Effect of Continuous Positive Airway Pressure on Glycemic Control in Patients with Obstructive Sleep Apnea and Type 2 Diabetes. A Randomized Clinical Trial

Am J Respir Crit Care Med. 2016 Aug 15;194(4):476-85. doi: 10.1164/rccm.201510-1942OC.


Rationale: Obstructive sleep apnea (OSA) is a risk factor for type 2 diabetes that adversely impacts glycemic control. However, there is little evidence about the effect of continuous positive airway pressure (CPAP) on glycemic control in patients with diabetes.

Objectives: To assess the effect of CPAP on glycated hemoglobin (HbA1c) levels in patients with suboptimally controlled type 2 diabetes and OSA, and to identify its determinants.

Methods: In a 6-month, open-label, parallel, and randomized clinical trial, 50 patients with OSA and type 2 diabetes and two HbA1c levels equal to or exceeding 6.5% were randomized to CPAP (n = 26) or no CPAP (control; n = 24), while their usual medication for diabetes remained unchanged.

Measurements and main results: HbA1c levels, Homeostasis Model Assessment and Qualitative Insulin Sensitivity Check Index scores, systemic biomarkers, and health-related quality of life were measured at 3 and 6 months. After 6 months, the CPAP group achieved a greater decrease in HbA1c levels compared with the control group. Insulin resistance and sensitivity measurements (in noninsulin users) and serum levels of IL-1β, IL-6, and adiponectin also improved in the CPAP group compared with the control group after 6 months. In patients treated with CPAP, mean nocturnal oxygen saturation and baseline IL-1β were independently related to the 6-month change in HbA1c levels (r(2) = 0.510, P = 0.002).

Conclusions: Among patients with suboptimally controlled type 2 diabetes and OSA, CPAP treatment for 6 months resulted in improved glycemic control and insulin resistance compared with results for a control group. Clinical trial registered with www.clinicaltrials.gov (NCT01801150).

Keywords: clinical trial; diabetes; glycemia; insulin; sleep apnea.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood Glucose / metabolism*
  • Comorbidity
  • Continuous Positive Airway Pressure*
  • Diabetes Mellitus, Type 2 / epidemiology
  • Diabetes Mellitus, Type 2 / therapy*
  • Female
  • Glycated Hemoglobin / analysis*
  • Humans
  • Insulin Resistance*
  • Male
  • Middle Aged
  • Risk Factors
  • Sleep Apnea, Obstructive / epidemiology
  • Sleep Apnea, Obstructive / therapy*


  • Blood Glucose
  • Glycated Hemoglobin A

Associated data

  • ClinicalTrials.gov/NCT01801150