The association of metformin use with vitamin B12 deficiency and peripheral neuropathy in Saudi individuals with type 2 diabetes mellitus

Dose dependent relationship of metformin use and diabetic peripheral neuropathy risk in patients with type 2 diabetes mellitus

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.

Metabolite Profiling and Integrated Network Pharmacology Based Mechanism of Benincasa hispida (Thunb.) Cogn. Fruit Against Non-insulin-Dependent Diabetes Mellitus

INTRODUCTION

Benincasa hispida (Thunb.) Cogn. (Cucurbitaceae) is an essential food plant in India possessing antihyperglycemic and antihyperlipidemic activities.

OBJECTIVE

The objective included comparative estimation of α-glucosidase and α-amylase enzyme inhibition potential of B. hispida fractions prepared by microwave-assisted extraction and prediction of metabolite interaction against non-insulin-dependent diabetes mellitus by metabolite profiling based network pharmacology analysis.

METHODS

A validated microwave-assisted extraction method was employed to obtain different fractions of B. hispida fruits. The in vitro enzyme assay was done with p-nitrophenyl-α-D-glucopyranoside and acarbose as standard to evaluate antidiabetic potential. The phytomolecules present in the active fraction were identified by UHPLC-QToF-MS/MS analysis. Network pharmacology analysis gave possible gene and disease association, combination synergy network, and predicted probable mechanism of action.

RESULTS

The highest enzyme inhibition potential (IC50) was shown by the ethyl acetate fraction (0.546 ± 0.17 mg/mL and 1.134 ± 0.42 mg/mL) compared to acarbose (0.298 ± 0.08 mg/mL and 0.532 ± 0.38 mg/mL), respectively, for α-glucosidase and α-amylase addressing the potential role in ameliorating non-insulin-dependent diabetes mellitus. Metabolite profiling resulted in the identification of 17 metabolites, and a synergy between the identified molecules suggested multimolecule action in the amelioration of non-insulin-dependent diabetes mellitus through insulin resistance pathway, AMPK signaling pathway, PPAR signaling pathway, and PI3K-Akt signaling pathway. Combination synergy of identified molecules was observed through a multitarget approach to manage non-insulin-dependent diabetes mellitus.

CONCLUSION

Polyphenol-enriched fraction of B. hispida fruits and identified phytocompounds ameliorate non-insulin-dependent diabetes mellitus. Thus, enriched extract of B. hispida can be further investigated in order to develop high-quality, safe, and effective products for the management of non-insulin-dependent diabetes mellitus.

Dose-Dependent Relationship Between Long-Term Metformin Use and the Risk of Diabetic Retinopathy: A Population-Based Cohort Study

BACKGROUND AND OBJECTIVE

Recent research has raised concerns about the association between metformin treatment in patients with diabetes mellitus (DM) and an increased risk of diabetic retinopathy. We sought to investigate this relationship, specifically examining if metformin use affects diabetic retinopathy risk in a dose-dependent manner.

METHODS

This study was a secondary data analysis based on a nationwide population database in Taiwan. Patients with new-onset DM, an age of 20 years or older, and a diagnosis of type 2 DM received at any time during 2002-2013 were included in the study. Patients diagnosed with new-onset type 2 DM between 2002 and 2013 were enrolled as the study population. We divided them into two groups: those treated with metformin and those treated with sulfonylureas. A Cox proportional hazards model was employed to estimate the risk of diabetic retinopathy after 5 years of follow-up, including cumulative defined daily dose and intensity of metformin treatment.

RESULTS

A total of 241,231 patients received treatment with metformin, while 152,617 patients were treated with sulfonylureas. Compared with patients treated with sulfonylureas, patients who received metformin treatment, at a cumulative defined daily dose < 30, had a lower risk of diabetic retinopathy (adjusted hazard ratio = 0.77; 95% confidence interval 0.60-0.98). However, those with varying defined daily doses, especially at a higher metformin treatment level (> 25 defined daily dose), had a 2.43 times higher risk of diabetic retinopathy (95% confidence interval 1.37-4.30) compared with patients treated with sulfonylureas.

CONCLUSIONS

Patients with DM treated with a lower cumulative dosage of metformin showed beneficial effects that were associated with a lower risk of diabetic retinopathy. In contrast, a higher intensity of metformin use had a greater risk of diabetic retinopathy.

Metformin for neurocognitive dysfunction in schizophrenia: a systematic review

Background

The efficacy and safety of metformin for addressing neurocognitive dysfunction in schizophrenia remain inconclusive. This systematic review evaluates the evidence from randomized controlled trials (RCTs) on the effects of metformin on neurocognitive function in patients with schizophrenia.

Methods

A comprehensive search of Chinese databases (WanFang, Chinese Journal Net) and English databases (PubMed, EMBASE, PsycINFO, and Cochrane Library) was conducted to identify RCTs assessing metformin's impact on neurocognitive outcomes in schizophrenia.

Results

Four RCTs involving 271 patients with schizophrenia were included. Three RCTs (75%) demonstrated significant improvements in neurocognitive function with metformin compared to controls, as assessed by the MATRICS Consensus Cognitive Battery, Repeatable Battery for the Assessment of Neuropsychological Status, and Mini-Mental State Examination, but not the Brief Assessment of Cognition in Schizophrenia. Two RCTs (50%) evaluated metformin's effects on total psychopathology and found no significant differences between groups. Adverse events were reported in two RCTs, with inconsistent findings on decreased appetite and diarrhea. Other adverse events and discontinuation rates were comparable between groups.

Conclusion

Preliminary evidence suggests that metformin may improve neurocognitive function in schizophrenia. However, further large-scale, double-blind, high quality RCTs are warranted to validate these findings.

1-Deoxynojirimycin affects high glucose-induced pancreatic beta-cell dysfunction through regulating CEBPA expression and AMPK pathway

This study aims to explore the role of 1-deoxynojirimycin (DNJ) in high glucose-induced β-cells and to further explore the molecular mechanism of DNJ effect on β-cells through network pharmacology. In the study, high glucose treatment of mouse INS-1 cells inhibited cell proliferation and insulin secretion, decreased the expression of Bcl-2 protein and Ins1 and Ins2 genes, promoted apoptosis, and increased cleaved caspase-3 and cleaved caspase-9 expression levels as well as intracellular reactive oxygen species production. DNJ treatment significantly restored the dysfunction of INS-1 cells induced by high glucose, and DNJ showed no toxicity to normal INS-1 cells. Silencing CEBPA promoted, while overexpression of CEBPA relieved the dysfunction of pancreatic β-cells induced by high glucose. DNJ treatment partially restored the pancreatic β-cell dysfunction caused by silencing CEBPA. In conclusion, DNJ can inhibit high glucose-induced pancreatic β-cell dysfunction by promoting the expression of CEBPA.

