Obstructive sleep apnea, CPAP use may not impact weight, glycemic outcomes in obesity

Presence of obstructive sleep apnea or CPAP use did not impact weight or glycemic outcomes at 2 months among adults with class 3 obesity, according to new research published in BMC Endocrine Disorders.

“Obesity can affect the pathogenesis of OSA in multiple ways, including upper airway fat deposition and muscle impairment, pressure from abdominal fat, leptin resistance and increased inflammatory state,” Sophie Kobuch, MD, a student at the School of Medicine at Western Sydney University in Campbelltown, New South Wales, Australia, and colleagues wrote. “Significant weight loss can also reduce symptoms of OSA, but long-term weight loss, which is sufficient enough to reduce the severity of OSA in individuals with class 3 obesity, is difficult to achieve and maintain, particularly without bariatric surgery.”

The single-center, retrospective cohort study included 178 patients who initiated an intensive multidisciplinary publicly funded weight-management program from March 2018 to 2019 in Sydney. OSA diagnoses were made via laboratory overnight sleep studies and CPAP use was confirmed if patients used CPAP 4 hours or more on average per night. Researchers collected demographic data, clinical data and CPAP use at baseline and at 12 months.

Sixty-two percent of patients completed 12 months of the multidisciplinary weight-management program. Of those, 70 (63.1%) patients had OSA, of whom 38 patients (54.3%) reported CPAP use. Researchers observed no significant difference in BMI at baseline between those with OSA and CPAP use, those with OSA and no CPAP use, and those without OSA (52.1 kg/m² and 50.3 kg/m² vs. 50.4 kg/m², respectively; P = .636); however, there were more women among those without OSA (57.9% and 63.5% vs. 90.2%, respectively; P = .003).

Significant weight loss was observed across all three groups by 12 months, but there was no significant difference in the percentage of weight loss among patients with OSA and CPAP use (6.3%), patients with OSA and no CPAP use (6.8%), and patients without OSA (7.2%). There was also no significant difference in the proportion of patients who achieved 5% or more weight loss among those with OSA and CPAP use (57.9%), OSA and no CPAP use (59.4%), and without OSA (65.9%).

Researchers also observed a reduction in HbA1c from 7.8% at baseline to 7.3% at 12 months among patients with type 2 diabetes (P = .03). There was no difference in HbA1c reduction between the three groups (P = .997).

“Findings from this study suggest that the focus should remain on implementing lifestyle changes and medical weight management in people with class 3 obesity, regardless of OSA status,” the researchers wrote.