Diabetes mellitus and risk of dementia: A meta-analysis of prospective observational studies

The Potential of a Stratified Approach to Drug Repurposing in Alzheimer's Disease

Alzheimer's disease (AD) is a complex neurodegenerative condition that is characterized by the build-up of amyloid-beta plaques and neurofibrillary tangles. While multiple theories explaining the aetiology of the disease have been suggested, the underlying cause of the disease is still unknown. Despite this, several modifiable and non-modifiable factors that increase the risk of developing AD have been identified. To date, only eight AD drugs have ever gained regulatory approval, including six symptomatic and two disease-modifying drugs. However, not all are available in all countries and high costs associated with new disease-modifying biologics prevent large proportions of the patient population from accessing them. With the current patient population expected to triple by 2050, it is imperative that new, effective, and affordable drugs become available to patients. Traditional drug development strategies have a 99% failure rate in AD, which is far higher than in other disease areas. Even when a drug does reach the market, additional barriers such as high cost and lack of accessibility prevent patients from benefiting from them. In this review, we discuss how a stratified medicine drug repurposing approach may address some of the limitations and barriers that traditional strategies face in relation to drug development in AD. We believe that novel, stratified drug repurposing studies may expedite the discovery of alternative, effective, and more affordable treatment options for a rapidly expanding patient population in comparison with traditional drug development methods.

Metformin: The Winding Path from Understanding Its Molecular Mechanisms to Proving Therapeutic Benefits in Neurodegenerative Disorders

Metformin, a widely prescribed medication for type 2 diabetes, has garnered increasing attention for its potential neuroprotective properties due to the growing demand for treatments for Alzheimer's, Parkinson's, and motor neuron diseases. This review synthesizes experimental and clinical studies on metformin's mechanisms of action and potential therapeutic benefits for neurodegenerative disorders. A comprehensive search of electronic databases, including PubMed, MEDLINE, Embase, and Cochrane library, focused on key phrases such as "metformin", "neuroprotection", and "neurodegenerative diseases", with data up to September 2023. Recent research on metformin's glucoregulatory mechanisms reveals new molecular targets, including the activation of the LKB1-AMPK signaling pathway, which is crucial for chronic administration of metformin. The pleiotropic impact may involve other stress kinases that are acutely activated. The precise role of respiratory chain complexes (I and IV), of the mitochondrial targets, or of the lysosomes in metformin effects remains to be established by further research. Research on extrahepatic targets like the gut and microbiota, as well as its antioxidant and immunomodulatory properties, is crucial for understanding neurodegenerative disorders. Experimental data on animal models shows promising results, but clinical studies are inconclusive. Understanding the molecular targets and mechanisms of its effects could help design clinical trials to explore and, hopefully, prove its therapeutic effects in neurodegenerative conditions.

Inflammatory Pathways in Overweight and Obese Persons as a Potential Mechanism for Cognitive Impairment and Earlier Onset Alzeihmer's Dementia in the General Population: A Narrative Review

The overweight status or obesity can be confirmed through classical methods such as the body mass index (BMI) and the waist-to-hip ratio (WHR). Apart from metabolic issues such as atherosclerosis, liver steatosis, or diabetes mellitus, long-term obesity or overweight status can pose a risk for cardiovascular and neurovascular complications. While some acute adverse events like coronary syndromes of strokes are well-documented to be linked to an increased body mass, there are also chronic processes that, due to their silent onset and evolution, are underdiagnosed and not as thoroughly studied. Through this review, we aimed to collect all relevant data with regard to the long-term impact of obesity on cognitive function in all ages and its correlation with an earlier onset of dementia such as Alzheimer's disease (AD). The exact mechanisms through which a decline in cognitive functions occurs in overweight or obese persons are still being discussed. A combination of factors has been acknowledged as potential triggers, such as a sedentary lifestyle and stress, as well as a genetic predisposition, for example, the apolipoprotein E (ApoE) alleles in AD. Most research highlights the impact of vascular dysfunction and systemic inflammation on the nervous system in patients with obesity and the subsequent neurological changes. Obesity during the early to mid-ages leads to an earlier onset of cognitive dysfunction in various forms. Also, lifestyle intervention can reverse cognitive dysfunction, especially dieting, to encourage weight loss.

Therapeutic choices in elderly diabetic patients

The care of elderly diabetic patients has now become a real public health issue due to the increase in the number of patients. In this population, complications are more serious and are intertwined with more specifically gerontological issues. Treatment goals should be individualized based on the patient's clinical presentation. New therapeutic drug classes are particularly interesting because of their effectiveness in terms of cardiovascular and renal protection, but the risk/benefit ratio needs to be well assessed on an individual basis. Insulin therapy is often necessary, either in case of failure of oral antidiabetics or because of comorbidities, particularly in the event of renal failure. Educating the patient and family early in the course of the disease is one of the keys to effective and safe treatment. The management of elderly diabetic patients must avoid both too much laxity in those who have successfully aged and unreasonable activism in fragile subjects because of the risk of hypoglycemia.

Dementia risk in patients with type 2 diabetes: Comparing metformin with no pharmacological treatment

INTRODUCTION

Metformin has been suggested as a therapeutic agent for dementia, but the relevant evidence has been partial and inconsistent.

METHODS

We established a national cohort of 210,237 type 2 diabetes patients in the UK Clinical Practice Research Datalink. Risks of incident dementia were compared between metformin initiators and those who were not prescribed any anti-diabetes medication during follow-up.

RESULTS

Compared with metformin initiators (n = 114,628), patients who received no anti-diabetes medication (n = 95,609) had lower HbA1c and better cardiovascular health at baseline. Both Cox regression and propensity score weighting analysis showed metformin initiators had lower risk of dementia compared to those non-users (adjusted hazard ratio = 0.88 [95% confidence interval: 0.84-0.92] and 0.90 [0.84-0.96]). Patients on long-term metformin treatment had an even lower risk of dementia.

DISCUSSION

Metformin may act beyond its glycemic effect and reduce dementia risk to an even lower level than that of patients with milder diabetes and better health profiles.

HIGHLIGHTS

Metformin initiators had a significantly lower risk of dementia compared with patients not receiving anti-diabetes medication. Compared with metformin initiators, diabetes patients not receiving pharmacological treatment had better glycemic profiles at baseline and during follow-up. Patients on long-term metformin treatment had an even lower risk of subsequent dementia incidence. Metformin may act beyond its effect on hyperglycemia and has the potential of being repurposed for dementia prevention.

Lipids and lipoproteins may play a role in the neuropathology of Alzheimer's disease

Alzheimer's disease (AD) and other classes of dementia are important public health problems with overwhelming social, physical, and financial effects for patients, society, and their families and caregivers. The pathophysiology of AD is poorly understood despite the extensive number of clinical and experimental studies. The brain's lipid-rich composition is linked to disturbances in lipid homeostasis, often associated with glucose and lipid abnormalities in various neurodegenerative diseases, including AD. Moreover, elevated low-density lipoprotein (LDL) cholesterol levels may be related to a higher probability of AD. Here, we hypothesize that lipids, and electronegative LDL (L5) in particular, may be involved in the pathophysiology of AD. Although changes in cholesterol, triglyceride, LDL, and glucose levels are seen in AD, the cause remains unknown. We believe that L5-the most electronegative subfraction of LDL-may be a crucial factor in understanding the involvement of lipids in AD pathology. LDL and L5 are internalized by cells through different receptors and mechanisms that trigger separate intracellular pathways. One of the receptors involved in L5 internalization, LOX-1, triggers apoptotic pathways. Aging is associated with dysregulation of lipid homeostasis, and it is believed that alterations in lipid metabolism contribute to the pathogenesis of AD. Proposed mechanisms of lipid dysregulation in AD include mitochondrial dysfunction, blood-brain barrier disease, neuronal signaling, inflammation, and oxidative stress, all of which lead ultimately to memory loss through deficiency of synaptic integration. Several lipid species and their receptors have essential functions in AD pathogenesis and may be potential biomarkers.

