Cognitive Impairment and Diabetes

World Journal of Diabetes, 2016

There is strong evidence that diabetes mellitus increases the risk of cognitive impairment and dementia. Insulin signaling dysregulation and small vessel disease in the base of diabetes may be important contributing factors in Alzheimer's disease and vascular dementia pathogenesis, respectively. Optimal glycemic control in type 1 diabetes and identification of diabetic risk factors and prophylactic approach in type 2 diabetes are very important in the prevention of cognitive complications. In addition, hypoglycemic attacks in children and elderly should be avoided. Anti-diabetic medications especially Insulin may have a role in the management of cognitive dysfunction and dementia but further investigation is needed to validate these findings.

Alzheimer's & Dementia, 2021

Background: Despite the well-established link between diabetes and dementia risk, the impact of prediabetes and diabetes on the prodromal dementia phase remains controversial. In this study, we investigated whether prediabetes and diabetes increase the risk of cognitive impairment-no dementia (CIND) and accelerate its progression to dementia, as well as the possible underlying mechanisms. Methods: In the Swedish National Study on Aging and Care-Kungsholmen (SNAC-K), one cohort of cognitivelyintact individuals (n=1,837) and one cohort of individuals with CIND (n=671) aged ≥60 years were followed for up to 15 years. At baseline and each follow-up (every 3 or 6 years), a neuropsychological test battery was administered, and the domains of episodic memory, processing speed, executive function, visuospatial abilities, and language were derived. CIND was defined as having no dementia and cognitive performance ≤1.5 SDs below age groupspecific means in at least one cognitive domain. Dementia was diagnosed according to DSM-IV criteria. Diabetes (controlled and poorly-controlled) was diagnosed by physicians through medical assessment, clinical records, and glycated hemoglobin (HbA1c) ≥6.5%. Prediabetes was identified as HbA1c 5.7-6.4% in diabetes-free participants. Clinicians diagnosed heart disease and collected blood samples used to measure C-reactive protein (CRP). Data were analyzed with Cox regression models adjusted for possible confounders. Results: At baseline, in the cognitively-intact cohort, 133 (7%) participants had diabetes and 615 (34%) had prediabetes. During follow-up (mean 9.2 ± 3.0 years [range=2.2-15.5 years]), 544 (30%) individuals in the cognitively-intact cohort developed CIND. Poorly-controlled diabetes (HbA1c ≥7.5%) was associated with 2-times higher risk of CIND (HR 2.0, 95% CI:1.11-3.48) than diabetes-free participants. In the CIND cohort, 84 (13%) had diabetes and 238 (36%) prediabetes. During follow-up (mean 7.7 ± 4.0 years [range=0.2-15.2 years]), 132 (20%) individuals progressed to dementia. Poorly-controlled diabetes was associated with 3-times higher risk of dementia progression (HR 3.3, 95% CI: 1.29-8.33). Furthermore, comorbid heart disease and diabetes was associated with 2.5-times higher risk of progression to dementia (HR 2.5, 95% CI: 1.17-5.47), particularly if the diabetes was poorly-controlled (HR 5.8, 95% CI: 1.72-19.3). Similarly, having elevated CRP levels and diabetes was associated with increased risk of progression to dementia (HR 4.1, 95% CI: 1.15-14.2), especially in participants with poorly-controlled diabetes (HR 13.6, 95% CI: 1.89-98). No associations between prediabetes and CIND were detected in either cohort. Conclusions: Diabetes, especially if poorly-controlled, increases the risk of cognitive impairment and accelerates its progression to dementia. The diabetes-associated progression from CIND to dementia is further exacerbated by the presence of heart disease and elevated levels of systemic inflammation.

Diabetologia, 2005

Aims/hypothesis: We systematically reviewed and summarised prospective data relating diabetes status to changes in cognitive function over time. Methods: Published reports of longitudinal studies that described assessment of cognitive function in people with diabetes were sought. Studies were included if they assessed cognitive function in participants with diabetes at the beginning and at follow-up. Studies were excluded if they had (1) a follow-up period of less than 1 year, (2) a rate of loss to followup in excess of 30%, or (3) described selected subgroups. Change in cognitive function was recorded as either the mean change in score and/or the proportion of individuals developing various degrees of change in cognitive function. A pooled estimate was calculated for the latter. Results: Of 1,165 abstracts and titles initially identified, 25 articles met the inclusion and exclusion criteria. Individuals with diabetes had a 1.2-to 1.5-fold greater change over time in measures of cognitive function than those without diabetes. When assessed by the Mini-Mental State Exam and the Digit Symbol Span tests, a diagnosis of diabetes increased the odds of cognitive decline 1.2-fold (95% CI 1.05-1.4) and 1.7-fold (95% CI 1.3-2.3), respectively. The odds of future dementia increased 1.6-fold (95% CI 1.4-1.8). Conclusions/ interpretation: Compared to people without diabetes, people with diabetes have a greater rate of decline in cognitive function and a greater risk of cognitive decline. Cognitive dysfunction should therefore be added to the list of chronic complications of diabetes.

