Clinical and polysomnographic characteristics of premenopausal women with obstructive sleep apnea: insights from a clinic-based study

The prevalence and clinical course of obstructive sleep apnea (OSA) differ among women with different reproductive status. OSA is understudied in premenopausal women. We investigated the clinical and polysomnographic characteristics of premenopausal women with OSA and explored the risk factors for and phenotypes or endotypes of OSA. This was a cross-sectional retrospective study. Consecutive women aged ≥ 18 years with suspected OSA and referred for overnight polysomnography were defined by apnea-hypopnea index (AHI): as “OSA” (≥ 15 events/h) and “without OSA” (< 15 events/h). Demographics, anthropometrics, comorbidities, lifestyle habits and sleep study indices of premenopausal women with OSA were compared with those without OSA and postmenopausal counterparts. Independent risk factors for OSA were determined by logistic regression analyses. Compared with postmenopausal women with OSA, premenopausal women with OSA had higher body mass index, more comorbid upper airway abnormality and polycystic ovary syndrome, with the former as an independent risk factor besides obesity. Premenopausal women with OSA had higher sleep efficiency, lower respiratory events-associated arousal index and minimum oxygen saturation, shorter hypopnea duration as well as higher rapid eye movement (REM) AHI and more proportions of REM predominant pattern. Premenopausal women with OSA were significantly more complicated with chronic kidney disease and marginally more hyperuricemia as well as glucose metabolism disorders than those without OSA, which was different from postmenopausal counterparts. Significant differences are found between premenopausal and postmenopausal women with OSA in risk factors, comorbidities, clinical and polysomnographic features. In addition to obesity and structural or functional abnormalities of upper airway, high loop gain has been suggested to contribute to airway collapse in premenopausal women with OSA.