Abstract MP19: Serum 25-hydroxyvitamin D is associated with incident heart failure in whites but not blacks: The Atherosclerosis Risk in Communities Study (ARIC)

Background: Suboptimal 25-hydroxyvitamin D [25(OH)D] is a potential cardiovascular risk factor, likely influencing cardiovascular events via established risk factors, namely hypertension, diabetes, and inflammation. Emerging evidence also suggests that the association between 25(OH)D and cardiovascular risk is stronger in whites than blacks, but these preliminary findings need further confirmation. Hypotheses: Serum 25(OH)D is inversely associated with incident heart failure, and (a) partly mediated by traditional cardiovascular risk factors and (b) stronger among whites than blacks. Methods: A total of 12,215 ARIC Study participants free of heart failure at baseline in 1990-92 (median age 56, 24% black) were followed through 2010. Total serum 25(OH)D was measured in stored samples at baseline using LCMS. Month of blood draw was accounted for. Incident heart failure events were identified via active surveillance and defined by a hospital discharge code of ICD9-428 and parallel ICD codes for deaths. Multivariable Cox proportional hazards regression models were employed. Results: During a median of 17 years of follow-up, there were 1,799 incident heart failure events. Median 25(OH)D was 26.2 and 19.0 ng/mL in whites and blacks, respectively. The association between 25(OH)D and heart failure varied by race (p-interaction = 0.01). Among whites, those in the lowest quintile of 25(OH)D were at 2-fold greater risk of heart failure relative to those in the highest quintile ( Table ). The HR was attenuated, but remained statistically significant after multivariable adjustment. In blacks there was no association between 25(OH)D and heart failure. Results were similar when race-specific quintiles were used. Conclusions: Low serum 25(OH)D was independently associated with risk of incident heart failure among whites, but not among blacks in this community-based population. Further work is needed to determine what mechanisms underlie racial variation in the association between vitamin D status and risk of heart failure.