Current Perspectives in Pre- and Diabetic Peripheral Neuropathy Diagnosis and Management: An Expert Statement for the Gulf Region

Peripheral neuropathy (PN) significantly impacts the quality of life, causing substantial morbidity and increased mortality, as well as escalating healthcare costs. While PN can have various causes, the most common form, diabetic peripheral neuropathy, poses considerable risks for potential complications. Diabetic peripheral neuropathy (DPN) affects over 50% of people with prediabetes and diabetes. Despite its prevalence, a global gap in diagnosis and management exists, exacerbated by the COVID-19 pandemic. This expert consensus was formulated through a comprehensive evaluation by a panel of experts, informed by a focused literature review, aiming to establish a clinically robust approach to diagnosing and managing pre- and diabetic PN with the early utilization of neurotropic B vitamins. This document offers a consensus perspective on the existing challenges in diagnosing and managing PN, focusing on DPN. The expert panel proposes measures to address this underdiagnosed burden, highlighting the importance of early intervention through innovative screening methods, integrated care approaches, and therapeutic strategies. The document advocates for increased awareness, targeted campaigns, and proactive care strategies to bridge gaps in the patient care of individuals with diabetes, emphasizing the importance of early detection and timely management to improve overall health outcomes. Specific recommendations include incorporating simplified questionnaires and innovative screening methods into routine care, prioritizing neurotropic B vitamin supplementation, optimizing glucagon-like peptide 1 (GLP-1) receptor agonist treatments, and adopting a holistic approach to neuropathy management. The consensus underscores the urgent need to address the underdiagnosis and undertreatment of PN, offering practical measures to enhance early detection and improve health outcomes for individuals with DPN.

Vitamin B12 deficiency in long-term metformin treated type 2 diabetic patients: Prevalence and risk factors in a Tunisian population

Objectives: To determine the prevalence of vitamin B12 deficiency in a Tunisian population with type 2 diabetes (T2D) on metformin treatment for more than three years and to identify its risk factors. Methods: This is a cross-sectional study conducted on 257 patients with T2D treated with metformin for at least three years. Patients were divided into two groups according to their vitamin B12 status. Low vitamin B12 was defined as ≤ 203 pg/mL. Results: The mean age of the patients was 59.8  ±  7.9 years. The mean duration of metformin use was 10.2  ±  5.2 years. The mean vitamin B12 level was 294.9  ±  156.4 pg/mL. The prevalence of vitamin B12 deficiency was 28.4%. Male gender, HbA1c < 7% and hyperhomocysteinemia were significantly associated with vitamin B12 deficiency (respectively p  =  0.02, p < 0.001, p < 0.001). Homocysteine level was negatively correlated with vitamin B12 level (r  =  -0.2, p  =  0.001). Dose and duration of metformin treatment, peripheral neuropathy and anemia were not associated with vitamin B12 deficiency. On multivariate analysis, HbA1c < 7% and hyperhomocysteinemia were independently associated with vitamin B12 deficiency (respectively OR = 3.2, 95%CI  =  [1.6-6.3] and OR = 2.3, 95%CI  =  [1.2-4.2]). Discussion: The prevalence of vitamin B12 deficiency in patients with T2D on metformin treatment was high. Hyperhomocysteinemia is associated with vitamin B12 deficiency suggesting that the deficit occurs at the tissue level.

Evaluating Physician Knowledge, Attitudes, and Practices in Screening and Supplementation for Vitamin B12 Deficiency in Type 2 Diabetes Patients Treated with Metformin

Background and Aim

Long-term metformin use in Type 2 Diabetes Mellitus (T2DM) patients is associated with Vitamin B12 deficiency. This study aims to evaluate physicians' knowledge, attitudes, and practices regarding Vitamin B12 screening and supplementation in this context.

Methods

A survey was administered to physicians across various specialties in government hospitals and primary care centers in Riyadh, Saudi Arabia, from January 2019 to January 2020. The survey assessed their knowledge, attitudes, and practices concerning Vitamin B12 deficiency screening and supplementation.

Results

Of the 402 participating physicians, 94.0% (378 respondents) demonstrated sufficient knowledge about Vitamin B12 deficiency. However, 26.1% believed that Vitamin B12 supplementation does not necessitate screening. 55.7% did not prescribe Vitamin B12 prophylactically, 41.5% omitted neurological examinations in patients presenting with neuropathy, and 22.4% were unaware of the recommended Vitamin B12 supplement dose. Only 49.8% routinely screened for Vitamin B12 deficiency in symptomatic patients. Physicians with more extended years of experience showed significantly better knowledge about Vitamin B12 screening and supplementation (p<0.001).

Conclusion

While most physicians were knowledgeable about Vitamin B12 deficiency and supplementation, a substantial gap in translating this knowledge into practice was observed. There is a critical need for institutional oversight to ensure adherence to American Diabetes Association (ADA) guidelines for Vitamin B12 screening and supplementation in T2DM patients on long-term metformin therapy.

Metformin Use and Vitamin B12 Deficiency in People with Type 2 Diabetes. What Are the Risk Factors? A Mini-systematic Review

Background and Aim: Metformin is recommended as the first-line agent for the management of type 2 diabetes following lifestyle and dietary changes. The long-term use of metformin has been associated with vitamin B12 deficiency. The aim of this review is to investigate the effect of metformin on vitamin B12 levels and identify any risk factors. Method: A literature search was conducted using MEDLINE, PubMed and ProQuest Central. Selected articles were peer-reviewed articles, written in English and published from 2015 and onwards. Excluded articles were case reports, reviews or meta-analyses, as well as those with no access to full text. Results: In total, 21 articles were included. There was a significant association between metformin use and vitamin B12 levels in 17 studies, while 4 studies found no such association. The risk factors examined were metformin dose, treatment duration, patient age and patient ethnicity. Conclusion: In summary, metformin use was associated with lower vitamin B12 concentrations, and higher doses and longer durations of treatment increase the risk of vitamin B12 deficiency. Routine vitamin B12 screening is recommended, prioritizing higher-risk patients. Further research is needed to identify when to initiate monitoring.

Vitamin B12 Deficiency in Patients Taking Metformin: Pathogenesis and Recommendations

Metformin is a cornerstone therapy for type 2 diabetes mellitus due to its glucose-lowering efficacy and additional benefits such as reducing cardiovascular mortality. However, accumulating evidence suggests an association between long-term metformin use and vitamin B12 deficiency, which can lead to serious clinical consequences. This review aims to synthesize current knowledge on the pathogenesis, prevalence, clinical implications, and management of metformin-induced vitamin B12 deficiency. Given the significant clinical implications, it is crucial to monitor and manage vitamin B12 levels in patients using metformin. This review emphasizes the importance of early detection and supplementation to prevent adverse outcomes. By analyzing the current evidence, the review aims to inform healthcare professionals about best practices for managing vitamin B12 deficiency in patients on metformin, offering insights to guide future clinical practices and research directions.

Vitamin B12 deficiency in diabetic patients treated with metformin: A narrative review

Metformin is the most prescribed oral hypoglycemic drug and is considered by many health practitioners as the first-line treatment for non-insulin-dependent diabetes mellitus (T2DM). It is used either as a monotherapy or adjuvant to other anti-hyperglycemic agents. Most of its side effects are usually mild and self-limiting. However, several studies have shown an association between the use of metformin and low vitamin B12 levels in diabetic patients. The current review aimed to provide a literature review of the current published reports on the association, the possible mechanisms, and the related individualized risk factors that might lead to this incidence. The most accepted mechanism of the effect of metformin on vitamin B12 level is related to the absorption process where metformin antagonism of the calcium cation and interference with the calcium-dependent IF-vitamin B12 complex binding to the ileal cubilin receptor. In addition, many risk factors have been associated with the impact of metformin on vitamin B12 levels in diabetic patients such as dose and duration where longer durations showed a greater prevalence of developing vitamin B12 deficiency. Male patients showed lower levels of vitamin B12 compared to females. Black race showed a lower prevalence of vitamin B12 deficiency in metformin-treated patients. Moreover, chronic diseases including T2DM, hyperlipidemia, coronary artery disease, polycystic ovary disease (PCOD), obesity, and metformin therapy were significantly associated with increased risk of vitamin B12 deficiency.

