Abstract
BACKGROUND: Focused studies in younger to middle-aged populations have demonstrated a relationship between obesity and adverse cardiac mechanics. We examined whether measures of overall and central adiposity are associated with cardiac mechanics, assessed by speckle-tracking echocardiography, in an older population without prevalent coronary heart disease or heart failure. METHODS: Body composition was measured by anthropometry, bioelectrical impedance, and dual-energy x-ray absorptiometry among participants in the Cardiovascular Health Study, a population-based cohort of adults aged 65 years or older. Systolic and diastolic cardiac mechanics were measured with speckle-tracking analysis of echocardiograms. Multi-variable adjusted linear regression models were used to investigate associations of body composition measures and cardiac mechanics. RESULTS: Mean age for the 3525 included participants was 72.6 years, 39% were male, and 10% were black. Mean body-mass index (BMI) was 26.3 ± 4.4 kg/m(2), waist circumference (WC) was 93.2 ± 12.9 cm, and waist-to-hip ratio was 0.92 ± 0.09. In fully adjusted analyses, all adiposity measures were associated with worse LV longitudinal strain, LV early diastolic strain rate, and left atrial reservoir strain; however, associations were strongest for WC and BMI (p < 0.001). When both BMI and WC were included in the same model, only WC remained associated with each cardiac strain measure. CONCLUSION: In this cross-sectional study of older adults, central obesity was most robustly associated with impaired left ventricular systolic and diastolic strain as well as left atrial strain. The adverse effects of central obesity appear to extend even into older age.