title: The impact of weight reduction in the prevention of the progression of obstructive sleep apnea: an explanatory analysis of a 5-year observational follow-up trial.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) is a chronic progressive disease, and it is well-documented that severe OSA is associated with an increased cardiovascular morbidity and mortality. Weight reduction has been shown to improve OSA; however, we need further evidence to determine if it may prevent the progression of OSA in the long term. The aim of our study was to assess the impact of weight change during a 5-year observational follow-up of an original 1-year randomized controlled trial.
  
  
  METHODS
  The participants were divided into the two groups according to the weight change at 5-year follow-up using the 5% weight loss as a cutoff point, which was later referred to as the successful (n = 20) or unsuccessful groups (n = 27). The change in apnea-hypopnea index (AHI) was the main objective outcome variable.
  
  
  RESULTS
  Fifty-seven patients participated in the 5-year follow-up. At 5 years from the baseline, the change in AHI between the groups was significant in the successful group (-3.5 [95% confidence interval {CI}, -6.1 to -0.9]) compared with the unsuccessful group (5.0 [95% CI, 2.0-8.5]) (P = .002). Successful weight reduction achieved an 80% reduction in the incidence of progression of OSA compared to the unsuccessful group (log-rank test, P = .016).
  
  
  CONCLUSIONS
  A moderate but sustained weight reduction can prevent the progression of the disease or even cure mild OSA in obese patients.
authors.affiliation: Oivauni Sleep Clinic, Kuopio, Finland; Institute of Public Health and Clinical Nutrition, Department of Clinical Nutrition, University of Eastern Finland, Finland. Electronic address: henri.tuomilehto@oivauni.fi.
authors.forename: Henri
authors.initials: H
authors.lastname: Tuomilehto
authors.affiliation: Department of Otorhinolaryngology, Kuopio University Hospital, Finland.
authors.forename: Juha
authors.initials: J
authors.lastname: Seppä
authors.affiliation: Institute of Public Health and Clinical Nutrition, Department of Clinical Nutrition, University of Eastern Finland, Finland; Clinical Research Center, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Uusitupa
authors.affiliation: Department of Health Promotion and Chronic Diseases Prevention, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Peltonen
authors.affiliation: Clinical Nutrition and Obesity Center, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Tarja
authors.initials: T
authors.lastname: Martikainen
authors.affiliation: Department of Otorhinolaryngology, Kuopio University Hospital, Finland.
authors.forename: Johanna
authors.initials: J
authors.lastname: Sahlman
authors.affiliation: Department of Respiratory Medicine, Kuopio University Hospital, Finland.
authors.forename: Jouko
authors.initials: J
authors.lastname: Kokkarinen
authors.affiliation: Department of Respiratory Medicine, Kuopio University Hospital, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Randell
authors.affiliation: Department of Otorhinolaryngology, Kuopio University Hospital, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Pukkila
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Finland.
authors.forename: Esko
authors.initials: E
authors.lastname: Vanninen
authors.affiliation: Center for Vascular Prevention, Danube-University Krems, Krems, Austria; South Ostrobothnia Central Hospital, Seinäjoki, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Tuomilehto
authors.affiliation: Clinical Research Center, Kuopio University Hospital, Kuopio, Finland; Department of Medicine, Division of Internal Medicine, University of Helsinki, Helsinki, Finland.
authors.forename: Helena
authors.initials: H
authors.lastname: Gylling
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018450:Disease Progression; D005500:Follow-Up Studies; D040242:Risk Reduction Behavior; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000517:prevention & control; D015431:Weight Loss; D061217:Weight Reduction Programs
keywords: Follow-up; Long term; Obstructive sleep apnea; Prevention; Progression; Sleep-disordered breathing; Weight loss