Poor self-rated health is associated with faster cognitive decline and greater small vessel disease in older adults with type 2 diabetes.

Abstract

Self-rated health (SRH) is a predictor for poor health outcomes and cognition. Older adults with type 2 diabetes mellitus (T2D) have multi-morbidity and greater cognitive impairment. In the present study we investigated the association of SRH with cognitive decline and brain pathology in older adults with T2D. Participants (n=1122) were from the Israel Diabetes and Cognitive Decline study, and SRH was categorised as low (n=202), moderate (n=400) or high (n=520). Cognition was measured by four cognitive domains: episodic memory, executive functions, language, and attention/working memory. Global cognition was the average of the cognitive domains. Statistical models adjusted for sociodemographic, cardiovascular, and clinical variables. In a randomly selected subsample (n=230) that had magnetic resonance imaging, we examined relationships between baseline SRH and brain characteristics (white matter hyperintensities [WMHs], hippocampal, and total grey matter [GM] volumes). Low SRH was associated with a decline in executive functions, which accelerated over time when compared to high SRH (est=-0.0036; p=<0.001). Compared to high SRH, low SRH was associated with a faster decline in global cognition (est=-0.0024; p=0.009). Low SRH at baseline was associated with higher volumes of WMHs (est=9.8420; p<0.0008). SRH was not associated with other cognitive domains, or with hippocampal and total GM. Low SRH is associated with cognitive decline in T2D older adults and may serve as a risk assessment. WMHs may represent an underlying mechanism.