Metformin-Induced Vitamin B12 Deficiency in Patients with Type 2 Diabetes: A Narrative Review with a Practical Approach for Screening, Diagnosing, and Managing Vitamin B12 Deficiency

Metformin is the most widely used antihyperglycemic drug in patients with type 2 diabetes (T2D). Over the past 2 decades, several studies have highlighted a substantial increase in the risk of vitamin B12 deficiency in patients with T2D on metformin therapy. This can lead to several complications and induce or exacerbate peripheral neuropathy. Despite these data, there are no definite guidelines for screening, diagnosing, and treating vitamin B12 deficiency in patients with T2D on metformin therapy. Therefore, in this narrative review, we aimed to suggest a practical diagnostic and therapeutic strategy to address vitamin B12 deficiency in patients with T2D receiving metformin treatment. Clinical evidence supporting an increased risk of vitamin B12 deficiency in patients with T2D on metformin therapy and its risk factors and potential complications are also discussed.

Serum vitamin B12, distal symmetrical polyneuropathy and anaemia in type 2 diabetes: the Fremantle Diabetes Study Phase 2

BACKGROUND

There are limited data relating to the effects of metformin-associated vitamin B12 deficiency on the risk of distal symmetrical polyneuropathy (DSPN) and megaloblastic anaemia in well-characterised community-based cohorts.

AIMS

To assess inter-relationships between metformin therapy, vitamin B12 deficiency assessed using serum active B12 concentrations, and DSPN and anaemia in 1492 Fremantle Diabetes Study Phase 2 (FDS2) participants with type 2 diabetes.

METHODS

Prevalence rates of vitamin B12 deficiency (total <80 pmol/L, active <23 pmol/L) and borderline deficiency (total ≥80 and ≤200 pmol/L, active ≥23 and ≤35 pmol/L) were determined using baseline sera. The relationship between vitamin B12 status and both DSPN and anaemia was assessed using multivariable analyses.

RESULTS

Most FDS2 participants (94.4%) were vitamin B12 replete (total serum concentration >200 pmol/L, active >35 pmol/L), 2.0% were deficient (total <80 pmol/L, active <23 pmol/L) and the remainder (3.6%) borderline. Although metformin treatment increased the odds of deficiency (4.2%, 3.1% borderline) in a dose-dependent fashion (odds ratio (95% confidence interval) 39.4 (4.90-316) for >2000 mg daily compared with no treatment; P < 0.001), there was no significant association between vitamin B12 status and DSPN, anaemia (haemoglobin ≤130 g/L males, ≤120 g/L females), haemoglobin concentration or mean corpuscular volume (P ≥ 0.147). Metformin increased the likelihood of anaemia, especially at high doses, independent of vitamin B12 deficiency.

CONCLUSIONS

Since nutritional sources likely attenuate metformin-associated vitamin B12 malabsorption and its clinical sequelae in developed countries such as Australia, there is no need for routine/opportunistic serum vitamin B12 screening in metformin-treated patients.

How vitamins act as novel agents for ameliorating diabetic peripheral neuropathy: A comprehensive overview

Diabetic peripheral neuropathy (DPN) is a pervasive and incapacitating sequela of diabetes, affecting a significant proportion of those diagnosed with the disease, yet an effective treatment remains elusive. Vitamins have been extensively studied, emerging as a promising target for diagnosing and treating various systemic diseases, but their role in DPN is not known. This review collates and synthesizes knowledge regarding the interplay between vitamins and DPN, drawing on bibliographies from prior studies and relevant articles, and stratifying the therapeutic strategies from prophylactic to interventional. In addition, the clinical evidence supporting the use of vitamins to ameliorate DPN is also evaluated, underscoring the potential of vitamins as putative therapeutic agents. We anticipate that this review will offer novel insights for developing and applying vitamin-based therapies for DPN.

Metformin ameliorates insulin resistance, thyroid nodules and thyroid function

OBJECTIVE

To evaluate the ameliorative impact of metformin on insulin resistance (IR), as well as thyroid nodules (TNs) and function in TN patients with IR.

METHODS

The clinical data of 128 TN patients with IR admitted to Yantai Laiyang Central Hospital from July 2018 to March 2020 were retrospectively analyzed and categorized into a control group (CNG, n = 64) and a study group (SG, n = 64). Patients in the CNG received standard lifestyle intervention, while those in the SG received standard lifestyle intervention in conjunction with metformin therapy for 1 year of course. Weight-related indicators, IR, thyroid function, TN diameter, and oxidative stress levels were compared between the two groups before and after treatment. Additionally, the safety of metformin was evaluated.

RESULTS

Before treatment, no significant differences were observed between the two groups in fasting plasma glucose (FPG), 2-h postprandial glucose (2hPG), glycated hemoglobin (HbA1c), fasting insulin (FINS), homeostatic model assessment of insulin resistance (HOMA-IR), systolic blood pressure (SBP), diastolic blood pressure (DBP), thyroid-stimulating hormone (TSH), malondialdehyde (MDA), TN diameter, and thyroid volume (P > 0.05). After treatment, significant statistical differences were observed in the aforementioned indicators between the two groups (P < 0.05). After 1 year of treatment, the SG exhibited lower levels of FPG, 2hPG, HbA1c, FINS, HOMA-IR, SBP, DBP, TSH, MDA, TN diameter, and thyroid volume, and showed higher levels of HOMA-β, superoxide dismutase, and glutathione peroxidase levels compared to before treatment (P < 0.05). The incidence of adverse reactions in the SG was significantly higher than that in the CNG (P < 0.05). Taking metformin and free thyroxine (FT4) were protective factors for TSH (P < 0.05).

CONCLUSION

Metformin could significantly improve IR and oxidative stress levels, regulate TSH levels, and shrink TNs in TN patients with IR, with high safety. The administration of metformin and FT4 were identified as protective factors for positive prognosis.

Prevalence of vitamin B12 deficiency in type 2 diabetic patients taking metformin, a cross-sectional study in primary healthcare

Background

Several studies documented that metformin use contributes to vitamin B12 deficiency in patients with type 2 diabetes mellitus (T2DM). However, there has been a lack of data assessing this issue in Jordan.

Aims

Assess the vitamin B12 serum levels, frequency of vitamin B12 deficiency, and related factors among Jordanian patients with T2DM patients treated with metformin.

Methods

a total of 447 subjects attending a primary health care center were included in this cross-sectional study consisting of T2DM patients who use metformin and a control group of non-diabetics. Serum B12 levels were evaluated and B12 deficiency was defined as serum B12 levels ≤ 200 pmol/L. Associations of B12 serum levels or B12 deficiency with other factors like gender, age, and duration of T2DM were analyzed.

Results

There was no significant difference in serum B12 levels nor the frequency of vitamin B12 deficiency between T2DM metformin-treated patients and control groups. Among metformin-treated patients there was no difference relating to age, type 2 diabetes mellitus duration, proton pump inhibitors use, and metformin use (duration, dose) between patients with or without B12 deficiency.

Conclusion

The prevalence of vitamin B12 deficiency among T2DM patients on metformin treatment in this study was high (48.9%). However, the treatment with metformin and the dose of metformin use was not associated with vitamin B12 deficiency.

