Benefits of continuous positive airway pressure on glycaemic control and insulin resistance in patients with type 2 diabetes and obstructive sleep apnoea: A meta-analysis.

ABSTRACT

AIM: To conduct a meta-analysis to determine the effects of continuous positive airway pressure (CPAP) treatment on glycaemic control and insulin resistance in patients with type 2 diabetes and obstructive sleep apnoea (OSA). METHODS: A systematic search was made of the MEDLINE, SCOPUS, ISI Web of Science, Cochrane databases, and clinicaltrials.gov, without language restrictions. Randomized controlled trials on treatment of type 2 diabetes and OSA with CPAP, compared with sham CPAP or no CPAP, were reviewed. Studies were pooled to obtain standardized mean differences (SMDs), with 95% confidence intervals (CIs). RESULTS: Seven trials (enrolling 691 participants) met the inclusion criteria. CPAP showed significant effects on glycated haemoglobin (HbA1c; SMD -0.32, 95% CI -0.60 to -0.03; P = 0.029), fasting glucose (SMD -0.39, 95% CI -0.76 to -0.02; P = 0.040), homeostatic model assessment of insulin resistance (HOMA-IR; SMD -1.05, 95% CI -1.91 to -0.19; P = 0.016), systolic blood pressure (SMD -1.18, 95% CI -2.29 to -0.07 mm Hg; P = 0.037), and diastolic blood pressure (SMD -1.29, 95% CI -2.48 to -0.09; P = 0.035). CONCLUSIONS: Continuous positive airway pressure treatment significantly improved glycaemic control and insulin resistance, as shown by the decreased HbA1c levels, fasting glucose levels and HOMA-IR values in patients with type 2 diabetes and OSA.