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

Chest. 2004 Nov;126(5):1467-72. doi: 10.1378/chest.126.5.1467.


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.

Participants and setting: Forty-six obese children from a pediatric obesity clinic and 44 age- and sex-matched normal weight control subjects from local schools.

Interventions: All subjects underwent two consecutive overnight polysomnographic studies. An obstructive apnea index (OAI) >/= 1/h was considered diagnostic of SDB.

Results: The mean age of the children was 11.21 years (SD 2.21). Forty-four obese children and 43 control subjects completed the 2-night study. Based on the criterion of the worst OAI over the 2 nights, 13 subjects were found to have SDB, 12 subjects were primary snorers, and 62 were normal subjects. In all subjects, the sleep efficiency improved and sleep-onset latency was reduced on the second night. While there was a rebound of rapid eye movement sleep with the associated worsening of respiratory indexes (mainly accounted for by an increase in central apneas and hypopneas) evident in normal subjects, there was a significant improvement of respiratory disturbances in the SDB group on the second night. The first-night polysomnography would have correctly identified 84.6% of cases as defined by the criteria of the worst OAI over the 2 nights. All cases missed by the first-night study had only borderline OAI.

Conclusions: The phenomenon of FNE in children was well demonstrated in our study. We proposed that a single-night sleep study is adequate and more cost-effective in assessing for childhood SDB.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Case-Control Studies
  • Child
  • Female
  • Humans
  • Male
  • Obesity / complications
  • Obesity / physiopathology
  • Polysomnography*
  • Severity of Illness Index
  • Sleep Apnea Syndromes / complications
  • Sleep Apnea Syndromes / diagnosis*
  • Sleep Apnea Syndromes / physiopathology
  • Time Factors