Risk of obstructive sleep apnea in patients with type 2 diabetes mellitus

Type 2 diabetes mellitus (DM) and obstructive sleep apnea (OSA) share several clinical findings: obesity, hypertension, and impaired glucose tolerance. OSA may be an under-recognized comorbidity of DM. The purpose of this study is to estimate the proportion of patients with type 2 DM at risk for OSA and describe factors associated with that risk.

This cross-sectional study enrolled 297 adults, ages 18 years and older, with type 2 DM from a university-based Family Medicine Center. Participants completed a research questionnaire recording sociodemographic information, medical history, and clinical data including medications and hemoglobin A1C. OSA risk was determined using the Berlin Questionnaire. Relationships between risk of OSA and sociodemographic and clinical variables were evaluated using bivariate analyses and covariate adjusted logistic regression models.

Thirty-seven participants (12.5%) had a prior diagnosis of OSA. Based on the Berlin Questionnaire, 124 (48.6%) of the remaining patients were classified as high risk for OSA. Patients less than age 60 years were at increased risk for OSA, adjusted OR=2.67 (1.57, 4.54; 95% CI). Non-Hispanic whites, adjusted OR=1.76 (1.01, 3.06; 95% CI), and patients with symptoms of depression, adjusted OR=2.64 (1.60, 4.52; 95% CI), were also at higher risk. Gender and hemoglobin A1C were not associated with increased risk of OSA.

Nearly half of adults with type 2 DM may be at high risk for OSA, and many may be undiagnosed. In a primary care setting, the Berlin Questionnaire is an easily applied screening instrument that identifies patients at increased risk of OSA who may benefit from further diagnostic studies and treatment of OSA.