Is a 2-night polysomnographic study necessary in childhood sleep-related disordered breathing?

Background And Objectives: There are limited data on the night-to-night variability of childhood sleep-related disordered breathing (SDB). We aim to assess for the presence of first-night effect (FNE) and to examine whether a single-night sleep study is adequate in the assessment of childhood SDB.

Design: In a case-control study investigating whether obesity is a risk factor for childhood SDB, the night-to-night variability of sleep and respiratory variables were studied.

The prevalence of narcolepsy among Chinese in Hong Kong.

Narcolepsy is a lifelong, crippling sleep disorder. Although the discovery of the hypocretin system has been a breakthough in genetics, the epidemiological aspects of narcolepsy remain elusive. Ethnic predisposition was suggested to partially account for the 2,500-fold difference in the reported prevalence rates of narcolepsy between Japanese (0.