FAMILIAL AGGREGATION OF CARDIOVASCULAR RESPONSE TO SUBMAXIMAL EXERCISE IN THE HERITAGE FAMILY STUDY

Cardiovascular reactivity, including responses of systolic blood pressure (SBP) and heart rate (HR) to exercise, has been postulated to be a predictor of future essential hypertension and coronary heart disease. The purpose of this study was to investigate the familial relationship of response of SBP and HR and their product to submaximal cycle ergometer exercise in 474 members of 99 sedentary Caucasian families participating in the HERITAGE Family Study. Familial aggregation due to genetic factors and shared social environment was assessed by analysis of variance and the use of the SEGPATH familial correlation model. Maximal heritability for HR response reached 52% at 50 W and 45% at 60% of maximal oxygen uptake (VO2 max), while estimates for SBP response reached 48% at 50W and 38% at 60% of VO2 max, and the estimates for their product were 56% and 45% at 50 W and 60% of VO2 max, respectively. We conclude that the cardiovascular response to the stress of light-to-moderate-intensity exercise is highly familial and includes a significant genetic component. This research was supported by multiple grants from the NHLBI.