Precision Medicine in Type 2 Diabetes Mellitus: Utility and Limitations

Type 2 diabetes mellitus (T2DM) is one of the most widespread diseases in Western countries, and its incidence is constantly increasing. Epidemiological studies have shown that in the next 20 years. The number of subjects affected by T2DM will double. In recent years, owing to the development and improvement in methods for studying the genome, several authors have evaluated the association between monogenic or polygenic genetic alterations and the development of metabolic diseases and complications. In addition, sedentary lifestyle and socio-economic and pandemic factors have a great impact on the habits of the population and have significantly contributed to the increase in the incidence of metabolic disorders, obesity, T2DM, metabolic syndrome, and liver steatosis. Moreover, patients with type 2 diabetes appear to respond to antihyperglycemic drugs. Only a minority of patients could be considered true non-responders. Thus, it appears clear that the main aim of precision medicine in T2DM is to identify patients who can benefit most from a specific drug class more than from the others. Precision medicine is a discipline that evaluates the applicability of genetic, lifestyle, and environmental factors to disease development. In particular, it evaluated whether these factors could affect the development of diseases and their complications, response to diet, lifestyle, and use of drugs. Thus, the objective is to find prevention models aimed at reducing the incidence of pathology and mortality and therapeutic personalized approaches, to obtain a greater probability of response and efficacy. This review aims to evaluate the applicability of precision medicine for T2DM, a healthcare burden in many countries.

Reduced risk of dementia in patients with type 2 diabetes mellitus using Chinese herbal medicine: A nested case-control study

BACKGROUND

Dementia is a prevalent condition in type 2 diabetes mellitus (T2DM) patients. While Chinese herbal medicine (CHM) is often employed as complementary therapy for glycemic control, its effect in controlling likelihood of dementia has not yet been fully elucidated.

AIM

To compare the risk of dementia between T2DM patients with and without CHM treatment.

METHODS

We undertook a nested case-control study and obtained data on patients 20-70 years of age who received medical care for T2DM between 2001 and 2010 from the National Health Insurance Research database in Taiwan. Cases, defined as those with dementia that occurred at least one year after the diagnosis of T2DM, were randomly matched to controls without dementia from the study cohort at a 1:1 ratio. We applied conditional logistic regression to explore the associations between CHM treatment and dementia.

RESULTS

A total of 11699 dementia cases were matched to 11699 non-dementia controls. We found that adding CHM to conventional care was related to a lower risk of dementia [adjusted odds ratio (OR) = 0.51], and high-intensity CHM treatment was associated with an adjusted OR of 0.22.

CONCLUSION

This study shows that the cumulative CHM exposure was inversely associated with dementia risk in an exposure-response manner, implying that CHM treatment may be embraced as a disease management approach for diabetic patients to prevent dementia.

Insights from insulin resistance pathways: Therapeutic approaches against Alzheimer associated diabetes mellitus

Alzheimer Associated Diabetes Mellitus, commonly known as Type 3 Diabetes Mellitus (T3DM) is a distinct subtype of diabetes with a pronounced association with Alzheimer's disease (AD). Insulin resistance serves as a pivotal link between these two conditions, leading to diminished insulin sensitivity, hyperglycemia, and impaired glucose uptake. The brain, a vital organ in AD context, is also significantly impacted by insulin resistance, resulting in energy deficits and neuronal damage, which are hallmark features of the neurodegenerative disorder. To pave the way for potential therapeutic interventions targeting the insulin resistance pathway, it is crucial to comprehend the intricate pathophysiology of T3DM and identify the overlapped features between diabetes and AD. This comprehensive review article aims to explore various pathway such as AMPK, PPARγ, cAMP and P13K/Akt pathway as potential target for management of T3DM. Through the analysis of these complex mechanisms, our goal is to reveal their interdependencies and support the discovery of innovative therapeutic strategies. The review extensively discusses several promising pharmaceutical candidates that have demonstrated dual drug action mechanisms, addressing both peripheral and cerebral insulin resistance observed in T3DM. These candidates hold significant promise for restoring insulin function and mitigating the detrimental effects of insulin resistance on the brain. The exploration of these therapeutic options contributes to the development of innovative interventions that alleviate the burden of T3DM and enhance patient care.

Acetylation in pathogenesis: Revealing emerging mechanisms and therapeutic prospects

Protein acetylation modifications play a central and pivotal role in a myriad of biological processes, spanning cellular metabolism, proliferation, differentiation, apoptosis, and beyond, by effectively reshaping protein structure and function. The metabolic state of cells is intricately connected to epigenetic modifications, which in turn influence chromatin status and gene expression patterns. Notably, pathological alterations in protein acetylation modifications are frequently observed in diseases such as metabolic syndrome, cardiovascular disorders, and cancer. Such abnormalities can result in altered protein properties and loss of function, which are closely associated with developing and progressing related diseases. In recent years, the advancement of precision medicine has highlighted the potential value of protein acetylation in disease diagnosis, treatment, and prevention. This review includes provocative and thought-provoking papers outlining recent breakthroughs in acetylation modifications as they relate to cardiovascular disease, mitochondrial metabolic regulation, liver health, neurological health, obesity, diabetes, and cancer. Additionally, it covers the molecular mechanisms and research challenges in understanding the role of acetylation in disease regulation. By summarizing novel targets and prognostic markers for the treatment of related diseases, we aim to contribute to the field. Furthermore, we discuss current hot topics in acetylation research related to health regulation, including N4-acetylcytidine and liquid-liquid phase separation. The primary objective of this review is to provide insights into the functional diversity and underlying mechanisms by which acetylation regulates proteins in disease contexts.

Five-Year Follow-Up of Diabetic Complications and Geriatric Alterations in French Older Patients with Type 2 Diabetes According to Treatment Modalities: The Observational Prospective GERODIAB Cohort

BACKGROUND

Little is known about clinical events occurring in older patients with type 2 diabetes mellitus according to their therapeutic modalities based on the prescription of insulin and/or oral antidiabetic drugs.

OBJECTIVE

The aim of this study was to compare the complications of diabetes and geriatric alterations that occurred according to three therapeutic modalities prescribed over 5 years.

METHODS

A total of 616 patients from the GERODIAB cohort (mean age 77.1 years) were divided into three groups: an insulin-only group (n = 200), a group receiving insulin and one or more oral antidiabetic drug (n = 169), and an oral antidiabetic drug group without insulin (n = 247). We compared the diabetic complications and geriatric alterations that occurred over 5 years in patients without these pre-existing complications.

RESULTS

At inclusion, there was a significant difference between glycosylated hemoglobin values, and between the frequencies of most diabetic complications and geriatric alterations, with higher frequencies in the insulin group and lower frequencies in the oral antidiabetic drug group. At the end of the follow-up, there was still a significant difference between the mean glycosylated hemoglobin of the three groups (mean for all patients 7.4 ± 0.8%). The frequencies of new clinical events were high and they were generally higher in the insulin group. They were not significantly different between the three groups, with the exception of four events: heart failure, retinopathy, transfer to a nursing home (more frequent in the insulin group), and hypoglycemia (more frequent in the insulin + oral antidiabetic drug group). Some frequencies of the total diabetic complications (including complications at inclusion and at the follow-up) in the oral antidiabetic drug group were close to those in the insulin group, although only at inclusion. Mortality was higher in the insulin group and lower in the oral antidiabetic drug group.

CONCLUSIONS

The increased frequency of hypoglycemia in the insulin + oral antidiabetic drug group raises doubts about the value of continuing a secretagogue drug when insulin is introduced. As the vast majority of patients were not yet receiving antidiabetic drugs with cardiovascular action, our results on heart failure could help in conducting specific studies on these drugs in older patients with type 2 diabetes.

Prevalence and incidence of mild cognitive impairment in adults with diabetes in the United States

BACKGROUND

Limited evidence exists about the prevalence and incidence of mild cognitive impairment (MCI) in individuals with diabetes in the U.S. We aimed to address such knowledge gaps using a nationally representative study dataset.

METHOD

We conducted a secondary analysis from the Health and Retirement Study (HRS) (1996-2018). The sample for examining the prevalence of MCI was14,988, with 4192 (28.0%) having diabetes, while the sample for the incidence was 21,824, with 1534 (28.0%) having diabetes.

RESULTS

Participants with diabetes had a higher prevalence of MCI than those without diabetes (19.9 % vs. 14.8 %; odds ratio [95 % confidence interval] (OR[95 %CI]): 1.468 [1.337, 1.611], p <.001). The incidence of MCI in participants with/without newly diagnosed diabetes was 42.9 % vs. 31.6 % after a mean 10-year follow-up, with the incidence rate ratio (IRR) [95 %CI] (1.314 [1.213, 1.424], p <.001). Newly diagnosed diabetes was associated with elevated risks of MCI compared with non-diabetes, with the uncontrolled hazard ratio (HR) [95 %CI] (1.498 [1.405, 1.597], p <.001).

CONCLUSIONS

Using a nationally representative study data in the U.S., participants with diabetes had a higher prevalence and incidence of MCI than those without diabetes. Findings show the importance of developing interventions tailored to the needs of individuals with diabetes and cognitive impairment.

