) were included in this cross-sectional study. Participants were divided into three age groups (0-2 years, 2.1-4 years, and 4.1-7 years). All children with CP were diagnosed according to clinical criteria and furtherly divided into clinical subtypes. The levels of total procollagen type I N-terminal propeptide (TPINP), N-MID osteocalcin (OC), beta-crosslaps (β-CTX), 25-hydroxyvitamin D (25-OHD) and parathyroid hormone (PTH) in the serum were measured with corresponding detection kits according to the manufacturer's instructions. Serum levels of TPINP and 25-OHD were lower with older age, whereas β-CTX and PTH were higher with older age. In the CP group, TPINP (age 0-2 years and 2.1-4 years) and OC (age 2.1-4 years) levels were higher, while β-CTX (age 2.1-4 years and 4.1-7 years) and PTH (age 2.1-4 years) values were lower than the control group. In addition, there were no statistically significant differences in the levels of these indicators among the CP subgroups with different clinical characteristics. Our study shows that bone turnover markers, indicators of bone metabolism, in children with CP differ significantly from healthy controls. The indicators we studied changed with age, and they did not correlate with disease severity.

The risk of fragility fractures is increased in both type 1 and type 2 diabetes. Numerous biochemical markers reflecting bone and/or glucose metabolism have been evaluated in this context. This review summarizes current data on biochemical markers in relation to bone fragility and fracture risk in diabetes.

Literature review by a group of experts from the International Osteoporosis Foundation (IOF) and European Calcified Tissue Society (ECTS) focusing on biochemical markers, diabetes, diabetes treatments and bone in adults.

Although bone resorption and bone formation markers are low and poorly predictive of fracture risk in diabetes, osteoporosis drugs seem to change bone turnover markers in diabetics similarly to non-diabetics, with similar reductions in fracture risk. Several other biochemical markers related to bone and glucose metabolism have been correlated with BMD and/or fracture risk in diabetes, including osteocyte-related markers such as sclerostin, HbA1c and advanced glycation end products (AGEs), inflammatory markers and adipokines, as well as IGF-1 and calciotropic hormones.

Several biochemical markers and hormonal levels related to bone and/or glucose metabolism have been associated with skeletal parameters in diabetes. Currently, only HbA1c levels seem to provide a reliable estimate of fracture risk, while bone turnover markers could be used to monitor the effects of anti-osteoporosis therapy.

To describe recent advances in the understanding of how gut-derived hormones regulate bone homeostasis in humans with emphasis on pathophysiological and therapeutic perspectives in diabetes.

The gut-derived incretin hormone glucose-dependent insulinotropic polypeptide (GIP) is important for postprandial suppression of bone resorption. The other incretin hormone, glucagon-like peptide 1 (GLP-1), as well as the intestinotrophic glucagon-like peptide 2 (GLP-2) has been shown to suppress bone resorption in pharmacological concentrations, but the role of the endogenous hormones in bone homeostasis is uncertain. For ambiguous reasons, both patients with type 1 and type 2 diabetes have increased fracture risk. In diabetes, the suppressive effect of endogenous GIP on bone resorption seems preserved, while the effect of GLP-2 remains unexplored both pharmacologically and physiologically. GLP-1 receptor agonists, used for the treatment of type 2 diabetes and obesity, may reduce bone loss, but results are inconsistent. GIP is an important physiological suppressor of postprandial bone resorption, while GLP-1 and GLP-2 may also exert bone-preserving effects when used pharmacologically. A better understanding of the actions of these gut hormones on bone homeostasis in patients with diabetes may lead to new strategies for the prevention and treatment of skeletal frailty related to diabetes.

A healthy skeleton depends on a continuous renewal and maintenance of the bone tissue. The process of bone remodeling is highly controlled and consists of a fine-tuned balance between bone formation and bone resorption. Biochemical markers of bone turnover are already in use for monitoring diseases and treatment involving the skeletal system, but novel biomarkers reflecting specific biological processes in bone and interacting tissues may prove useful for diagnostic, prognostic, and monitoring purposes. The Wnt-signaling pathway is one of the most important pathways controlling bone metabolism and consequently the action of inhibitors of the pathway such as sclerostin and Dickkopf-related protein 1 (DKK1) have crucial roles in controlling bone formation and resorption. Thus, they might be potential markers for clinical use as they reflect a number of physiological and pathophysiological events in bone and in the cross-talk with other tissues in the human body. This review focuses on the clinical utility of measurements of circulating sclerostin and DKK1 levels based on preanalytical and analytical considerations and on evidence obtained from published clinical studies. While accumulating evidence points to clear associations with a number of disease states for the two markers, and thus, the potential for especially sclerostin as a biochemical marker that may be used clinically, the lack of standardization or harmonization of the assays still hampers the clinical utility of the markers.

The present study explores the relationship between glycemic excursion and bone turnover markers.

