Abstract
BACKGROUND:
Whether the cardioprotective characteristic of higher cardiorespiratory fitness (CRF) extends to adults with manifest hypertension (HTN) is poorly understood.
METHODS:
We examined the association between CRF and nonfatal cardiovascular disease (CVD) events in 8147 men and 1268 women, who, at baseline, were free of known CVD and had HTN based on a history of physician diagnosis or a measured resting blood pressure (BP) > or =140/90 mm Hg. The CVD events (myocardial infarction, stroke, coronary revascularization) were ascertained from mail-back surveys. The CRF was quantified as maximal treadmill exercise test duration and was grouped for analysis as low (lowest 20% of exercise duration), moderate (middle 40%), and high (upper 40%).
RESULTS:
A total of 71 CVD events occurred during 12,224 woman-years, and 837 CVD events occurred during 82,366 man-years of follow-up. Age and examination year adjusted CVD rates per 1000 person-years according to low, moderate, and high CRF groups were 10.8, 8.4, and 3.8 (trend P = .001) in women, and were 15.3, 10.9, and 7.2 (trend P < .001) in men. After further controlling for CVD risk factors, abnormal exercise electrocardiogram (ECG) responses, and family history of CVD, hazards ratios (95% CI) for CVD events across incremental CRF categories were 1.00 (referent), 0.88 (0.74 to 1.06), 0.70 (0.57 to 0.86), trend P < .001, in men, and were 1.00 (referent), 0.87 (0.48 to 1.58), 0.41 (0.20 to 0.84), trend P = .01, in women.
CONCLUSIONS:
In adults with HTN, higher CRF is associated with lower risk of nonfatal CVD events, independent of other clinical risk predictors.