The correlation between vitamin B12 and folate levels and bone mineral density among the Saudi population in a primary care setting

Purpose

Bone health and osteoporosis are significant health problems in Saudi Arabia. Approximately 40%-50% of women and 25%-33% of men sustain osteoporotic fractures in their lifetimes. Hence, identifying the risk factors for osteoporosis is crucial in reducing the incidence of fractures.

Materials and Methods

We retrospectively reviewed the electronic medical records of 557 patients (female 60%, male 40%) aged ≥18 years (mean age, 66.53 years [standard deviation ± 14.169]) who underwent bone mineral density (BMD) scans at the Department of Family Medicine & Polyclinics, King Faisal Specialist Hospital and Research Centre (KFSH&RC) between January 2004 and June 2019. Data collected included demographics, BMD values, vitamin B12 levels, and folate levels.

Results

This study indicated that the prevalence rates of vitamin B12 and folate deficiencies among the study population were 8.4% and 1.3%, respectively. There was a statistically significant association between vitamin B12 levels and fracture risk (P =0.044). However, no statistically significant correlation was observed between BMD at either site (lumbar spine or femoral neck) and vitamin B12 (P =0.926.,070) and folate levels (P =.683.,79). BMD showed a significant positive correlation with body mass index at the lumbar spine and femoral neck (P = 0.000). There was no statistically significant association between vitamin B12 levels and the use of metformin (P =.26).

Conclusion

Vitamin B12 is associated with fracture risk; however, vitamin B12 and folate levels are not correlated to BMD (femoral neck and lumbar spine).

The Correlation between Metformin Use and Incident Dementia in Patients with New-Onset Diabetes Mellitus: A Population-Based Study

The evidence of metformin's effect on dementia is conflicting. This study investigates the association between metformin use and the risk of dementia among patients with diabetes mellitus (DM). This study included patients with new-onset DM between 2002 and 2013. We divided the patients into patients who used metformin and patients who did not. Two models were used to assess metformin use: the cumulative defined daily dose (cDDD) of metformin use and the intensity of metformin use. This study with 3-year and 5-year follow-ups investigated the risk of dementia among patients with DM who used metformin. At the 3-year follow-up, patients who received cDDD < 300 had an odds ratio (OR) of developing dementia of 0.92 (95% confidence interval [CI] = 0.89-0.96); patients who used metformin at intensities <10 and 10-25 DDD/month had ORs of 0.92 (95% CI: 0.87-0.97) and 0.92 (95% CI: 0.85-1.00), respectively. Metformin use at cDDD 300-500 (OR = 0.80, 95% CI = 0.56-1.15) or >500 (OR = 1.48, 95% CI = 0.48-4.60) or at an intensity >25 DDD/month (OR = 0.84, 95% CI = 0.60-1.18) were not associated with an incident of dementia. There were similar results at the 5-year follow-up. Patients with a low intensity of metformin use had a lower risk of dementia. However, higher doses of metformin with higher intensity exhibited no protective role in dementia. Prospective clinical trials are warranted to evaluate the actual underlying mechanisms between metformin dosage and the risk of dementia.

Metformin treatment and risk of diabetic peripheral neuropathy in patients with type 2 diabetes mellitus in Beijing, China

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

[Diabetic neuropathy and diabetic foot syndrome (update 2023)]

These are the guidelines for diagnosis and treatment of diabetic neuropathy and diabetic foot.The position statement summarizes characteristic clinical symptoms and techniques for diagnostic assessment of diabetic neuropathy, including the complex situation of the diabetic foot syndrome. Recommendations for the therapeutic management of diabetic neuropathy, especially for the control of pain in sensorimotor neuropathy, are provided. The needs to prevent and treat diabetic foot syndrome are summarized.

Effect of Metformin on Vitamin B12 Deficiency in Patients With Type 2 Diabetes Mellitus and Factors Associated With It: A Meta-Analysis

The current meta-analysis aims to explore the effect of metformin use on vitamin B12 deficiency in patients with type 2 diabetes mellitus (T2DM) and the factors associated with it. This meta-analysis followed the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines and the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. We searched PubMed and EMBASE from January 1, 2010, to October 31, 2022, to collect the studies that reported the effect of metformin on the deficiency of vitamin B12 in patients with T2DM and the factors associated with it. A total of 17 studies were included in the current meta-analysis. Among all the included studies, 13 were cross-sectional studies, 3 were retrospective cohorts, and one was a case-control study. The pooled rate of deficiency of vitamin B12 in patients receiving metformin (23.16%) was significantly higher compared to patients who were not on metformin (17.4%) (OR: 2.95, 95% CI: 2.18-4.00, p-value: 0.001). Factors significantly associated with vitamin B12 deficiency in patients with T2DM and receiving metformin include the duration of metformin use and a greater dose of metformin. In conclusion, our meta-analysis found that the prevalence of vitamin B12 deficiency is greater in patients receiving metformin compared to patients who did not receive metformin. Given the importance of vitamin B12 in nutrition, metformin-induced B12 decrease may be harmful to patients with T2DM. Supplemental vitamin B12 may be advantageous for those on metformin.

Correlation between long-term use of metformin and incidence of NAFLD among patients with type 2 diabetes mellitus: A real-world cohort study

BACKGROUND AND AIMS

Studies have demonstrated that the short-term use of metformin benefits liver function among patients with type 2 diabetes mellitus (T2DM). However, few studies have reported on the effects of long-term metformin treatment on liver function or liver histology. This study investigated the correlation between metformin use and the incidence of nonalcoholic fatty liver disease (NAFLD) among patients with T2DM.

METHODS

This population-based study investigated the risk of NAFLD among patients with T2DM who received metformin treatment between 2001-2018. Metformin users and metformin nonusers were enrolled and matched to compare the risk of NAFLD.

RESULTS

After 3 years, the patients who received <300 cDDD of metformin and those with metformin use intensity of <10 and 10-25 DDD/month had odds ratios (ORs) of 1.11 (95% confidence interval [CI] = 1.06-1.16), 1.08 (95% CI = 1.02-1.13), and 1.18 (95% CI = 1.11-1.26) for NAFLD, respectively. Moreover, metformin users who scored high on the Diabetes Complications and Severity Index (DCSI) were at high risk of NAFLD. Patients with comorbid hyperlipidemia, hyperuricemia, obesity, and hepatitis C were also at high risk of NAFLD.

CONCLUSION

Patients with T2DM who received metformin of <300 cDDD or used metformin at an intensity of <10 and 10-25 DDD/month were at a high risk of developing NAFLD. The results of this study also indicated that patients with T2DM receiving metformin and with high scores on the DCSI were at a high risk of developing NAFLD.

The relationship between anemia and obesity

INTRODUCTION

Obesity is linked to a variety of unfavourable outcomes, including anaemia, which is a serious global public health problem. The prevalence of obesity along with anaemia suggests a relationship between obesity and anaemia. Recent studies have demonstrated strong associations between anaemia and obesity, chronic diseases, ageing, hepato-renal impairment, chronic infection, autoimmune diseases, and widespread malignancy. Thus, the intersection point of obesity and anaemia is an important area of attention.

AREA COVERED

This paper reviews the pathophysiology of obesity and anaemia. Then, It deliberates the relationship between obesity and different types of anaemia and other clinical forms associated with anaemia.

