Abstract
STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is associated with gestational diabetes mellitus (GDM). This study assessed the effects of continuous positive airway pressure (CPAP) in obese pregnant females with GDM and OSA. METHODS: A randomized controlled trial was conducted (April 2014 - June 2016). Obese females at 24 to 34 weeks gestation and with diet-controlled GDM were screened for OSA. Those with OSA were randomly assigned to receive 2 weeks nightly CPAP or be part of a waitlist control group. After 2 weeks, all patients were offered CPAP. The primary outcome was glucose metabolism, obtained from an oral meal tolerance test (MTT) at baseline and 2 weeks. Pregnancy outcomes were collected. RESULTS: Eighteen patients were randomized to CPAP and 18 to control groups. There were no significant changes between groups in fasting glucose, glucose response to MTT, and insulin sensitivity or secretion after 2 weeks. Those adherent to CPAP had significantly improved insulin secretion (P = .016) compared to the control group. When a counterfactual instrumental variable approach was applied to deal with nonadherence, the CPAP group had significantly improved insulin secretion (P = .002) and insulin sensitivity (P = .015). Lower rates of preterm delivery (P = .002), unplanned cesarean section (P = .005), and neonatal intensive care unit admissions (P < .001) were observed among those who used CPAP longer than 2 weeks. CONCLUSIONS: Two weeks of CPAP in females with GDM and OSA did not result in improved glucose levels, but insulin secretion improved in those adherent to CPAP. Continued CPAP use was possibly associated with improved pregnancy outcomes. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Title: Obstructive Sleep Apnea and Gestational Diabetes: Incidence and Effects of Continuous Positive Airway Pressure Treatment on Glucose Metabolism; Identifier: NCT02108197; URL: https://clinicaltrials.gov/ct2/show/NCT02108197.