Association of Central Adiposity With Adverse Cardiac Mechanics

Abstract

Background Central obesity, defined by increased waist circumference (WC) or waist-hip ratio (WHR), is associated with increased cardiovascular (CV) events, including heart failure. However, the pathophysiological link between central obesity and adverse CV outcomes remains poorly understood. We hypothesized that central obesity and larger WHR are independently associated with worse cardiac mechanics (reduced left ventricular [LV] strain and systolic [s’] and early diastolic [e’] tissue velocities). Methods and Results We performed speckle-tracking analysis of echocardiograms from participants in the HyperGEN study, a population- and family-based epidemiologic study (N=2181). Multiple indices of systolic and diastolic cardiac mechanics were measured. We evaluated the association between central obesity and cardiac mechanics using multivariable-adjusted linear mixed effects models to account for relatedness among participants. The mean age of the cohort was 51±14 years, 58% were female, and 47% were African-American. Mean body-mass index (BMI) was 30.8±7.1 kg/m2, WC 102±17 cm, WHR 0.91±0.08, and 80% had central obesity based on WC and WHR criteria. After adjusting for multiple potential confounders, including age, sex, race, physical activity, BMI, heart rate, smoking status, systolic blood pressure, fasting glucose, total cholesterol, anti-hypertensive medication use, glomerular filtration rate, LV mass index, wall motion abnormalities, and ejection fraction, central obesity and WHR remained associated with worse global longitudinal strain, early diastolic strain rate, s’ velocity, and e’ velocity (P < 0.05 for all comparisons). There were no significant statistical interactions between WHR and obesity status. Conclusions In this cross-sectional study of participants with multiple comorbidities, central obesity was found to be associated with adverse cardiac mechanics.

Getting at the Heart of Central Obesity and the Metabolic Syndrome

“…Arterial pulsatile load is increased with central obesity 22 but was not directly measured in the current analysis. 20 However, it has previously been shown that increases in body weight are correlated with increased LV diastolic stiffness even after adjusting for arterial load. 7 Central obesity is also associated with greater age-related increases in LV systolic stiffness in women, which is also typical of HFpEF, even as other indices of LV systolic function become impaired.…”

“…Compared to participants without central obesity, subjects with central obesity displayed more comorbidities including hypertension, dyslipidemia, diabetes and kidney disease, higher blood pressure and BMI, greater insulin resistance, worse kidney function and lower baseline activity levels. 20 Centrally obese patients also displayed more dilated ventricles, increased LV mass, left atrial dilatation, and altered systolic and diastolic LV mechanics. Notably, there was no difference in EF, reinforcing the limitations of this index of LV performance.…”

“…20 The authors analyzed echocardiographic images from the HyperGEN study, which is a cross-sectional, population based study of 2181 paired first degree relatives without HF. This was a largely young (mean age 51), overweight to obese population with a mean BMI of 31 kg/m 2 .…”

“…The authors appropriately conclude from these data that central obesity is independently associated with adverse cardiac mechanics. 20 …”

“…9 Together with these earlier studies, the current data from Selvaraj et al establishes that there is something very important and specific about central adiposity that is particularly detrimental to cardiac function. 20 …”