2009

2009 Jun - Evaluation of Subjective Sleepiness and prevalence of Sleep-Disordered Breathing

Dr Ng So Shan, Department of Medicine & Therapeutics, Prince of Wales Hospital

Introduction and Objectives
Obstructive sleep apnoea syndrome (OSAS) is a common form of sleep-disordered breathing (SDB) characterized by repetitive episodes of cessation of breathing during sleep due to upper airway collapse. OSAS is equally common among the middle-aged male Caucasian and Hong Kong (HK) Chinese populations, with a prevalence of at least 4%. However, the prevalence of OSAS in the elderly in Southeast Asia is unknown. We aim to evaluate the prevalence rates of SDB, OSAS and other sleep disturbances, such as restless leg syndrome (RLS), in the elderly subjects living in the community in HK.

Methods
We randomly interviewed 540 elderly subjects from the community elderly centres using the Epworth Sleepiness Scale (ESS) and the Sleep & Health Questionnaire (SHQ). One hundred and nine subjects were randomly selected to have partial home study with a portable sleep study device (ApneaLink sleep screener, ResMed, Poway, Calif).

Results
The mean (SD) age, BMI and ESS of these 540 subjects (104 males) were 74.7 +/- 7.2 years, 24.2 +/- 3.7 kg/m2, and 6.55.3 respectively. From the SHQ, daytime sleepiness occurred in 384(71.2%) and was reported as severe by 106 (19.7%). One hundred and three (19.1%) subjects reported sleepiness interfering with their daily task. Sixty six subjects (15.1%) felt their snoring was loud enough to disturb others whereas 14 (2.6%) had witnessed apnoea. Sixty one subjects (11.3%) had symptoms of RLS. Of the 109 subjects who had undergone home sleep study, 67 (61.4%), 36 (33%), 21 (19.2%) and 14 (12.8%) subjects had AHI ≥ 5, ≥ 10, ≥ 15, ≥ 20 per hour of sleep respectively. Forty subjects (36.7%) had AHI ≥ 15 or AHI ≥ 5 with ESS ≥10.

Conclusion
Subjective sleepiness and OSAS are common among elderly Hong Kong Chinese living in the community. Health education and promotion programmes are needed to increase the awareness of OSAS in this population.