LAUSR

Evidence remains unclear whether treatment of OSA with CPAP results in improved glycemic control. This study evaluated if CPAP improved glucose control compared to sham-CPAP and the effect of adherence to active CPAP on glucose control after 6 and 12 weeks of treatment. This was a multi-center, double-blind clinical trial. Participants were adults with type 2 diabetes (T2D), A1C≥6.5%, apnea + hypopnea index (AHI)≥10, and naïve to CPAP. All participants received diabetes education. Glucose control was evaluated with frucostamine and A1C levels; CPAP adherence with a wireless modem system. Statistical analysis followed an “intent-to-treat” approach with linear mixed modeling. The dose of active CPAP was calculated as the percentage of days with active CPAP use≥4 hours and the average adherence of active CPAP with sham coded as “0”dose”. Randomized participants (N=98, CPAP=50; sham-CPAP=48) were primarily middle-aged (age=58.7±9.8 years), White (75%), males (57%) obese (BMI=36.2±6.6), suboptimal glucose control (A1C=7.9%±0.9) and OSA (AHI=23.9±14.4). There were no significant baseline differences except in A1C (Active CPAP=7.7%±0.8; sham-CPAP=8.1%±1.0). There was no significant difference in use of their devices at 6 or 12 weeks. Based on linear mixed modeling, participants on active CPAP had improved A1C (b (SE): -.76 (.24), P<.01) and frucostamine (-21.8 (10.5), P=.04) at 6 weeks with A1C trending to significance at 12 weeks (p=0.10). Both the % of cumulative days of active CPAP usage (≥4 hours/day) (.002 (.003), P=.09) and cumulative hours of active CPAP use (.03 (.03), P=.08) showed a trend being associated with greater change in A1C but not in frucostamine (P=.61, P=.51). The rate of change in A1C varied by time, increasing the % of cumulative days of CPAP use (≥4 hours/day) at week 6 predicted greater change in A1C (.006 (.002), P=.01) than week 12 (.002 (.003), P=.38). Higher average hours of CPAP usage were associated with greater change in A1C (.08 (.03), P=.01) at week 6 compared to week 12 (.03 (.03), P=.47). In our study, individuals with T2D and OSA, adherence to active CPAP use improved glycemic control over 6 weeks. NIDDK grant R01DK096028; CTRI grant UL1TR001857 and UL1TR000005.