Correlation of Vit B12 levels with metformin usage among type 2 diabetic patients in a tertiary care hospital

Abstract

Background: T2DM is a metabolic disorder that is increasingly becoming a public health concern. The disease is associated with a variety of systemic macrovascular and microvascular complications. Diabetic peripheral neuropathy (DPN) is the most common complication, and it may eventually develop in up to 50% of patients. It is assumed that prolonged use of metformin causes vitamin B12 deficiency. The clinical presentation of vitamin B12 deficiency generally includes haematological and neurological manifestations. The aim of the study is to correlate vit b12 levels in relation to duration of usage of metformin for a period of more than 1 year. Methods: The study was conducted from November 2017 to June 2018 for a period of 7 months which included 50 subjects from both sex groups, aged 18 years and above, on metformin with subjective evidence of neuropathy and compared with vit b12 levels. Results: The study results indicate that there is no significant drop in vit b12 levels in metformin users in significant proportions to cause vitb12 deficient-neuropathy. The p value being 0.658 comparing vit b12 with metformin usage years (<2 yrs, 2-5yrs, 5-8yrs, ≥8yrs). Conclusions: This cross-sectional study indicates that diabetic patients who were on metformin were not having any vit b12 deficiency, though all patients had subjective neuropathy. This suggests that neuropathy is not related to metformin induced Vit B12 deficiency. Therefore, prescribing of vit b12 supplementation in any long term metformin treated patients is no longer necessary and reduces patients financial burden.

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

“…American Diabetes Association 2019 recommended Metformin for the treatment of type 2 DM and should be continued as long as it is tolerated 3 . Nareddy et al reported that metformin can cause cobalamin deficiency 4 . Cobalamin is associated with various metabolic functions, including red cell generation and intact nervous system, and so its dysfunction can cause anemia and neurological impairment 5 , 6 .…”

Vitamin B12 deficiency in patients of type 2 diabetes mellitus treated with metformin: a cross section observational study from a tertiary care centre in Sub-Himalayan region of North India

“…31,32 Authors observations do not support the findings and recommendation of one of the studies from India which reported that the diabetic patients on metformin were not having any vitamin B12 deficiency and that the supplementation of vitamin B12 in long term metformin treatment was not necessary and reduced the financial burden. 22…”

“…21 A study from India reported negative correlation between metformin use and vitamin B12 levels and that the supplementation of vitamin B12 was not necessary and reduced the financial burden. 22 Therefore, we are more interested and aim to further correlate metformin use in treatment of T2DM and vitamin B12 levels through this study in Sub-Himalayan region of north India.…”

Vitamin B12 Status Among Patients With Type 2 Diabetes Mellitus

“…Numerous observational studies [9,10] and case reports [11][12][13] have reported an elevation in the prevalence of vit. B12 insufficiency in patients with type 2 diabetes mellitus (T2DM), especially with the chronic use of metformin [14][15][16][17].…”

“…B12 levels by 22% versus placebo and 29% versus glyburide. Several consequent crosssectional studies [9,10], case reports [11,13], and randomized controlled trials [14,15] have demonstrated the downsides of metformin too.…”