Cardiorespiratory Fitness in Young Adulthood and the Development of Cardiovascular Disease Risk Factors

To test whether low fitness, estimated by short duration on a maximal treadmill test, predicted the development of cardiovascular disease risk factors and whether improving fitness (increase in treadmill test duration between examinations) was associated with risk reduction. DESIGN, SETTING, AND PARTICIPANTS: Population-based longitudinal cohort study of men and women 18 to 30 years of age in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants who completed the treadmill examination according to the Balke protocol at baseline were followed up from 1985-1986 to 2000-2001. A subset of participants (n = 2478) repeated the exercise test in 1992-1993. MAIN OUTCOME MEASURES: Incident type 2 diabetes, hypertension, the metabolic syndrome (defined according to National Cholesterol Education Program Adult Treatment Panel III), and hypercholesterolemia (low-density lipoprotein cholesterol > or =160 mg/dL [4.14 mmol/L]).

During the 15-year study period, the rates of incident diabetes, hypertension, the metabolic syndrome, and hypercholesterolemia were 2.8, 13.0, 10.2, and 11.7 per 1000 person-years, respectively. After adjustment for age, race, sex, smoking, and family history of diabetes, hypertension, or premature myocardial infarction, participants with low fitness ( or =60th percentile), all P