Impact of treatment with continuous positive airway pressure (CPAP) on weight in obstructive sleep apnea.

Study Objective: To determine the impact of continuous positive airway pressure (CPAP) on weight change in persons with obstructive sleep apnea (OSA). Design, Setting, and Participants: The Apnea Positive Pressure Long-term Efficacy Study (APPLES) was a 6-month, randomized, double-blinded sham-controlled multicenter clinical trial conducted at 5 sites in the United States. Of 1,105 participants with an apnea hypopnea index >= 10 events/hour initially randomized, 812 had body weight measured at baseline and after 6 months of study. Intervention: CPAP or Sham CPAP. Measurements: Body weight, height, hours of CPAP or Sham CPAP use, Epworth Sleepiness Scale score. Results: Participants randomized to CPAP gained 0.35 +/- 5.01 kg, whereas those on Sham CPAP lost 0.70 +/- 4.03 kg (mean +/- SD, p = 0.001). Amount of weight gain with CPAP was related to hours of device adherence, with each hour per night of use predicting a 0.42 kg increase in weight. This association was not noted in the Sham CPAP group. CPAP participants who used their device >= 4 h per night on >= 70% of nights gained the most weight over 6 months in comparison to non-adherent CPAP participants (1.0 +/- 5.3 vs. -0.3 +/- 5.0 kg, p = 0.014). Conclusions: OSA patients using CPAP may gain a modest amount of weight with the greatest weight gain found in those most compliant with CPAP.