Physical fitness and physical activity at age 13 years as predictors of cardiovascular disease risk factors at ages 15, 25, 33, and 40 years: extended follow-up of the Oslo Youth Study.

OBJECTIVE: Few studies have examined the association of childhood physical activity and physical fitness with cardiovascular disease risk factors in adulthood. Furthermore, interpretation of these findings is hampered by methodologic shortcomings. In a population-based cohort study, we explored the influence, if any, of childhood physical activity and physical fitness on later cardiovascular disease risk factors.
METHODS: Data were taken from the Oslo Youth Study, a prospective cohort study that began in 1979, when 1016 students (mean age: 13 years; range: 11-15 years) who were attending 6 schools were invited to participate in a health education intervention. Cardiovascular disease risk factor data were collected at baseline and again in 1981 (mean age: 15 years; range: 13-17 years), 1991 (mean age: 25; range: 23-27 years), 1999 (mean age: 33; range: 31-35 years), and 2006 (mean age: 40; range: 38-42 years).
RESULTS: At baseline, physical fitness was inversely related to BMI, triceps skinfold thickness, and blood pressure (systolic and diastolic; N = 716). These associations were also present in prospective analyses at ages 15 (N = 472), 25 (N = 280; except for systolic blood pressure), and 33 years (N = 410, only BMI measured)-albeit with progressively diminishing magnitude-but were lost at 40 years (N = 294). There were fewer relationships with cardiovascular disease risk factors when physical activity was the exposure of interest. Controlling for educational attainment of both the parent and the study member had little impact on these associations.
CONCLUSIONS: Although childhood physical fitness seems to reveal some inverse associations with obesity and blood pressure in early adulthood, these effects diminished markedly into middle age.