Sex-specific associations of obesity with exercise capacity and diastolic function in Koreans

Background and aims: Women with obesity are highly predominant among patients with heart failure with preserved ejection fraction (HFpEF). We aimed to elucidate sex-specific associations of obesity with exercise capacity and diastolic function. Methods and results: Healthy individuals without known cardiovascular diseases undergoing cardiopulmonary exercise test and echocardiography (n = 736) were included and categorized into 4 groups according to their sex and obesity. Exercise capacity was lower in women than men. Obesity was associated with a lower exercise capacity in women (23.5 ± 7.3 vs. 21.3 ± 5.4 ml/kg/min, p < 0.05) but not in men (28.2 ± 7.8 vs. 28.0 ± 6.6 ml/kg/min, p > 0.10). Overall, women had a higher E/e′ than men. Women without obesity had a similar E/e′ to men with obesity (8.2 ± 1.8 vs. 8.4 ± 2.1, p > 0.10), and women with obesity had the highest E/e′. Among 5 risk factors (aging, obesity, elevated blood pressure, elevated heart rate, and elevated fasting glucose), obesity was a significant determinant of exercise intolerance in women but not men. Furthermore, obesity was associated with a greater risk of diastolic dysfunction in women than men (women, adjusted odds ratio 4.35 [95% confidence interval 2.44–7.74]; men, adjusted odds ratio 2.91 [95% confidence interval 1.42–5.95]). Conclusion: Obesity had a more deleterious effect on exercise capacity and diastolic function in women than men, even in a healthy cohort. These subclinical changes might contribute to the development of a female predominance among HFpEF patients, particularly among individuals with obesity.