Background: Although recent evidence suggests that OSA treatment may cause weight gain, the long-term effects of CPAP on weight are not well established.
Methods: This study was a post hoc analysis of the Sleep Apnea Cardiovascular Endpoints (SAVE) study, a multicenter, randomized trial of CPAP plus standard care vs standard care alone in adults with a history of cardiac or cerebrovascular events and moderate to severe OSA. Participants with weight, BMI, and neck and waist circumferences measured at baseline and during follow-up were included. Linear mixed models were used to examine sex-specific temporal differences, and a sensitivity analysis compared high CPAP adherers (≥ 4 h per night) with propensity-matched control participants.
Results: A total of 2,483 adults (1,248 in the CPAP group and 1,235 in the control group) were included (mean 6.1 ± 1.5 measures of weight available). After a mean follow-up of 3.78 years, there was no difference in weight change between the CPAP and control groups, for male subjects (mean [95% CI] between-group difference, 0.07 kg [–0.40 to 0.54]; P =.773) or female subjects (mean [95% CI] between-group difference, –0.14 kg [–0.37 to 0.09]; P =.233). Similarly, there were no significant differences in BMI or other anthropometric measures. Although male participants who used CPAP ≥ 4 h per night gained slightly more weight than matched male control subjects without CPAP (mean difference, 0.38 kg [95% CI, 0.04 to 0.73]; P =.031), there were no between-group differences in other anthropometric variables, nor were there any differences between female high CPAP adherers and matched control subjects.
Conclusions: Long-term CPAP use in patients with comorbid OSA and cardiovascular disease does not result in clinically significant weight change. Trial Registry: ClinicalTrials.gov; No.: NCT00738179; URL: www.clinicaltrials.gov.