title: Effects of long-term continuous positive airway pressure on body composition and IGF1.
abstract: OBJECTIVE
  To investigate the long-term effects of nasal continuous positive airway pressure (CPAP) ventilation in patients with obstructive sleep apnea syndrome (OSAS) on body composition (BC) and IGF1.
  
  
  METHODS
  Observational study.
  
  
  METHODS
  Seventy-eight (11 females and 67 males) OSAS patients who were compliant with CPAP (age 51+/-1.1 years) participated in the study. We assessed body mass index (BMI), total body mass (TBM), total body fat (TBF; kg) and lean body mass (LBM; kg), abdominal subcutaneous (SC) and visceral (V) fat (cm(2)), and waist circumference (WC; cm) by magnetic resonance imaging, and IGF1 (ng/ml) before and after 7.8+/-1.3 months of CPAP use of an average of 5.9+/-1.2 h.
  
  
  RESULTS
  Women had a higher BMI, WC; TBM, TBF, and more SC fat. Men had a higher LBM and more V fat. CPAP increased WC (+2.8+/-9.6 cm, P=0.02) and LBM (2.2+/-0.5 kg, P=0.006), but not IGF1. In men, CPAP increased BMI (0.5+/-0.2 kg/m(2), P=0.02), WC (1.7+/-6.9 cm, P=0.002), TBM (1.7+/-0.4 kg, P=0.0001), LBM (1.5+/-0.4 kg, P=0.0003), SC fat (12.9+/-5.1 cm(2), P=0.02), and IGF1 (13.6+/-4.2 ng/ml, P=0.002). Compliance with CPAP increased LBM in men aged <60 years, but not in those aged >60 years, and IGF1 increased in men aged 40-60 years only.
  
  
  CONCLUSIONS
  Long-term CPAP increased LBM in both sexes and IGF1 in men, while fat mass remained unchanged, suggesting a sexually dimorphic response of IGF1 to CPAP. The role of the GH axis activity and age to this response is unclear. The metabolic consequences of changes in LBM are still to be determined. Future studies on the effects of CPAP on BC should include LBM as an outcome.
authors.affiliation: Geriatrische Klinik, Kompetenzzentrum Gesundheit und Alter, Rorschacherstrasse 94, 9004 St Gallen, Switzerland. thomas.muenzer@geriatrie-sg.ch
authors.forename: Thomas
authors.initials: T
authors.lastname: Münzer
authors.forename: Andrea
authors.initials: A
authors.lastname: Hegglin
authors.forename: Tobias
authors.initials: T
authors.lastname: Stannek
authors.forename: Otto D
authors.initials: OD
authors.lastname: Schoch
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Korte
authors.forename: Daniel
authors.initials: D
authors.lastname: Büche
authors.forename: Christoph
authors.initials: C
authors.lastname: Schmid
authors.forename: Christoph
authors.initials: C
authors.lastname: Hürny
mesh_terms: D000328:Adult; D000368:Aged; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D050152:Intra-Abdominal Fat / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010349:Patient Compliance; D017286:Polysomnography; D012737:Sex Factors; D020181:Sleep Apnea, Obstructive / Q000097:blood / Q000378:metabolism* / Q000628:therapy*; D055815:Young Adult
chemical_list: D007334:Insulin-Like Growth Factor I