A total of 250 patients with type 2 diabetes mellitus (T2DM) (142 female and 108 male patients) were enrolled in this study. All participants underwent 72 hours of continuous glycemic monitoring to evaluate the mean amplitude of glycemic excursions (MAGE) of each person. Bone turnover markers and other biochemical data were measured for each patient. Linear regression was performed to explore the relationship between bone turnover markers and glycemic excursion. A value of P < 0.05 was considered statistically significant.

MAGE was negatively correlated to N-terminal propeptide of type 1 collagen (P1NP) female: [odds ratios (95% confidence interval) (OR (95% CI)), -2.516 (-5.389, 0.356)]; male: [-2.895, (-6.521, -0.731)] and C-terminal telopeptide fragments of type-I collagen (β-CTX) female [-0.025, (-0.036, 0.005)]; male [-0.043, (-0.082, 0.003)]. MAGE was still negatively correlated with β-CTX female [-0.036, (-0.198, -0.030)]; male [-0.048, (-0.089, -0.007)] after adjusting for clinical data and biochemical indices.

An independent negative relationship between glycemic excursion and bone turnover markers in patients with T2DM was identified in this study.

The accumulation of advanced glycation end-products (AGEs) in the organic matrix of bone with aging and chronic disease such as diabetes is thought to increase fracture risk independently of bone mass. However, to date, there has not been a clinical trial to determine whether inhibiting the accumulation of AGEs is effective in preventing low-energy, fragility fractures. Moreover, unlike with cardiovascular or kidney disease, there are also no pre-clinical studies demonstrating that AGE inhibitors or breakers can prevent the age- or diabetes-related decrease in the ability of bone to resist fracture. In this review, we critically examine the case for a long-standing hypothesis that AGE accumulation in bone tissue degrades the toughening mechanisms by which bone resists fracture. Prior research into the role of AGEs in bone has primarily measured pentosidine, an AGE crosslink, or bulk fluorescence of hydrolysates of bone. While significant correlations exist between these measurements and mechanical properties of bone, multiple AGEs are both non-fluorescent and non-crosslinking. Since clinical studies are equivocal on whether circulating pentosidine is an indicator of elevated fracture risk, there needs to be a more complete understanding of the different types of AGEs including non-crosslinking adducts and multiple non-enzymatic crosslinks in bone extracellular matrix and their specific contributions to hindering fracture resistance (biophysical and biological). By doing so, effective strategies to target AGE accumulation in bone with minimal side effects could be investigated in pre-clinical and clinical studies that aim to prevent fragility fractures in conditions that bone mass is not the underlying culprit.

The extended microbial genome-the gut microbiome (GM)-plays a significant role in host health and disease. It is able to influence a number of physiological functions. During dysbiosis, GM is associated with the development of various chronic diseases with impaired bone quality. In general, GM is important for bone homeostasis and can affect it via several mechanisms. This review describes the roles of GM in bone homeostasis through influencing the immune and endocrine functions, short-chain fatty acids production, calcium absorption and the gut-brain axis. The relationship between GM composition and several bone-related diseases, specifically osteoporosis, osteoarthritis, rheumatoid arthritis, diabetes mellitus, obesity and bone cancer, is also highlighted and summarized. GM manipulation may become a future adjuvant therapy in the prevention of many chronic diseases. Therefore, the beneficial effects of probiotic therapy to improve the health status of individuals with aforementioned diseases are provided, but further studies are needed to clearly confirm its effectiveness. Recent evidence suggests that GM is responsible for direct and indirect effects on drug efficacy. Accordingly, various GM alterations and interactions related to the treatment of bone-related diseases are mentioned as well.

Osteocalcin, a protein secreted mainly by mature osteoblasts, has been shown to be involved in glucose metabolism through various pathways. However, few studies has explored the association between osteocalcin and Time in range (TIR). Continuous glucose monitoring (CGM) -derived metrics, such as TIR and other indexes have been gradually and widely used in clinical practice to assess glucose fluctuations. The main purpose of this study was to investigate the correlation between osteocalcin and indexes from CGM in patients with type 2 diabetes mellitus (T2DM).

The total number of 376 patients with T2D were enrolled, all of them performed three consecutive days of monitoring. They were divided into four groups on account of the quartile of osteocalcin. Time in range, Time below range (TBR), Time above range(TAR) and measures of glycemic variability (GV) were assessed for analysing. After a 100 g standard steamed bread meal, blood glucose (Glu0h Glu0.5 h, Glu1h, Glu2h, GLu3h), C-peptide (Cp0h, Cp0.5 h, Cp1h, Cp2h, Cp3h), serum insulin (INS0h, INS0.5 h, INS1h, INS2h, INS3h) concentrations at different time points were obtained. HOMA-IS, HOMA-βwas calculated to evaluate insulin sensitivity and insulin secreting of the participants.

Patients with higher osteocalcin level had higher TIR (P < 0.05). Spearman correlation analysis showed that osteocalcin was positively correlated with TBR (although the P value for TBR was greater than 0.05) (r = 0.227, P < 0.001 r = 0.068, P = 0.189) and negatively correlated with TAR (- 0.229, P < 0.001). Similarly, there was a negative correlation between osteocalcin and glycemic variability (GV) indicators, including SD, MBG, MODD, ADDR, and MAGE (P value of MAGE > 0.05). Multiple stepwise regression showed that osteocalcin was an independent contributor to TIR, TAR and HOMA-IS.

