USA: A recent study found diabetes but not prediabetes to be consistently associated with increased depressive symptoms and worse cognitive performance in older adults. The study appears in the Journal of Diabetes and its Complications.
"Mediation findings suggest that depression may be a biobehavioral pathway that connects diabetes to impaired cognition in the older adults, although we could not establish the temporal sequence," Claire J.Hoogendoorn, Ferkauf Graduate School of Psychology, Yeshiva University, Bronx, NY, USA, and colleagues wrote in their study. "If causal, addressing both diabetes and depressive symptoms in this population may protect cognitive function."

The study was conducted to evaluate whether diabetes and prediabetes are associated with impaired cognitive performance among older adults and examine depressive symptoms as a mediator.
For this purpose, the researchers used cross-sectional data from a systematically recruited, community-based cohort study of diverse older adults called Einstein Aging Study -- consisting of 794 individual, mean age = 78.9 years; 64.4% Non-Hispanic White, 28.7% Non-Hispanic Black, 5.7% Hispanic. Self-reported diagnosis, prescribed medications, and fasting blood glucose were the parameters used to determine the diabtes status. Geriatric Depression Scale was used for assessing depressive symptoms. Cognitive tests included Digit Symbol, Trails-B, Free Recall, Category Fluency, Boston Naming, and Block Design. Linear regression and mediation analyses were applied.
Based on the study, the researchers reported the following:
Compared to those without diabetes, diabetes was associated with worse performance on all cognitive tests, except Trails-B, and increased depressive symptoms.
For diabetes, mediation via increased depressive symptoms was observed for Free Recall, Category Fluency, and Boston Naming.
"Findings of this study suggest that depression may be a biobehavioral pathway that links diabetes to impaired cognition in older adults, although the temporal sequence could not be established," the authors concluded.
Reference:
Journal of Diabetes and its Complications. Depressive symptoms mediate the relationship between diabetes and cognitive performance in a community-based sample of older adults. J Diabetes Complicat 2022 Mar 23;[EPub Ahead of Print], CJ Hoogendoorn, J Qin, C Wang, N Roque, JP Laurenceau, MJ Katz, CA Derby, RB Lipton, JS Gonzalez
DOI: https://doi.org/10.1016/j.jdiacomp.2022.108183
KEYWORDS: Journal of Diabetes and its Complications, depressive symptoms, diabetes, cognitive performance, older adults, type 2 diabetes, Alzheimer's disease, Claire J Hoogendoorn, dementia, cognition