Gender-related changes of the epicardial fat thickness and leptin in obstructive sleep apnea

Epicardial fat thickness (EFT), an indicator of visceral obesity, and leptin are 2 novel markers for studying the obstructive sleep apnea (OSA) population. This study aimed to investigate the effects of gender on leptin levels and EFT, and the relation with OSA severity.

A total of 149 patients with OSA (female/male 55/94 and mean age 50.8 ± 9.2 years) and 50 control patients (female/male 24/26 and mean age 48.9 ± 8.8 years) were included in the study. The study population was divided into 4 groups according to apnea/hypopnea index (AHI) as control (AHI <5), the mild OSA (AHI 5-14), the moderate OSA (AHI 15-29), and the severe OSA (AHI ≥30). EFT was obtained from parasternal long-axis and parasternal short-axis echocardiographic images.

Leptin levels among females were significantly higher than among males (10.5 [7.8] vs. 5.4 [4.5] ng/mL, P = 0.001, respectively). Among women, leptin levels were significantly higher in the severe OSA group compared to the control group (9.8 [9.0] vs. 15.5 [10.1] ng/mL, P = 0.05, respectively). Conversely, no relation was observed between OSA severity and the leptin levels among men. EFT was not significantly different between the 2 genders (P > 0.05). EFT was thicker in the severe OSA group than in the control and mild OSA groups among women, whereas EFT was not changed according to OSA severity among males (P > 0.05).

Leptin and EFT may be a valuable parameter in the evaluation of OSA severity in women than in men.