Muscular Strength And Incidence Of Hypertension In Normotensive And Prehypertensive Men

Abstract

Hypertension (HTN) is the most prevalent cardiovascular disease in the United States. The influence of resistance exercise on HTN status is unclear. PURPOSE To examine the association between muscular strength and the incidence of HTN in initially normotensive and prehypertensive men. METHODS Study participants were 1883 normotensive and 2337 prehypertensive men (age 43.4 ± 9.4 years) who received a preventive medical examination between 1981 and 1989, during which they submitted to voluntary strength testing and returned at least one follow-up health survey in 1982, 1986, 1990, 1995, 1999 or 2004. Normal blood pressure (BP) and prehypertension were defined as having resting BP <120/80 mmHg and as having systolic BP of 120–139 mmHg or diastolic BP of 80–89 mmHg, respectively. Muscular strength was quantified by combining body weight-adjusted 1-repetition maximum measures for leg and bench presses. Cardiorespiratory fitness was assessed by a maximal treadmill test. Cases were defined as self-reported physician diagnosed HTN from the follow-up surveys. Multivariable logistic regression was used to compute odds ratios (OR) and 95% confidence intervals (CI) as an index of the association between strength and incident HTN. RESULTS During an average (SD) follow-up of 11.8 (6.7) years, a total of 173 and 476 HTN cases occurred among normotensive and prehypertensive men, respectively. After adjusting for age, year of exam, the pattern of survey responses, baseline BP, smoking, health status, family history of HTN and cardiorespiratory fitness, the OR (95% CI) of incident HTN across incremental quartiles of muscular strength were 1.00, 1.18 (0.58–2 .44), 1.96(0.97–3 .94), 0.71 (0.32–1 .59) (P for trend =0.85) among normotensive men, and 1.00, 0.65 (0.41–1 .03), 0.79 (0.51–1 .24), 0.52 (0.31–0 .87) (P for trend = 0.037) among prehypertensive men, respectively. CONCLUSION Muscular strength was inversely associated with HTN incidence in prehypertensive men, even after accounting for maximal aerobic fitness. Higher levels of muscular strength, thus presumably higher levels of habitual resistance exercise, were not associated with an increased incidence of HTN, irrespective of baseline blood pressure status. Supported by NIH Grant AG06945