Objective: To investigate the correlation between the oxygen desaturation rate (ODR) associated with obstructive respiratory events and type 2 diabetes mellitus (T2DM) as well as its vascular complications in patients with obstructive sleep apnea (OSA). Methods: A total of 493 patients with OSA who underwent polysomnography (PSG) at the Affiliated Huai' an No.1 People's Hospital of Nanjing Medical University between June 2023 and December 2024 were retrospectively included. Patients were divided into two groups: the T2DM group(n=218) and the non-T2DM group(n=275). Based on the peripheral oxygen saturation(SpO₂) signal from PSG, event-level ODR (ΔSpO₂/Δt) associated with obstructive respiratory events was calculated; individual-level ODR was defined as the median across all night events. Participants were stratified into tertiles according to ODR (with the Low-ODR group as reference), and a multivariable logistic regression model was constructed to assess the associations of ODR and conventional PSG parameters with the risk of T2DM and diabetic vascular complications. Results: There were no significant differences in age, apnea-hypopnea index(AHI), or oxygen desaturation index (ODI) between the two groups. However, the ODR was significantly higher in the T2DM group than that in the non-T2DM group [0.50(0.35, 0.67)%/s vs. 0.38(0.29, 0.52)%/s, P < 0.001]. Multivariable logistic regression analysis showed that, High-ODR was significantly associated with T2DM(OR=2.96,95%CI: 1.73-5.09, P < 0.001) and diabetic vascular complications(OR=3.91,95%CI:1.04-14.66,P < 0.05). Stratified analysis by sex further revealed that the association between ODR and the risk of T2DM was statistically significant only in male patients; the OR for T2DM in the males of High-ODR group was 3.64 times of the males in Low-ODR group(OR=3.64,95%CI: 1.78-7.43, P < 0.001). Conclusion: ODR is significantly associated with T2DM and its vascular complications in patients with OSA, and this association exhibits gender-related differences.