Treatment of obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP) definitely benefits people who have the condition along with type 2 diabetes, but whether it improves blood glucose remains a matter of debate, as indicated by the conflicting results of two new studies.

Both studies were published online recently in the American Journal of Respiratory and Critical Care Medicine. Onefound that among 50 patients with suboptimally controlled type 2 diabetes and OSA randomized to CPAP or placebo for 6 months, CPAP treatment improved glycemic control and insulin resistance.

But the second study showed no effect of CPAP on blood glucose in patients with relatively well-controlled type 2 diabetes, although the therapy did reduce diastolic blood pressure and daytime sleepiness and improved quality of life.