Significance of Adipose Tissue Quantity and Distribution on Obesity Paradox in Heart Failure

Obesity is a predictor of the development of systolic and diastolic heart failure (HF), but once established, patients with HF and obesity have better outcomes than their leaner counterparts, a phenomenon termed the "obesity paradox." We sought to investigate the impact of adipose tissue quantity and distribution, measured by way of computed tomography, on outcomes in patients with HF. Patients admitted for acute decompensated HF between January 2017 to December 2018 were retrospectively analyzed. Body composition measurements were made on computed tomography of the abdomen/pelvis. Visceral, subcutaneous, and intermuscular adipose tissues were measured at the mid-third lumbar vertebra, along with skeletal muscle and waist circumference. Paracardial (pericardial and epicardial) adipose tissue was measured at the mid-eight thoracic vertebra. Visceral adipose tissue index (VATI) and subcutaneous adipose tissue index (SATI), along with skeletal muscle index, were indexed for patient height. A total of 200 patients were included, 44.5% female. Body mass index and waist circumference did not significantly predict outcomes. Patients with high SATI (highest sex-stratified tertile) had significantly better survival (hazard ratio 0.58, 95% confidence interval 0.39 to 0.87, p = 0.009), whereas high VATI was nonsignificant. Patients were further divided into 4 groups based on both VATI and SATI. One- and 4-year mortality risks were lowest in those with low VATI high SATI compared with the other groups; this persisted after multivariable adjustment for covariates, including albumin and skeletal muscle index. In conclusion, the "obesity paradox" appears to be largely driven by subcutaneous adipose tissue, independent of nutrition or skeletal muscle.