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. Design: Observational study. Subjects: Seventy-eight (11 females and 67 males) OSAS patients who were compliant with CPAP (age 51G1.1 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 7.8G1.3 months of CPAP use of an average of 5.9G1.2 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 (C2.8G9.6 cm, PZ0.02) and LBM (2.2G0.5 kg, PZ0.006), but not IGF1. In men, CPAP increased BMI (0.5G0.2 kg/m 2 , PZ0.02), WC (1.7G6.9 cm, PZ0.002), TBM (1.7G0.4 kg, PZ0.0001), LBM (1.5G0.4 kg, PZ0.0003), SC fat (12.9G5.1 cm 2 , PZ0.02), and IGF1 (13.6G4.2 ng/ml, PZ0.002). Compliance with CPAP increased LBM in men aged !60 years, but not in those aged O60 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.

Sleep apnoea and visceral adiposity in middle-aged male and female subjects

“…Two studies showed that CPAP can reduce the amount of visceral fat [7,8]. However, our negative findings are in agreement with two previous studies [4,9]. A possible explanation could be that, in our study, either the duration (2 months) was too short for a significant effect to be observed or that the study did not have enough power to detect such a difference.…”

“…A possible explanation could be that, in our study, either the duration (2 months) was too short for a significant effect to be observed or that the study did not have enough power to detect such a difference. Nonetheless, MÜ NZER et al [9], whose total study sample size was similar to ours, also did not find a significant difference, even after an 8-month CPAP treatment period. Consistent with our findings, two studies reported no improvement in weight in a clinical sample of males and females treated with CPAP after a 1-yr follow-up [29,30].…”

“…This Japanese study included a very small number of nonobese females, which did not allow for an appropriate analysis stratified by sex. Additionally, the very few studies on continuous positive airway pressure (CPAP) effects on body composition are primarily in obese males, and the results are contradictory [4,[7][8][9]]. …”

Effects of 8 weeks of continuous positive airway pressure on abdominal adiposity in obstructive sleep apnoea

“…In the present study, although our patients maintained a stable body weight throughout the trial, there was no accompanying change in visceral fat with CPAP use relative to sham CPAP. In contrast to the studies with positive findings, a more recent nonrandomised observational study by MUNZER et al [9] failed to demonstrate a reduction in subcutaneous or visceral fat after 8 months of CPAP use, where compliance with CPAP averaged 6 h per night. Similar results were also shown in an observational study by VGONTZAS et al [10] in which OSA patients were treated with nasal CPAP for 3 months.…”

“…Some observational studies have shown a reduction [7,8] while others showed no change [3,9,10]. Factors that could contribute to the differences observed include mean CPAP compliance, duration of treatment and OSA severity.…”