A community study of sleep-disordered breathing in middle-aged chinese women in Hong Kong - Prevalence and gender differences

Study objectives: To investigate the prevalence of sleep-disordered breathing (SDB) and obstructive sleep apnea syndrome (OSAS) in community-based, middle-aged Chinese women, and to compare the differences between gender with a similar study in men. Design: A cross-sectional study conducted in Hong Kong from 1998 to 2000. Setting: Sleep questionnaires were distributed to women. (30 to 60 years old) in three offices and two community centers. All were invited to undergo full polysomnography in a sleep laboratory. Participants: Questionnaires were distributed to 1,532 women, and 854 questionnaires were returned. Polysomnography was conducted in 106 respondents. Measurements and results: Conservative estimated prevalence of SDB (apnea-hypopnea index [AHI] greater than or equal to 5) and OSAS (AHI greater than or equal to 5 plus excessive daytime sleepiness [EDS]) were 3.7% and 2.1%, respectively. Age-specific prevalence of OSAS was 0.5%, 2.2%, and 6.1% in the 30- to 39-year-old, 40- to 49-year-old, and 50- to 60-year-old age groups, respectively. Stepwise multiple logistic regression analysis identified body mass index (BMI) and age as predictors of SDB. Compared to Chinese men, the prevalence of SDB and OSAS in women was lower, but the gender difference decreased with age. The AHI of affected women was also significantly lower despite comparable BMI. Compared to men, women with SDB had same degree of self-reported snoring and a similar degree of EDS despite the lower AHI. Conclusions: This study demonstrated an estimated prevalence of OSAS at 2.1% among middle-aged Chinese women in Hong Kong, with a 12-fold rise from the fourth to the sixth decade of life. BMI and age were significant independent predictors of SDB. Compared to men, women with SDB had lower AHIs, despite similar BMIs.