Cerebral morphology significantly associated with HbA1c SD and HbA1c CV after adjustment for Model III. (A) Cortical thickness of the left superior parietal cortex, right postcentral gyrus, and insula showed significant negative associations with HbA1c SD (P_FDR < 0.05). (B) Cortical thickness of the left superior parietal cortex and right postcentral gyrus demonstrated significant negative associations with HbA1c CV (P_FDR < 0.05). No significant associations were found between glucose variability and gray matter volume or cortical surface area after FDR correction.