Type 2 Diabetes Associated With Poorer Cognitive Function Following a Stroke

According to a recent study, patients with type 2 diabetes mellitus (T2D), but not prediabetes, demonstrated poorer cognitive performance 3 to 6 months after a stroke.

Although prior research had shown that T2D is associated with cognitive impairment and an increased risk of dementia, previously the association between prediabetes and cognitive impairment had remained less clear, particularly in relation to occurrences of major cerebrovascular events.

The researchers used data from 7 international observational studies from the STROKOG (Stroke and Cognition) consortium in order to analyze these correlations further. The mean age of participants in the studies was 66 years, with 70% of participants self-identifying as Asian, 26% as white, and 2.6% as African American.

The aim of the study was to assess the impact of impaired fasting glucose and T2D on cognitive performance in a stroke population, so the researchers used fasting glucose level (FGL) during hospitalization to define 3 groups: T2D (FGL ≥7.0 mmol/L), impaired fasting glucose (FGL 6.1—6.9 mmol/L), and normal (FGL <6.1 mmol/L). For the T2D group, a history of diabetes mellitus and diabetes mellitus medication were used as references to support diagnoses of T2D.

In order to assess cognitive impairment, the researchers used standardized neuropsychological test scores that allowed them to obtain domain and global cognition Z scores. The resulting cross-sectional association between glucose status and cognitive performance at 3 to 6 months post-stroke was then examined with the use of linear mixed models. During the examination of these models, adjustments were made for age, sex, education, stroke type, ethnicity, and vascular risk factors.

The resulting data showed that patients with T2D had significantly poorer performance in global cognition and in all domains compared with patients with normal FGL. However, no significant difference was found between impaired fasting glucose patients and those with normal FGL in global cognition or in any cognitive domain, supporting the correlation between diabetes mellitus, but not prediabetes, and poorer cognitive performance following a stroke, according to the study authors.

REFERENCE

Lo JW, Crawford JD, Samaras K, et al. Association of Prediabetes and Type 2 Diabetes With Cognitive Function After Stroke. Stroke. 2020;51:1640—1646. doi: 10.1161/STROKEAHA.119.028428.