A pancreatic player in dementia: pathological role for islet amyloid polypeptide accumulation in the brain

Type 2 diabetes mellitus patients have a markedly higher risk of developing dementia. While multiple factors contribute to this predisposition, one of these involves the increased secretion of amylin, or islet amyloid polypeptide, that accompanies the pathophysiology of type 2 diabetes mellitus. Islet amyloid polypeptide accumulation has undoubtedly been implicated in various forms of dementia, including Alzheimer's disease and vascular dementia, but the exact mechanisms underlying islet amyloid polypeptide's causative role in dementia are unclear. In this review, we have summarized the literature supporting the various mechanisms by which islet amyloid polypeptide accumulation may cause neuronal damage, ultimately leading to the clinical symptoms of dementia. We discuss the evidence for islet amyloid polypeptide deposition in the brain, islet amyloid polypeptide interaction with other amyloids implicated in neurodegeneration, neuroinflammation caused by islet amyloid polypeptide deposition, vascular damage induced by islet amyloid polypeptide accumulation, and islet amyloid polypeptide-induced cytotoxicity. There are very few therapies approved for the treatment of dementia, and of these, clinical responses have been controversial at best. Therefore, investigating new, targetable pathways is vital for identifying novel therapeutic strategies for treating dementia. As such, we conclude this review by discussing islet amyloid polypeptide accumulation as a potential therapeutic target not only in treating type 2 diabetes mellitus but as a future target in treating or even preventing dementia associated with type 2 diabetes mellitus.

Interaction of Proteins Involved in Neuronal Proteinopathies

Proteinopathy is characterized by the accumulation of aggregates of a specific protein in a target organ, tissue, or cell. The aggregation of the same protein can cause different pathologies as single protein can adopt various amyloidogenic, disease-specific conformations. The conformation governs the interaction of amyloid aggregates with other proteins that are prone to misfolding and, thus, determines disease-specific spectrum of concomitant pathologies. In this regard, a detailed description of amyloid protein conformation as well as spectrum of its interaction with other proteins become a key point for drafting of precise description of the disease. The majority of clinical cases of neuronal proteinopathies is caused by the aggregation of rather limited range of amyloidogenic proteins. Here, we provided the characterization of pathologies, related to the aggregation of amyloid β peptide, tau protein, α-synuclein, TDP-43, and amylin, giving a short description of pathologies themselves, recent advances in elucidation of misfolded protein conformation, with emphasis on those protein aggregates extracted from biological samples, what is known about the interaction of this proteins, and the influence of this interaction on the progression of underlying disease and comorbidities.

Behavioral and biochemical investigations to explore the efficacy of quercetin and folacin in experimental diabetes induced vascular endothelium dysfunction and associated dementia in rats

OBJECTIVES

Vascular dementia (VaD), being strongly associated with metabolic conditions is a major health concern around the world. Diabetes is a major risk factor for the development of VaD. This study investigates the efficacy of quercetin and folacin in diabetes induced vascular endothelium dysfunction and related dementia.

METHODS

Single dose streptozotocin (STZ) (50 mg/kg i.p) was administered to albino Wistar rats (male, 200-250 g) by dissolving in citrate buffer. Morris water maze (MWM) and attentional set shifting tests were used to assess the spatial learning, memory, reversal learning, and executive functioning in animals. Body weight, serum glucose, serum nitrite/nitrate, vascular endothelial function, aortic superoxide anion, brains' oxidative markers (thiobarbituric acid reactive species-TBARS, reduced glutathione-GSH, superoxide dismutase-SOD, and catalase-CAT), mitochondrial enzyme complex (I, II, and IV), inflammatory markers (interleukin-IL-6, IL-10, tumor necrosis factor-TNF-α, and myeloperoxidase-MPO), and acetylcholinesterase activity-AChE were also assessed. Quercetin (30 mg kg-1/60 mg kg-1) and folacin (30 mg kg-1/60 mg kg-1) were used as the treatment drugs. Donepezil (0.5 mg kg-1) was used as a positive control.

RESULTS

STZ administered rats showed reduction in learning, memory, reversal learning, executive functioning, impairment in endothelial function, increase in brains' oxidative stress; inflammation; AChE activity, and decrease in mitochondrial complex (I, II, and IV) activity. Administration of quercetin and folacin in two different doses, significantly attenuated the STZ induced diabetes induced impairments in the behavioral, endothelial, and biochemical parameters.

CONCLUSIONS

STZ administration caused diabetes and VaD which was attenuated by the administration of quercetin and folacin. Therefore, these agents may be studied further for the assessment of their full potential in diabetes induced VaD conditions.

Insulin-degrading enzyme: Roles and pathways in ameliorating cognitive impairment associated with Alzheimer's disease and diabetes

Accumulation of amyloid-β in the central nervous system is a common feature of Alzheimer's disease (AD) and diabetes-related cognitive impairment. Since the insulin-degrading enzyme (IDE) can break down amyloid-β plaques, there is considerable interest in using this enzyme to treat both neurological disorders. In this review, we have summarized the pre-clinical and clinical research on the potential application of IDE for the improvement of cognitive impairment. Furthermore, we have presented an overview of the main pathways that can be targeted to mitigate the progression of AD and the cognitive impairment caused by diabetes.

Tirzepatide ameliorates spatial learning and memory impairment through modulation of aberrant insulin resistance and inflammation response in diabetic rats

Background: One of the typical symptoms of diabetes mellitus patients was memory impairment, which was followed by gradual cognitive deterioration and for which there is no efficient treatment. The anti-diabetic incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were demonstrated to have highly neuroprotective benefits in animal models of AD. We wanted to find out how the GLP-1/GIP dual agonist tirzepatide affected diabetes's impairment of spatial learning memory. Methods: High fat diet and streptozotocin injection-induced diabetic rats were injected intraperitoneally with Tirzepatide (1.35 mg/kg) once a week. The protective effects were assessed using the Morris water maze test, immunofluorescence, and Western blot analysis. Golgi staining was adopted for quantified dendritic spines. Results: Tirzepatide significantly improved impaired glucose tolerance, fasting blood glucose level, and insulin level in diabetic rats. Then, tirzepatide dramatically alleviated spatial learning and memory impairment, inhibited Aβ accumulation, prevented structural damage, boosted the synthesis of synaptic proteins and increased dendritic spines formation in diabetic hippocampus. Furthermore, some aberrant changes in signal molecules concerning inflammation signaling pathways were normalized after tirzepatide treatment in diabetic rats. Finally, PI3K/Akt/GSK3β signaling pathway was restored by tirzepatide. Conclusion: Tirzepatide obviously exerts a protective effect against spatial learning and memory impairment, potentially through regulating abnormal insulin resistance and inflammatory responses.

Pantethine Ameliorates Recognition Impairment in a Mouse Model of Alzheimer's Disease by Modulating Cholesterol Content and Intestinal Flora Species

SCOPE

As a natural dietary low-molecular-weight thiol, pantethine helps maintain brain homeostasis and function in Alzheimer's disease (AD) mice. The current study aims to investigate the protective effects and underlying mechanisms of pantethine on the mitigation of cognitive deficits and pathology in a triple transgenic AD mouse model.

METHODS AND RESULTS

Compared to control mice, oral administration of pantethine improve spatial learning and memory ability, relieve anxiety, and reduce the production of amyloid-β (Aβ), neuronal damage, and inflammation in 3×Tg-AD mice. Pantethine reduces body weight, body fat, and the production of cholesterol in 3×Tg-AD mice by inhibiting sterol regulatory element-binding protein (SREBP2) signal pathway and apolipoprotein E (APOE) expression; lipid rafts in the brain, which are necessary for the processing of the Aβ precursor protein (APP), are also decreased. In addition, pantethine regulates the composition, distribution, and abundance of characteristic flora in the intestine; these floras are considered protective and anti-inflammatory in the gastrointestinal tract, suggesting a possible improvement in the gut flora of 3×Tg-AD mice.

CONCLUSION

This study highlights the potential therapeutic effect of pantethine in AD by reducing cholesterol and lipid raft formation and regulating intestinal flora, suggesting a new option for the development of clinical drugs for AD.

Association between triglyceride glucose index and suicide attempts in patients with first-episode drug-naïve major depressive disorder

Objective

Triglyceride glucose (TyG) index has been suggested as an alternative indicator of insulin resistance (IR); however, the association between TyG index and suicide attempts (SA) in major depressive disorder (MDD) is unclear. The aim of this study was to investigate the relationship between TyG index and SA in Chinese patients with first-episode drug-naïve (FEDN) MDD.

