Lacunes and type 2 diabetes mellitus have a joint effect on cognitive impairment: a retrospective study

OBJECTIVE: To evaluate the joint effects of cerebral small vessel disease (CSVD)-related imaging biomarkers in patients of type 2 diabetes mellitus (T2DM) with cognitive impairment. METHODS: This study is a retrospective cohort study. A total of 227 participants (115 patients with T2DM and 112 healthy control subjects) were enrolled in this study. Cognitive function assessments were evaluated using the Mini-Mental State Examination and the Montreal Cognitive Assessment. The burden of CSVD markers, including the lacunes, white matter hyperintensities (WMH), cerebral microbleeds (CMBs), and enlarged perivascular spaces (PVS), was identified by magnetic resonance imaging and evaluated using small vessel disease (SVD) scores (0–4). The subjects were divided into two groups based on the results of the cognitive function assessments. The synergy index was used to estimate the biological interactions between T2DM and lacunes. RESULTS: There was a significant correlation between T2DM and cognitive impairment (p < 0.001, χ(2) test). In patients with diabetes, cognitive impairment was significantly associated with both the presence of lacunes (p < 0.01, χ(2) test) and increased total SVD burden scores (p < 0.01, χ(2) test). Regarding CMBs, only the existence of lobar CMBs was correlated with cognitive impairment (p < 0.05, χ(2) test). The joint effect tended to be larger than the independent effects of T2DM and lacunes on cognitive impairment (adjusted odds ratio [OR]: 7.084, 95% CI [2.836–17.698]; synergy index: 10.018, 95% CI [0.344–291.414]). CONCLUSIONS: T2DM and the presence of lacunes are significantly correlated with cognitive impairment. There was a joint effect of T2DM and lacunes on cognitive impairment.