Obstructive sleep apnoea in Singapore: polysomnography data from a tertiary sleep disorders unit

Li Ling Lim, Kwang Wei Tham, Stephanie M C Fook-Chong
Annals of the Academy of Medicine, Singapore 2008, 37 (8): 629-36

INTRODUCTION: Comprehensive sleep architecture and respiratory event data in local patients with suspected obstructive sleep apnoea (OSA) from overnight polysomnography (PSG), the gold standard for the evaluation of sleep-related breathing disorders, are not widely available. We present 1 year retrospective PSG data with the objective of describing PSG characteristics of patients evaluated for OSA in Singapore.

MATERIALS AND METHODS: PSG data of patients evaluated for OSA in 1 year (January through December 2005) in the Sleep Laboratory of a public tertiary hospital were retrospectively reviewed.

RESULTS: Five hundred and eighty-four diagnostic PSG studies were performed in patients with symptoms suggestive of sleep-disordered breathing, including snoring, excessive daytime sleepiness, unrefreshing sleep, or recurrent unexplained awakenings. There were 449 male patients (76.9%) and 135 female patients (23.1%), with a mean age of 47.5 years (SD 12.7). Men were on average younger than women, 46.1 years versus 52.0 years (P <0.0005). The mean body mass index (BMI) was 27.9 (SD 6.7), with no significant difference between genders. An association was shown between apnoea-hypopnoea index (AHI) and BMI (Pearson correlation index r = 0.362). Men had overall significantly higher AHI (16.5 vs 9), shorter mean sleep onset latency (11 vs 16.5 minutes), more light sleep (65.5% vs 58.9%), less deep sleep (17.7% vs 23%), and more respiratory event related arousals per hour of sleep (11.6 vs 5.1) (P <0.0005). Severity was classified: AHI <5 ("Normal Overall AHI") (28.3%), AHI 5-15 ("Mild") (22.3%), AHI >15-30 ("Moderate") (18.3%), AHI >30 ("Severe") (31.2%). There was no significant age difference among the 4 groups. More severe OSA patients were significantly heavier, and had more light sleep, less deep sleep, less REM sleep, more respiratory event related arousals and lower levels of oxygen desaturation.

CONCLUSION: OSA is predominant in middle-aged, overweight Singapore males and much less common in females who tend to be older. A majority of patients have moderate to severe OSA, which significantly disturbs normal sleep architecture. The relatively lower BMI compared to Caucasian OSA populations may be related to local craniofacial characteristics and/or higher percentage of body fat for BMI which has been described in Singaporeans.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"