Comparison of cardiorespiratory fitness versus leisure time physical activity as predictors of coronary events in men aged ≤65 years and >65 years

Both high peak oxygen consumption (VO2) and high levels of leisure time physical activity (LTPA) are associated with a reduced risk of cardiovascular morbidity and mortality. We examined the contributions of LTPA and peak VO2 to the risk of coronary events (CEs) in healthy younger (less than or equal to65 years, In = 522) and older (>65 years, n = 167) men from the Baltimore Longitudinal Study of Aging. LTPA derived from self reports of time spent in 97 activities were converted into METs-minutes/24 hours and grouped into high (;2:6 METs), moderate- (4 to 5.9 METs), and low-intensity LTPA (<4 METs). Cardiorespiratory fitness was determined by measuring peak VO2 during a maximal treadmill exercise test. Over a mean follow-up of 13.4 +/- 6.3 years, CEs occurred in 63 men. After accounting for coronary risk factors, proportional-hazards analyses showed a relative CE risk of 0.53 (p <0.0001) for a SD increase in peak VO2 in younger men and 0.61 (p = 0.024) in older men, whereas total LTPA was unrelated to coronary risk in either age group. When the 3 LTPA intensity levels were substituted for total LTPA in the model, peak VO2 remained the only predictor of events in younger men, whereas high-intensity LTPA (RR = 0.39 for tertile 3 vs tertiles I and 2, p 0.016) and peak VO2 (RR = 0.61/SD increase, p 0.024) were of similar importance in older men. Thus, in healthy younger men, higher cardio respiratory fitness but not LTPA predicts a A reduced risk of coronary heart disease, independent of conventional risk factors. For older men, high-intensity LTPA and fitness appear to be of similar importance in reducing coronary risk. (C) 2002 by Excerpta Medica, Inc.