Obstructive sleep apnea in type 2 diabetes: prevalence and limitations of the Berlin questionnaire and Epworth sleepiness scale in identifying high-risk patients.

PURPOSE: Obstructive sleep apnea (OSA) is common in type 2 diabetes (T2D). This study examined the prevalence of undiagnosed moderate-to-severe OSA (apnea-hypopnea index ≥ 15) in T2D patients, and assessed the diagnostic performance of the Berlin Questionnaire (BerlinQ) and Epworth Sleepiness Scale (ESS) compared with cardio-respiratory monitoring (CRM). We hypothesized that BerlinQ and ESS would have sufficient sensitivity to identify patients with treatment-recommended OSA, thereby supporting their use as triage tools to select patients for CRM.

METHODS

This cross-sectional study recruited T2D patients attending a tertiary diabetes clinic between September 2023 and September 2024. In 149 participants completing the BerlinQ and ESS, 115 underwent CRM for OSA diagnosis. Logistic regression analysis was used to examine the association between OSA, clinical variables, and microvascular complications. The predictive performance of the questionnaires was assessed by calculating sensitivity and specificity.

RESULTS

100 participants had valid CRM with 60% of those having moderate-to-severe OSA. Logistic regression showed higher odds of OSA with age (OR 1.07, 95%CI 1.02-1.12), BMI (OR 1.15, 95%CI 1.06-1.25), and positive BerlinQ (OR 3.64, 95%CI 1.33-10.00). The BerlinQ demonstrated high sensitivity (80.0%), but low specificity (47.5%) for treatment-recommended OSA. In contrast, the ESS exhibited high specificity (75.0%), but low sensitivity (28.3%).

CONCLUSIONS

Moderate-to-severe OSA is highly prevalent (60%) among T2D patients attending a tertiary diabetes clinic. Our findings support the need for systematic OSA screening using CRM in this population, instead of BerlinQ or ESS.