Diabetes is associated with poorer allocentric processing compared to non‐diabetic participants in the EPAD LCS cohort

Abstract

AbstractBackgroundDementia and type 2 diabetes mellitus (T2D) are prevalent disorders in older adults, and increasingly T2D is recognized as a robust predictor of cognitive impairment, decline and dementia. Older adults with T2D experience global cognitive decline at a rate that is double those without T2D over a 5‐year period. With regard to specific cognitive domains, associations between T2D and pre‐diabetic levels of insulin resistance are most commonly reported with both episodic memory and decreased executive function, including verbal fluency, working memory, processing speed, cognitive flexibility, and cognitive control. Identification of those living with diabetes at risk for cognitive decline is critically important for early intervention.MethodWe used the EPAD LCS vIMI baseline dataset (n=1324, excluding participants with missing data). Our primary outcome measure was performance on the Four Mountains Test (4MT), a measure of allocentric processing. Diabetes was recorded in the medical history. Covariates were age, sex, years of education, family history, APOE status, pTau and Aβ1‐42. Our statistical analysis approach was linear regression.ResultThere were 90 participants with diabetes included in the sample. Their mean score on the 4MT was 8.32 (±2.32) correct (out of 15) compared to 9.24 (±2.60) for participants without diabetes. In uncorrected models, diabetes was significantly associated with worse 4MT total scores (β=‐0.92, p=0.001). This relationship remained significant in a fully adjusted model including sex, age, education, family history of dementia and APOE status (β=‐0.71, p=0.0017). There was no significant interaction between diabetes and APOE status. pTau was significantly higher in participants with diabetes compared to those without. Including pTau and Aβ1‐42 in the fully adjusted model further attenuated it but it remained significant (β: ‐0.62, p=0.02)ConclusionIndividuals with diabetes performed worse on the 4MT compared to those without diabetes in the EPAD LCS v.IMI dataset. Novel cognitive tests, such as the 4MT, may be appropriate to identify early cognitive changes in this high‐risk group. Future research will investigate longitudinal associations between diabetes and 4MT performance over multiple visits.