Dementia in Diabetes: The Role of Hypoglycemia

Continuous Glucose Monitoring in Comorbid Dementia and Diabetes: The Evidence So Far

BACKGROUND

Type 2 diabetes mellitus (T2DM) and dementia are two of the leading chronic diseases in aging and are known to influence each other's disease progression. There is well-established evidence that T2DM increases the risk for cognitive decline and dementia. At the same time, people with cognitive changes or dementia can find it difficult to manage their diabetes, resulting in hyper- or hypoglycemic events which can exacerbate the dementia disease progression further. Monitoring of glucose variability is, therefore, of critical importance during aging and when people with T2DM develop dementia. The advent of continuous glucose monitoring (CGM) has allowed the monitoring of glucose variability in T2DM more closely. The CGM seems to be highly feasible and acceptable to use in older people with T2DM and has been shown to significantly reduce their hypoglycemic events, often resulting in falls. Less is known as to whether CGM can have a similar beneficial effect on people with T2DM who have cognitive impairment or dementia in community or hospital settings.

AIMS

The current perspective will explore how CGM has made an impact on T2DM management in older people and those with comorbid cognitive impairment or dementia. We will further explore opportunities and challenges of using CGM in comorbid T2DM and dementia in community and hospital settings.

Postprandial hypoglycemia as a complication of bariatric and metabolic surgery: a comprehensive review of literature

Postprandial hypoglycemia (PPH) is a challenging and significant complication that can occur following bariatric and metabolic surgery. Symptoms of PPH are typical of hypoglycemia, such as sweating, weakness, disorientation, palpitation, etc. The complex nature of PPH is essential to achieve accurate diagnosis and effective management. This review aims to give extensive coverage of the intricate nature of PPH common with bariatric and metabolic surgery, outlining its pathogenesis, risk factors, clinical presentation, diagnostic strategies, and treatment options. The study explores various clinical forms and pathogenic mechanisms behind PPH while discussing diagnostic tools like continuous glucose monitoring or mixed meal tolerance tests. Furthermore, it considers possible interventions, including dietary changes, pharmaceutical therapies, and surgeries, to relieve symptoms and improve patient's quality of life. It aims to comprehensively understand how healthcare professionals can effectively manage this disorder for patients undergoing bariatric and metabolic surgery.

Cognitive Disorders in Type 1 Diabetes: Role of Brain Glucose Variation, Insulin Activity, and Glucocorticoid Exposure

BACKGROUND

The number of patients with type 2 diabetes (T2D) and type 1 diabetes (T1D) is on the rise, partly due to a global increase in new T1D cases among children. Beyond the well-documented microvascular and macrovascular complications, there is now substantial evidence indicating that diabetes also impacts the brain, leading to neuropsychological impairments. The risk of developing neuropsychiatric symptoms is notably higher in childhood due to the ongoing maturation of the brain, which makes it more susceptible to damage. Despite this awareness, the specific effects of diabetes on cognitive function remain poorly understood.

SUMMARY

This review synthesizes literature on the impact of diabetes on cognition and its relationship with brain structural changes. It presents data and hypotheses to explain how T1D contributes to cognitive dysfunction, with a particular focus on children and adolescents. The emphasis on the pediatric population is intentional, as young diabetic patients typically have fewer comorbidities, reducing confounding factors and simplifying the investigation of cognitive alterations.

KEY MESSAGE

We examine the roles of hypo- and hyperglycemia, as well as the emerging role of glucocorticoids in the development of neuropsychological disorders. When specific mechanisms related to T1D are available, they are highlighted; otherwise, data and hypotheses applicable to both T1D and T2D are discussed.

