Diabetes is known to be a risk factor for cognitive impairment. However, the impact of diabetes on cognitive impairment after stroke is unclear. Severe renal dysfunction is related to cognitive dysfunction. The goal of this study was to investigate the impact of the combination of diabetes and renal dysfunction on cognitive function after stroke.

Patients with acute lacunar infarction were admitted to this hospital, cognitive function assessment and blood biochemical testing were performed one month after discharge from hospital. Renal dysfunction was defined as eGFR<90 mL/min/1.73m². The post-stroke cognitive impairment was defined based on Montreal Cognitive Assessment (MoCA) or Mental State Examination (MMSE) scores.

Of the 92 patients with lacunar infarction included for the statistical analysis, 31 cases (33.7%) had diabetes mellitus and 13 cases (14.1%) had diabetes with renal dysfunction. Except for one patient with the eGFR of 58 mL/min/1.73m², the rest of patients were greater than 60 mL/min/1.73m². Multivariate analysis showed that the risk of cognitive impairment in diabetic patients with mild renal dysfunction was nearly 20 times that of non-diabetic patients with normal renal function (p=0.002) using the MoCA score to define cognitive dysfunction.

The relationship between diabetes and cognitive impairment after stroke partially depends on the renal dysfunction.