Influences of cardiorespiratory fitness levels and other predictors on cardiovascular disease mortality in men. Med. Sci. Sports Exerc., Vol. 30, No. 6, pp. 899-905, 1998.
Purpose: This investigation quantifies the relation between cardiorespiratory fitness levels and cardiovascular disease (CVD) mortality within strata of other CVD predictors.
Methods: Participants included 25,341 male Cooper Clinic patients who underwent a maximal graded exercise test. CVD death rates were determined for low (least fit one-fifth), moderate (next two-fifths), and high (top two-fifths) cardiorespiratory fitness categories by strata of smoking habit, blood cholesterol level, resting blood pressure, and health status. There were 226 cardiovascular deaths during 211,996 man-years of follow-up.
Results: For individuals with none of the major CVD predictors (smoking, elevated resting systolic blood pressure, elevated blood cholesterol), there was a strong inverse relation (P = 0.001) between fitness level and CVD mortality. An inverse relation between CVD mortality and fitness level was seen within strata of cholesterol levels and health status. No evidence of a trend (P = 0.60) for decreased mortality was seen across fitness levels for individuals with elevated systolic blood pressure; however, a strong inverse gradient (P < 0.001) was seen across fitness levels for individuals with normal systolic blood pressure. There was a tendency for association between high levels of fitness and decreased CVD mortality in smokers compared with low and moderately fit smokers (P < 0.076). There was no significant association between level of fitness and CVD mortality for individuals with multiple (two or more) predictors (P = 0.325). Approximately 20% of the 226 CVD deaths in the population studied were attributed to low fitness level.
Conclusions: Moderate and high levels of cardiorespiratory fitness seem to provide some protection from CVD mortality, even in the presence of well established CVD predictors.
Cooper Institute for Aerobics Research, Dallas, TX 75230; Baylor Sports Medicine Institute, Houston, TX 77030; School of Public Health, University of South Carolina, Columbia, SC 29208; Stanford University School of Medicine, Palo Alto, CA 94305; and Cooper Clinic, Dallas TX 75230
Submitted for publication February 1997.
Accepted for publication December 1997.
This study was supported in part by US Public Health Service Research Grant AG06945 from the National Institute on Aging, Bethesda, MD.
We thank our many study participants; Kenneth H. Cooper, M.D., for establishing the Aerobics Center Longitudinal Study; the Cooper Clinic physicians and technicians for collecting the baseline data; Melba Morrow, M.A., for editorial assistance; Roberta Bannister and her staff for data entry; and Marilu Meredith, Ed.D., and Lee Andrus for computer services support.
Address for correspondence: Stephen W. Farrell, Ph.D., Cooper Institute for Aerobics Research, 12330 Preston Rd., Dallas TX 75230.