The impact of diabetes on cognitive impairment and its progression to dementia

Abstract

Introduction Diabetes is a well‐established risk factor for dementia, but its impact on the prodromal phase of dementia is unclear. Methods Cohorts of older adults who were cognitively healthy (n = 1840) or had cognitive impairment‐no dementia (CIND; n = 682) were followed over 12 years to detect incident CIND and dementia, respectively. Results Poorly controlled diabetes (glycated hemoglobin [HbA1c] ≥7.5%; reference = normoglycemia) was associated with double the risk of CIND (Cox regression multi‐adjusted hazard ratio [HR] 2.01, 95% confidence interval [CI] 1.13‐3.58) and triple the risk CIND progressing to dementia (HR 2.87, 95% CI 1.20‐6.85). Co‐morbid diabetes and heart disease doubled the risk of incident CIND and dementia, although neither disease conferred a significant risk of either outcome alone. Elevated systemic inflammation contributed to the diabetes‐associated increased dementia risk. Conclusions Diabetes characterized by poor glycemic control or cardiovascular complications is related to a greater risk of the development and progression of cognitive impairment. Inflammation may play a role in these relationships.

Association of gut microbiota with sort-chain fatty acids and inflammatory cytokines in diabetic patients with cognitive impairment: A cross-sectional, non-controlled study

“…Inflammation significantly exacerbated DCI by increasing Aβ accumulation, tau hyperphosphorylation, and neuronal cell death (19)(20)(21)(22). Remarkably, the gut microbiota alterations promoted immune activation and the blood-brain barrier (BBB) (11,23).…”

Therapeutic Approach to Alzheimer’s Disease: Current Treatments and New Perspectives

“…In fact, the adoption of this type of dietary pattern has been found to be effective in reducing insulin resistance [139]. This finding is particularly important, as DM doubles the risk of dementia [140]. Among the different foods that comprise this diet, we can highlight those containing vitamin C (citrus fruits and some vegetables) and vitamin E (nuts, cereals and egg yolk), as they have been shown to reduce the accumulation of Aβ and improve cognitive capacity [138,139].…”

Novel insights into non-alcoholic fatty liver disease and dementia: insulin resistance, hyperammonemia, gut dysbiosis, vascular impairment, and inflammation

“…Inflammation is positively correlated with NAFLD and dementia [136][137][138][139]. In NAFLD, the excessive production of proinflammatory cytokines and chemokines is triggered by hepatic fat accumulation and hepatocyte damage [137].…”

“…Immune cells, such as macrophages and natural killer T cells, induce the progression of NAFLD [ 137 , 141 ]. Chronic neuroinflammation by the activated microglia and cytokines is observed in the brain of patients with AD [ 136 ], and elevated systemic inflammation results in increased risk for diabetes dementia [ 139 ].…”

“…Thereby, chronic or systemic inflammation induces the secretion of inflammatory cytokines in the microglia and immune cells and ultimately the development of both NAFLD and dementia [ 136 , 137 , 139 ]. The modulation of systemic inflammation and neuroinflammation is an important strategy in attenuating the pathological problems associated with NAFLD and dementia.…”