Obstructive sleep apnea in children: relative contributions of body mass index and adenotonsillar hypertrophy.

BACKGROUND: The obesity epidemic has prompted remarkable changes in the proportion of obese children who are referred for habitual snoring. However, the contribution of obesity to adenotonsillar hypertrophy remains undefined. METHODS: In our study, 206 nonobese habitually snoring children with polysomnographically diagnosed obstructive sleep apnea (OSA) were matched for age, gender, ethnicity, and obstructive apnea-hypopnea index (OAHI) to 206 obese children. Size estimates of tonsils and adenoids, and Mallampati class scores were obtained, and allowed for the assessment of potential relationships between anatomic factors and obesity in pediatric OSA. RESULTS: The mean OAHI for the two groups was approximately 10.0 episodes/h total sleep time. There was a modest association between adenotonsillar size and OAHI in nonobese children (r = 0.22; p < 0.001) but not in obese children. The mean (+/- SEM) adenotonsillar size was larger in nonobese children (3.85 +/- 0.16 vs 3.01 +/- 0.14, respectively; p < 0.0001), and conversely Mallampati class scores were significantly higher in obese children (p < 0.0001). CONCLUSION: The magnitude of adenotonsillar hypertrophy required for any given magnitude of OAHI is more likely to be smaller in obese children compared to nonobese children. Increased Mallampati scores in obese children suggest that soft-tissue changes and potentially fat deposition in the upper airway may play a significant role in the global differences in tonsillar and adenoidal size among obese and nonobese children with OSA.

Nocturnal body position in sleeping children with and without obstructive sleep apnea.

OBJECTIVES: To assess whether body position during sleep differs among children with obstructive sleep apnea (OSAS) and controls, and to assess the effects of body position, obesity, and tonsillar size on respiratory disturbance. Four hundred and thirty consecutive children with polysomnographically demonstrated OSAS. And 185 age-, gender-, and ethnically matched children (Controls) were compared. The effect of sleep body position on respiratory disturbance was examined in OSAS, and also in relation to obesity and tonsillar size. Children with OSAS spent more time in the supine position than Controls (P<0.01), with less time spent in the side position (P<0.005). Obstructive apnea and hypopnea index (AHI) was similar in the three sleep-related positions, but apnea index (AI) was significantly greater (4.6 +/- 0.7/hr TST) in the supine position than in the side position (2.7 +/- 0.3/hr TST; P<0.001) or prone position (3.3 +/- 0.5/hr TST; P<0.01). Tonsillar size was not a contributing factor to positional differences in AI or AHI. Obese OSAS children had increased prone position (20.4 +/- 2.0%TST vs. non-obese: 10.9 +/- 2.5%TST; P<0.05), and displayed increased AHI and AI while supine. Non-obese OSAS increased AHI in prone or side positions compared to supine (P<0.01), with no significant differences in position-dependent AI. Children with OSAS spend more time sleeping supine and less time on the side. Obese children with OSAS are more likely to sleep prone, suggesting that this position may promote upper airway patency in the presence of obesity. Although tonsillar size is not associated with positional differences in breathing, the presence or absence of obesity markedly modifies the effect of body position on respiratory disturbance.