The association between diabetes and cognitive changes during aging

Abstract

Background: Worldwide, we are observing a rising prevalence of dementia and mild cognitive impairments that often co-occur with the heightened incidence of non-communicable diseases in the elderly. It is suggested that type 2 diabetes and defects in glucose metabolism might predispose to poorer cognitive performances and more rapid decline in old age. Methods: to address existing knowledge gaps in this area, we systematically reviewed the literature to identify whether patients with type 2 diabetes (T2DM) and pre-diabetes are at a higher risk of poorer cognitive performance, and whether the risk (if any) might affect specific cognitive abilities. We concentrated the review on elderly individuals (65 years or older) at intake. In total, 3251 original articles were retrieved, of which 17 met our inclusion and quality control criteria, which comprised 12 structured questions used to define the articles. Results: 11 of 17 studies found a statistically significant decline in cognition among individuals who had T2DM or pre-diabetes compared to their non-diabetic counterparts. The association between diabetes and cognitive decline was not always clear, and the extent of the cognitive tests used seemed to have the greatest effect on the results. Conclusion: Focusing on a population age 65 years and over, we found insufficient evidence to support an association between pre-diabetes stages and mild cognitive impairment. However, there is consistent evidence to support diabetes as an independent risk factor for low cognitive ability in the elderly. Finally, we found insufficient evidence to support effect of T2DM on distinct cognitive ability due to the scarcity of comparable findings.

Aging-related cerebral microvascular changes visualized using ultrasound localization microscopy in the living mouse

“…These findings imply that there is a relationship between compromised cerebral blood flow and cognitive impairment, where there are paralleled deteriorations in both small vessel function and cognitive ability. This relationship is reinforced by overlapping epidemiological risk factors 13 ; both late-stage cognitive decline and vascular disease are associated with diabetes 14 , obesity 15 , and hypertension 16 . Furthermore, clinical evidence suggests that microvascular changes accelerate clinical decline in cognitive impairment 17 , 18 , and decreased macroscopic cerebral blood flow is associated with worsened cognitive performance in both normal and pathological states 19 – 21 .…”

Nervous-mental stress and cognitive disorders as components of stress state in type 2 diabetic patients

“…Тривалі спостереження та метааналізи свідчать, що наявність ЦД 2 типу у середньому віці асоціюється з вищим ризиком розвитку деменції в подаль-REVIEW • ОГЛЯД ЛІТЕРАТУРИ шому житті [13,14]. До передбачуваних механізмів, що опосередковують цей зв'язок, належать периферичне запалення, гіперглікемія, резистентність до інсуліну, а також порушене функціонування гіпоталамо-гіпофізарно-надниркової осі, окрім її ключової ролі в розвитку судинної патології та запалення [15].…”

“…В іншому метааналізі (17 досліджень) ризику погіршення пізнавальної діяльності в осіб з ЦД 2 типу та предіабетом віком понад 65 років, в 11 роботах було виявлено статистично значуще зниження когнітивних функцій в осіб, які страждали на ЦД 2 типу або предіабет, порівняно з учасниками без ЦД [36].…”

Cognitive consequences of metabolic disorders

“…Despite the fact that the human brain is only about 2% of the total body weight, it consumes approximately 75% of the glucose available, and is therefore the most metabolically demanding human organ [33]. Disturbances in the metabolism of glucose affect the efficiency of cognitive functions, as evidenced by the numerous studies carried out in type 1 and type 2 diabetic patients [34][35][36][37][38][39]. Kerti et al showed that in people with pre-diabetes a lower level of blood glucose in comparison to the control group was associated with better cognitive efficiency in terms of cognitive functions, such as learning and memory abilities.…”