This study investigated the correlation between metformin use and diabetic peripheral neuropathy (DPN) risk in patients with type 2 diabetes mellitus (T2DM) and its dose-dependent relationship. The study included new-onset T2DM patients from 2002 to 2013. Patients were divided into two groups based on metformin treatment, and DPN risk was assessed at 2- and 5-year follow-ups. After adjusting for various factors, two logistic models, metformin cumulative defined daily dose (cDDD) and metformin treatment intensity (defined daily dose [DDD]/month), evaluated the metformin-DPN risk association. Results showed that patients with metformin cDDD < 300, 300-500, and > 500 had higher DPN risk at both follow-ups. Odds ratios (ORs) and confidence intervals (CIs) for DPN were 1.74 (1.69-1.79), 2.05 (1.81-2.32), and 2.36 (1.34-4.16) at 2 years and 1.63 (1.60-1.65), 1.82 (1.69-1.96), and 2.17 (1.56-3.03) at 5 years. Similarly, patients with < 10, 10-25, and > 25 DDD/month had higher DPN risk at both follow-ups. Metformin use correlated with DPN risk in T2DM patients, with a dose-dependent relationship. Higher metformin cDDD or treatment intensity increased DPN risk. However, the absence of vitamin B12 data limits the understanding of the underlying mechanisms. Well-designed, large-scale studies are required to evaluate the potential risks of metformin therapy for DPN in patients with T2DM.

Background Metformin is frequently prescribed as a first-line oral hypoglycemic drug to treat insulin resistance-causing type 2 diabetes mellitus (T2DM). Long-term metformin use results in vitamin B12 deficiency, which is frequently overlooked and undiagnosed. A severe deficit may cause severe anemia and gastrointestinal, or neurological issues. Studies are scarce on this issue in Pakistani patients with T2DM. The current study aimed to estimate the prevalence of metformin-induced vitamin B12 deficiency in T2DM patients and to explore how it relates to metformin dosage or duration of therapy. Methodology A descriptive cross-sectional study was conducted on 260 T2DM patients using metformin therapy for more than a year and attending the outpatient diabetes clinic and the medicine department of Sheikh Zayed Hospital, Rahim Yar Khan, Pakistan, from August 2022 to October 2023. All socio-demographic, clinical, and general characteristics were collected. Blood samples were taken to measure the serum vitamin B12 levels, and based on these levels, deficient and normal group characteristics were compared. Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 23 (Released 2015; IBM Corp., Armonk, New York, United States). Results Based on the serum levels of vitamin B12 of the studied T2DM on the metformin regimen, the overall prevalence of vitamin B12 deficiency was found to be 36.54% (95). The B12 deficiency was higher among the age group of 41-50 years (109, 41.9%), female gender (150, 57.7%, p-value=0.0035), urban residents (194, 74.6%), non-smokers (197, 75.8%), and with a history of chronic disease (131, 50.4%). There was a statistically significant difference in vitamin B12 levels based on T2DM duration (p=0.012), with a higher prevalence in patients with a longer diabetes history of more than two years. There was no discernible statistical relationship between patients receiving different dosages of metformin (odds ratio (OR)=0.8627; 95% confidence interval (CI) (0.5195, 1.4326); p-value=0.568), durations of metformin (OR=0.7400; 95% CI (0.442, 1.2325); p-value=0.247), or intake of vitamin B12 (OR=0.8532; 95% CI (0.5073, 1.4351); p-value=0.549). Conclusion The prevalence of vitamin B12 deficiency impacted more than one-third of T2DM patients using metformin (36.54%). The risk of vitamin B12 deficiency may increase in females with higher metformin dosages and longer durations of treatment. Furthermore, a statistically significant correlation exists between vitamin B12 deficiency and the longer duration of T2DM. These findings highlight the relevance of routinely monitoring serum levels of vitamin B12 among those with T2DM, especially when metformin is being given for over a year or at doses greater than 1000 mg per day. These preventive strategies will aid in the early detection of vitamin B12 deficiency, allowing patients to be treated with supplementation before problems such as anemia or neuropathies arise, resulting in improved quality of life and a lower socioeconomic burden.

