Abstract 11392: Sex Differences in Fat Deposition: The Relationship with Exercise Capacity and Symptom Severity in a Case-Control Model in Heart Failure with Preserved Ejection Fraction

Abstract

Introduction: Obesity is prevalent in HFpEF, a syndrome that disproportionality affects women, and is associated with poor exercise tolerance (VO 2 ), reduced quality of life, and greater symptoms. Visceral adipose tissue (VAT), more than general obesity, is related to metabolic and cardiovascular dysfunction common to HFpEF. While fat deposition varies between sexes, these differences and the relation to exercise tolerance remain unclear in HFpEF. Hypothesis: Compared to sex-matched controls, HFpEF patients will demonstrate reduced lean mass, excess VAT, subcutaneous, visceral, and intramuscular fat, and will be associated with reduced VO 2 . Methods: HFpEF females (F) and males (M) (n=78; 37 F/41 M; age 70±9) and non-HFpEF controls (n=50; 30 F/20 M; age 65±5) prospectively underwent body composition measurement via dual-energy x-ray absorptiometry and magnetic resonance imaging (MRI) and cardiopulmonary exercise testing for measurement of peak oxygen consumption (peak VO 2 ). Muscle quality calculated as peak Watts (W) achieved divided by MRI thigh lean mass. Results: HFpEF had greater VAT, subcutaneous (SAT) and intramuscular (IMAT), and poorer muscle quality than controls (all p<0.01). Exercise performance was lower in HFpEF (peak VO 2 : 14±4 vs. 22±6; peak W: 69±29 vs. 116±34; both p<0.01). HFpEF demonstrated increased odds for VAT (OR: 2.02, 95% CI: 1.22-3.37), SAT (OR: 2.05, 95% CI: 1.20-3.49), and IMAT (OR: 2.04, 95% CI: 1.35-3.39) (all p<0.01). Sex-stratification revealed increased odds of excess VAT in HFpEF females (OR: 2.76, 95% CI: 1.16-7.72, p=0.03), SAT in HFpEF males (OR: 3.64, 95% CI: 1.10-12.07, p=0.03), and IMAT in HFpEF females (OR: 2.38, 95%CI: 1.10-5.29, p=0.03) with a trend in males (OR: 1.67, 95%CI: 0.97-2.86, p=0.06). Impaired VO 2 was associated with all AT depots as a combined cohort and among controls (all p<0.01) and linked to poor muscle quality individually for men and women in HFpEF and controls (all p<0.01). Conclusion: HFpEF patients have significantly altered body composition profiles and reduced exercise tolerance compared to controls. Sex differences in regional fat deposition impact peak VO 2 and may serve a distinct role in the pathophysiology of HFpEF.