Methods

This cross-sectional study enrolled 1,718 patients with FEDN MDD aged 34.9 ± 12.4 years from the First Hospital of Shanxi Medical University (Taiyuan, Shanxi Province, China) from September 2016 to December 2018. Multivariable binary logistic regression analysis was used to estimate the association between TyG index and the risk of SA. A two-piecewise linear regression model was used to investigate the threshold effects if non-linearity associations existed. Interaction and stratified analyses were performed based on sex, education, marital status, comorbid anxiety, and psychotic symptoms.

Results

Multivariable logistic regression analysis revealed that TyG index was positively associated with the risk of SA after adjusting for confounders (OR = 1.35, 95% CI: 1.04-1.75, p = 0.03). Smoothing plots also showed a nonlinear relationship between TyG index and SA, with the inflection point of TyG index being 9.29. On the right of the inflection point, a positive association between TyG index and SA was detected (OR = 3.47, 95% CI: 1.81 to 6.66, p < 0.001), while no significant association was observed on the left side of the inflection point (OR = 1.14, 95% CI: 0.79 to 1.66, p = 0.476).

Conclusion

The relationship between TyG index and SA risk was non-linear and exhibited a threshold effect in Chinese patients with FEDN MDD. When TyG index was greater than 9.29, they showed a significant positive correlation.

Modifiable cardiovascular risk factors and genetics for targeted prevention of dementia

Dementia is a major global challenge for health and social care in the 21st century. A third of individuals >65 years of age die with dementia, and worldwide incidence numbers are projected to be higher than 150 million by 2050. Dementia is, however, not an inevitable consequence of old age; 40% of dementia may theoretically be preventable. Alzheimer's disease (AD) accounts for approximately two-thirds of dementia cases and the major pathological hallmark of AD is accumulation of amyloid-β. Nevertheless, the exact pathological mechanisms of AD remain unknown. Cardiovascular disease and dementia share several risk factors and dementia often coexists with cerebrovascular disease. In a public health perspective, prevention is crucial, and it is suggested that a 10% reduction in prevalence of cardiovascular risk factors could prevent more than nine million dementia cases worldwide by 2050. Yet this assumes causality between cardiovascular risk factors and dementia and adherence to the interventions over decades for a large number of individuals. Using genome-wide association studies, the entire genome can be scanned for disease/trait associated loci in a hypothesis-free manner, and the compiled genetic information is not only useful for pinpointing novel pathogenic pathways but also for risk assessments. This enables identification of individuals at high risk, who likely will benefit the most from a targeted intervention. Further optimization of the risk stratification can be done by adding cardiovascular risk factors. Additional studies are, however, highly needed to elucidate dementia pathogenesis and potential shared causal risk factors between cardiovascular disease and dementia.

Potential Role of Glucagon-like Peptide-1 Receptor Agonists in the Treatment of Cognitive Decline and Dementia in Diabetes Mellitus

Dementia is a permanent illness characterized by mental instability, memory loss, and cognitive decline. Many studies have demonstrated an association between diabetes and cognitive dysfunction that proceeds in three steps, namely, diabetes-associated cognitive decrements, mild cognitive impairment (MCI; both non-amnesic MCI and amnesic MCI), and dementia [both vascular dementia and Alzheimer's disease (AD)]. Based on this association, this disease has been designated as type 3 diabetes mellitus. The underlying mechanisms comprise insulin resistance, inflammation, lipid abnormalities, oxidative stress, mitochondrial dysfunction, glycated end-products and autophagy. Moreover, insulin and insulin-like growth factor-1 (IGF-1) have been demonstrated to be involved. Insulin in the brain has a neuroprotective role that alters cognitive skills and alteration of insulin signaling determines beta-amyloid (Aβ) accumulation, in turn promoting brain insulin resistance. In this complex mechanism, other triggers include hyperglycemia-induced overproduction of reactive oxygen species (ROS) and inflammatory cytokines, which result in neuroinflammation, suggesting that antidiabetic drugs may be potential treatments to protect against AD. Among these, glucagon-like peptide-1 receptor agonists (GLP-1RAs) are the most attractive antidiabetic drugs due to their actions on synaptic plasticity, cognition and cell survival. The present review summarizes the significant data concerning the underlying pathophysiological and pharmacological mechanisms between diabetes and dementia.

Prenatal stress aggravates age-dependent cognitive decline, insulin signaling dysfunction, and the pro-inflammatory response in the APPNL-F/NL-F mouse model of Alzheimer's disease

Accumulating evidence indicates that early adverse life experiences may be involved in the pathogenesis of Alzheimer's disease (AD). Prenatal stress (PS) can affect brain maturation and neuroimmune and metabolic interactions, leading to age-dependent cognitive deficits in offspring. However, a multi-faceted cause-and-effect impact of PS on the development of cognitive deficits in the process of physiological ageing and in the APP^NL-F/NL-F mouse model of Alzheimer's disease has not yet been evaluated. We have identified age-dependent cognitive learning and memory deficits using male C57BL/6 J (wild type, WT) and the knock-in APP^NL-F/NL-F (KI) aged 12, 15, and 18 months. An increase in the Aβ42/Aβ40 ratio and mouse ApoE levels in the hippocampus and frontal cortex preceded the onset of cognitive deficits in the KI mice. Moreover, dysfunction in insulin signaling, including increased IRS-1 serine phosphorylation in both brain areas and the tyrosine phosphorylation deficit in the frontal cortex, suggested age-dependent insulin/IGF-1 resistance. Resistance was reflected by disturbances in mTOR or ERK1/2 kinase phosphorylation and excessive pro-inflammatory (TNF-α, IL-6, and IL-23) status in the KI mice. Importantly, our study has provided insights into the higher vulnerability to PS-induced exacerbation of age-dependent cognitive deficits and biochemical dysfunction in KI mice than in WT animals. We anticipate our study will lead to future investigation of a multi-faceted cause-and-effect relationship between stress during neurodevelopment and the onset of AD pathology, distinguishing it from changes in the course of dementia during normal ageing.

Cardiometabolic health, menopausal estrogen therapy and the brain: How effects of estrogens diverge in healthy and unhealthy preclinical models of aging

Research in preclinical models indicates that estrogens are neuroprotective and positively impact cognitive aging. However, clinical data are equivocal as to the benefits of menopausal estrogen therapy to the brain and cognition. Pre-existing cardiometabolic disease may modulate mechanisms by which estrogens act, potentially reducing or reversing protections they provide against cognitive decline. In the current review we propose mechanisms by which cardiometabolic disease may alter estrogen effects, including both alterations in actions directly on brain memory systems and actions on cardiometabolic systems, which in turn impact brain memory systems. Consideration of mechanisms by which estrogen administration can exert differential effects dependent upon health phenotype is consistent with the move towards precision or personalized medicine, which aims to determine which treatment interventions will work for which individuals. Understanding effects of estrogens in both healthy and unhealthy models of aging is critical to optimizing the translational link between preclinical and clinical research.

Molecular Aspects of a Diet as a New Pathway in the Prevention and Treatment of Alzheimer's Disease

Alzheimer's disease is the most common cause of dementia in the world. Lack of an established pathology makes it difficult to develop suitable approaches and treatment for the disease. Besides known hallmarks, including amyloid β peptides cumulating in plaques and hyperphosphorylated tau forming NFTs, inflammation also plays an important role, with known connections to the diet. In AD, adhering to reasonable nutrition according to age-related principles is recommended. The diet should be high in neuroprotective foods, such as polyunsaturated fatty acids, antioxidants, and B vitamins. In addition, foods capable of rising BDNF should be considered because of the known profitable results of this molecule in AD. Adhering to beneficial diets might result in improvements in memory, cognition, and biomarkers and might even reduce the risk of developing AD. In this review, we discuss the effects of various diets, foods, and nutrients on brain health and possible connections to Alzheimer's disease.

Predicting depressive symptom by cardiometabolic indicators in mid-aged and older adults in China: a population-based cross-sectional study

Objective

Depressive symptom is a serious mental illness often accompanied by physical and emotional problems. The prevalence of depressive symptom in older adults has become an increasingly important public health priority. Our study used cardiometabolic indicators to predict depressive symptom in middle-aged and older adults in China.

Methods

The data came from the China Health and Retirement Longitudinal Study 2011 (CHARLS2011), which was a cross-sectional study. The analytic sample included 8,942 participants aged 45 years or above. The study evaluated the relationship between cardiometabolic indicators and depression by measuring 13 indicators, including body mass index (BMI), waist circumference, waist-height ratio (WHtR), conicity index, visceral adiposity index (VAI), Chinese visceral adiposity index (CVAI), lipid accumulation product (LAP), a body shape index (ABSI), body roundness index (BRI), triglyceride glucose index (TyG-index) and its correlation index (TyG-BMI, TyG-waist circumference, TyG-WHtR). Binary logistic regression analysis was used to examine the association between thirteen cardiometabolic indicators and depressive symptom. In addition, the receiver operating characteristic (ROC) curve analysis and area under curve (AUC) were used to evaluate the predictive anthropometric index and to determine the optimum cut-off value.

