455 Obesity Modifies the Effect of 4 Months of CPAP on Glucose Levels in Adults with Obstructive Sleep Apnea

Abstract Introduction Continuous positive airway pressure (CPAP) therapy may improve insulin sensitivity and glucose tolerance seen in individuals with obstructive sleep apnea (OSA), however there is a lack of studies on whether obesity modifies the effect. We examined the baseline and follow-up levels of insulin and glucose following 4 months of CPAP treatment among participants with body mass index (BMI) <30, 30≤ BMI<35, and BMI≥35 kg/m2. Methods We identified 221 adults (84% males) with newly diagnosed OSA in the Penn Icelandic Sleep Apnea (PISA) Study, with a mean (±SD) BMI 31.7 +- 4.2 kg/m2 and apnea-hypopnea index (AHI) of 35.7+-15.6 events/hour. Associations between changes in natural log of the biomarkers within BMI groups were explored, controlling for a priori baseline covariates of age, baseline BMI, race, sex, site, and current smoking status. Results The mean proportional change (from baseline to follow-up) in log-transformed glucose in CPAP adherent participants was significantly larger in the BMI ≥35 and 30≤ BMI<35 groups compared to BMI <30. Within the BMI ≥35 group, the baseline to follow up increase in glucose post-CPAP was 1.08 (95% CI 1.01–1.15), while there were no significant changes in the other 2 BMI groups. A mediation analysis was performed with models including BMI change, and glucose was found to be significantly different between groups. There was no statistically significant association for insulin. Conclusion Our findings show that obesity modifies the effect of four months of CPAP on glucose levels. Support (if any) 1P01-1HL094307