Diabetes mellitus (DM) is the most common metabolic disease worldwide. Hence, the prevalence of the disease continues to increase across the globe. Metformin is used as a first-line oral hypoglycemic drug to keep control of type-2 DM (T2DM) in adults. Diabetic patients on metformin have been largely seen to be suffering from a deficiency of vitamin B12. It is a water-soluble vitamin mainly obtained from animal food like meat. At the basic cell level, it acts as a cofactor for enzymes essential for DNA synthesis and neuroprotection. As a result, vitamin B12 deficiency can show clinical effects such as progressive demyelination, peripheral neuropathy and haematological abnormalities (such as macrocytic anaemia and neutrophil hypersegmentation). Various studies also show a relation between vitamin B12 insufficiency and metformin-treated T2DM patients as decreased absorption of vitamin B12. There could be a severe complication of vitamin B12 deficiency in T2DM patients. The use of proton pump inhibitors, gastric bypass surgery, older patients and patients with a higher red blood cell turnover are factors that hasten the depletion of vitamin B12 reserves in the liver. Methylmalonic acid and homocysteine levels can be measured to identify vitamin B12 insufficiency at its early stage if blood vitamin B12 levels are borderline. The action of metformin on vitamin B12 absorption and its potential mechanisms of inhibition will be the main topics of discussion in this review. The review will also discuss how vitamin B12 deficiencies in T2DM patients using metformin affect their clinical results.

Vitamin B₁₂ (B₁₂) is an essential cofactor of two important biochemical pathways, the degradation of methylmalonic acid and the synthesis of methionine from homocysteine. Methionine is an important donor of methyl groups for numerous biochemical reactions, including DNA synthesis and gene regulation. Besides hematological abnormalities (megaloblastic anemia or even pancytopenia), a deficiency in B₁₂ may cause neurological symptoms, including symptoms resembling diabetic neuropathy. Although extensively studied, the underlining molecular mechanism for the development of diabetic peripheral neuropathy (DPN) is still unclear. Most studies have found a contribution of oxidative stress in the development of DPN. Detailed immunohistochemical investigations in sural nerve biopsies obtained from diabetic patients with DPN point to an activation of inflammatory pathways induced via elevated advanced glycation end products (AGE), ultimately resulting in increased oxidative stress. Similar results have been found in patients with B₁₂ deficiency, indicating that the observed neural changes in patients with DPN might be caused by cellular B₁₂ deficiency. Since novel results show that B₁₂ exerts intrinsic antioxidative activity in vitro and in vivo, B₁₂ may act as an intracellular, particularly as an intramitochondrial, antioxidant, independent from its classical, well-known cofactor function. These novel findings may provide a rationale for the use of B₁₂ for the treatment of DPN, even in subclinical early states.

Years of use of the antidiabetic drug metformin has long been associated with the risk of vitamin B12 (B12) deficiency in type 2 diabetes (T2D) patients, although the underlying mechanisms are unclear. Accumulating evidence has shown that metformin may exert beneficial effects by altering the metabolism of the gut microbiota, but whether it induces human B12 deficiency via modulation of bacterial activity remains poorly understood. Here, we show that both metformin and the other biguanide drug phenformin markedly elevate the accumulation of B12 in E. coli. By functional and genomic analysis, we demonstrate that both biguanides can significantly increase the expression of B12 transporter genes, and depletions of vital ones, such as tonB, nearly completely abolish the drugs' effect on bacterial B12 accumulation. Via high-throughput screens in E. coli and C. elegans, we reveal that the TetR-type transcription factor RcdA is required for biguanide-mediated promotion of B12 accumulation and the expressions of B12 transporter genes in bacteria. Together, our study unveils that the antidiabetic drug metformin helps bacteria gather B12 from the environment by increasing the expressions of B12 transporter genes in an RcdA-dependent manner, which may theoretically reduce the B12 supply to T2D patients taking the drug over time.

Metformin treatment is associated with vitamin B12 deficiency, which is a risk factor for neuropathy. However, few studies have examined the relationship between metformin treatment and diabetic peripheral neuropathy (DPN), and the available findings are contradictory. We aimed to assess whether metformin treatment is associated with DPN in patients with type 2 diabetes mellitus (T2DM) in Beijing, China.