Results

The study included 8,942 participants, of whom 4,146 (46.37%) and 4,796 (53.63%) were male and female. The prevalence of depressive symptom in mid-aged and older adults in China was 41.12% in males and 55.05% in females. The results revealed that BMI [AUC = 0.440, 95%CI: 0.422-0.457], waist circumference [AUC = 0.443, 95%CI: 0.425-0.460], WHtR [AUC = 0.459, 95%CI: 0.441-0.476], LAP [AUC = 0.455, 95%CI: 0.437-0.472], BRI [AUC = 0.459, 95%CI: 0.441-0.476], CVAI [AUC = 0.449, 95%CI: 0.432-0.467], TyG-BMI [AUC = 0.447, 95%CI: 0.429-0.465], and TyG-waist circumference [AUC =0.452, 95%CI: 0.434-0.470] were weak predictors of depressive symptom (p < 0.05) in males. In females, BMI [AUC = 0.470, 95%CI: 0.453-0.486], LAP [AUC = 0.484, 95%CI: 0.467-0.500], TyG-BMI [AUC = 0.470, 95%CI: 0.454-0.487], and TyG-waist circumference [AUC =0.481, 95%CI: 0.465-0.498] were weak predictors of depressive symptom (p < 0.05). On the other side, VAI, ABSI, conicity index and TyG index could not predict depressive symptom in middle-aged and older adults.

Conclusion

Most cardiometabolic indicators have important value in predicting depressive symptom. Our results can provide measures for the early identification of depressive symptom in middle-aged and older adults in China to reduce the prevalence of depressive symptom and improve health.

Dementia in Diabetes: The Role of Hypoglycemia

Hypoglycemia, a common consequence of diabetes treatment, is associated with severe morbidity and mortality and has become a major barrier to intensifying antidiabetic therapy. Severe hypoglycemia, defined as abnormally low blood glucose requiring the assistance of another person, is associated with seizures and comas, but even mild hypoglycemia can cause troubling symptoms such as anxiety, palpitations, and confusion. Dementia generally refers to the loss of memory, language, problem-solving, and other cognitive functions, which can interfere with daily life, and there is growing evidence that diabetes is associated with an increased risk of both vascular and non-vascular dementia. Neuroglycopenia resulting from a hypoglycemic episode in diabetic patients can lead to the degeneration of brain cells, with a resultant cognitive decline, leading to dementia. In light of new evidence, a deeper understating of the relationship between hypoglycemia and dementia can help to inform and guide preventative strategies. In this review, we discuss the epidemiology of dementia among patients with diabetes, and the emerging mechanisms thought to underlie the association between hypoglycemia and dementia. Furthermore, we discuss the risks of various pharmacological therapies, emerging therapies to combat hypoglycemia-induced dementia, as well as risk minimization strategies.

Geriatric Syndromes in Older Adults with Diabetes

Over one-quarter of adults ≥65 years old have diabetes in the United States. Guidelines recommend individualization of glycemic targets in older adults with diabetes as well as implementing treatment strategies that minimize risk for hypoglycemia. Patient-centered management decisions should be informed by comorbidities, the individual's capacity for self-care, and the presence of key geriatric syndromes that may impact self-management and patient safety. Key geriatric syndromes include cognitive impairment, depression, functional impairments (eg, vision, hearing, and mobility challenges), falls and fractures, polypharmacy, and urinary incontinence. Screening for geriatric syndromes in older adults is recommended to inform treatment strategies and optimize outcomes.

Volume atrophy in medial temporal cortex and verbal memory scores in American Indians: Data from the Strong Heart Study

INTRODUCTION

Distinguishing Alzheimer's disease (AD) patient subgroups may optimize positive clinical outcomes. Cortical atrophy is correlated with memory deficits, but these associations are understudied in American Indians.

METHODS

We collected imaging and cognition data in the Strong Heart Study (SHS), a cohort of 11 tribes across three regions. We processed 1.5T MRI using FreeSurfer and iterative principal component analysis. Linear mixed models estimated volumetric associations with diabetes.

RESULTS

Over mean 7 years follow-up (N = 818 age 65-89 years), overall volume loss was 0.5% per year. Significant losses associated with diabetes were especially strong in the right hemisphere. Annualized hippocampal, parahippocampal, entorhinal atrophy were worse for men, older age, diabetes, hypertension, stroke; and associated with both encoding and retrieval memory losses.

DISCUSSION

Our findings suggest that diabetes is an important risk factor in American Indians for cortical atrophy and memory loss. Future research should examine opportunities for primary prevention in this underserved population.

Onset age of diabetes and incident dementia: A prospective cohort study

BACKGROUND

Relationship between age at diagnosis of diabetes and dementia is lacking. The aim of the study was to investigate whether diabetes onset at a younger age was associated with a higher incidence of dementia.

METHODS

466,207 participants free of dementia in the UK biobank (UKB) were included in the analysis. Propensity score matching (PSM) was adopted to match diabetic and non-diabetic participants in different onset age of diabetes groups to evaluate onset age of diabetes and incident dementia.

RESULTS

Compared with non-diabetic participants, diabetes participants had an adjusted hazard ratio (HR) of 1.87 (95 % confidence interval [CI]: 1.73-2.03) for all-cause dementia, 1.85 (95 % CI: 1.60-2.04) for Alzheimer's disease (AD), and 2.86 (95 % CI: 2.47-3.32) for vascular dementia (VD). Among diabetic participants who reported onset age, the adjusted HRs for incident all-cause dementia, AD, and VD were 1.20 (95 % CI: 1.14-1.25), 1.19 (95 % CI: 1.10-1.29), and 1.19 (95 % CI: 1.10-1.28), respectively, per 10 years decrease in age at diabetes onset. After PSM, strength of association between diabetes and all-cause dementia increased with decreasing onset age of diabetes (≥60 years: HR = 1.47, 95 % CI: 1.25-1.74; 45-59 years: HR = 1.66, 95 % CI: 1.40-1.96; <45 years: HR = 2.92, 95 % CI: 2.13-4.01) after multivariable adjustment. Similarly, diabetic participants with onset age <45 years had greatest HRs for incident AD and VD, compared with their matched controls.

LIMITATIONS

Our results only reflect the characteristics of UKB participants.

CONCLUSIONS

Younger age at diabetes onset was significantly associated with a higher risk of dementia in this longitudinal cohort study.

Systemic Metabolism and Mitochondria in the Mechanism of Alzheimer's Disease: Finding Potential Therapeutic Targets

Elderly people over the age of 65 are those most likely to experience Alzheimer's disease (AD), and aging and AD are associated with apparent metabolic alterations. Currently, there is no curative medication against AD and only several drugs have been approved by the FDA, but these drugs can only improve the symptoms of AD. Many preclinical and clinical trials have explored the impact of adjusting the whole-body and intracellular metabolism on the pathogenesis of AD. The most recent evidence suggests that mitochondria initiate an integrated stress response to environmental stress, which is beneficial for healthy aging and neuroprotection. There is also an increasing awareness of the differential risk and potential targeting strategies related to the metabolic level and microbiome. As the main participants in intracellular metabolism, mitochondrial bioenergetics, mitochondrial quality-control mechanisms, and mitochondria-linked inflammatory responses have been regarded as potential therapeutic targets for AD. This review summarizes and highlights these advances.

Parkinson's Disease and Diabetes Mellitus: Individual and Combined Effects on Motor, Cognitive, and Psychosocial Functions

BACKGROUND/OBJECTIVE

Understanding the effects of multimorbidity on motor and cognitive function is important for tailoring therapies. Individuals with diabetes mellitus (DM) have a greater risk of developing Parkinson's disease (PD). This study investigated if individuals with comorbid PD and DM experienced poorer functional ability compared to individuals with only PD or DM.

METHODS

A cross-sectional analysis of 424 individuals: healthy older adults (HOA), n = 170; PD without DM (PD-only), n = 162; DM without PD (DM-only), n = 56; and comorbid PD and DM (PD+DM), n = 36. Motor, motor-cognitive, cognitive, and psychosocial functions and PD motor symptoms were compared among groups using a two-way analyses of covariance with PD and DM as factors.

RESULTS

The PD-only and DM-only participants exhibited slower gait, worse balance, reduced strength, and less endurance. Motor-cognitive function was impaired in individuals with PD but not DM. DM-only participants exhibited impaired inhibition. Individuals with comorbid PD+DM had worse PD motor symptoms and exhibited impaired attention compared to the PD-only group.

