Effects of long-term continuous positive airway pressure on body composition and IGF1.
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.
Münzer
Thomas
T
Geriatrische Klinik, Kompetenzzentrum Gesundheit und Alter, Rorschacherstrasse 94, 9004 St Gallen, Switzerland. thomas.muenzer@geriatrie-sg.ch
Hegglin
Andrea
A
Stannek
Tobias
T
Schoch
Otto D
OD
Korte
Wolfgang
W
Büche
Daniel
D
Schmid
Christoph
C
Hürny
Christoph
C
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
D007334:Insulin-Like Growth Factor I