A recent study conducted at the University of Chicago "demonstrates for the first time that there is a clear, graded, inverse relationship between OSA (obstructive sleep apnea) severity and glucose control in patients with type 2 diabetes," writes lead author, Renee S. Aronsohn, MD. The study also confirmed that undiagnosed OSA is common among patients with type 2 diabetes.

Aronsohn and colleagues recruited 60 patients with type 2 diabetes from outpatient clinics to participate in the study. The researchers found that 77% of participants had OSA, but only five had been previously evaluated for the disease, and none were undergoing treatment. Of the study sample, 38% were classified as having mild OSA, 25% had moderate OSA, and 13% had severe OSA.

More severe OSA was associated with poorer glucose control. Relative to patients without OSA, the presence of mild, moderate, or severe OSA significantly increased mean adjusted HbA1c values (the main clinical marker of glycemic control in diabetes) by 1.49%, 1.93%, and 3.69%, respectively. According to the study authors, these effect sizes are comparable to those of widely used hypoglycemic medications, meaning that having OSA may negate the beneficial effects of antidiabetic drugs.

"Our findings have important clinical implications as they support the hypothesis that reducing the severity of OSA may improve glycemic control," said Aronsohn. "Thus effective treatment of OSA may represent a novel and nonpharmacologic intervention in the management of type 2 diabetes."
The findings appear in the American Journal of Respiratory and Critical Care Medicine.