CONCLUSIONS

Having PD or DM was independently associated with poorer physical and mental quality of life, depression, and greater risk for loss of function. Both PD and DM have independent adverse effects on motor function. Comorbid PD+DM further impairs attention compared to the effect of PD-only, suggesting the importance of therapies focusing on attention. Understanding the functional ability levels for motor and cognitive domains will enhance the clinical care for PD, DM, and PD+DM.

Type 2 diabetes and cognitive performance in middle age: a cross-sectional study

INTRODUCTION

Type 2 diabetes has been associated with cognitive decrements already in middle-age. However, the sample sizes of the studies have been small and the neuropsychological tests used have been heterogeneous. In addition, only a few studies have matched the groups in terms of age, education and gender. In this cross-sectional matched pairs study, we investigated the cognitive performance of Finnish middle-aged type 2 diabetes patients compared to healthy individuals.

METHOD

A neuropsychological test battery consisting of 16 tests and 21 outcome measures was applied to 28 patients and 28 age-, education- and gender-matched healthy individuals. Various exclusion criteria were applied to minimize the risk of cognitive dysfunction due to factors other than diabetes.

RESULTS

We did not find between-group differences in any of the neuropsychological tests measuring attention, concept formation and reasoning, construction and motor performance, executive functions, memory, processing speed or working memory. In addition, there were no group differences in the frequency or severity of subjective cognitive symptoms, or in anxiety, depression, burnout, fatigue or alcohol use disorder symptoms. The effect sizes in this study were mostly negligible or small, with the mean effect size being -0.12.

CONCLUSIONS

In a carefully matched sample of middle-aged type 2 diabetes patients and healthy individuals, we found no significant effects and no meaningful evidence of cognitive differences between the groups.

Diabetic Retinopathy and Dementia Association, Beyond Diabetes Severity

PURPOSE

To investigate whether associations between diabetic retinopathy (DR) and dementia and Alzheimer's disease (AD) remain significant after controlling for several measures of diabetes severity.

DESIGN

Retrospective cohort study.

METHODS

Adult Changes in Thought (ACT) is a prospective cohort study of adults aged ≥65 years, randomly selected and recruited from the membership rolls of Kaiser Permanente Washington, who are dementia free at enrollment and followed biennially until incident dementia. The ACT participants were included in this study if they had type 2 diabetes mellitus at enrollment or developed it during follow-up, and data were collected through September, 2018 (3516 person-years of follow-up). Diabetes was defined by ≥ 2 diabetes medication fills in 1 year. Diagnosis of DR was based on International Classification of Diseases Ninth and Tenth Revision codes. Estimates of microalbuminuria, long-term glycemia, and renal function from longitudinal laboratory records were used as indicators of diabetes severity. Alzheimer's disease and dementia were diagnosed using research criteria at expert consensus meetings.

RESULTS

A total of 536 participants (median baseline age 75 [interquartile range 71-80], 54% women) met inclusion criteria. Significant associations between DR >5 years duration with dementia (hazard ratio 1.81 [95% CI 1.23, 2.65]) and AD (1.80 [1.15, 2.82]) were not altered by adjustment for estimates of microalbuminuria, long-term glycemia, and renal function (dementia: 1.69 [1.14, 2.50]; AD: 1.73 [1.10, 2.74]).

CONCLUSIONS

Among people with type 2 diabetes, DR itself appears to be an important biomarker of dementia risk in addition to glycemia and renal complications.

Circulating levels of endothelial progenitor cells are associated with better cognitive function in older adults with glucagon-like peptide 1 receptor agonist-treated type 2 diabetes

AIMS

To evaluate cognitive function in subjects with type 2 diabetes (T2D) treated with glucagon-like peptide 1 receptor agonist (GLP-1RA) plus metformin or metformin alone and its association with endothelial progenitor cells (EPCs).

METHODS

Adults with T2D treated with GLP-1RA plus metformin (GLP-1RA + MET) or MET alone for at least 12 months were included. Montreal Cognitive Assessment test (MoCA), Mini-Mental State Examination (MMSE), Mini Nutritional Assessment (MNA) and disability tests were administered. Circulating levels of seven EPCs phenotypes were measured by flow cytometry.

RESULTS

A total of 154 elderly patients were included, of whom 78 in GLP-1RA + MET group and 76 in MET group. The GLP-1RA + MET group showed better cognitive function as indicated by a significant higher MoCA and MMSE scores, and higher levels of CD34⁺ CD133⁺, CD133⁺ KDR⁺, and CD34⁺ CD133⁺ KDR⁺ as compared with MET group. The number of CD34⁺ CD133⁺ KDR⁺ cells was an independent predictor of higher MoCA, MMSE and MNA scores.

CONCLUSIONS

People with T2D on GLP-1RA + MET treatment had better cognitive function and higher circulating levels of EPCs as compared with those on MET alone warranting further studies to understand the interrelationship between EPCs, GLP-RA treatment and cognitive health.

Diabetes influences the fusion of autophagosomes with lysosomes in SH-SY5Y cells and induces Aβ deposition and cognitive dysfunction in STZ-induced diabetic rats

Diabetes has been regarded as an independent risk factor for Alzheimer's disease (AD). Our previous study found that diabetes activated autophagy, but lysosome function was impaired. Autophagy-lysosome dysfunction may be involved in Aβ deposition in diabetic cognitive impairment. In the present study, we used STZ-induced diabetic rats and SH-SY5Y cells to investigate whether diabetes inhibits autophagosome fusion with lysosomes. We found that in the in vivo study, STZ-induced diabetic rats exhibited cognitive dysfunction, and the lysosome function-related factors CTSL, CTSD, and Rab7 were decreased (P < 0.05). In an in vitro study, the mRFP-GFP-LC3 assay showed that the fusion of autophagosomes with lysosomes was partly blocked in SH-SY5Y cells. High glucose treatment downregulated the number of autophagolysosomes, downregulated CTSD, CTSL, and Rab7 expression (P < 0.05), and then influenced the function of ACP2 to partly block the fusion of autophagosomes and lysosomes to inhibit Aβ clearance. These findings indicate that high glucose treatment affected lysosome function, interfered with the fusion of autophagosomes with lysosomes, and partly blocked autophagic flux to influence Aβ clearance.

2023 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease, including prevalence and incidence, mortality and morbidity, use and costs of care, and the overall impact on family caregivers, the dementia workforce and society. The Special Report examines the patient journey from awareness of cognitive changes to potential treatment with drugs that change the underlying biology of Alzheimer's. An estimated 6.7 million Americans age 65 and older are living with Alzheimer's dementia today. This number could grow to 13.8 million by 2060 barring the development of medical breakthroughs to prevent, slow or cure AD. Official death certificates recorded 121,499 deaths from AD in 2019, and Alzheimer's disease was officially listed as the sixth-leading cause of death in the United States. In 2020 and 2021, when COVID-19 entered the ranks of the top ten causes of death, Alzheimer's was the seventh-leading cause of death. Alzheimer's remains the fifth-leading cause of death among Americans age 65 and older. Between 2000 and 2019, deaths from stroke, heart disease and HIV decreased, whereas reported deaths from AD increased more than 145%. This trajectory of deaths from AD was likely exacerbated by the COVID-19 pandemic in 2020 and 2021. More than 11 million family members and other unpaid caregivers provided an estimated 18 billion hours of care to people with Alzheimer's or other dementias in 2022. These figures reflect a decline in the number of caregivers compared with a decade earlier, as well as an increase in the amount of care provided by each remaining caregiver. Unpaid dementia caregiving was valued at $339.5 billion in 2022. Its costs, however, extend to family caregivers' increased risk for emotional distress and negative mental and physical health outcomes - costs that have been aggravated by COVID-19. Members of the paid health care workforce are involved in diagnosing, treating and caring for people with dementia. In recent years, however, a shortage of such workers has developed in the United States. This shortage - brought about, in part, by COVID-19 - has occurred at a time when more members of the dementia care workforce are needed. Therefore, programs will be needed to attract workers and better train health care teams. Average per-person Medicare payments for services to beneficiaries age 65 and older with AD or other dementias are almost three times as great as payments for beneficiaries without these conditions, and Medicaid payments are more than 22 times as great. Total payments in 2023 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $345 billion. The Special Report examines whether there will be sufficient numbers of physician specialists to provide Alzheimer's care and treatment now that two drugs are available that change the underlying biology of Alzheimer's disease.