All patients with newly diagnosed T2DM between January 2010 and September 2012 in the Medical Claim Data for Employees database were included. Metformin treatment was defined as any record of metformin prescription. The average daily dose of metformin during follow-up was calculated. DPN was defined as DPN admissions occurring after a diagnosis of T2DM in the database. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards models.

Among 49,705 T2DM patients, 1,933 DPN events were recorded during a median follow-up of 6.36 years. The crude incidence rates were 7.12 and 3.91 per 1000 person-years for patients treated with metformin (N=37,052) versus those not treated (N=12,653). Patients treated with metformin had an 84% increased risk of DPN compared with patients not using metformin (HR, 1.84; 95% CI, 1.62, 2.10). The daily dose was positively associated with DPN risk (HR, 1.48; 95% CI, 1.46, 1.51; P for trend <0.001). The risk of DPN was 1.53-fold (1.30, 1.81) and 4.31-fold (3.76, 4.94) higher in patients with daily doses of 1.0-2.0 g and >2.0 g, respectively, than in patients who did not receive treatment. Patients aged less than 60 years had a higher risk of DPN (P<0.05 for interaction test). Among patients taking vitamin B12 at baseline, there was no increased risk of DPN in the metformin group (1.92: 0.79, 4.69).

In Chinese patients with T2DM, metformin treatment was associated with an increased risk of DPN admission and this risk responds positively to the daily dose of metformin. In particular, metformin use was a major risk factor for DPN in younger patients. Concomitant use of vitamin B12 may avoid the increased risk of DPN associated with metformin use.

Gut microbiota has implications in Central Nervous System (CNS) disorders. Our study systematically identified preclinical studies aimed to investigate the possible gut microbiota contribution in neuropathy and neuropathic pain. The systematic review is reported in accordance with PRISMA checklist and guidelines outlined updated to 2020. We included research articles reporting neuropathy-related behavioral evaluations and/or neurological scores coupled to gut microbiota analysis performed by high-throughput technologies in the last ten years. Two investigators performed a search through 3 electronic bibliographic databases for full-text articles (PubMed, Scopus, and EMBASE) and three registries (Prospero, SyRF, and bioRxiv), cross-references, and linear searches. We assessed the methodological quality via the CAMARADES checklist and appraised the heterogeneous body of evidence by narrative synthesis. In total, there were 19 eligible studies. The most of these reports showed significant changes in gut microbiota setting in neuropathy conditions. The major gut microbiome remodeling was through fecal microbiome transplantation. Mechanistic proof of the gut-CNS communication was achieved by measuring inflammatory mediators, metabolic products, or neurotransmitters. As a limitation, we found considerable heterogeneity across eligible studies. We conclude that the current understanding of preclinical findings suggested an association between neuropathy and/or neuropathic pain and gut microbiota modifications. Our analysis provides the basis for further studies targeting microbiota for managing symptoms of neuropathy or other neuroinflammation-based CNS disorders. The systematic review protocol was registered on the international database Prospero under the registration number (# 257628).

To investigate the effect of normalizing vitamin B12 (B12) levels with oral B12 (methylcobalamin) 1000 μg/day for one year in patients with diabetic neuropathy (DN).

In this prospective, double-blind, placebo-controlled trial, 90 patients with type 2 diabetes on metformin for at least four years and both peripheral and autonomic DN were randomized to an active treatment group (n = 44) receiving B12 and a control group (n = 46) receiving a placebo. All patients had B12 levels less than 400 pmol/L. Subjects underwent measurements of sural nerve conduction velocity (SNCV), sural nerve action potential (amplitude) (SNAP), and vibration perception threshold (VPT), and they performed cardiovascular autonomic reflex tests (CARTs: mean circular resultant (MCR), Valsalva test, postural index, and orthostatic hypotension). Sudomotor function was assessed with the SUDOSCAN that measures electrochemical skin conductance in hands and feet (ESCH and ESCF, respectively). We also used the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE, respectively) and questionnaires to evaluate quality of life (QoL) and level of pain (pain score).

B12 levels increased from 232.0 ± 71.8 at baseline to 776.7 ± 242.3 pmol/L at follow-up, p < 0.0001, in the active group but not in the control group. VPT, MNSIQ, QoL, pain score, SNCV, SNAP, and ESCF significantly improved in the active group (p < 0.001, p = 0.002, p < 0.0001, p < 0.000, p < 0.0001, p < 0.0001, and p = 0.014, respectively), whereas CARTS and MNSIE improved but not significantly. MCR, MNSIQ, SNCV, SNAP, and pain score significantly deteriorated in the control group (p = 0.025, p = 0.017, p = 0.045, p < 0.0001, and p < 0.0001, respectively).

