The impact of obstructive sleep apnea treatment on microvascular complications in patients with type 2 diabetes: a feasibility randomized controlled trial.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is associated with an increased risk of diabetes-related complications. Hence, it is plausible that Continuous Positive Airway Pressure (CPAP) could have a favorable impact on these complications. To assess the feasibility of conducting a randomized control trial (RCT) in patients with type 2 diabetes (T2D) and OSA over 2 years.

METHODS: An open-label multicenter feasibility RCT of CPAP vs no CPAP in patients with T2D and OSA. Patients with resting oxygen saturation <90%, central apnea index >15/hour or Epworth Sleepiness Scale (ESS) ≥11 were excluded. OSA was diagnosed using a multichannel portable device (ApneaLink Air, ResMed). The primary outcome measures were related to feasibility, and the secondary outcomes were changes in various clinical and biochemical parameters related to diabetes outcomes.

RESULTS: Eighty-three (40 CPAP vs 43 no CPAP) patients were randomized, with a median (IQR) follow-up of 645 [545, 861] days. CPAP compliance was inadequate, with a median usage of approximately 3.5 hours/night. Early CPAP use predicted longer-term compliance. The adjusted analysis showed a possible favorable association between being randomized to CPAP and several diabetes-related endpoints (chronic kidney disease (CKD), neuropathy, and quality of life (QoL)).

CONCLUSIONS: It was feasible to recruit, randomize, and achieve a high follow-up rate over 2 years in patients with OSA and T2D. CPAP compliance might improve by a run-in period before randomization. A full RCT is necessary to assess the observed favorable association between CPAP and CKD, neuropathy, and QoL in patients with T2D.

CLINICAL TRIAL REGISTRATION: Registry: ISRCTN; URL: https://www.isrctn.com/ISRCTN12361838; Title: The impact of sleep disorders in patients with type 2 diabetes; Identifier: ISRCTN12361838.