Poor CPAP adherence may increase BMI in adults with obstructive sleep apnea

CPAP therapy may have an effect on BMI in adults with obstructive sleep apnea, especially among those with poorer adherence, researchers reported in the Annals of the American Thoracic Society.

“Since weight gain is significantly associated with OSA and cardiometabolic disease, we performed an updated meta-analysis to examine the effects of CPAP treatment on BMI in OSA patients, focusing on not only the overall effects on BMI, but also assessing whether the CPAP adherence and comorbid disorders modulate the BMI response to CPAP treatment,” Baixin Chen, MD, from the department of sleep medicine at Shantou University Mental Health Center and the Sleep Medicine Center at Shantou University Medical College, China, and colleagues wrote.

Researchers assessed PubMed/MEDLINE, Embase and Cochrane databases through December 2019 and included 39 randomized controlled trials that evaluated 6,954 participants (mean age, 54.1 years; 78% men). All trials assessed a CPAP group (n = 3,510) vs. a control group (n = 3,444), with treatments lasting 4 weeks or more.

In an intention-to-treat analysis, there was an increase in the BMI after CPAP treatment compared with the control group (0.148 kg/m²; 95% CI, 0.04-0.26; P = .001).

Researchers also reported significant increases in waist (0.839 cm; 95% CI, –0.018 to 1.696) and neck circumferences (0.235 cm; 95% CI, 0.047-0.422) in studies in which CPAP was associated with a BMI increase, according to the results.

In subgroup analyses, increased BMI was associated with CPAP use of 5 hours or less per night (weighted mean difference, 0.231), but not in those with CPAP use of more than 5 hours per night (weighted mean difference, .001; P = .049).

In patients without cardiovascular disease, BMI increased (weighted mean difference, 0.2) compared with a decrease in patients with CVD at baseline (weighted mean difference, –0.188; P < .001). BMI increased in patients with dysglycemia (weighted mean difference, 0.499), but did not increase among patients without dysglycemia at baseline (weighted mean difference, 0.1; P = .032).

“Enhancing CPAP adherence and weight management should be encouraged to achieve a better improvement of cardiometabolic outcomes in OSA patients,” the researchers wrote. “Future studies should shed light on the underlying mechanisms of BMI changes after CPAP treatment in the short- and long-term period.”