The treatment of patients with DN with 1 mg of oral methylcobalamin for twelve months increased plasma B12 levels and improved all neurophysiological parameters, sudomotor function, pain score, and QoL, but it did not improve CARTS and MNSIE.

Our objective was to assess whether increased duration of metformin therapy is associated with incident peripheral neuropathy (PN) in older Veterans with diabetes.

Using national Veterans Affairs registry data from 2002 to 2015, we examined Veterans (50 + years) with diabetes. Long-term metformin therapy was defined as prescription ≥ 500 mg/day, filled for ≥ 6 consecutive months. Metformin therapy duration was examined both as continuous and categorical measures. Incident PN was defined by medical chart review. We estimated unadjusted and adjusted (variables selecteda priori)odds ratios (OR) and 95% confidence intervals (CI) using logistic regression.

The study included n = 210,004 individuals (mean ± SD: age: 66.2 ± 8.4 yrs, 96% male) prescribed metformin for 47.0 ± 34.0 months. Nineteen percent developed PN during follow-up. After adjusting for age, body mass index, duration of time receiving health care within the VA, smoking status, alcohol abuse, and vitamin B12 testing and treatment, the number of months of metformin treatment was associated with elevated odds for incident PN (aOR (metformin treatment - continuous) = 1.009 (95% CI = 1.009, 1.010); aOR (metformin treatment - categorical (ref: 6-<18 months): 18-<44.1 months = 1.57 (1.51-1.63), 44.1-<61 months = 2.05 (1.97-2.14), 61 + months = 2.69 (2.58-2.79), all p-values < 0.0001).

Our study suggests that Veterans treated for at least 18 months with metformin are approximately 2-3 times more likely to develop PN than those treated at least six, but<18 months. Future studies are needed to determine whether the association we found may be due to a decline in vitamin B12 status following metformin initiation.

To assess the prevalence of vitamin B₁₂ deficiency in people with type 2 diabetes mellitus (T2DM) on metformin and without metformin.

Between May 2018 and January 2019, this prospective multicenter observational study recruited participants from seven centers in four provinces of Pakistan (Sindh, Punjab, Baluchistan and Khyber Pakhtunkhwa). Participants with T2DM treated with metformin for >2 years and those not on metformin underwent assessment of hemoglobin, vitamin B₁₂, homocysteine and diabetic neuropathy (vibration perception threshold (VPT) >15V) and painful diabetic neuropathy (Douleur Neuropathique 4 (DN4) ≥4) and Diabetic Neuropathy Symptom (DNS) score ≥1.

Of 932 subjects, 645 (69.2%) were treated with metformin, while 287 (30.8%) were not on metformin. Overall, B₁₂ deficiency (<200 pg/mL) was significantly higher in metformin users of 25 (3.9%), compared with non-metformin users of 6 (2.1%), while B₁₂ insufficiency (200-300 pg/mL) was significantly lower in metformin users of 117 (18.4%) compared with non-metformin users of 80 (27.9%). Subjects with B₁₂ deficiency and insufficiency with hyperhomocysteinemia (≥15) were found in 19 (76%) µmol/L and 69 (60.5%) µmol/L in metformin users compared with 6 (100%) µmol/L and 57 (73.1%) μmol/L in non-metformin users, respectively. VPT>25 and DN4 score ≥4 were significantly higher in B₁₂-deficient metformin users compared with non-metformin users. Similarly, DNS score ≥1 was non-significantly higher in B₁₂-deficient metformin users compared with non-metformin users.

This study shows that vitamin B₁₂ insufficiency was frequently found in our population and may progress into B₁₂ deficiency. It is also associated with neuropathy in subjects on metformin. Further interventional studies to assess the benefit of B₁₂ treatment on painful neuropathy in patients on metformin may be warranted. B₁₂ levels may be checked in people with T2DM using metformin for >2 years.