The Intersection between Frailty, Diabetes, and Hypertension: The Critical Role of Community Geriatricians and Pharmacists in Deprescribing

Background: Frailty is a clinical syndrome prevalent among the elderly, characterised by a decline in physiological reserves and increased susceptibility to stressors, resulting in higher morbidity and mortality. Diabetes and hypertension are common in frail older individuals, often leading to polypharmacy. In this narrative review, we aimed to evaluate the relationship between frailty, diabetes, and hypertension and to identify effective management strategies and future research directions. Methods: This narrative review was conducted using the Scopus, Medline, PubMed, Cochrane Library, and Google Scholar databases. Results: Frailty significantly impacts the management and prognosis of diabetes and hypertension, which, in turn, affects the progression of frailty. Managing these conditions often involves multiple drugs to achieve strict glycaemic control and blood pressure targets, leading to polypharmacy and associated morbidities, including orthostatic hypotension, falls, fractures, hypoglycaemia, and reduced medication adherence. Identifying frailty and implementing strategies like deprescribing can mitigate the adverse effects of polypharmacy and improve outcomes and quality of life. Despite the availability of effective tools for identifying frailty, many frail individuals continue to be exposed to complex treatment regimens for diabetes and hypertension, leading to increased hospital admissions, morbidity, and mortality. Conclusions: Managing diabetes and hypertension in the frail ageing population requires a multidisciplinary approach involving hospital and community geriatricians and pharmacists. This is important due to the lack of sufficient clinical trials dedicated to diabetes and hypertension in the context of frailty. Future large population studies are needed to assess the best approaches for managing diabetes and hypertension in frail individuals.

Diabetes accelerates Alzheimer's disease progression in the first year post mild cognitive impairment diagnosis

BACKGROUND

Mild cognitive impairment (MCI) heightens Alzheimer's disease (AD) risk, with diabetes mellitus (DM) potentially exacerbating this vulnerability. This study identifies the optimal intervention period and neurobiological targets in MCI to AD progression using the Alzheimer's Disease Neuroimaging Initiative dataset.

METHODS

Analysis of 980 MCI patients, categorized by DM status, used propensity score matching and inverse probability treatment weighting to assess rate of conversion from MCI to AD, neuroimaging, and cognitive changes.

RESULTS

DM significantly correlates with cognitive decline and an increased risk of progressing to AD, especially within the first year of MCI follow-up. It adversely affects specific brain structures, notably accelerating nucleus accumbens atrophy, decreasing gray matter volume and sulcal depth.

DISCUSSION

Findings suggest the first year after MCI diagnosis as the critical window for intervention. DM accelerates MCI-to-AD progression, targeting specific brain areas, underscoring the need for early therapeutic intervention.

HIGHLIGHTS

Diabetes mellitus (DM) accelerates mild cognitive impairment (MCI)-to-Alzheimer's disease (AD) progression within the first year after MCI diagnosis. DM leads to sharper cognitive decline within 12 months of follow-up. There is notable nucleus accumbens atrophy observed in MCI patients with DM. DM causes significant reductions in gray matter volume and sulcal depth. There are stronger correlations between cognitive decline and brain changes due to DM.

Effects of prediabetes and type 2 diabetes on cognitive functions

INTRODUCTION

We aimed to investigate the effect of glycemic impairment in prediabetes on cognitive impairment and the impact of glycemic control on cognitive function in patients with diabetes.

MATERIALS AND METHODS

This age- and sex-matched case-control study included a total of 80 individuals: 20 patients with prediabetes, 20 patients with well-controlled type 2 diabetes mellitus (T2DM) (HbA1C < %7.5), 20 patients with poorly controlled T2DM (HbA1C >% 7.5), and 20 healthy controls.

RESULTS

The poorly controlled T2DM patients performed significantly worse than controls and patients with prediabetes in the verbal memory process test (p = 0.041). In Trail Making Test B, the well-controlled and poorly-controlled groups with diabetes performed significantly worse (p = 0.015) than patients with prediabetes and controls, and in the Wisconsin Card Sorting Test (WCST), all three patient groups performed significantly worse (p = 0.007) than controls.

CONCLUSION

T2DM causes early brain aging and declines cognitive functions since the prediabetic stage. Poor glycemic control in T2DM patients contributes to cognitive impairments, especially in learning.

