Obstructive sleep apnea syndrome in obese Singapore children

We set out to determine the prevalence of obstructive sleep apnea syndrome (OSAS) among obese Singapore school children and identify risk factors for OSAS. This study was designed as a prospective study in three phases. Paren ts completed a questionnaire with regards to sleep and daytime symptoms in Phase 1. Children suspected to have OSAS based on the questionnaire and all with a percent ideal body weight (IBW) greater than or equal to 180 were c alled for clinic visits in Phase 2. All whose percent IBW greater than or e qual to 180 and those in whom the physicians strongly suspected OSAS were s ubjected to a polysomnogram in phase 3. The children were recruited from th e School Health Nutritional Clinic for obese children. The investigations w ere carried out at Tan Tock Seng Hospital. In all, 3,671 children were screened with the questionnaire. Of these, 146 were selected to undergo polysomnography. Twenty-six had abnormal sleep stu dies with apnea/hypoxia indices (AHIs) > 5/hr. The significant clinical fea ture which correlated with OSAS was sleep sitting up (P = 0.005). The risk is higher in morbidly obese (IBW greater than or equal to 180), with a prev alence of 13.3% (8/60), than in less obese children (IBW <180). One in eigh t (12.556) of these children was asymptomatic and would have been missed ba sed on the questionnaire. Presence of adenotonsillar hypertrophy led to inc reased risk of OSAS. The prevalence of OSAS was 0.7% (26/3,671) among the obese schoolchildren i n Singapore, which is similar to the prevalence reported by others. Using d iscriminant analysis, the estimated prevalence increased to 5.7%. In the mo rbidly obese (IBW greater than or equal to 180), the prevalence rate is hig her at 13.3%. (C) 2000 Wiley-Liss. Inc.