Childhood obstructive sleep apnoea

Editor—An important effect is missing in the editorial on childhood obstructive sleep apnoea by Kotagal.¹ The neuropsychological sequelae of this condition were mentioned, but another effect was not—namely, high blood pressure.

This omission is not uncommon as shown by a report on the global burden of hypertension.² Currently, there is good evidence—for example, the report by the Tucson Group³—that childhood obstructive sleep apnoea leads to raised blood pressure. Our unpublished data on childhood obstructive sleep apnoea and 24 hour ambulatory blood pressure show that 18% of children had nocturnal hypertension only. Childhood obstructive sleep apnoea was also associated with blood pressure dysregulation that could lead to lower blood pressure in a subgroup of children. Other cardiovascular consequences such as left ventricular hypertrophy and altered sympathetic activation were also identified. The report from our centre also showed that snoring children without obstructive sleep apnoea had higher blood pressure but not hypertension and decreased arterial distensibility compared with controls.⁴

The study quoted by Kotagal to support the use of comprehensive clinical assessment to diagnose childhood obstructive sleep apnoea included a sample of 41 children. He did not cite a meta-analysis that showed that history and physical assessment alone for the diagnosis of childhood obstructive sleep apnoea in snoring children gave a combined positive predictive value of 55.8% (95% confidence interval 42.1 to 69.9)—that is, not significantly better than chance.⁵ The comprehensive clinical assessment may be useful in a healthy population without the risk factors of regular snoring, observed apnoea, obesity, dysmorphic syndromes, attention-deficit/hyperactivity disorder, or daytime sleepiness. For children with risk factors, sleep polysomnography should be offered.