Alterations in Brain Morphometric Networks and Their Relationship with Memory Dysfunction in Patients with Type 2 Diabetes Mellitus

Cognitive dysfunction, a significant complication of type 2 diabetes mellitus (T2DM), can potentially manifest even from the early stages of the disease. Despite evidence of global brain atrophy and related cognitive dysfunction in early-stage T2DM patients, specific regions vulnerable to these changes have not yet been identified. The study enrolled patients with T2DM of less than five years' duration and without chronic complications (T2DM group, n=100) and demographically similar healthy controls (control group, n=50). High-resolution T1-weighted magnetic resonance imaging data were subjected to independent component analysis to identify structurally significant components indicative of morphometric networks. Within these networks, the groups' gray matter volumes were compared, and distinctions in memory performance were assessed. In the T2DM group, the relationship between changes in gray matter volume within these networks and declines in memory performance was examined. Among the identified morphometric networks, the T2DM group exhibited reduced gray matter volumes in both the precuneus (Bonferroni-corrected p=0.003) and insular-opercular (Bonferroni-corrected p=0.024) networks relative to the control group. Patients with T2DM demonstrated significantly lower memory performance than the control group (p=0.001). In the T2DM group, reductions in gray matter volume in both the precuneus (r=0.316, p=0.001) and insular-opercular (r=0.199, p=0.047) networks were correlated with diminished memory performance. Our findings indicate that structural alterations in the precuneus and insular-opercular networks, along with memory dysfunction, can manifest within the first 5 years following a diagnosis of T2DM.

Glucose Transport and Utilization in the Hippocampus: From Neurophysiology to Diabetes-Related Development of Dementia

The association of diabetes with cognitive dysfunction has at least 60 years of history, which started with the observation that children with type 1 diabetes mellitus (T1D), who had recurrent episodes of hypoglycemia and consequently low glucose supply to the brain, showed a deficit of cognitive capacity. Later, the growing incidence of type 2 diabetes mellitus (T2D) and dementia in aged populations revealed their high association, in which a reduced neuronal glucose supply has also been considered as a key mechanism, despite hyperglycemia. Here, we discuss the role of glucose in neuronal functioning/preservation, and how peripheral blood glucose accesses the neuronal intracellular compartment, including the exquisite glucose flux across the blood-brain barrier (BBB) and the complex network of glucose transporters, in dementia-related areas such as the hippocampus. In addition, insulin resistance-induced abnormalities in the hippocampus of obese/T2D patients, such as inflammatory stress, oxidative stress, and mitochondrial stress, increased generation of advanced glycated end products and BBB dysfunction, as well as their association with dementia/Alzheimer's disease, are addressed. Finally, we discuss how these abnormalities are accompained by the reduction in the expression and translocation of the high capacity insulin-sensitive glucose transporter GLUT4 in hippocampal neurons, which leads to neurocytoglycopenia and eventually to cognitive dysfunction. This knowledge should further encourage investigations into the beneficial effects of promising therapeutic approaches which could improve central insulin sensitivity and GLUT4 expression, to fight diabetes-related cognitive dysfunctions.

Diabetes-Alzheimer's connection in older age: SGLT2 inhibitors as promising modulators of disease pathways

Late-onset Alzheimer's disease (LOAD) is the most frequent cause of dementia in older persons. Subjects affected by type 2 diabetes mellitus (T2DM) are at higher risk of vascular disease, cognitive decline, and dementia. LOAD has many characteristics shared with impaired insulin signaling pathways, and substantial evidence has demonstrated a pivotal role in dysregulated glucose metabolism in its pathogenesis. Recent studies have shown that some anti-diabetic drugs, other than regulating the metabolism of peripheral tissues, can also modulate the brain's metabolism, reduce inflammation, and have a direct neuroprotective effect. Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are a newer class with many pleiotropic effects that may have strong neuroprotective potential. After a summary of the principal "anti-diabetic" drugs acting as suitable candidates in treating LOAD, this narrative review explored the potential role of SGLT2i on cognition from pre-clinical to clinical studies.