Physical Activity, Vitamin D, and Incident Atherosclerotic Cardiovascular Disease in Whites and Blacks: The ARIC Study.

Context: Physical activity (PA) is associated with 25-hydroxyvitamin D [25(OH) D] levels. Both are associated with atherosclerotic cardiovascular disease (ASCVD), but their joint association with ASCVD risk is unknown. Objective: To examine the relationship between PA and 25(OH) D, and assess effect modification of 25(OH) D and PA with ASCVD. Design: Cross-sectional and prospective study. Setting: Community-dwelling cohort. Participants: A total of 10,342 participants free of ASCVD, with moderate-to vigorous-intensity PA assessed (1987 to 1989) and categorized per American Heart Association (AHA) guidelines (recommended, intermediate, or poor). Main Outcome Measures: Serum 25(OH) D levels (1990 to 1992) and ASCVD events (i.e., incident myocardial infarction, fatal coronary disease, or stroke) through 2013. Results: Participants had mean age of 54 years, and were 57% women, 21% black, 30% 25(OH) D deficient [<20 ng/mL (<50 nmol/L)], and <40% meeting AHA-recommended PA. PA was linearly associated with 25(OH) D levels in whites. Whites meeting recommended PA were 37% less likely to have 25(OH) D deficiency [relative risk, 0.63 (95% confidence interval [CI], 0.56, 0.71)]; there was no significant association in blacks. Over 19.3 years of follow-up, 1800 incident ASCVD events occurred. Recommended PA was associated with reduced ASCVD risk [hazard ratio [HR], 0.78 (95% CI, 0.65, 0.93) and 0.76 (95% CI, 0.62, 0.93)] among participants with intermediate [20 to,30 ng/mL (50 to,75 nmol/L)] and optimal [> 30 ng/mL (>75 nmol/L)] 25(OH) D, respectively, but not among those with deficient 25(OH) D (P for interaction = 0.04). Conclusion: PA is linearly associated with higher 25(OH) D levels in whites. PA and 25(OH) D may have synergistic beneficial effects on ASCVD risk.