EXPERT OPINION

Obesity, especially obesity-related to excessive visceral fat distribution, is accompanied by several disturbances at the endothelial, hormonal, and inflammatory levels. These disturbances induce activation of several mechanisms that contribute to the anaemic state. Over-weight patients with chronic anaemias are required to maintain the related vitamins and minerals at optimum levels and appropriate BMI. In addition, a regular clinical follow-up is essential to be scheduled to reduce the risk of complications associated with anaemia in obese patients.

MiR-574-3p inhibits glucose toxicity-induced pancreatic β-cell dysfunction by suppressing PRMT1

BACKGROUND

Pancreatic β-cell dysfunction is commonly observed in patients with type 2 diabetes mellitus. Protein arginine methyltransferase 1 (PRMT1) plays an important role in pancreatic β-cell dysfunction. However, the detailed mechanisms remain largely unknown.

METHODS

RT-qPCR, western blotting, and immunofluorescence assays were used to evaluate PRMT1 and miR-574-3p levels. Cell Counting Kit-8, Advanced Dlycation End products (AGEs), Reactive Oxygen Species (ROS), and glucose-stimulated insulin secretion were assayed, and flow cytometry and RT-qPCR were performed to detect the role of PRMT1 and miR-574-3p in MIN6 cells. Luciferase reporter assays were performed to determine the interactions between PRMT1 and miR-574-3p.

RESULTS

High-glucose treatment resulted in the high expression of PRMT1. PRMT1 silencing could alleviate the reduced proliferation, insulin secretion, and GLUT1 level, in addition to suppressing the induced apoptosis, and AGEs and ROS levels, under high glucose conditions. MiR-574-3p was established as an upstream regulator of PRMT1 using luciferase reporter assays. More importantly, miR-574-3p reversed the effect of PRMT1 silencing in MIN6 cells.

CONCLUSIONS

miR-574-3p suppresses glucose toxicity-induced pancreatic β-cell dysfunction by targeting PRMT1.

Vitamin B12 Deficiency in Patients with Diabetes on Metformin: Arab Countries

Background: Diabetes is a global pandemic, especially in Arab countries. Aim: The goal of this study was to review the published studies that were conducted to determine the relationship between metformin treatment for type 2 diabetes mellitus (T2DM) and vitamin B12 deficiency and to identify possible complications in this relationship. Methods: I searched for all relevant studies published in English before 2020 on the PubMed and Web of Knowledge databases using the following terms: “metformin”, “vitamin B12”, “neuropathy”, “diabetes mellitus”, and Middle Eastern countries. Results: Eleven studies were included in this review which indicated an association between taking metformin and B12 deficiency in patients with T2DM in Arab countries. This B12 deficiency was found to be negatively associated with the dose and duration of metformin therapy. The physician’s knowledge of current ADA recommendations regarding supplementation with and screening of the B12 level for T2DM patients on metformin was also found to have an effect. Conclusion: Metformin therapy is associated with B12 deficiency among people with T2DM in Arabic countries. Thus, diabetes must be managed in compliance with current guidelines and recommendations, and B12 levels must be routinely monitored, particularly in those who have been long-term takers of metformin, to ensure the suitable management of diabetes and its complications.

Fully Convolutional Neural Network Deep Learning Model Fully in Patients with Type 2 Diabetes Complicated with Peripheral Neuropathy by High-Frequency Ultrasound Image

This study was aimed at exploring the diagnostic value of high-frequency ultrasound imaging based on a fully convolutional neural network (FCN) for peripheral neuropathy in patients with type 2 diabetes (T2D). A total of 70 patients with T2D mellitus were selected and divided into a lesion group (n = 31) and a nonlesion group (n = 39) according to the type of peripheral neuropathy. In addition, 30 healthy people were used as controls. Hypervoxel-based and FCN-based high-frequency ultrasound images were used to examine the three groups of patients to evaluate their diagnostic performance and to compare the changes of peripheral nerves and ultrasound characteristics. The results showed that the Dice coefficient (92.7) and mean intersection over union (mIOU) (82.6) of the proposed algorithm after image segmentation were the largest, and the Hausdorff distance (7.6) and absolute volume difference (AVD) (8.9) were the smallest. The high-frequency ultrasound based on the segmentation algorithm showed higher diagnostic accuracy (94.0% vs. 86.0%), sensitivity (87.1% vs. 67.7%), specificity (97.1% vs. 94.2%), positive predictive value (93.1% vs. 86.7%), and negative predictive value (94.4% vs. 84.0%) (P < 0.05). There were significant differences in the detection values of the three major nerve segments of the upper limbs in the control group, the lesion group, and the nonlesion group (P < 0.05). Compared with the nonlesion group, the patients in the lesion group were more likely to have reduced nerve bundle echo, blurred reticular structure, thickened epineurium, and unclear borders of adjacent tissues (P < 0.05). In summary, the high-frequency ultrasound processed by the algorithm proposed in this study showed a high diagnostic value for peripheral neuropathy in T2D patients, and high-frequency ultrasound can be used to evaluate the morphological changes of peripheral nerves in T2D patients.

RJX Improves Wound Healing in Diabetic Rats

BACKGROUND

We recently reported the clinical safety profile of RJX, a well-defined intravenous GMP-grade pharmaceutical formulation of anti-oxidant and anti-inflammatory vitamins as active ingredients, in a Phase 1 study in healthy volunteers (ClinicalTrials.gov Identifier: NCT03680105) (Uckun et al., Front. Pharmacol. 11, 594321. 10.3389/fphar.2020.594321). The primary objective of the present study was to examine the effects of GMP-grade RJX on wound and burn injury healing in diabetic rats.

METHODS

In the present study, a rat model of T2DM was used that employs HFD in combination with a single injection of STZ intraperitoneally (i.p) at a moderate dose level (45 mg/kg). Anesthetized diabetic rats underwent full-thickness skin excision on the back or were subjected to burn injury via a heated brass probe and then started on treatments with normal saline (NS = vehicle) or RJX administered via intraperitoneal injections for three weeks.

FINDINGS

Notably, diabetic rats treated with the 1.25 mL/kg or 2.5 mL/kg RJX (DM+RJX groups) rapidly healed their wounds as fast as non-diabetic control rats. Inflammatory cell infiltration in the dermis along with fibrin and cell debris on the epithelial layer persisted for up to 14 days in the DM+NS group but not in RJX-treated groups. The histopathological score of wound healing on days 7 and 14 was better in diabetic rats treated with RJX than diabetic rats treated with NS and comparable to the scores for non-diabetic healthy rats consistent with an accelerated healing process. The residual wound area of RJX-treated rats was significantly smaller than that of NS-treated diabetic rats at each evaluation time point (P<0.001). The accelerating effect of RJX on diabetic wound healing was dose-dependent. We obtained similar results in the burn injury model. Our results demonstrate that RJX - at a dose level >10-fold lower than its clinical maximum tolerated dose (MTD) - accelerates the healing of excision wounds as well burn injury in diabetic rats.

Association of vitamin B12 deficiency with metformin use in patients with type 2 diabetes treated in the largest tertiary care hospital in Qatar

BACKGROUND

Data on the effect of metformin on serum vitamin B12 (VitB12) level in patients with type 2 diabetes mellitus (T2DM) in Qatar are limited; therefore, we aimed to assess the prevalence of VitB12 deficiency and its related factors among patients with tbl2DM treated with metformin at Hamad General Hospital in Doha, Qatar, from January 1, 2017, to December 31, 2017.

