Effects of body fatness and physical activity on cardiovascular risk: risk prediction using the bioelectrical impedance method.

AIMS: To explore the effects of body fat percentage (BF%) on incidence of and mortality from cardiovascular disease (CVD) and to study the cardio-protective effect of physical activity in relation to BF%.

METHODS: A total of 26,942 men and women, aged 45-73 years, without history of CVD were followed up for incidence of coronary events (CE), ischaemic stroke, and CVD mortality over seven years in relation to sex-specific quartiles (Q1-Q4) of BF%. The cardio-protective effect of leisure-time physical activity was studied in relation to BF%.

RESULTS: In men, the relative risk (RR) for CE and CVD mortality increased progressively with BF%. RR for CE in Q4 was 1.37 (95% confidence interval: 1.07-1.74), adjusted for age, height, smoking, high alcohol intake, and physical activity, compared with Q1. In women, BF% was significantly associated with incidence of CE and stroke. BF% was more strongly correlated to body mass index (BMI) (r = 0.83) and waist circumference (r = 0.76) in women than in men (r = 0.59 and r = 0.66, respectively). BF% was a stronger risk factor than BMI in women, and equally strong as waist circumference. A significant interaction (p = 0.013 for incidence of CE, p = 0.026 for ischaemic stroke) was found between BF% and sex. The raised cardiovascular risk was reduced by physical activity in subjects with high BF%.

CONCLUSIONS: BF% is a risk factor for CE, ischaemic stroke, and CVD mortality. An interaction between BF% and sex suggests that BF% is a stronger CVD risk factor in women. The raised cardiovascular risk associated with high BF% is reduced by physical activity.