Vitamin D deficiency in diabetes exacerbates longitudinal risk for atherosclerotic cardiovascular disease in Lanzhou, China

Background and Objectives: Vitamin D deficiency has been considered a risk factor for atherosclerotic cardiovascular disease (ASCVD). The aim of this study was to investigate the correlation between serum 25(OH)D concentration and the risk of ASCVD in Chinese, especially in Type 2 diabetes mellitus (T2DM) patients. Methods and Study Design: Based on the "REACTION" study conducted in 2011, some 9,014 Lanzhou residents aged 40-75 years were followed from 2014 to 2016. A total of 7,061 with complete data were analyzed. Baseline population was classified into four groups based on 25(OH)D quartiles. Cox proportional hazard models were used to estimate relations between 25(OH)D concentration and ASCVD. Results: The prevalence of vitamin D deficiency [25(OH)D <20 ng/mL] was 75.1%. Followed-up for 3.3 years, those with the lowest of 25(OH)D concentration had higher rates of ASCVD (HR: 1.748, 95% CI: 1.149-2.660, p<0.01). A 10 ng/mL increase in baseline serum 25(OH)D was accompanied by a 24 % decrease in ASCVD risk (HR: 0.760, 95% CI: 0.590-0.980, p<0.05). For 25(OH)D and ASCVD risk with glycaemic status, low 25(OH)D plus T2DM was highly associated with ASCVD (HR: 2.296, 95% CI: 1.246-4.232, p<0.01). With diabetes, ASCVD risk decreased by 36% when serum 25(OH)D increased by 10 ng/mL (HR: 0.644, 95% CI: 0.440-0.941, p<0.05). Conclusions: Serum 25(OH)D is independently and inversely associated with the risk of ASCVD in Lanzhou Chinese, especially those with T2DM. Maintaining sufficient levels of vitamin D may be an effective measure in ASCVD prevention.