Abstract 11327: Central Adiposity is Independently Associated With Cardiac Mechanics: A Speckle-Tracking Analysis of 2196 Participants From the HyperGEN Study
Introduction: Central obesity, defined by an elevated waist circumference (>88cm for women, >102cm for men) or waist-hip ratio (WHR) (>0.85 for women, >0.90 for men), predicts cardiovascular (CV) morbidity (including heart failure) and mortality in the general population. However, the pathophysiological link between central obesity and adverse CV outcomes remains poorly understood. We hypothesized that central obesity and higher WHR are both independently associated with worse cardiac mechanics (reduced left ventricular [LV] strain and early diastolic [e’] tissue velocities).
Methods: We performed speckle-tracking analysis on echocardiograms from participants in the HyperGEN study, a family- and population-based epidemiologic study (N=2196). Global longitudinal, circumferential, and radial strain, early diastolic strain rate, and e’ velocities were measured. E/e’ was calculated as an estimate of LV filling pressure. We evaluated the association between central obesity/WHR and cardiac mechanics using multivariable-adjusted linear mixed effects models to account for relatedness among subjects.
Results: The mean age of the cohort was 51±14 years, 58% were female, and 47% were African American. Mean BMI was 30.8±7.1 kg/m2, mean waist circumference was 102±17 cm, mean WHR was 0.91±0.08, and 80% had central obesity. After adjusting for age, sex, center, race, image quality, BMI, systolic blood pressure, LV mass index, wall motion abnormalities, and EF, both central obesity and WHR each remained associated with global longitudinal strain, early diastolic strain rate, e’ velocity, and E/e’ ratio (P≤0.01 for all comparisons). Results were similar in non-obese (BMI < 30 kg/m2 [N=1163]) and overweight patients (BMI 25-30 kg/m2 [N=739]) (P≤0.01 for all comparisons). Additional adjustment for serum aldosterone and fasting insulin levels attenuated, but did not eliminate, the observed associations.
Conclusions: Central obesity and higher WHR are both independently associated with worse cardiac mechanics, even in non-obese individuals. The deleterious effect of central obesity on cardiac mechanics may provide mechanistic insight into the association between central obesity and worse CV outcomes.
- © 2013 by American Heart Association, Inc.