A community study of sleep-disordered breathing in middle-aged Chinese menin Hong Kong

Background: Sleep-disordered breathing (SDB) in Asian populations is being increasingly recognized. This study investigated the prevalence of SDB in C hinese middle-aged office-based male workers in Hong Kong. Methods: Sleep questionnaires were distributed to 1,542 men (age range, 30 to 60 years), and 784 questionnaires were returned. Subsequently, full poly somnographic (PSG) examinations were conducted in 153 questionnaire respond ents. Subjects with an apnea-hypopnea index (AHI) greater than or equal to 5 were recalled for clinical assessment. Results: Questionnaire respondents were similar in age and body mass index (BMI) to the general community in the target age range and gender. Habitual snoring was reported by 23% of this cohort and was associated with excessi ve daytime sleepiness (EDS), hypertension, witnessed abnormal breathing pat tern, BMI, and leg movements during sleep. Allowing for subject bias in und ergoing PSG, the estimated prevalence of SDB and obstructive sleep apnea sy ndrome (OSAS) (defined as SDB in the presence of EDS) at various AHI cutoff threshold values was 8.8% and 4.1% (AHI greater than or equal to 5), 6.3% and 3.2% (AHI greater than or equal to 10), and 5.3% and 3.1% (AHI greater than or equal to 15). Multiple stepwise logistic regression analysis identi fied BMI, habitual snoring, time taken to fall asleep, and age as predictor s of SDB at AHI greater than or equal to 5. Analysis of anthropometric para meters indicated that the relative risk of OSAS attributable to obesity was less than in white subjects. Conclusion: This community-based study of sleep apnea among middle-aged men in Hong Kong using full PSG demonstrated an estimated prevalence of OSAS ( AHI greater than or equal to 5 and EDS) at 4.1%. Increasing BMI and age wer e associated with SDB, although factors other than adiposity may also have an important pathogenic role in OSA in Chinese subjects.