Cardiorespiratory Fitness and Adiposity as Mortality Predictors in Older Adults

To determine the association among cardiorespiratory fitness ("fitness"), adiposity, and mortality in older adults. DESIGN, SETTING, AND PATIENTS: Cohort of 2603 adults aged 60 years or older (mean age, 64.4 [SD, 4.8] years; 19.8% women) enrolled in the Aerobics Center Longitudinal Study who completed a baseline health examination during 1979-2001. Fitness was assessed by a maximal exercise test, and adiposity was assessed by body mass index (BMI), waist circumference, and percent body fat. Low fitness was defined as the lowest fifth of the sex-specific distribution of maximal treadmill exercise test duration. The distributions of BMI, waist circumference, and percent body fat were grouped for analysis according to clinical guidelines. MAIN OUTCOME MEASURE: All-cause mortality through December 31, 2003.

There were 450 deaths during a mean follow-up of 12 years and 31 236 person-years of exposure. Death rates per 1000 person-years, adjusted for age, sex, and examination year were 13.9, 13.3, 18.3, and 31.8 across BMI groups of 18.5-24.9, 25.0-29.9, 30.0-34.9, and > or =35.0, respectively (P = .01 for trend); 13.3 and 18.2 for normal and high waist circumference (> or =88 cm in women; > or =102 cm in men) (P = .004); 13.7 and 14.6 for normal and high percent body fat (> or =30% in women; > or =25% in men) (P = .51); and 32.6, 16.6, 12.8, 12.3, and 8.1 across incremental fifths of fitness (P