Abstract MP29: Body Fat and Cardiovascular Disease Risk in Postmenopausal Women With Normal Body Mass Index: the Women’s Health Initiative

Abstract

Introduction: Excess body weight characterized by higher BMI is associated with increased risk of cardiovascular disease (CVD). In individuals with normal BMI, the extent to which body fat distribution may impact CVD risk is unclear, particularly in postmenopausal women who often experience fat redistribution. Hypothesis: We hypothesized a detrimental impact of trunk fat and a favorable impact of leg fat on risk of CVD risk among postmenopausal women with normal BMI. Methods: We analyzed data from 2683 normal-weight (BMI: 18.5-24.9 kg/m 2 ) women in the Women’s Health Initiative study without known CVD at baseline (1993-1998). Body composition including whole body and regional fat mass (FM) were determined by dual-energy X-ray absorptiometry. Incident CVD events including coronary heart disease (coronary death, nonfatal myocardial infarction, or coronary revascularization) and stroke were ascertained through February 2017. Results: There were 291 incident cases of CVD during a median 17.9 years of follow-up. After multivariable adjustment, whole body FM or FM percentage was not significantly associated with CVD risk. Higher trunk FM percentage was associated with increased risk of CVD (HR comparing extreme quartiles = 1.91, 95% CI: 1.33-2.74, P -trend <0.001), while higher leg FM percentage was associated with lower risk of CVD (HR = 0.62, 95% CI: 0.43-0.89, P -trend = 0.008) ( Figure ). These associations were slightly attenuated but remained significant after further adjustment for waist circumference or waist-to-hip ratio. Higher trunk fat combined with lower leg fat was associated with particularly higher risk of CVD (HR comparing extreme groups = 3.33, 95% CI: 1.46-7.62). Similar significant associations of trunk fat and leg fat were observed for coronary heart disease but not for stroke. Conclusions: Among postmenopausal women with normal BMI, higher trunk fat was associated with increased risk of CVD, while higher leg fat was associated with decreased risk of CVD, independently of central adiposity measures.