METHODS

This cross-sectional analytical study involved patients with tbl2DM aged ≥ 18 years who used metformin for at least 3 months. The serum VitB12 was quantified on a chemiluminescent enzyme immunoassay analyzer using Cobas e 801 module, Roche, and VitB12 deficiency was defined as serum VitB12 level of ≤ 145 pmol/L. All data were obtained from the patients' electronic medical records.

RESULTS

The study recruited 3124 eligible patients with tbl2DM. The overall prevalence of metformin-associated VitB12 deficiency was 30.7% [95% confidence of interval, 0.290-0.323]. A significant difference exists in the median VitB12 levels between the VitB12-normal and VitB12-deficient groups [129 vs. 286; p < 0.001]. Compared with the VitB12-normal group, the VitB12-deficient group had higher mean body mass index (BMI) (p < 0.001) and consumed higher doses of metformin (p = 0.001). They also more often used sulfonylurea (p = 0.004), dipeptidyl peptidase-4 inhibitor (p < 0.001), thiazolidinediones (p < 0.001), glucagon-like peptide 1 [GLP-1] receptor agonists (p < 0.001), alpha-glucosidase inhibitor (p < 0.001), and H2 blocker/proton pump inhibitors [PPI] (p < 0.001) than the VitB12-normal group. Moreover, the VitB12-normal group consumed more calcium supplements (p < 0.001) than the VitB12-deficient group. In the multivariate analysis, independent risk factors for metformin-associated VitB12 deficiency in patients with tbl2DM include high daily dose of metformin >2000 mg, male gender, high BMI, smoking, sulfonylurea, dipeptidyl peptidase-4 inhibitor, H2 blockers/PPI, low fasting blood glucose, and low hemoglobin.

CONCLUSION

This study showed a high prevalence of VitB12 deficiency in patients with tbl2DM taking metformin and a significant negative correlation between the daily dose of metformin and serum VitB12 level. Therefore, regular screening for serum VitB12 is necessary in patients with tbl2DM on metformin treatment, especially those who have the abovementioned risk factors.

Sleep Quality Is Associated with Vitamin B12 Status in Female Arab Students

Studies have explored how vitamin B12 status affects sleep among elders and children, but this remains to be investigated among young adults. We used the Pittsburgh Sleep Quality Index (PSQI) to assess the association between serum vitamin B12 and sleep among female college students in Saudi Arabia. In this cross-sectional study, we enrolled 355 participants (age (years), 20.7 ± 1.5; body mass index, 23.6 kg/m² ± 5.2) at King Saud University, Riyadh, Saudi Arabia. Fasting blood samples were analyzed regarding the serum vitamin B12 and blood lipids. Anthropometric, socio-demographic, clinical history, stress, physical activity, and dietary data were collected. We assessed the sleep statuses of the participants using the PSQI. Around 72% of the participants were “poor” sleepers (PSQI > 5). Subgroup analysis within the tertiles showed that participants with higher vitamin B12 in the second and third tertiles reported better scores for sleep quality (B ± SE = −12.7 ± 5.6, p = 0.03; B ± SE = −32.7 ± 16.4, p = 0.05, respectively) and also reported a lower use of sleep medication (B ± SE = −21.2 ± 9.9, p = 0.03, in the second tertile only), after adjusting for the waist–hip ratio and stress. However, sleep was not found to be directly associated with either serum vitamin B12 or dietary vitamin B12. In conclusion, the serum vitamin B12 results show that the participants with higher vitamin B12 in the second and third tertiles reported better scores on the sleep quality scale and a lower use of sleep medication. However, no such associations were observed with the overall PSQI. More studies with larger sample sizes are needed to establish a direct relationship between sleep and vitamin B12.

Vitamin B12 deficiency in patients with type 2 diabetes mellitus using metformin and the associated factors in Saudi Arabia

OBJECTIVES

To assess the presence of vitamin B12 deficiency among metformin users and associated factors in patients with type 2 diabetes mellitus.

METHODS

An observational cross-sectional study was conducted with 307 diabetic patients in the primary health care centers at King Abdulaziz Medical City (KAMC), Riyadh, Saudi Arabia between October 2017 and January 2018. Face-to-face interviews were conducted with the participants, using a designed checklist.

RESULTS

The prevalence of vitamin B12 deficiency was (3.6%) and the majority of the sample had borderline B12 levels (66.1%). The vitamin B12 deficiency and borderline levels were strongly associated with the dose of metformin. Patients taking doses of metformin more than 1000 mg had lower levels of vitamin B12. The use of multivitamin and vitamin B complex was assessed, and it was found that there was a marked decrease in the prevalence of vitamin B12 deficiency in patients using vitamin B complex containing more than 200 mcg vitamin B12.

CONCLUSION

Our findings show a low prevalence of vitamin B12 deficiency in type 2 diabetic patients taking metformin. The majority of the sample had borderline deficiency; therefore, additional investigation and management are required.

Vitamin B12 Supplementation in Diabetic Neuropathy: A 1-Year, Randomized, Double-Blind, Placebo-Controlled Trial

AIM

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).

PATIENTS AND METHODS

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).

RESULTS

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).

CONCLUSIONS

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.

The relationship between exacerbated diabetic peripheral neuropathy and metformin treatment in type 2 diabetes mellitus

Metformin-treated diabetics (MTD) showed a decrease in cobalamin, a rise in homocysteine, and methylmalonic acid, leading to accentuated diabetic peripheral neuropathy (DPN). This study aimed to determine whether or not metformin is a risk factor for DPN. We compared MTD to non-metformin-treated diabetics (NMTD) clinically using the Toronto Clinical Scoring System (TCSS), laboratory (methylmalonic acid, cobalamin, and homocysteine), and electrophysiological studies. Median homocysteine and methylmalonic acid levels in MTD vs. NMTD were 15.3 vs. 9.6 µmol/l; P < 0.001 and 0.25 vs. 0.13 µmol/l; P = 0.02, respectively with high statistical significance in MTD. There was a significantly lower plasma level of cobalamin in MTD than NMTD. Spearman’s correlation showed a significant negative correlation between cobalamin and increased dose of metformin and a significant positive correlation between TCSS and increased dose of metformin. Logistic regression analysis showed that MTD had significantly longer metformin use duration, higher metformin dose > 2 g, higher TCSS, lower plasma cobalamin, and significant higher homocysteine. Diabetics treated with metformin for prolonged duration and higher doses were associated with lower cobalamin and more severe DPN.

Assessment of Serum Vitamin B12 and Folate Levels and Macrocytosis in Patients with Type 2 Diabetes Mellitus on Metformin Attending Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia: A Cross-Sectional Study

BACKGROUND

Metformin is the first-line drug in the treatment of type 2 diabetes mellitus. Monitoring vitamin B₁₂ deficiency associated with long-term and high-dose therapy is not a common practice in many clinical settings in Ethiopia.

OBJECTIVE

The study aimed to measure levels of serum vitamin B₁₂ and folate and to assess the macrocytic status of type 2 diabetes mellitus patients on metformin.

METHODS

A cross-sectional study was conducted on 80 type 2 diabetes mellitus patients who had been on metformin for 5 months or more at the diabetic clinic of Tikur Anbessa Specialized Teaching Hospital. Serum vitamin B₁₂ and folate levels were quantified by chemiluminescent immunoassays. Mean corpuscular volume was determined by complete blood count. Differences in vitamin B₁₂ and folate levels and mean corpuscular volume between different groups were assessed using Kruskal-Wallis H and Mann-Whitney U tests.

