OBJECTIVE:The relationship between weight status, adenotonsillar hypertrophy and obstructive sleep apnea (OSA) in children has not yet been well studied. As the sleep parameters may show a disparity in different weight statuses, this study examined the relationship between the data of over-night polysomnography and different weight statuses, as well as the impact of adenotonsillar hypertrophy on children with OSA. METHODS: Children with sleep disturbances were recruited from our clinics. Standard physical examinations, history taking, lateral neck roentgenography, and full-night polysomnography were obtained. Children were divided into four groups based on the age-and gender-corrected body mass index (BMI): underweight, normal weight, overweight and obese. An adenoidal/ nasopharyngeal ratio of more than 0.67 was considered adenoidal hypertrophy. Tonsillar hypertrophy was defined as having Grade III tonsils or above. RESULTS: From July 2006 to January 2009, 197 children were included in this study. Obese children had a significantly higher apnea --hypopnea index (AHI), obstructive apnea index and lower minimum oxygen saturation (MinSaO 2 ) than those of the other groups. Underweight children had the second highest AHI. A negative correlation was also found between BMI z scores and MinSaO 2 (r ¼ À0.194; P ¼ 0.007). Children with tonsillar hypertrophy (P ¼ 0.001) were associated with a higher risk of having OSA. The risk of having OSA was significantly higher in obese children (P ¼ 0.001) and underweight children (P ¼ 0.043) than in those with a normal weight. CONCLUSION: Obesity, underweight status and tonsillar hypertrophy are associated with children having OSA, and obese children have a significantly higher risk than children with underweight status.

Although sleep parameters improved in all weight statuses, obese children had a higher incidence of residual OSA postoperatively. About half of the underweight children shifted to normal weight status after T&A.