25-Hydroxyvitamin D deficiency is a risk factor for atherosclerotic cardiovascular disease: a prospective study

Abstract Background Vitamin D, a fat-soluble vitamin, play a protective role in the cardiovascular system. Increasing evidence has suggested that the vitamin D deficiency is a significant risk factor for atherosclerotic cardiovascular disease (ASCVD). The aim of the present study was to investigate the correlation between serum 25-hydroxyvitamin D[25(OH)D] and the risk of ASCVD in Chinese, especially in people with type 2 diabetes mellitus(T2DM). Methods Based on the "REACTION" study conducted in 2011, 9014 residents aged 40 to 75 in Lanzhou, Gansu province were followed up from 2014 to 2016. A total of 7061 subjects with complete data from the two surveys in present study were analyzed. Baseline population was classified into four groups based on 25(OH)D quartiles, comparing the different 25(OH)D groups of ASCVD incidence after follow-up, multivariate Cox proportional hazards regression modelling was used to estimate associations between 25(OH)D levels and the risk of ASCVD and to further analyze the relationship between ASCVD risk and 25(OH)D levels in different glucose metabolism status. Results Among 7,061 subjects aged 40 to 75 years, the median serum 25(OH)D level was 15.91ng/ml, and the prevalence of vitamin D deficiency was 75.1%, merely 2.0% of those with vitamin D sufficiency. During the follow-up period of 3.3 years, 216 cases of ASCVD events were recorded. The cumulative incidence of ASCVD from lowest of 25(OH)D levels to the highest were 4.1%, 3.0%, 3.1% and 2.0%, respectively. Cox regression analysis indicated that the individuals in quartile 1 but not quartile 2 or 3 of 25(OH)D level had significantly higher rate of ASCVD than that in highest quartile, additionally, 10 ng/ml per increase in serum 25(OH)D at baseline, the ASCVD risk was reduced by 24%[hazard ratio(HR):0.761, 95% confident interval(CI):0.590- 0.980, P <0.05]. When the effects of 25(OH)D on ASCVD risk was assessed in different glucose metabolism status, the results showed that the low 25(OH)D plus T2DM was associated with high risk of ASCVD after adjustment of confounding risk factors (HR: 2.284, 95% CI: 1.242-4.202, P <0.05).The risk of ASCVD decreased by 35% as serum 25(OH)D increased by 10 ng/ml, which remained significant after stepwise adjustments ( P <0.05). Conclusions Serum 25(OH)D is independently and inversely associated with the risk of ASCVD in Chinese.Increasing vitamin D levels can effectively reduce the risk of ASCVD incidence, especially in T2DM populations.