Exercise capacity and blood pressure associations with left ventricular mass in prehypertensive individuals

Abstract

Prehypertensive individuals are at increased risk for developing hypertension and cardiovascular disease compared with those with normal blood pressure. Early compromises in left ventricular structure may explain part of the increased risk. We assessed echocardiographic and exercise parameters in prehypertensive individuals (n=790) to determine associations between exercise blood pressure and left ventricular structure. The exercise systolic blood pressure at 5 metabolic equivalents (METs) and the change in blood pressure from rest to 5 METs were the strongest predictors of left ventricular hypertrophy. We identified the systolic blood pressure of 150 mm Hg at the exercise levels of 5 METs as the threshold for left ventricular hypertrophy. There was a 4-fold increase in the likelihood for left ventricular hypertrophy for every 10-mm Hg increment in systolic blood pressure beyond this threshold (OR: 1.15; 95% CI: 1.12 to 1.18). There was also a 42% reduction in the risk for left ventricular hypertrophy for every 1 MET increase in the workload (OR: 0.58; P<0.001). When compared with low-fit, moderate, and high-fit individuals exhibited significantly lower systolic blood pressure at an exercise workload of 5 METs (155+/-14 versus 146+/-10 versus 144+/-10; P<0.05), lower left ventricular mass index (48+/-12 versus 41+/-10 versus 41+/-9; P<0.05), and prevalence of left ventricular hypertrophy (48.3% versus 18.7% versus 21.6%; P<0.001). This suggests that moderate improvements in cardiorespiratory fitness achieved by moderate intensity physical activity can improve hemodynamics and cardiac performance in prehypertensive individuals and reduce the work of the left ventricle, ultimately resulting in lower left ventricular mass.