Association between obstructive sleep apnea hypopnea syndrome and arteriosclerosis in patients with type 2 diabetes mellitus: mediating effect of blood pressure

Objective: This study aims to explore the relationship between Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS) and arteriosclerosis in type 2 diabetes mellitus (T2DM) patients and to evaluate the mediating effect of blood pressure in this process. Methods: A total of 411 T2DM patients admitted to the Third Affiliated Hospital of Soochow University from January 2021 to December 2023 were selected and divided into the arteriosclerosis group (n = 299) and the non-arteriosclerosis group (n = 112) based on brachial-ankle pulse wave velocity (ba-PWV). General clinical data, metabolic indicators, and sleep-related parameters were collected. The relationship between the apnea-hypopnea index (AHI) and arteriosclerosis was analyzed using univariable and multivariable logistic regression models, while a generalized additive model (GAM) was applied for curve fitting. A segmented regression model was used to explain nonlinearity, and subgroup analysis was conducted to assess interactions. Finally, a mediation effect model evaluated AHI's direct and indirect effects on arteriosclerosis. Results: The AHI of the arteriosclerosis group was significantly higher than that of the non-arteriosclerosis group (P < 0.001). In the unadjusted, partially adjusted, and fully adjusted regression analyses, elevated AHI significantly increased the risk of arteriosclerosis (P < 0.05). Curve fitting indicated a near-linear positive correlation (P = 0.033). The segmented regression model showed that when AHI < 8.8 events/hour, the risk of arteriosclerosis significantly increased with higher AHI (P = 0.008), but the risk increase was not significant when AHI > 8.8 events/hour (P = 0.124). There was no significant interaction between AHI and blood pressure-related index subgroup indicators (P > 0.05). Mediation analysis revealed that systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) had significant mediating effects on the relationship between AHI and arteriosclerosis (P < 0.05), but the direct effect of AHI on arteriosclerosis was not significant (P > 0.05). Conclusion: OSAHS severity elevates arteriosclerosis risk in T2DM patients. Blood pressure is a partial intermediary in this effect.