Metformin is the first-choice drug in uncomplicated type 2 diabetes (T2DM) and is effective in improving glycaemic control. It is the most widely prescribed oral antidiabetic medicine and has a good safety profile. However, there is an abundance of evidence that metformin use is associated with decreased Vitamin B12 status, though the clinical implications of this in terms of increased risk of diabetic peripheral neuropathy are debated. There is growing evidence that other B vitamins, vitamin D and magnesium may also be impacted by metformin use in addition to alterations to the composition of the microbiome, depending on the dose and duration of therapy. Patients using metformin for prolonged periods may, therefore, need initial screening with intermittent follow-up, particularly since vitamin B₁₂ deficiency has similar symptoms to diabetic neuropathy which itself affects 40-50% of patients with T2DM at some stage. Among patients with T2DM, 40% are reported to experience symptomatic gastroesophageal reflux disease (GORD), of whom 70% use oral antidiabetic medications. The most common medications used to treat GORD are proton pump inhibitors (PPIs) and antagonists of histamine selective H₂ receptors (H₂RAs), both of which independently affect vitamin B₁₂ and magnesium status. Research indicates that co-prescribing metformin with either PPIs or H₂RAs can have further deleterious effects on vitamin B₁₂ status. Vitamin B12 deficiency related to metformin and polypharmacy is likely to contribute to the symptoms of diabetic neuropathy which may frequently be under-recognised. This review explores current knowledge surrounding these issues and suggests treatment strategies such as supplementation.

Metformin can cause serum vitamin B12 deficiency, but studies on the influence of its duration and dose are lacking. We investigated vitamin B12 deficiency in patients with type 2 diabetes using metformin, in conjunction with other related factors.

This cross-sectional study included 1111 patients with type 2 diabetes who took metformin for at least 6 months. Serum vitamin B12 levels were quantified using a competitive-binding immunoenzymatic assay, and vitamin B12 deficiency was defined as serum B12 <300 pg/mL. Information on metformin use and confounding variables were collected from records or questionnaires and interviews.

Serum vitamin B12 deficiency occurred in 22.2% of patients (n = 247). After adjusting for confounders, a 1 mg increase in daily metformin dose was associated with a 0.142 pg/mL decrease in vitamin B12 (P < .001). Compared with a daily dose of <1000 mg, the adjusted odds ratios for 1000 to 1500, 1500 to 2000, and ≥2000 mg metformin were 1.72 (P = .080), 3.34 (P < .001), and 8.67 (P < .001), respectively. Vitamin B12 deficiency occurred less often in patients taking multivitamins (odds ratio 0.23; P < .001). After adjusting for confounding factors, there was no correlation between B12 deficiency and duration of metformin use. Serum homocysteine levels showed significant negative correlation with vitamin B12.

Metformin at ≥1500 mg/d could be a major factor related to vitamin B12 deficiency, whereas concurrent supplementation of multivitamins may potentially protect against the deficiency. Serum homocysteine levels were negatively correlated with vitamin B12 levels, suggesting that B12 deficiency due to metformin use may occur at the tissue level. However, this hypothesis will require further study.

Metformin is first-line therapy for patients with diabetes. However, it may lower vitamin B₁₂ concentrations, which could have hematological or neurological implications. This meta-analyses reviewed all available studies on associations between metformin use and vitamin B₁₂ levels, anemia, and neuropathy in diabetic patients.

PubMed, Web of Knowledge, Cochrane Library, and Embase were searched to identify all relevant studies published in English prior to March 2018. Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated for dichotomous outcomes and pooled mean differences (MDs) and 95% CIs were calculated for continuous outcomes.

Thirty-one studies were included in the meta-analyses. Compared with diabetic patients not taking metformin, patients taking metformin had a significantly higher risk of vitamin B₁₂ deficiency (RR 2.09; 95% CI 1.49, 2.93; P < 0.0001; I²  = 64%) and significantly lower serum vitamin B₁₂ concentrations (MD -63.70; 95% CI -74.35, -53.05] pM; P < 0.00001; I²  = 87%), which depended on dose and duration of treatment. Metformin use was also associated with significantly greater percentage decrease in serum vitamin B₁₂ concentrations from baseline in diabetic patients (MD -14.68%; 95% CI -17.98%, -11.39%; P < 0.00001; I²  = 33%). Analyses revealed no significant association between metformin use and the prevalence of anemia or neuropathy.