Increased Expression of Autophagy-Related Genes in Alzheimer's Disease-Type 2 Diabetes Mellitus Comorbidity Models in Cells

The association between Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM) has been extensively demonstrated, but despite this, the pathophysiological mechanisms underlying it are still unknown. In previous work, we discovered a central role for the autophagy pathway in the common alterations observed between AD and T2DM. In this study, we further investigate the role of genes belonging to this pathway, measuring their mRNA expression and protein levels in 3xTg-AD transgenic mice, an animal model of AD. Moreover, primary mouse cortical neurons derived from this model and the human H4Swe cell line were used as cellular models of insulin resistance in AD brains. Hippocampal mRNA expression showed significantly different levels for Atg16L1, Atg16L2, GabarapL1, GabarapL2, and Sqstm1 genes at different ages of 3xTg-AD mice. Significantly elevated expression of Atg16L1, Atg16L2, and GabarapL1 was also observed in H4Swe cell cultures, in the presence of insulin resistance. Gene expression analysis confirmed that Atg16L1 was significantly increased in cultures from transgenic mice when insulin resistance was induced. Taken together, these results emphasise the association of the autophagy pathway in AD-T2DM co-morbidity, providing new evidence about the pathophysiology of both diseases and their mutual interaction.

The Burden of Dementia Spectrum Disorders and Associated Comorbid and Demographic Features

Dementia spectrum disorders (DSDs) are a major cause of mortality and disability worldwide. DSDs encompass a large group of medical conditions that all ultimately lead to major functional and cognitive decline and disability. Demographic and comorbid conditions that are associated with DSDs have significant prognostic and preventive implications. In this article, we will discuss the global and regional burden of DSDs and cover key demographic and clinical conditions linked with DSDs. In the absence of disease-modifying treatments, the role of primary prevention has become more prominent. Implementation of preventive measures requires an understanding of predisposing and exacerbating factors.

The Role of Vascular Risk Factors in Cognitive Impairment and Dementia and Prospects for Prevention

One of the most challenging clinical expressions of population aging is cognitive impairment and dementia. Among risk factors for the development of dementia, modifiable vascular risk factors have emerged as contributors to both vascular and nonvascular types of dementia. Epidemiologic studies have been particularly informative in understanding the link between vascular risks and dementia across the life course. We discuss vascular risks for dementia and cognitive impairment and practical management recommendations.

Mechanisms and Clinical Manifestations of Cognitive Decline in Atrial Fibrillation Patients: Potential Implications for Preventing Dementia

Atrial fibrillation (AF) patients face an approximate 1.5-fold increased risk of cognitive decline compared with the general population. Among poststroke AF patients, the risk of cognitive decline is even higher with an estimated threefold increase. This article provides a narrative review on the current evidence and highlights gaps in knowledge and areas for future research. Although earlier studies hypothesized that the association between AF and cognitive decline is mainly a consequence of previous ischemic strokes, more recent evidence also suggests such an association in AF patients without a history of clinical stroke. Because AF and cognitive decline mainly occur among elderly individuals, it is not surprising that both entities share multiple risk factors. In addition to clinically overt ischemic strokes, silent brain infarcts and other brain injury are likely mechanisms for the increased risk of cognitive decline among AF patients. Oral anticoagulation for stroke prevention in AF patients with additional stroke risk factors is one of the only proven therapies to prevent brain injury. Whether a broader use of oral anticoagulation, or more intense anticoagulation in some patients are beneficial in this context needs to be addressed in future studies. Although direct studies are lacking, it is reasonable to recommend optimal treatment of comorbidities and risk factors for the prevention of cognitive decline and dementia.

Relationship between glycemic control and cognitive impairment: A systematic review and meta-analysis

Background

Diabetes mellitus, or hyperglycemia, is an independent risk factor for cognitive impairment. Here we systematically analyzed whether glycemic control could improve cognitive impairment in patients with diabetes mellitus (DM), hyperglycemia, or insulin resistance.

Methods

Three databases (PubMed, EMBASE, and Cochrane Library) and ClinicalTrials.gov were searched for randomized controlled trials analyzing the relationship between glycemic control and cognitive function assessments, published from database inception to June 2022. Patients in experimental groups were treated with antidiabetic drugs, while control groups were treated with a placebo or alternative antidiabetic drugs. Data analysis was conducted using RevMan 5.3 and StataSE-64, and standardized mean difference (SMD) and 95% confidence intervals (CIs) were calculated.

Results

Thirteen studies comprising 19,314 participants were included. Analysis revealed that glycemic control significantly attenuated the degree of decline in cognitive function assessment scores (SMD  =  0.15; 95% CI 0.05, 0.26; p  <  0.00001), and funnel plots confirmed no publication bias. Seven studies used Mini-Mental State Examination as the primary cognitive function assessment, showing that glycemic control significantly delayed the degree of decline in cognitive function assessment scores (SMD  =  0.18; 95% CI 0.03, 0.34; p  =  0.02). Similar results were seen in two studies using the Montreal Cognitive Assessment scale, but without significant difference (SMD  =  0.05; 95% CI-0.10, 0.21; p  =  0.51). One study using Auditory Word Learning Test (AVLT) showed that glycemic control significantly delayed the decline in cognitive function assessment scores (SMD  =  0.52; 95% CI 0.11,0.93; p  =  0.01), and another used Wechsler Memory Scale Revised, showing similar results (SMD  =  1.45; 95% CI 0.86, 2.04; p  <  0.00001). Likewise, a study that used Modified Mini-Mental State scale showed that glycemic control significantly delayed the decline in cognitive function assessment scores (SMD  =  -0.10; 95% CI-0.16, -0.03; p  =  0.005). Lastly, one study used AVLT subtests to show that glycemic control delayed the decline in cognitive function assessment scores, although not statistically significant (SMD  =  0.09; 95% CI-0.53, 0.71; p  =  0.78).

Conclusion

Glycemic control through antidiabetic treatment correlates with the improvement of cognitive impairment in patients with DM, hyperglycemia or insulin resistance. However, further studies are needed to validate the results of this study.

Systematic Review Registration

PROSPERO, identifier CRD42022342260.

Effects of Peroxisome Proliferator-Activated Receptor-Gamma Agonists on Cognitive Function: A Systematic Review and Meta-Analysis

Diabetes mellitus (DM) is known to be a risk factor for dementia, especially in the elderly population, and close associations between diabetes and Alzheimer disease (AD) have been determined. Peroxisome proliferator-activated receptor-gamma (PPAR-γ) agonists are insulin-sensitising drugs. In addition to their anti-diabetic properties, their effectiveness in preventing and decreasing cognitive impairment are the most recent characteristics that have been studied. For this study, we conducted a systematic review and meta-analysis to critically analyse and evaluate the existing data on the effects of PPAR-γ agonist therapy on the cognitive status of patients. For this purpose, we first analysed both early intervention and later treatment with PPAR-γ agonists, according to the disease status. The involved studies indicated that early PPAR-γ agonist intervention is beneficial for patients and that high-dose PPAR-γ therapy may have a better clinical effect, especially in reversing the effects of cognitive impairment. Furthermore, the efficacy of pioglitazone (PIO) seems to be promising, particularly for patients with comorbid diabetes. PIO presented a better clinical curative effect and safety, compared with rosiglitazone (RSG). Thus, PPAR-γ agonists play an important role in the inflammatory response of AD or DM patients, and clinical therapeutics should focus more on relevant metabolic indices.

4. Comprehensive Medical Evaluation and Assessment of Comorbidities: Standards of Care in Diabetes-2023

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Cognitive Performance and Diabetic Retinopathy: What Your Eyes Can Reveal About Your Brain

BACKGROUND

Diabetic retinopathy (DR) is a chronic diabetes complication. People with Type 2 Diabetes Mellitus (T2DM) have two times the risk for dementia, suggesting it is a new chronic diabetes complication.

OBJECTIVE

Evaluate the association of DR with cognitive performance in a T2DM population.

METHODS

Cross-sectional study with 400 T2DM adults from whom socio-demographic, clinical, laboratory data were collected, and screening test for depression symptoms (Patient Health Questionaire- 9 (PHQ-9)), Mini-Mental State Examination (MMSE), Semantic Verbal Fluency Test, Trail Making Test A and B, Word Memory test were performed. All cognitive test scores were converted into Global Cognition z-Score (GCS(z)). The association between GCS(z) < 0 with DR was performed using a multivariate binary logistic regression model adjusted for age ≥ 65 years, school years ≤ 6 years, DM duration ≥ 10 years, depression symptoms score > 9 at PHQ-9, arterial hypertension, physical activity, diabetic retinopathy, macular edema, and cardiovascular disease.