RESULTS

Vitamin B₁₂ and folate deficiency were documented in 5% and 23.8% of participants, respectively, and 6.2% of patients were macrocytic. Levels of vitamin B₁₂ and folate in patients who had been on metformin >1,500 mg/day ≥4 years were significantly lower those who had been on metformin 1,000-1,500 mg/day and <1,000 mg/day <4 years, respectively.

CONCLUSION

Low serum vitamin B₁₂ and folate levels and macrocytosis were found to be associated with prolonged metformin treatment.

Prevalence and Indicators of Vitamin B12 Insufficiency among Young Women of Childbearing Age

Vitamin B12 insufficiency is a global health issue among women of childbearing age, yet few studies have investigated its prevalence and risk factors among healthy Middle Eastern populations. This cross-sectional study included 346 Saudi women aged 19–30 years and enrolled at King Saud University, Riyadh, Saudi Arabia. A series of questionnaires were administered to record the study participants’ sociodemographic status, medical history, dietary intake, and physical activity. Participants’ anthropometric data were also recorded and their fasting blood samples were analyzed. The rate of vitamin B12 insufficiency (≤220 pmol/L) was approximately 6% among the study participants. After adjusting for confounding factors, it was observed that the risk factors for vitamin B12 insufficiency included daily sitting time ≥ 7 h, low income (<10,000 Saudi riyal) and increasing age. The recommended dietary allowance of vitamin B12 (>2.4 mcg/day) has been shown to confer reasonable protection against vitamin B12 insufficiency. These study findings highlight that a combination of increased physical activity and dietary vitamin B12 intake above the current recommended dietary allowance may help improve the serum vitamin B12 levels of young women of childbearing age, especially those with a low socioeconomic status. Timely detection and protection against vitamin B12 insufficiency in this subpopulation are important to prevent maternal and fetal health risks.

Low Serum Vitamin B12 Levels Are Associated with Adverse Lipid Profiles in Apparently Healthy Young Saudi Women

An abnormal lipid profile is an independent risk factor for cardiovascular diseases. The relationship between vitamin B12 deficiency and lipid profile is inconclusive, with most studies conducted in unhealthy populations. In this study, we aimed to assess the relationship between serum vitamin B12 levels and lipid profiles in a cross-sectional study that included 341 apparently healthy Saudi women, aged 19-30 years, from different colleges at King Saud University, Saudi Arabia. Sociodemographic, anthropometric, biochemical, and lifestyle data were collected, including diet and physical activity. Serum vitamin B12 deficiency was defined as serum B12 level of <148 pmol/L. The prevalence of vitamin B12 deficiency was approximately 0.6%. Using multivariable linear regression models, serum vitamin B12 levels were found to be inversely associated with total cholesterol (B = -0.26; p < 0.001), low-density lipoprotein cholesterol levels (B = -0.30; p < 0.001), and triglyceride (B = -0.16; p < 0.01) after adjusting for potential confounders, while obesity indices of body mass index, central obesity, and fat percentage showed no association. Therefore, we conclude that low serum vitamin B12 levels are independently associated with abnormal lipid profiles in healthy young Saudi women. Further interventional studies are needed to determine whether improving serum vitamin B12 levels in a healthy population can improve lipid profiles.

Relationship between metformin use and vitamin B12 status in patients with type 2 diabetes in Japan

AIMS/INTRODUCTION

Metformin therapy has been associated with vitamin B12 (VB12) deficiency, but information regarding this adverse effect in Asian populations is limited. We have now examined the relationship between metformin use and VB12 status in individuals with type 2 diabetes mellitus in Japan.

MATERIALS AND METHODS

This cross-sectional study was carried out with type 2 diabetes mellitus patients treated (Met group, n = 122) or not treated (control group, n = 63) with metformin. The primary end-point was the difference in the serum concentration of homocysteine, a marker of VB12 activity, between the two groups. The serum concentrations of VB12, blood hemoglobin level and mean corpuscular volume were also compared between the groups. Subset analysis was carried out with individuals aged ≥70 years. The potential correlation between the daily dose or duration of metformin treatment and the other measured parameters was also examined.

RESULTS

The level of homocysteine, as well as the VB12 level, hemoglobin concentration and mean corpuscular volume, did not differ significantly between the control and treated with metformin groups. The level of homocysteine was positively and that of VB12 negatively correlated with the daily dose of metformin. Among elderly individuals, the hemoglobin level was significantly lower in the treated with metformin group than in the control group, although the mean corpuscular volume was similar in the two groups.

CONCLUSIONS

The risk of VB12 deficiency during metformin treatment appears to be low in Japanese type 2 diabetes mellitus patients. However, high doses of metformin might result in a moderate decrease in the circulating VB12 level, as well as in anemia in elderly individuals.

The Use of Metformin to Increase the Human Healthspan

Metformin is a safe, effective and useful drug for glucose management in patients with diabetes. However in recent years, more attention has been paid to the possibility of using metformin as an anti-aging drug. It was shown to significantly increase the lifespan in some model organisms and delay the onset of age-associated declines. The current review summarizes advances in clinical research on the potential role of metformin in the field of lifespan and healthspan extension. Growing amounts of evidence from clinical trials suggest that metformin can effectively reduce the risk of many age-related diseases and conditions, including cardiometabolic disorders, neurodegeneration, chronic inflammation and frailty. Metformin also holds promise as a drug that could be repurposed for chemoprevention or adjuvant therapy for certain types of cancer. Moreover, metformin induces autophagy by activation of AMPK and can thus be potentially used to promote heathspan by hormesis-like mechanisms. Although long-term intake of metformin is associated with low risk of adverse events, well-designed clinical trials are still required to uncover the potential use of this drug as a geroprotector.

Association of vitamin B12 deficiency in people with type 2 diabetes on metformin and without metformin: a multicenter study, Karachi, Pakistan

OBJECTIVE

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

METHODOLOGY

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.

RESULTS

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.

CONCLUSION

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.

Adjunctive metformin for antipsychotic-induced dyslipidemia: a meta-analysis of randomized, double-blind, placebo-controlled trials

Antipsychotic-induced dyslipidemia could increase the risk of cardiovascular diseases. This is a meta-analysis of randomized double-blind placebo-controlled trials to examine the efficacy and safety of adjunctive metformin for dyslipidemia induced by antipsychotics in schizophrenia. The standardized mean differences (SMDs) and risk ratios (RRs) with their 95% confidence intervals (CIs) were calculated using the random-effects model with the RevMan 5.3 version software. The primary outcome was the change of serum lipid level. Twelve studies with 1215 schizophrenia patients (592 in metformin group and 623 in placebo group) were included and analyzed. Adjunctive metformin was significantly superior to placebo with regards to low density lipoprotein cholesterol (LDL-C) [SMD: -0.37 (95%CI:-0.69, -0.05), P = 0.02; I² = 78%], total cholesterol [SMD: -0.47 (95%CI:-0.66, -0.29), P < 0.00001; I² = 49%], triglyceride [SMD: -0.33 (95%CI:-0.45, -0.20), P < 0.00001; I² = 0%], and high density lipoprotein cholesterol [SMD: 0.29 (95%CI:0.02, 0.57), P = 0.03; I² = 69%]. The superiority of metformin in improving LDL-C level disappeared in a sensitivity analysis and 80% (8/10) of subgroup analyses. Metformin was significantly superior to placebo with regards to decrease in body weight, body mass index, glycated hemoglobin A1c, fasting insulin, and homeostasis model assessment-insulin resistance (P = 0.002-0.01), but not regarding changes in waist circumference, waist-to-hip rate, leptin, fasting glucose, and blood pressure (P = 0.07-0.33). The rates of discontinuation due to any reason [RR: 0.97 (95%CI: 0.66, 1.43), P = 0.89; I² = 0%] was similar between the two groups. Adjunctive metformin could be useful to improve total cholesterol and triglyceride levels, but it was not effective in improving LDL-C level in schizophrenia.

