title: Prevalence of new-onset insomnia in patients with obstructive sleep apnoea syndrome treated with nocturnal ventilatory support.
abstract: BACKGROUND
  New-onset insomnia (NOI) associated with nocturnal ventilatory support (NVS) is becoming a reality in clinical practice; however there is a lack of data about its prevalence. Our aim was to determine the prevalence of NOI in patients with obstructive sleep apnoea syndrome (OSAS) under NVS and its associated risk factors.
  
  
  METHODS
  Descriptive cross-sectional study of 80 patients with OSAS under NVS. We compared two groups, with and without NOI, considering demographic characteristics, disease features, and personality. Patients under anxiolytic and/or antidepressant medication, with a weight loss of 10% or greater, and with restless legs symptoms were excluded.
  
  
  RESULTS
  Median age of patients was 60.0 (interquartile range (IQR) 10.0) years; 82.5% were male. Median initial Epworth Sleepiness Scale (ESS) and apnoea-hypopnoea index (AHI) were 12.5 (IQR 9.0) and 44.1 (IQR 22.4)/hr, respectively. The majority of patients (91.3%) were under auto-adjusting positive airway pressure (APAP). Insomnia at baseline was present in 30% of patients (n=24). Prevalence of NOI was 21.4% (12/56). Initial and/or intermediate insomnia were the most frequent subtypes (n=11). We found a statistically significant negative relation between NOI and pressure on 90% night-time (P(90)) (p=0.040).
  
  
  CONCLUSIONS
  OSAS patients under NVS presented a high prevalence of NOI. Patients with NOI presented lower levels of pressure using NVS, compared to the others.
authors: Serviço de Pneumologia, Hospital de São João, Porto, Portugal. patmota@net.sapo.pt
authors: P
authors: P
authors: Caetano Mota
authors: S
authors: S
authors: Morais Cardoso
authors: M
authors: M
authors: Drummond
authors: A C
authors: AC
authors: Santos
authors: J
authors: J
authors: Almeida
authors: J C
authors: JC
authors: Winck
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012121:Respiration, Artificial / Q000009:adverse effects* / Q000379:methods; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000628:therapy*; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology* / Q000209:etiology*; D011795:Surveys and Questionnaires