Search

Background: This study assessed the prevalence of obstructive sleep apnea syndrome (OSAS) and CPAP adherence in the elderly Chinese in Hong Kong., Methods: We conducted a sleep questionnaire survey among the elders aged ≥60 years in the community centres followed by level 3 home sleep study (Embletta). Subjects with an apnea hypopnea index (AHI) ≥ 15/hr alone and those with AHI ≥ 5/hr plus either cardiovascular risk factors or Epworth Sleepiness Score (ESS) ≥ 10 were offered CPAP treatment., Results: Altogether 819 subjects were interviewed with mean (SD) age of 73.9 (7.5) years, BMI 24.2 (3.6) kg/m2, neck circumference 34.9 (3.4) cm and ESS 6.6 (5.2). Daytime sleepiness was reported by 72.4%, snoring loudly 5.1% and witnessed apnea 4%. Among 234 subjects who underwent home sleep study, 156 (66.7%), 102 (43.6%), 70 (29.9%) and 45 (19.2%) had AHI ≥ 5, ≥ 10, ≥ 15 and ≥ 20/hr respectively, with the prevalence increasing with age and BMI. In the sample, 149 subjects (63.7%) were classified as having OSAS, as defined by an AHI ≥ 5/hr with associated symptoms, involving 81 men (74.3%) and 68 women (54.4%). Neck circumference and snoring frequency were the only positive independent factors associated with the AHI and the diagnosis of OSAS. Among 141 subjects who were offered CPAP treatment, 30 accepted CPAP prescription with improvement of ESS and cognitive function over 12 months with CPAP usage of 4.2 (2.2) h/night., Conclusion: This study showed a high prevalence of OSAS among the community elders in Hong Kong. Home CPAP acceptance was low but there was significant improvement of subjective sleepiness and cognitive function among those on CPAP treatment.

Objective: To examine the long-term effect of CPAP on carotid artery intima-media thickness (IMT) in patients with Obstructive sleep apnea syndrome(OSAS)., Methods: A prospective observational study over 12 months at a teaching hospital on 50 patients newly diagnosed with OSAS who received CPAP or conservative treatment (CT). Carotid IMT was assessed with B-mode Doppler ultrasound from both carotid arteries using images of the far wall of the distal 10 mm of the common carotid arteries at baseline, 6 months and 12 months. MEASUREMENTS AND RESULTS [MEAN (SE)]: Altogether 28 and 22 patients received CPAP and CT respectively without significant differences in age 48.8(1.8) vs 50.5(2.0)yrs, BMI 28.2(0.7) vs 28.0(1.2)kg/m2, ESS 13.1(0.7) vs 12.7(0.6), AHI 38(3) vs 39(3)/hr, arousal index 29(2) vs 29(2)/hr, minimum SaO2 75(2) vs 77(2)% and existing co-morbidities. CPAP usage was 4.6(0.3) and 4.7(0.4)hrs/night over 6 months and 1 year respectively. Carotid artery IMT at baseline, 6 months, and 12 months were 758(30), 721(20), and 705(20)micron for the CPAP group versus 760(30), 770(30), and 778(30)micron respectively for the CT group, p = 0.002. Among those free of cardiovascular disease(n = 24), the carotid artery IMT at baseline, 6 months and 12 months were 722(40), 691(40), and 659(30)micron for the CPAP group (n = 12) with usage 4.5(0.7) and 4.7(0.7) hrs/night over 6 months and 12 months whereas the IMT data for the CT group(n = 12) were 660(20), 685(10), and 690(20)micron respectively, p = 0.006., Conclusions: Reduction of carotid artery IMT occurred mostly in the first 6 months and was sustained at 12 months in patients with reasonable CPAP compliance.

Objective and Background: Sleep-disordered breathing may predispose drivers to road traffic accidents. However, CPAP acceptance and compliance among commercial bus drivers is unknown., Methods: We conducted a sleep questionnaire survey at a bus depot followed by random selection of bus drivers for home sleep study with the mesam iv device. Bus drivers with a respiratory disturbance index (RDI)>or=5/h were invited to have hospital-based polysomnography for confirmation followed by nasal CPAP treatment., Results: Out of 1477 bus drivers, 1016 (971 men) were interviewed with mean (SD) age of 45.3 (7.5) years, BMI 24.9 (3.6) kg/m2, neck circumference 38.9 (3.1) cm and Epworth sleepiness score 4.8 (4.0). Sleepiness at work was reported by 60.9%, snoring>or=3 nights per week 23.9%, witnessed apnoea 3.7% and having fallen asleep during driving by 24%. Among 211 who underwent home sleep study, 85 (40.3%), 55 (26.1%) and 37 (17.5%) had RDI>or=5, >or=10 and >or=15/h respectively. BMI, snoring intensity and neck circumference were the positive independent factors associated with the RDI. Of the 25 drivers who attended polysomnography, nine accepted CPAP prescription with improvement of Epworth sleepiness score, trail B and digit span after 3 months with CPAP usage of 4.5 (1.3) h/night., Conclusion: The estimated minimum prevalence rates of sleep-disordered breathing and obstructive sleep apnoea syndrome were 8.4% and 5.4% respectively among the bus drivers. Home CPAP acceptance was low among bus drivers with sleep apnoea but there was significant improvement of subjective sleepiness and cognitive function among those on CPAP treatment.