Dietary Folate, Vitamin B6, and Vitamin B12 and Risk of Cardiovascular Diseases among Individuals with Type 2 Diabetes: A Case-Control Study

Abstract

Background: Emerging evidence suggests that dietary one-carbon metabolism-related B-vitamins are associated with the reduced risk of cardiovascular disease (CVD) in the general population. However, only a few studies have assessed their associations in patients with type 2 diabetes (T2D). Objective: This study aimed to assess the associations between the intake of three one-carbon metabolism-related B-vitamins (folate, vitamin B₆, and vitamin B₁₂) and CVD risk in Chinese patients with T2D. Methods: A hospital-based case-control study of 419 patients with T2D and newly diagnosed CVD and 419 age- (±5 years) and sex-matched T2D-only controls was carried out in China. A validated 79-item semi-quantitative food-frequency questionnaire administered in face-to-face interviews was used to measure dietary B-vitamin intake. Conditional logistic regression was used to assess associations, which were tested by estimating odds ratios (ORs) with 95% confidence intervals (CIs). Results: Compared with the lowest quartile, the multivariable-adjusted ORs and 95% CIs for highest quartile were 0.32 (95% CI: 0.20, 0.52; p trend <0.001) for folate, 0.47 (95% CI: 0.30, 0.76; p trend = 0.002) for vitamin B₆, and 1.02 (95% CI: 0.67, 1.55; p trend = 0.841) for vitamin B₁₂. Consistent inverse associations were found for folate intake from eggs, vegetables, fruits, soy, and other foods but not for folate intake from grains. Conclusions: Findings suggest that the high consumption of folate and vitamin B₆, but not that of vitamin B₁₂, might be associated with the low risk of CVD in patients with T2D. This study suggests that dietary folate and vitamin B₆ protect against CVD in patients with T2D.