Association between vitamin D and risk of cardiovascular disease in Chinese rural population

Abstract

Previous studies have suggested that vitamin D is associated with cardiovascular disease (CVD), however, the relationship between vitamin D levels and CVD risk is still unclear. The purpose of this study was to assess the relationship of serum concentration of 25-hydroxyvitamin D (25(OH)D) with CVD in rural residents of Henan province of China. Basic information and medical history were gathered through face-to-face surveys from July 2013 to August 2015, and biochemical indicators were gathered in a laboratory setting. Logistic and restricted cubic splines regression analyses were used to estimate odd ratios (ORs) and 95% confidence intervals (95%CI) of CVD. A total of 1078 participants were included, the mean serum 25(OH)D concentration was determined to be 25 ± 18 ng/ml, with 54.45% of the participants presenting vitamin D deficiency [25(OH)D < 20 ng/mL]. Moreover, the prevalence of CVD was 59.28% in the vitamin D deficient group, which was higher than in the insufficient (48.55%) and sufficient groups (52.78%). After adjusting for potential confounders, compared with the deficient group, the ORs (95%CI) of CVDs were 0.68 (0.50, 0.91) in the insufficient group and 0.81 (0.56, 1.16) in the sufficient group. A nonlinear (U-shaped) association was observed between the risk of CVD and 25(OH)D concentration. Further research suggested that the risk of CVD was higher in males than in females. In conclusion, a U-shape association between serum levels of 25(OH)D and the risk of CVD was identified in our study, suggesting a nonlinear relationship between vitamin D with the prevalence of CVD.

Fig 1. The prevalence of CVD in different serum 25(OH)D levels.

Fig 2. The risk of CVD according to the serum 25(OH)D concentration.

Serum 25(OH)D concentration and risk of CVD in the participants. OR (solid line) and 95% CI (dashed lines) from logistic regression using restricted cubic splines. Adjusted for age, gender, education, marital status, smoking, drinking, high-fat diet, physical activity, BMI groups and T2DM (model 3). The light blue area indicates the distribution of serum 25(OH)D concentrations in participants.

Fig 3. Adjusted OR (95%CI) for CVD in subgroup analysis.

Subgroup analysis of serum 25(OH)D levels and risk of CVD. Circles represent the ORs, horizontal bars represent 95% CI. Adjusted for the covariates of age, gender, education, smoking, alcohol drinking, high-fat diet, physical activity, BMI groups and T2DM (model 3).