Abstract 11422: Body Composition and Mortality in Patients With Coronary Heart Disease - “The Obesity Paradox”
Background: Despite the well-known adverse effects of obesity on almost all aspects of coronary heart disease (CHD), many studies of CHD cohorts have demonstrated an inverse relationship between obesity, as determined by both body mass index (BMI) and percent body fat (BF), on subsequent prognosis (the “obesity paradox”). To our knowledge, the combined effects of a BMI and BF on prognosis in CHD have not been reported.
Patients and Methods: We studied 581 patients with CHD following major CHD events, who were divided into low (< 25 kg/m2) and high BMI (≥ 25 kg/m2), as well as low ( 25≤ men and ≤ 35% women) and high BF (> 25% in men and > 35% in women) as determined by the sum of the skin-fold method. Four groups were analyzed by total mortality over 3-year follow-up by National Death Index: Low BF/Low BMI (n=119), High BF/Low BMI (n=26), Low BF/High BMI (n=125) and High BF/High BMI (n=311).
Results: During 3-year follow-up, mortality was highest in the Low BF/Low BMI group (11%), which was significantly (p<0.0001) higher than the other 3 groups (3.9%, 3.2%, and 2.6%, respectively; Figure). Excluding 6 patients with underweight BMI < 18.5 kg/m2 who had 50% mortality, the results were similar (8.9% mortality in Low BF/Low BMI, p<0.0001 compared with other groups). In multivariate logistic regression for mortality, when entered individually both high BMI (OR 0.79; CI 0.69–0.90) and high BF (OR 0.89; CI 0.82–0.95) were independent predictors of lower mortality.
Conclusions: Although both Low BF and Low BMI are independent predictors of mortality in patients with CHD, only those patients with combined Low BF/Low BMI appear to be at particularly high risk for mortality during follow-up. These results suggest that the “obesity paradox” is confined to Low BF/Low BMI subgroups.
- © 2010 by American Heart Association, Inc.