Metformin use led to significantly lowered vitamin B₁₂ concentrations and significantly higher risk of vitamin B₁₂ deficiency in diabetic patients. More quality studies are needed to explore the associations between metformin use and anemia and neuropathy in these patients. Annual vitamin B₁₂ assessment in diabetic patients taking metformin is recommended.

Cardiac autonomic neuropathy (CAN) is a serious complication of diabetes mellitus (DM) that is strongly associated with approximately five-fold increased risk of cardiovascular mortality. CAN manifests in a spectrum of things, ranging from resting tachycardia and fixed heart rate (HR) to development of "silent" myocardial infarction. Clinical correlates or risk markers for CAN are age, DM duration, glycemic control, hypertension, and dyslipidemia (DLP), development of other microvascular complications. Established risk factors for CAN are poor glycemic control in type 1 DM and a combination of hypertension, DLP, obesity, and unsatisfactory glycemic control in type 2 DM. Symptomatic manifestations of CAN include sinus tachycardia, exercise intolerance, orthostatic hypotension (OH), abnormal blood pressure (BP) regulation, dizziness, presyncope and syncope, intraoperative cardiovascular instability, asymptomatic myocardial ischemia and infarction. Methods of CAN assessment in clinical practice include assessment of symptoms and signs, cardiovascular reflex tests based on HR and BP, short-term electrocardiography (ECG), QT interval prolongation, HR variability (24 h, classic 24 h Holter ECG), ambulatory BP monitoring, HR turbulence, baroreflex sensitivity, muscle sympathetic nerve activity, catecholamine assessment and cardiovascular sympathetic tests, heart sympathetic imaging. Although it is common complication, the significance of CAN has not been fully appreciated and there are no unified treatment algorithms for today. Treatment is based on early diagnosis, life style changes, optimization of glycemic control and management of cardiovascular risk factors. Pathogenetic treatment of CAN includes: Balanced diet and physical activity; optimization of glycemic control; treatment of DLP; antioxidants, first of all α-lipoic acid (ALA), aldose reductase inhibitors, acetyl-L-carnitine; vitamins, first of all fat-soluble vitamin B1; correction of vascular endothelial dysfunction; prevention and treatment of thrombosis; in severe cases-treatment of OH. The promising methods include prescription of prostacyclin analogues, thromboxane A2 blockers and drugs that contribute into strengthening and/or normalization of Na+, K+-ATPase (phosphodiesterase inhibitor), ALA, dihomo-γ-linolenic acid (DGLA), ω-3 polyunsaturated fatty acids (ω-3 PUFAs), and the simultaneous prescription of ALA, ω-3 PUFAs and DGLA, but the future investigations are needed. Development of OH is associated with severe or advanced CAN and prescription of nonpharmacological and pharmacological, in the foreground midodrine and fludrocortisone acetate, treatment methods are necessary.

This study was carried out to assess the incidence and risk factors of diabetic foot ulcer (DFU).

In this prospective cohort study in a university hospital, all the participants were examined and followed up for new DFU as final outcome for two years. To analyze the data, the variables were first evaluated with a univariate analysis. Then variables with P value < 0.2 were tested with a multivariate analysis, using backward-elimination multiple logistic regression.

Among 605 patients, 39 cases had DFU, so we followed up the remaining 566 patients without any present or history of DFU. A two-year cumulative incidence of diabetic foot ulcer was 5.62% (95% CI 3.89-8.02). After analysis, previous history of DFU or amputation [OR = 9.65, 95% CI (2.13-43.78), P value = 0.003], insulin usage [OR = 5.78, 95% CI (2.37-14.07), P value < 0.01], gender [OR = 3.23, 95% CI (1.33-7.83), P value = 0.01], distal neuropathy [OR = 3.37, 95% CI (1.40-8.09), P value = 0.007], and foot deformity [OR = 3.02, 95% CI (1.10-8.29), P value = 0.032] had a statistically significant relationship with DFU incidence.

Our data showed that the average annual DFU incidence is about 2.8%. Independent risk factors of DFU development were previous history of DFU or amputation, insulin consumption, gender, distal neuropathy, and foot deformity. These findings provide support for a multifactorial etiology for DFU.