Original ArticleFunctional capacity is a better predictor of coronary heart disease than depression or abnormal sleep duration in Black and White Americans

ObjectiveTo assess whether functional capacity is a better predictor of coronary heart disease (CHD) than depression or abnormal sleep duration.MethodsAdult civilians in the USA (n = 29,818, mean age 48 ± 18 years, range 18-85 years) were recruited by a cross-sectional household interview survey using multistage area probability sampling. Data on chronic conditions, estimated habitual sleep duration, functional capacity, depressed moods, and sociodemographic characteristics were obtained.ResultsThirty-five percent of participants reported reduced functional capacity. The CHD rates among White and Black Americans were 5.2% and 4%, respectively. Individuals with CHD were more likely to report extreme sleep durations (short sleep [⩽5 h] or long sleep [⩾9 h]; odds ratio [OR] 1.65, 95% confidence interval [CI] 1.38-1.97; P < 0.0001), less likely to be functionally active (anchored by the ability to walk one-quarter of a mile without assistance [OR 6.27, 95% CI 5.64-6.98; P < 0.0001]) and more likely to be depressed (OR 1.78, 95% CI 1.60-1.99; P < 0.0001) than their counterparts. On multivariate regression analysis adjusting for sociodemographic factors and health characteristics, only functional capacity remained an independent predictor of CHD (OR 1.81, 95% CI 1.42-2.31; P < 0.0001).ConclusionFunctional capacity was an independent predictor of CHD in the study population, whereas depression and sleep duration were not independent predictors.