Vitamin B12 deficiency is associated with adverse lipid profile in Europeans and Indians with type 2 diabetes

Abstract

BackgroundMetformin, a standard therapy in type 2 diabetes, reduces vitamin B12 levels. Studies linking low vitamin B12 levels and cardiovascular disease are equivocal and suggest improving B12 levels may help in primary prevention. The role of vitamin B12 deficiency on cardiovascular risk factors, especially in type 2 diabetes has not been explored. The aim of this study is to investigate whether vitamin B12 deficiency in type 2 diabetes patients is associated with cardiovascular risk factors in two different ethnic groups in UK and India.MethodsType 2 diabetes patients from two secondary care diabetic centres (Europeans - UK and Indians - India) were studied. Serum vitamin B12, folate and biochemical parameters were measured.ResultsThe prevalence rates of vitamin B12 deficiency (<191 ng/L) were 27% and 12% in Europeans and Indians, respectively and higher in metformin treated type 2 diabetes patients. In linear regression analysis, after adjusting for all likely confounding factors, vitamin B12 independently associated with triglycerides in both the populations and cholesterol/HDL ratio in Indians. Logistic regression showed type 2 diabetes patients with vitamin B12 deficiency were at significantly higher odds of having coexisting coronary artery disease (CAD) in Europeans with similar but non-significant trend in Indians, after adjusting for all likely confounding factors.ConclusionsThe prevalence of vitamin B12 deficiency is common in type 2 diabetes patients and is associated with adverse lipid parameters. Type 2 diabetes management guidelines should include the recommendation for regular testing for B12 levels, especially for those on metformin.Electronic supplementary materialThe online version of this article (doi:10.1186/s12933-014-0129-4) contains supplementary material, which is available to authorized users.

Vitamin B12 deficiency among adult diabetic patients in Uganda: relation to glycaemic control and haemoglobin concentration

“…Comparable prevalence of vitamin B12 deficiency of 9.5–14.2 % has been reported in similar studies among South Korean [3, 11] and Indian [12] adult individuals with diabetes. However, despite the comparable prevalence noted in the South Korean studies [3, 11], different study definitions of vitamin B12 deficiency were used (serum vitamin B12 levels ≤300 pg/mL without folate deficiency).…”

“…A cross sectional study by Pflipsen et al involving 203 outpatient type 2 diabetic patients at a large military primary care clinic in USA documented a prevalence of definite vitamin B12 deficiency of 22 % [2]. Similar studies done in Europe have reported prevalence of about 27 % [12, 13]. …”

Vitamin B12 Status among Pregnant Women in the UK and Its Association with Obesity and Gestational Diabetes

“…Interestingly, the frying and roasting of meat products reduces the bioavailability of B12 by 20%–40% [29], so higher consumption of processed foods may increase the risk of both B12 insufficiency and metabolic diseases. Additionally, B12 has been shown to be negatively associated with other markers of obesity such as triglycerides [7], blood pressure [30], and the metabolic syndrome [31], which lends support to a possible pathological association between them. In one trial, the supplementation of B12 and folate in adults with metabolic syndrome improved insulin resistance by ameliorating endothelial dysfunction, providing further insight into how these conditions may be linked [32].…”

“…One step in this process is the conversion of homocysteine (Hcy) to a methyl donor, methionine, for which B12 and folate are necessary cofactors. Additionally, the mitochondrial conversion of methylmalonyl-CoA to succinyl-CoA requires B12 as a coenzyme and in its absence, accumulation of the former compound inhibits fatty acid oxidation, thereby promoting lipogenesis [7,8]. Therefore it can be postulated that low B12, at a cellular level, may be linked to adipocyte dysfunction and obesity-related complications by modulating lipid metabolism, cellular inflammation [9], and causing hypomethylation of cholesterol biosynthesis pathways [10].…”

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

“…Adaikalakoteswari Et. al 19 Study has shown that the prevalence rates of vitamin B12 deficiency (<191 ng/L) were 27% and 12% in Europeans and Indians, respectively and higher in metformin-treated type 2 diabetes patients. K. S Akindale, Et.…”