Diabetes and Cognition

Type 2 diabetes mellitus (DM) is a risk factor for cognitive decline, but evidence from Irish population-based studies is lacking. The aim of this work was to investigate the association between DM and the risk of cognitive decline in the Irish Longitudinal Study on Ageing (TILDA).

This is a longitudinal cohort study, totalling a 6-year follow-up.

TILDA is a nationally representative observational study of community-dwelling adults over 50 years old.

DM was assessed via self-reported medical diagnosis. Cognition was assessed with Montreal Cognitive Assessment (MoCA, baseline and wave 3) and the Mini-Mental State Examination (MMSE, all waves) total score and error count. We incorporated individuals’ variability as a random effect and used zero-inflated mixed-effects to model MMSE error counts as a function of DM longitudinally. The model was adjusted for age, sex, history of stroke, hypertension, and any emotional, nervous, or psychiatric problems.

A total of 3,687 participants were evaluated. At baseline, the prevalence of diabetes was 6.4%. Participants with DM had significantly lower MoCA and MMSE scores and higher error counts than those without DM. Age, male sex, DM, stroke, and hypertension were significantly associated with higher error counts in MMSE at baseline. Over six years, DM was significantly associated with an accelerated decline in cognition.

Having DM predicted cognitive decline in TILDA participants over 6-years. These findings corroborate the importance of screening and managing DM in community-dwelling older adults to prevent future cognitive impairment.

There is paucity of information on the prevalence of mild cognitive impairment (MCI) among individuals with type 2 diabetes mellitus (T2DM) in sub-Saharan Africa, including Nigeria. In addition, the role of hyperinsulinaemia in the development of MCI needs further investigation. This study sought to assess cognition and hyperinsulinaemia, with the associated characteristics in patients with advanced T2DM. Cognition was assessed using Montreal cognitive assessment test (MoCA), while fasting plasma insulin was measured using an ELISA kit. Sixty one diabetic subjects and 32 non-diabetic controls, matched for age, gender and level of education were studied. The diabetics had MCI while the controls had normal cognitive function. About 88.5% of the diabetic subjects had MCI, in contrast with only 50% of the non-diabetic controls. The most significantly affected cognitive domains among the diabetics were executive function, naming, attention, abstraction and delayed recall. Among the diabetics, MCI correlated with age, weight and body mass index (BMI); and in addition, age and weight found to be significant predictors of MCI. Plasma insulin concentration among the diabetics (16.24 ± 13.5 µIU/ml) was more than twice that of the controls (7.59 ± 2.9 µIU/ml). Hyperinsulinaemia among the diabetics correlated with weight, BMI, blood pressure and fasting blood sugar (FBS). Glycated haemoglobin and FBS levels were higher among diabetics compared with the controls. In conclusion, Africans with advanced T2DM show multi-domain MCI with high prevalence, coexisting with hyperinsulinaemia. Majority of the patients have diabetic complications and poor glycaemic control. Hyperinsulinaemia may play a complementary role in the pathophysiology of MCI in T2DM.

There is snowballing evidence that type 2 diabetes (T2D) predisposes to neuropathophysiological alterations including oxidative stress and triggered inflammatory responses in brain that eventually culminates into cognitive impairment.Accumulating evidences suggest that SGLT2 inhibitor can be a promising intervention for cognitive decline in T2DM. In the present paper, the potential effects of Empagliflozin (EMPA), a SGLT2 inhibitor, against T2D induced cognitive dysfunction have been explored. The effect of EMPA on array of inflammatory mediators including Interleukin-6(IL-6), Interleukin -1β (IL-1β), and Tumour necrosis factor-α(TNF-α)), neuronal proteins including glycogen synthase kinase-3β (GSK- 3β), Phosphorylated tau (p-tau), amyloid beta (Aβ) (1–40, 1–42) and altered oxidative parameters including SOD, catalase, TBARS was determined in the high fructose diet induced hyperglycaemic mice. The obtained results were compared with EMPA nanoparticles (Nps) formulated in our laboratory and found that EMPA Nps significantly showed reduced levels of inflammatory mediators and oxidative stress. Further, decrease in levels of p-tau, Aβ (1–40) and Aβ (1–42) were also observed with EMPA nanoparticles.Thus, the study has demonstrated that EMPA Nps could be a promising therapy to alleviate the progression of cognitive decline in T2D.