Racial Differences in Heart Age and Impact on Mortality

Abstract

BackgroundHeart age is an estimate of the age of a person's cardiovascular system given their cardiovascular disease (CVD) risk factors. The difference between a person's chronological age and heart age (excess heart age) represents their added CVD risk. ObjectiveTo examine racial differences in excess heart age and whether race impacts the association between excess heart age and CVD mortality. MethodsThis analysis included 5110 participants (2449 non-Hispanic white, 1287 non-Hispanic black, and 1374 Mexican-American) from the NHANES III who were free of CVD. Heart age was calculated using the sex-specific non-laboratory-based Framingham risk prediction functions. Multivariable Cox proportional-hazards regression models were used to evaluate the relationship (overall and by race) between excess heart age and CVD mortality. ResultsMean excess heart age was greatest in non-Hispanic blacks (13.0 years), followed by Mexican-Americans (10.5 years), and non-Hispanic whites (8.5 years); p < 0.001 for pairwise differences. Over a mean follow-up of 13.0 years, 394 CVD deaths occurred. Each 10 years of excess heart age was associated with 65% increased risk of CVD mortality (HR, 95% CI: 1.65, 1.53–1.78). This association was stronger in non-Hispanic whites (1.83, 1.63–2.02) compared to non-Hispanic blacks (1.50, 1.29–1.72) and Mexican American (1.60, 1.33–1.87), interaction p = 0.065. ConclusionsCompared to non-Hispanic whites, non-Hispanic blacks and Mexican Americans have more excess heart age, but the risk of CVD death for the same level of excess heart age appears more pronounced in non-Hispanic whites. Further investigation is needed to show the usefulness of these findings in directing future efforts and resource allocation for reduction of health disparities between ethnic groups.