title: Natural history of primary snoring in school-aged children: a 4-year follow-up study.
abstract: BACKGROUND
  The objective of this study was to examine the natural history of childhood primary snoring (PS) and to identify predictive clinical symptoms and risk factors associated with PS progression to obstructive sleep apnea (OSA).
  
  
  METHODS
  Children aged 6 to 13 years old who received a diagnosis of PS in our previous community-based OSA prevalence study were invited to undergo repeat polysomnography (PSG) at 4-year follow-up. Subjects with an obstructive apnea hypopnea index (OAHI) ≥ 1 were classified as having OSA at follow-up.
  
  
  RESULTS
  Seventy children (60% boys) with a mean age of 14.7 ± 1.8 years were analyzed in this follow-up study. The mean duration of follow-up was 4.6 ± 0.6 years. At follow-up, 26 subjects (37.1%) progressed to OSA, of whom five (7.1%) had moderate to severe disease (OAHI ≥ 5). Twenty-two (31.4%) remained at PS, and 18 (25.7%) had complete resolution of their snoring with normal PSG. Persistent snoring had a positive predictive value of 47.7% and a negative predictive value of 86.4% for progression from PS to OSA. Multivariate logistic regression analysis showed that persistent overweight/obesity was a significant risk factor for the development of OSA at follow-up, with an OR of 7.95 (95% CI, 1.43-44.09).
  
  
  CONCLUSIONS
  More than one-third of school-aged children with PS progressed to OSA over a 4-year period, although only 7.1% developed moderate to severe disease. Weight control may be an important component in the management of PS because obesity was found to be a significant risk factor for PS progression.
authors.affiliation: Department of Pediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong. Electronic address: albertmli@cuhk.edu.hk.
authors.forename: Albert M
authors.initials: AM
authors.lastname: Li
authors.affiliation: Department of Pediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Yin
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Pediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Chun T
authors.initials: CT
authors.lastname: Au
authors.affiliation: Department of Otorhinolaryngology - Head and Neck Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Dennis L Y
authors.initials: DLY
authors.lastname: Lee
authors.affiliation: Department of Psychiatry, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Crover
authors.initials: C
authors.lastname: Ho
authors.affiliation: Department of Psychiatry, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Yun K
authors.initials: YK
authors.lastname: Wing
mesh_terms: D000293:Adolescent; D002648:Child; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D050177:Overweight / Q000453:epidemiology; D017286:Polysomnography; D011237:Predictive Value of Tests; D012307:Risk Factors; D012891:Sleep Apnea Syndromes; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology*; D012913:Snoring / Q000453:epidemiology*