Total energy expenditure in children with obstructive sleep apnoea syndrome.

Childhood obstructive sleep apnoea syndrome (OSAS) acts as a check on growth and nutritional status. An increase in sleeping energy expenditure has been proposed as a possible mechanism, but to date, no studies have determined whether energy requirements (total energy expenditure; TEE) are raised in OSAS. The aim of this study was to test the hypothesis that OSAS is associated with increased TEE. Eleven children (mean+/-SD 5.8+/-2.2 yrs of age) with OSAS confirmed by nocturnal polysomnography were each matched with a pair of healthy controls (n=22) of the same age and sex. TEE was measured using the doubly-labelled water method in all subjects. In 10/11 patients TEE was also measured after adenotonsillectomy and changes in TEE assessed. There was no significant difference in TEE between patients (mean+/-SD 325+/-44 kJ x kg(-1) x day(-1)) and controls (339+/-48 kJ x kg(-1) x day(-1)), nor between patients and age- and sex-specific literature data on TEE, using the doubly-labelled water method. Differences in TEE within patients, before versus after surgery, were minor and not statistically significant. This study does not support the hypothesis that obstructive sleep apnoea syndrome in childhood is associated with increased energy requirements, and suggests that alternative explanations for the effect of this syndrome on growth and energy balance should be sought.