Body fat estimates from bioelectrical impedance equations in cardiovascular risk assessment: The PREVEND cohort study

Aims To investigate prospectively the association of body fat percentage (BF%) estimates using various equations from bioelectrical impedance analysis (BIA) with cardiovascular events, compared with body mass index (BMI) and waist circumference. Methods and results We used data of 34 BIA-BF%-equations that were used for estimation of BF% in 6486 (men = 3194, women = 3294) subjects. During a median follow-up of 8.3 years, 510 (7.9%) cardiovascular events (363 in men; 147 in women) occurred. In men, the crude hazard ratio (95% confidence interval) for BF% from the best predicting BIA-BF%-equation was 3.97 (3.30-4.78) against 2.13 (1.85-2.45) for BF% from the BIA device's BIA-BF%-equation, 1.34 (1.20-1.49) for BMI and 1.49 (1.40-1.73) for waist circumference per log-1-SD increase of all. In women, the hazard ratios for best predicting BIA-BF%-equation, BIA device estimation, BMI and waist circumference were 3.80 (2.85-4.99), 1.89 (1.57-2.28), 1.35 (1.21-1.51) and 1.52 (1.31-1.75), respectively. After adjustments for age, Framingham cardiovascular disease risk score and creatinine excretion - a marker of muscle mass - BF%s and BMI remained independently associated with cardiovascular events in both men and women, while waist circumference was independently associated with cardiovascular events in men, but not in women. According to discrimination ability (C-index) and additive predictive value (net reclassification index and integrated discrimination index) on obesity measures to the Framingham cardiovascular disease risk score, BF% was superior to BMI and waist circumference in both men and women. Conclusions BF% was independently associated with future cardiovascular events. Body fat estimates from the best-predicting BIA-BF%-equations can be a more predictive measurement in cardiovascular risk assessment than BMI or waist circumference.