Introduction:
The aim of the current study was to evaluate the efficiency of the STOP-Bang questionnaire for obstructive sleep apnea (OSA) screening among Chinese patients with type 2 diabetes mellitus (T2DM).

Material and methods:
A total of 262 patients with T2DM were enrolled for STOP-Bang questionnaire evaluation and polysomnography (PSG) monitoring between May 2015 and September 2016. Patients were divided into non-OSA and different OSA severity groups (mild, moderate, and severe) according to the apnea-hypopnea index (AHI). The value of the STOP-Bang questionnaire for OSA screening was evaluated.

Results:
Efficiency of the STOP-Bang questionnaire for OSA screening among Chinese patients with T2DM was as follows: when AHI ≥ 5/h, the area under the curve (AUC) was 0.825 (95% confidence interval CI: 0.763–0.887, p < 0.05), sensitivity was 85.6% (95% CI: 85.55–85.65%, p < 0.05) and specificity was 60% (95% CI: 59.85–60.15%, p < 0.05); when AHI > 15/h, the AUC was 0.856 (95% CI: 0.799–0.913, p < 0.05), sensitivity was 88.6% (95% CI: 88.55–88.65%, p < 0.05) and specificity was 38.4% (95% CI: 38.30–38.49%, p < 0.05); when AHI > 30/h, the AUC was 0.891 (95% CI: 0.836–0.946, p < 0.05), sensitivity was 90.5% (95% CI: 90.44–90.56%, p < 0.05), and specificity was 27% (95% CI: 26.94-27.07%, p < 0.05).

Conclusions:
The STOP-Bang questionnaire is an effective tool for OSA screening among Chinese patients with T2DM. A cut-off score of 3 distinguishes OSA from non-OSA with high sensitivity.