Gender differences in clinical manifestations and polysomnographic findings in Chinese patients with obstructive...

The gender differences in patients with obstructive sleep apnea (OSA) are not fully understood so far, as previous studies had conflicting results. No reports have addressed the differences in OSA between Chinese men and women. Therefore, the purpose of this study was to investigate the clinical and polysomnographic differences between Chinese men and women with OSA.

This case-paired control retrospective study included 580 consecutive Chinese patients (290 males and 290 females) newly diagnosed as OSA by overnight polysomnography from the Sleep Disorders Center of Tangdu Hospital affiliated to the Fourth Military Medical University of China. Demographic, clinical, and polysomnographic data of men and women with OSA were compared. Order logistic regression analysis was used to determine the risk factors for OSA severity.

Male and female patients had similar age (57.3 ± 9.2 vs. 58.2 ± 8.9, p > 0.05) and body mass index (BMI) (25.4 ± 3.4 vs. 25.5 ± 3.9, p > 0.05). Women more commonly presented with insomnia (70.3% vs. 40.3%, p < 0.001), poor sleep quality (58.3% vs. 40.7%, p < 0.001), and headache on awakening (23.1% vs. 13.8%, p < 0.01) than men, while men more frequently reported habitual snoring (69.0% vs. 52.1%, p < 0.001) compared with women. The apnea-hypopnea index (AHI) during total sleep time and non-rapid eye movement sleep was higher in men compared with women (25.8 ± 20.4 vs. 19.3 ± 16.8; 22.0 ± 18.2 vs. 15.1 ± 15.4; p < 0.001, respectively), whereas AHI during rapid eye movement sleep was higher in women than in men (4.2 ± 3.6 vs. 3.7 ± 4.3, p < 0.01). Compared with men, women had lower sleep efficiency (75.4 ± 15.7 vs. 78.1 ± 15.5, p < 0.05), longer REM latency (128.9 ± 88.6 vs. 107.7 ± 72.4, p < 0.01), and greater wakefulness after sleep onset (WASO) (98.3 ± 70.2 vs. 88.0 ± 70.3, p < 0.05). No significant differences in the lowest oxygen desaturation and oxygen desaturation index (ODI) were observed between men and women (80.4 ± 10.8 vs. 80.8 ± 9.0; 17.0 ± 20.9 vs. 13.1 ± 16.5; p > 0.05, respectively). In addition, ordinal logistic regression analysis identified neck circumference as an independent risk factor for OSA severity in male patients (OR, 1.161; 95% CI, 1.020-1.325; p < 0.05) and in female patients (OR, 1.163; 95% CI, 1.013-1.338; p < 0.05).

Overall, female patients had less severe OSA when compared with male patients. The female patients more commonly reported "atypical" OSA symptoms, while male patients more frequently reported "typical" OSA symptoms. In clinical practices, physicians dealing with OSA need to take the gender disparity into consideration for more precise diagnosis and treatment, as women may be atypically symptomatic at a less severe OSA.