RESULTS

After exclusions, the 251 eligible patients were 56.6% female, with a mean age of 61.1 (±9.8) years, DM duration of 12.6 (±8.9) years, and 7.6 (±4.2) years of school education. DR prevalence was 46.5%. Multivariate Logistic Regression Model showed an association between DR and GCS(z) < 0, with odds ratio (CI95%) of 2.50 (1.18-5.34), adjusted for age, low education level, arterial hypertension and depression symptoms (OD and CI95% respectively: 5.46(2.42-12.34); 12.19 (5.62-26.46); 2.55 (0.88-7.39); 3.53 (1.55-8.07)).

CONCLUSION

In this T2DM population, having DR increased the chance for worse cognitive performance even when adjusted for age, low education level, presence of arterial hypertension, and depression symptoms.

The application of cross-sectionally derived dementia algorithms to longitudinal data in risk factor analyses

PURPOSE

Dementia algorithms are often developed in cross-sectional samples but implemented in longitudinal studies to ascertain incident dementia. However, algorithm performance may be higher in cross-sectional settings, and this may impact estimates of risk factor associations.

METHODS

We used data from the Religious Orders Study and the Memory and Aging Project (N = 3460) to assess the performance of example algorithms in classifying prevalent dementia in cross-sectional samples versus incident dementia in longitudinal samples. We used an applied example and simulation study to characterize the impact of varying sensitivity, specificity, and unequal sensitivity or specificity between exposure groups (differential performance) on estimated hazard ratios from Cox models.

RESULTS

Using all items, algorithm sensitivity was higher for prevalent (0.796) versus incident dementia (0.719); hazard ratios had slight bias. Sensitivity differences were larger using a subset of items (0.732 vs. 0.600) and hazard ratios were 13%-19% higher across adjustment sets compared to estimates using gold-standard dementia status. Simulations indicated specificity and differential algorithmic performance between exposure groups may have large effects on hazard ratios.

CONCLUSIONS

Algorithms developed using cross-sectional data may be adequate for longitudinal settings when performance is high and non-differential. Poor specificity or differential performance between exposure groups may lead to biases.

Is type 2 diabetes associated dementia a microvascular early-Alzheimer's phenotype induced by aberrations in the peripheral metabolism of lipoprotein-amyloid?

There is increasing evidence of a positive association of type 2 diabetes with Alzheimer's disease (AD), the most prevalent form of dementia. Suggested pathways include cerebral vascular dysfunction; central insulin resistance, or exaggerated brain abundance of potentially cytotoxic amyloid-β (Aβ), a hallmark feature of AD. However, contemporary studies find that Aβ is secreted in the periphery by lipogenic organs and secreted as nascent triglyceride-rich lipoproteins (TRL's). Pre-clinical models show that exaggerated abundance in blood of TRL-Aβ compromises blood-brain barrier (BBB) integrity, resulting in extravasation of the TRL-Aβ moiety to brain parenchyme, neurovascular inflammation and neuronal degeneration concomitant with cognitive decline. Inhibiting secretion of TRL-Aβ by peripheral lipogenic organs attenuates the early-AD phenotype indicated in animal models, consistent with causality. Poorly controlled type 2 diabetes commonly features hypertriglyceridemia because of exaggerated TRL secretion and reduced rates of catabolism. Alzheimer's in diabetes may therefore be a consequence of heightened abundance in blood of lipoprotein-Aβ and accelerated breakdown of the BBB. This review reconciles the prevailing dogma of amyloid associated cytotoxicity as a primary risk factor in late-onset AD, with substantial evidence of a microvascular axis for dementia-in-diabetes. Consideration of potentially relevant pharmacotherapies to treat insulin resistance, dyslipidaemia and by extension plasma amyloidemia in type 2 diabetes are discussed.

Exploring the common pathogenesis of Alzheimer's disease and type 2 diabetes mellitus via microarray data analysis

Background

Alzheimer's Disease (AD) and Type 2 Diabetes Mellitus (DM) have an increased incidence in modern society. Although more and more evidence has supported that DM is prone to AD, the interrelational mechanisms remain fully elucidated.

Purpose

The primary purpose of this study is to explore the shared pathophysiological mechanisms of AD and DM.

Methods

Download the expression matrix of AD and DM from the Gene Expression Omnibus (GEO) database with sequence numbers GSE97760 and GSE95849, respectively. The common differentially expressed genes (DEGs) were identified by limma package analysis. Then we analyzed the six kinds of module analysis: gene functional annotation, protein-protein interaction (PPI) network, potential drug screening, immune cell infiltration, hub genes identification and validation, and prediction of transcription factors (TFs).

Results

The subsequent analyses included 339 common DEGs, and the importance of immunity, hormone, cytokines, neurotransmitters, and insulin in these diseases was underscored by functional analysis. In addition, serotonergic synapse, ovarian steroidogenesis, estrogen signaling pathway, and regulation of lipolysis are closely related to both. DEGs were input into the CMap database to screen small molecule compounds with the potential to reverse AD and DM pathological functions. L-690488, exemestane, and BMS-345541 ranked top three among the screened small molecule compounds. Finally, 10 essential hub genes were identified using cytoHubba, including PTGS2, RAB10, LRRK2, SOS1, EEA1, NF1, RAB14, ADCY5, RAPGEF3, and PRKACG. For the characteristic Aβ and Tau pathology of AD, RAPGEF3 was associated significantly positively with AD and NF1 significantly negatively with AD. In addition, we also found ADCY5 and NF1 significant correlations with DM phenotypes. Other datasets verified that NF1, RAB14, ADCY5, and RAPGEF3 could be used as key markers of DM complicated with AD. Meanwhile, the immune cell infiltration score reflects the different cellular immune microenvironments of the two diseases.

Conclusion

The common pathogenesis of AD and DM was revealed in our research. These common pathways and hub genes directions for further exploration of the pathogenesis or treatment of these two diseases.

Socioeconomic Status, Race/Ethnicity, and Unexpected Variation in Dementia Classification in Longitudinal Survey Data

OBJECTIVES

As dementia affects a growing number of older adults, it is important to understand its detection and progression. We identified patterns in dementia classification over time using a longitudinal, nationally representative sample of older adults. We examined the relationship between socioeconomic status and race/ethnicity, and patterns in dementia classification.

METHODS

Data for 7,218 Medicare beneficiaries from the 2011-2017 National Health and Aging Trends Study (NHATS) were classified into five categories: consistently no dementia, consistently cognitive impairment, "typical" dementia progression, "expected" variation, and "unexpected" variation. Multivariable multinomial logistic regression assessed relative risk of dementia classification by sociodemographic and health factors.

RESULTS

Among NHATS respondents, 59.5% consistently were recorded as having no dementia, 7% consistently cognitively impaired, 13% as having typical progression, 15% as having expected variation, and 5.5% as having unexpected variation. In multivariable models, compared with consistent dementia classification, less education, Medicare-Medicaid-dual enrollment, and identifying as non-Hispanic Black were associated with increased likelihood of unexpected variation (e.g., non-Hispanic Black adjusted risk ratio: 2.12, 95% CI: 1.61-2.78, p < .0001).

DISCUSSION

A significant minority of individuals have unexpected patterns of dementia classification over time, particularly individuals with low socioeconomic status and identifying as non-Hispanic Black. Dementia classification uncertainty may make it challenging to activate resources (e.g., health care, caregiving) for effective disease management, underscoring the need to support persons from at-risk groups and to carefully evaluate cognitive assessment tools to ensure they are equally reliable across groups to avoid magnifying disparities.

Type 2 Diabetes Mellitus, Platelet Activation and Alzheimer's Disease: A Possible Connection

Type 2 diabetes mellitus DM (T2DM) is associated with a 70% increased risk for dementia, including Alzheimer's disease (AD). Insulin resistance has been proposed to play a pivotal role in both T2DM and AD and the concept of "brain insulin resistance" has been suggested as an interpretation to the growing literature regarding cognitive impairment and T2DM. Subjects with T2DM present an abnormal platelet reactivity that together with insulin resistance, hyperglycaemia and dyslipidaemia effect the vascular wall by a series of events including endothelial dysfunction, oxidative stress and low-grade inflammation. Activated platelets directly contribute to cerebral amyloid angiopathy (CAA) by promoting the formation of β-amyloid (Aβ) aggregates and that Aβ, in turn, activates platelets, creating a feed-forward loop suggesting the involvement of platelets in the AD pathogenesis. Moreover, islet amyloid polypeptide deposition, co-localized with Aβ deposits, is a common finding in the brain of patients with T2DM. These observations raise the intriguing prospect that traditional or novel antiplatelet therapeutic strategies may alleviate fibril formation and could be used in the prevention or treatment of AD subjects with diabetes.