Current Concepts in Pharmacometabolomics, Biomarker Discovery, and Precision Medicine

Pharmacometabolomics (PMx) studies use information contained in metabolic profiles (or metabolome) to inform about how a subject will respond to drug treatment. Genome, gut microbiome, sex, nutrition, age, stress, health status, and other factors can impact the metabolic profile of an individual. Some of these factors are known to influence the individual response to pharmaceutical compounds. An individual’s metabolic profile has been referred to as his or her “metabotype.” As such, metabolomic profiles obtained prior to, during, or after drug treatment could provide insights about drug mechanism of action and variation of response to treatment. Furthermore, there are several types of PMx studies that are used to discover and inform patterns associated with varied drug responses (i.e., responders vs. non-responders; slow or fast metabolizers). The PMx efforts could simultaneously provide information related to an individual’s pharmacokinetic response during clinical trials and be used to predict patient response to drugs making pharmacometabolomic clinical research valuable for precision medicine. PMx biomarkers can also be discovered and validated during FDA clinical trials. Using biomarkers during medical development is described in US Law under the 21st Century Cures Act. Information on how to submit biomarkers to the FDA and their context of use is defined herein.

Vitamin B12 Deficiency in Diabetic Patients on Metformin Therapy: A cross-sectional study from Oman

Objectives

This study aimed to determine the prevalence of vitamin B12 deficiency amongst diabetic patients on metformin therapy.

Methods

This cross-sectional study was conducted at general clinics at the University Health Center and diabetes outpatient clinics at Sultan Qaboos University Hospital, Muscat, Oman, between January and December 2017. All Omani adults who were diagnosed with type 2 diabetes mellitus and took metformin were invited to participate in the study. The variables included in this study were age, gender, duration of diabetes, dose and duration of metformin therapy, haemoglobin and glycosylated haemoglobin level.

Results

A total of 248 subjects were included (response rate = 95.4%) of which 26 (10.5%) were vitamin B12 deficient and 53 (21.4%) were borderline deficient. The mean daily dose of metformin was highest among vitamin B12 deficient group (1,981 ± 222 mg; P = 0.004).

Conclusion

The prevalence of vitamin B12 deficiency is considerable among diabetic patients on metformin therapy. Further research is needed to confirm the need for routine screening and monitoring.

Metformin and Micronutrient Status in Type 2 Diabetes: Does Polypharmacy Involving Acid-Suppressing Medications Affect Vitamin B12 Levels?

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.

Vitamin B12 Deficiency and Foot Ulcers in Type 2 Diabetes Mellitus: A Case-Control Study

OBJECTIVE

To assess the association between vitamin B12 deficiency and the development of diabetic foot ulcers (DFU) in type 2 diabetes mellitus (T2DM).

METHODS

This is a case-control study that enrolled 323 Saudi adults with T2DM randomly selected from the Jazan Diabetes & Endocrine Center, Saudi Arabia from January 1, 2019, to July 31, 2019. The sample included 108 newly diagnosed cases with DFU and 215 control participants with T2DM unaffected by and free of foot ulcers (1:2 ratio). Logistic regression analysis was performed to determine the DFU predictors and to examine the association of DFU and vitamin B12 deficiency.

RESULTS

The highest DFU rates were found among the male participants and the participants older than 45 years. Neuropathy, vasculopathy, vitamin B12 deficiency, poor glycemic control, poor feet self-care, Charcot foot, physical inactivity, and spending long time standing at work were significantly associated with DFU, and all except physical inactivity and spending long time standing at work were independent predictors of DFU. After adjustment for the covariates, vitamin B12 deficiency was significantly associated with DFU (odds ratio 3.1), indicating that the patients with T2DM and vitamin B12 deficiency had a three times higher risk of developing DFU than those with normal vitamin B12 levels.

CONCLUSION

Vitamin B12 deficiency had a significant association with DFU among the Saudi participants with T2DM. Establishing the causality and clarifying the biological role of vitamin B12 deficiency in DFU is important aims for future studies.

Metabolic and Non-Metabolic Peripheral Neuropathy: Is there a Place for Therapeutic Apheresis?

As the rate of obesity and the incidence of diabetes mellitus have been increasing, diabetic neuropathy has become the most common cause of peripheral neuropathy in developed countries. In addition, a variety of pathogenetically heterogeneous disorders can lead to impairment of the peripheral nervous system including amyloidosis, vitamin deficiencies, uremia and lipid disorders, alcohol abuse, autoimmune and infectious diseases as well as exposure to environmental toxins. We have noted that a combination of these disorders may aggravate the manifestations of peripheral diabetic neuropathy, an effect, which is most pronounced when metabolic and non-metabolic pathologies lead to cumulative damage. Current treatment options are limited and generally have unsatisfactory results in most patients. Therapeutic apheresis (INUSpherese®) allows the removal of metabolic, inflammatory, immunologic and environmental contributors to the disease process and may be an effective treatment option. We reviewed the developments in therapeutic apheresis for metabolic and non-metabolic peripheral neuropathy, including the current literature as well as data from our university diabetes center.

Vitamin B12 deficiency and diabetic neuropathy in patients taking metformin: a cross-sectional study

OBJECTIVE

Vitamin B12 deficiency resulting from metformin use has been demonstrated in multiple studies. In this study, we aimed to evaluate the prevalence of vitamin B12 deficiency in patients with chronic metformin use and the relationship between vitamin B12 deficiency and diabetic neuropathy.

METHODS

A cross-sectional study was conducted with 162 patients. Vitamin B12 levels were measured by chemiluminescence immunoassay. Diabetic neuropathy was evaluated by patient record, nerve conduction and Michigan test for the diagnosis of diabetic neuropathy. Additional data, including demographic characteristics were collected. A linear regression model was used to evaluate variables that correlated with vitamin B12 levels and diabetic neuropathy.

RESULTS

Low vitamin B12 levels were found in 7.3% (95% CI: 4.0-12%) of patients. In those with diabetic neuropathy, altered (low and borderline) vitamin B12 level was 64% (95% CI: 47-78%) compared to 17% (95% CI: 10-26%) in patients without diabetic neuropathy (coefficient: -110.8; CI 95%: -165.8, -59.7). Those taking a higher metformin dose had lower levels of vitamin B12 (coefficient: -0.061; CI 95%: -0.09, -0.024). In addition, female patients had higher levels of vitamin B12 compared to men (coefficient: 49.1; CI 95%: 2.3-95).

CONCLUSIONS

Vitamin B12 deficiency is highly prevalent, especially in patients with diabetic neuropathy. In this study an inverse correlation was found between diabetic neuropathy and the plasma level of vitamin B12. Higher doses of metformin and male sex were factors related to lower levels of vitamin B12.