Circulating osteocalcin is positively correlated with TIR and negatively correlated with MODD, ADDR, and MAGE. Osteocalcin may have a beneficial impact on glucose homeostasis in T2DM patients.

Bone fragility is a common complication in subjects with type 2 diabetes mellitus (T2DM). However, traditional techniques for the evaluation of bone fragility, such as dual-energy X-ray absorptiometry (DXA), do not perform well in this population. Moreover, the Fracture Risk Assessment Tool (FRAX) usually underestimates fracture risk in T2DM. Importantly, novel technologies for the assessment of one microarchitecture in patients with T2DM, such as the trabecular bone score (TBS), high-resolution peripheral quantitative computed tomography (HR-pQCT), and microindentation, are emerging. Furthermore, different serum and urine bone biomarkers may also be useful for the evaluation of bone quality in T2DM. Hence, in this article, we summarize the limitations of conventional tools for the evaluation of bone fragility and review the current evidence on novel approaches for the assessment of quality and bone microstructure alterations in patients with T2DM.

Metabolic syndrome (MetS), type 1 diabetes (T1D), and type 2 diabetes, are associated with an increased risk of fractures; however, the impact of obesity on bone deficits in diabetes is unknown. We aimed to compare markers of bone structure, bone density, and bone turnover in non-diabetic overweight men with MetS and overweight men with T1D or T2D.

In this cross-sectional study we included participants from two previously described study cohorts consisting of participants with diabetes and participants with MetS. Participants underwent dual-energy X-ray absorptiometry measuring areal bone mineral density (aBMD) at the hip and lumbar spine, High Resolution peripheral Quantitative (HRpQCT) scan of the tibia and radius and measurement of circulating bone turnover markers. We compared groups with unpaired t test and performed multiple linear regression with adjustment for age, body mass index, and smoking.

We included 33 participants with T1D, 25 participants with T2D, and 34 participants with MetS. Bone turnover markers levels were comparable between T1D and MetS. aBMD at the hip was lower in T1D compared to MetS, also after adjustment. P1NP and Osteocalcin levels were lower among individuals with T2D compared to MetS, whereas aBMD were similar between the groups after multiple adjustments. We observed no difference in volumetric BMD at the tibia or radius between MetS and T1D and T2D, respectively. Participants with T2D had a higher trabecular number and lower trabecular separation compared to individuals with MetS at the tibia, which remained signficant after multiple adjustments.

In conclusion, we observed no clinically important differences in bone density or structure between men with T2D, T1D, or MetS. However, men with T2D displayed lower bone turnover compared to MetS highlighting that T2D per se and not obesity, is associated with low bone turnover.

Type 2 diabetes mellitus (T2DM) is well-known to be associated with normal bone density but, concurrently, low bone turnover and increased risk for fracture. One of the proposed mechanisms is possible derangement in bone precursor cells, which could be represented by deficiencies in circulating osteogenic progenitor (COP) cells and osteoclast precursors (OCP). The objective of our study is to understand whether extent of glycemic control has an impact on these cells, and to identify other factors that may as well.

This was a secondary analysis of baseline data from 51 male participants, aged 37-65 in an ongoing clinical trial at Michael E. DeBakey VA Medical Center, Houston, Texas, USA. At study entry serum Hemoglobin A1c was measured by high-performance liquid chromatography osteocalcin (OCN) and C-terminal telopeptide of type 1 collagen (CTx) were measured by ELISA, and testosterone and estradiol by liquid-chromatography/mass-spectrometry. Areal bone mineral density (BMD), trabecular bone score and body composition were measured by dual energy x-ray absorptiometry, while COP and OCP were measured by flow cytometry.

When adjusted for serum testosterone, parathyroid hormone, and 25-hydroxyvitamin D, those with poor long-term glycemic control had significantly higher percentage of COP (p = 0.04). COP correlated positively with visceral adipose tissue (VAT) volume (r = 0.37, p = 0.01) and negatively with free testosterone (r = -0.28, p = 0.05) and OCN (r = -0.28, p = 0.07), although only borderline for the latter. OCP correlated positively with age, FSH, lumbar spine BMD, and COP levels, and negatively with glucose, triglycerides, and free estradiol. Multivariable regression analyses revealed that, in addition to being predictors for each other, another independent predictor for COP was VAT volume while age, glucose, and vitamin D for OCP.

Our results suggest that high COP could be a marker of poor metabolic control. However, given the complex nature and the multitude of factors influencing osteoblastogenesis/adipogenesis, it is possible that the increase in COP is a physiologic response of the bone marrow to increased osteoblast apoptosis from poor glycemic control. Alternatively, it is also likely that a metabolically unhealthy profile may retard the development of osteogenic precursors to fully mature osteoblastic cells.