Drug Development Research, 2019

Diabetes mellitus (DM) is a gradually rising metabolic disease which is currently affecting millions of people worldwide. Diabetes is associated with various complications like nephropathy, neuropathy, retinopathy, diabetic foot, cognitive impairment, and many more. Evidence suggests that cognitive dysfunction is a rising complication of diabetes which adversely affects the brain of patients suffering from diabetes. Age-related memory impairment is a complication having its major effect on people suffering from diabetes and Alzheimer's. Patients suffering from diabetes are at two times higher risk of developing cognitive dysfunction as compared with normal individuals. Multiple factors which are involved in diabetes related complications are found to play a role in the development of neurodegeneration in Alzheimer's. The problem of insulin deficiency and insulin resistance is well reported in diabetes but there are many studies which suggest dysregulation of insulin levels as a reason behind the development of Alzheimer's. As the link between diabetes and Alzheimer disease (AD) is deepening, there is a need to understand the plausible tie-ins between the two. Emerging role of major factors like insulin imbalance, advanced glycation end products and micro-RNA's involved in diabetes and Alzheimer's have been discussed here. This review helps in understanding the plausible mechanism underlying the pathophysiology of amyloid beta (Aβ) plaque formation and tau hyperphosphorylation as well provides information about studies carried out in this area of research. The final thought is to enhance the scientific knowledge on this correlation and develop future therapeutics to treat the same.

Pharmaspire, 2022

Diabetes mellitus (DM) is a complex metabolic condition characterized by persistent hyperglycemia and poor metabolism due to insulin production irregularities and/or insulin resistance type 2 DM (T2DM) and dementia are linked through a variety of methods. Thus, in terms of the long-term repercussions of diabetes, the current idea focuses on cognitive damage, the exact pathophysiology of which is unknown. A new term, "diabetes-associated cognitive decline," has recently been proposed to aid study in this field. This review discusses how different variables contribute to the development of T2DM. Furthermore, we investigated an expanding body of literature on insulin signaling in diabetics, as well as various factors such as insulin resistance, hyperglycemia, neuroinflammation, and Aβ (amyloid beta) plaques that may act alone or in combination to link T2DM with cognitive impairments. Finally, we looked at how physical activity and a balanced diet might help fight the condition.

The Lancet. Neurology, 2015

Diabetes mellitus is associated with an increase in the risk of dementia and the proportion of patients who convert from mild cognitive impairment (MCI) to dementia. In addition to MCI and dementia, the stages of diabetes-associated cognitive dysfunction include subtle cognitive changes that are unlikely to affect activities of daily life or diabetes self-management. These diabetes-associated cognitive decrements have structural brain correlates detectable with brain MRI, but usually show little progression over time. Although cognitive decrements do not generally represent a pre-dementia stage in patients below the age of 60-65 years, in older individuals these subtle cognitive changes might represent the earliest stages of a dementia process. Acknowledgment of diabetes-associated cognitive decrements can help to improve understanding of patients' symptoms and guide management. Future challenges are to establish the importance of screening for cognitive impairment in people wit...

The Cochrane database of systematic reviews, 2017

Prevention of cognitive impairment and dementia is an important public health goal. Epidemiological evidence shows a relationship between cognitive impairment and Type 2 diabetes mellitus. The risk of dementia increases with duration of disease. This updated systematic review investigated the effect on cognitive function of the type of treatment and level of metabolic control in people with Type 2 diabetes. To assess the effects of different strategies for managing Type 2 diabetes mellitus on cognitive function and the incidence of dementia. We searched ALOIS (the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (CDCIG)), the Cochrane Library, MEDLINE, Embase, PsycINFO, CINAHL and LILACS on 15 October 2016. ALOIS contains records from all major health care databases, (CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, LILACS), as well as from many trials' registers and grey literature sources. We included randomised controlled trials (RCTs) which compared t...

Archives of Neurology, 2004

Background: Few prospective studies have assessed diabetes mellitus as a risk factor for incident Alzheimer disease (AD) and decline in cognitive function.

Neurología Argentina, 2015

ABSTRACT

Journal of Basic and Clinical Physiology and Pharmacology, 2020

Mild cognitive impairment (MCI) is a modifiable risk factor in progression of several diseases including dementia and type 2 diabetes. If cognitive impairments are not reversed at an early stage of appearance of symptoms, then the prolonged pathogenesis can lead to dementia and Alzheimer’s disease (AD). Therefore, it is necessary to detect the risk factors and mechanism of prevention of cognitive dysfunction at an early stage of disease. Poor lifestyle, age, hyperglycemia, hypercholesterolemia, and inflammation are some of the major risk factors that contribute to cognitive and memory impairments in diabetic patients. Mild cognitive impairment was seen in those individuals of type 2 diabetes, who are on an unhealthy diet. Physical inactivity, frequent alcohol consumptions, and use of packed food products that provides an excess of cheap calories are found associated with cognitive impairment and depression in diabetic patients. Omega fatty acids (FAs) and polyphenol-rich foods, espe...