Association between serum 25(OH)D sub(3) and cardiovascular morbidity and mortality in people with Type 2 diabetes: a community-based cohort study

• Published in: Diabetic medicine 2017-03, Vol.34 (3), p.372-379
• Main Authors: Samefors, M, Scragg, R, Laenne, T, Nystrom, F H, Oestgren, C J
• Format: Article
• Language: English
• ISSN: 0742-3071; 1464-5491
• DOI: 10.1111/dme.13290

Aim We aimed to explore the association between vitamin D and cardiovascular morbidity and mortality in people with Type 2 diabetes recruited from a community-based study because there is limited and inconsistent research of this group. Methods A prospective community-based cohort study among people aged 55-66 years with Type 2 diabetes as part of The Cardiovascular Risk in Type 2 Diabetes - A Prospective Study in Primary Care (CARDIPP). We analysed serum 25-hydroxyvitamin D sub(3) [25(OH)D sub(3)] at baseline. Cox regression analyses were used to calculate hazard ratios (HR) for the first myocardial infarction, stroke or cardiovascular mortality according to 25(OH)D sub(3). Results We examined 698 people with a mean follow-up of 7.3 years. Serum 25(OH)D sub(3) was inversely associated with the risk of cardiovascular morbidity and mortality: HR 0.98 [95% confidence interval (CI) 0.96 to 0.99, P = 0.001]. Compared with the fourth quartile (Q4) [25(OH)D sub(3) > 61.8 nmol/l], HR (with 95% CI) was 3.46 (1.60 to 7.47) in Q1 [25(OH)D sub(3) < 35.5 nmol/l] (P = 0.002); 2.26 (1.01 to 5.06) in Q2 [25(OH)D sub(3) 35.5-47.5 nmol/l] (P = 0.047); and 1.62 (0.70 to 3.76) in Q3 [25(OH)D sub(3) 47.5-61.8 nmol/l] (P = 0.26) when adjusting for age, sex and season. The results remained significant after adjusting also for cardiovascular risk factors, physiological variables including parathyroid hormone and previous cardiovascular disease (P = 0.027). Conclusions Low 25(OH)D sub(3) is associated with an increased risk of cardiovascular morbidity and mortality in people with Type 2 diabetes independent of parathyroid hormone. Vitamin D could be considered as a prognostic factor. Future studies are needed to explore whether vitamin D deficiency is a modifiable risk factor in Type 2 diabetes. What's new? * There is limited research on vitamin D and cardiovascular disease in people with Type 2 diabetes. * We found that serum 25-hydroxyvitamin D sub(3) was inversely associated with the risk of cardiovascular morbidity and mortality in people with Type 2 diabetes. * The results remained significant after adjusting for cardiovascular risk factors, physiological variables and previous cardiovascular disease. * The results of our study expand the current knowledge of the importance of vitamin D in relation to cardiovascular disease because we incorporated data on parathyroid hormone levels and physical activity in the analyses. * Vitamin D could be considered as a prognostic factor.