title: Nocturnal sweating--a common symptom of obstructive sleep apnoea: the Icelandic sleep apnoea cohort.
abstract: OBJECTIVE
  To estimate the prevalence and characteristics of frequent nocturnal sweating in obstructive sleep apnoea (OSA) patients compared with the general population and evaluate the possible changes with positive airway pressure (PAP) treatment. Nocturnal sweating can be very bothersome to the patient and bed partner.
  
  
  METHODS
  Case-control and longitudinal cohort study.
  
  
  METHODS
  Landspitali-The National University Hospital, Iceland.
  
  
  METHODS
  The Icelandic Sleep Apnea Cohort consisted of 822 untreated patients with OSA, referred for treatment with PAP. Of these, 700 patients were also assessed at a 2-year follow-up. The control group consisted of 703 randomly selected subjects from the general population.
  
  
  METHODS
  PAP therapy in the OSA cohort.
  
  
  METHODS
  Subjective reporting of nocturnal sweating on a frequency scale of 1-5: (1) never or very seldom, (2) less than once a week, (3) once to twice a week, (4) 3-5 times a week and (5) every night or almost every night. Full PAP treatment was defined objectively as the use for ≥4 h/day and ≥5 days/week.
  
  
  RESULTS
  Frequent nocturnal sweating (≥3× a week) was reported by 30.6% of male and 33.3% of female OSA patients compared with 9.3% of men and 12.4% of women in the general population (p<0.001). This difference remained significant after adjustment for demographic factors. Nocturnal sweating was related to younger age, cardiovascular disease, hypertension, sleepiness and insomnia symptoms. The prevalence of frequent nocturnal sweating decreased with full PAP treatment (from 33.2% to 11.5%, p<0.003 compared with the change in non-users).
  
  
  CONCLUSIONS
  The prevalence of frequent nocturnal sweating was threefold higher in untreated OSA patients than in the general population and decreased to general population levels with successful PAP therapy. Practitioners should consider the possibility of OSA in their patients who complain of nocturnal sweating.
authors.affiliation: Department of Respiratory Medicine and Sleep, Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland.
authors.forename: Erna Sif
authors.initials: ES
authors.lastname: Arnardottir
authors.forename: Christer
authors.initials: C
authors.lastname: Janson
authors.forename: Erla
authors.initials: E
authors.lastname: Bjornsdottir
authors.forename: Bryndis
authors.initials: B
authors.lastname: Benediktsdottir
authors.forename: Sigurdur
authors.initials: S
authors.lastname: Juliusson
authors.forename: Samuel T
authors.initials: ST
authors.lastname: Kuna
authors.forename: Allan I
authors.initials: AI
authors.lastname: Pack
authors.forename: Thorarinn
authors.initials: T
authors.lastname: Gislason
keywords: Hypertension < Cardiology