Prevalence of vitamin B12 deficiency in type 2 diabetic patients using metformin: a cross-sectional study

Abstract

CONTEXT AND OBJECTIVE: The prevalence of vitamin B12 deficiency varies from 5.8% to 30% among patients undergoing long-term treatment with metformin. Because of the paucity of data on Brazilian patients, this study aimed to determine the frequency of B12 deficiency and related factors among Brazilian patients with type 2 diabetes mellitus (T2DM) using metformin. DESIGN AND SETTING: Cross-sectional study at a public university hospital. METHODS:Patients with T2DM and a control group of non-diabetics were included. Serum B12 levels were measured and biochemical B12 deficiency was defined as serum levels < 180 pg/ml. Associations between B12 deficiency and age, duration of T2DM, duration of use and dosage of metformin, and use of proton pump inhibitors (PPIs) or histamine H2 antagonists were determined. RESULTS: 231 T2DM patients using metformin (T2DM-met) and 231 controls were included. No difference in the frequency of PPI or H2-antagonist use was seen between the groups. B12 deficiency was more frequent in the T2DM-met group (22.5% versus 7.4%) and this difference persisted after excluding PPI/ H2-antagonist users (17.9% versus 5.6%). The factors that interfered with serum B12 levels were PPI/H2-antagonist use and duration of metformin use ≥ 10 years. Use of PPI/H2-antagonists was associated with B12 deficiency, with an odds ratio of 2.60 (95% confidence interval, 1.34-5.04). CONCLUSIONS: Among T2DM patients, treatment with metformin and concomitant use of PPI/H2-antagonists are associated with a higher chance of developing B12 deficiency than among non-diabetics. RESUMO CONTEXTO E OBJETIVO:A prevalência de deficiência de vitamina B12 varia de 5,8% a 30% nos pacientes em tratamento a longo prazo com metformina. Devido à escassez de dados em pacientes brasileiros, este estudo determinou a frequência de deficiência de B12 e fatores relacionados em pacientes brasileiros com diabetes mellitus tipo 2 (DM2) usando metformina. TIPO DE ESTUDO E LOCAL: Estudo transversal em hospital público universitário. MÉTODOS: Pacientes com DM2 e um grupo controle de não diabéticos foram incluídos. Os níveis séricos de vitamina B12 foram dosados e deficiência bioquímica de B12 foi definida como níveis séricos < 180 pg/ml. Foi investigada a associação entre deficiência de B12 e idade, duração do DM2, duração do uso e dose de metformina, uso de inibidores de bomba de prótons (IBP) ou antagonistas dos receptores histamínicos H2 (antagonistas-H2). RESULTADOS: 231 pacientes DM2 usando metformina (DM2-met) e 231 controles foram incluídos. Não houve diferença na frequência de uso de IBP/antagonistas-H2 entre os grupos. Deficiência de B12 foi mais frequente no grupo DM2-met (22,5% versus 7,4%) e essa diferença persistiu após exclusão dos usuári-os de IBP/antagonistas-H2 (17,9% versus 5,6%). Fatores que interferiram nos níveis séricos de B12 foram: uso de IBP/antagonistas-H2 e duração do uso de metformina ≥ 10 anos. O uso de IBP/antagonistas-H2 associou-se com deficiência de B12, com um risco relativo de 2,60 (95% intervalo de confian...

Vitamin B12 deficiency in type 2 diabetic patients on metformin: a cross-sectional study from South-Western part of Ghana

“…Another study by Sparre Hermann et al reported a 26.7% prevalence of vitamin B 12 deficiency in metformin-treated T2DM patients in Sweden [29]. Additionally, a study by Damião et al [30] and Pflipsen et al [23] found a 22.5% and 22% prevalence of B 12 deficiency among Brazilian and American T2DM patients using metformin. Wulffele [10,12,27,31].…”

A clinical study to determine metformin as a cause of serum vitamin B12 decrease and effect of combination of metformin and mecobalamin on serum vitamin B12 levels in type 2 diabetics

“…29 Damião CP et al, conducted a cross sectional clinical trial with 462 T2DM patients on metformin in Brazil. 30 The study demonstrated vitamin B12 deficiency in 22.5% of patients on metformin as compared to 7.4% of controls. The mean serum vitamin B12 was 272 pg/ml and was significantly (p <0.001) lower than controls with 348 pg/ml.…”

Assessment of Metformin Induced Vitamin-B12 Deficiency amongst Type-II Diabetic Patients Vis-À-Vis Evaluating the Quality of Life

“…Similar studies done in Europe have reported a prevalence of about 27%. 16,17 Akabwai et al 18 , Study has shown that the prevalence of vitamin B12 deficiency was 10. 7%.…”