Diabetes in a Large Dementia Cohort: Clinical Characteristics and Treatment From the Swedish Dementia Registry

True or false? Alzheimer's disease is type 3 diabetes: Evidences from bench to bedside

Globally, Alzheimer's disease (AD) is the most widespread chronic neurodegenerative disorder, leading to cognitive impairment, such as aphasia and agnosia, as well as mental symptoms, like behavioral abnormalities, that place a heavy psychological and financial burden on the families of the afflicted. Unfortunately, no particular medications exist to treat AD, as the current treatments only impede its progression.The link between AD and type 2 diabetes (T2D) has been increasingly revealed by research; the danger of developing both AD and T2D rises exponentially with age, with T2D being especially prone to AD. This has propelled researchers to investigate the mechanism(s) underlying this connection. A critical review of the relationship between insulin resistance, Aβ, oxidative stress, mitochondrial hypothesis, abnormal phosphorylation of Tau protein, inflammatory response, high blood glucose levels, neurotransmitters and signaling pathways, vascular issues in AD and diabetes, and the similarities between the two diseases, is presented in this review. Grasping the essential mechanisms behind this detrimental interaction may offer chances to devise successful therapeutic strategies.

The relationship between diabetes and the dementia risk: a meta-analysis

BACKGROUND

The link between diabetes and dementia risk is not well understood. This study evaluates the factors linking diabetes to dementia onset, providing guidance for preventing dementia in diabetic patients.

METHODS

This analysis utilized databases such as PubMed, Embase, Web of Science, and the Cochrane Library to review literature from January 31, 2012, to March 5, 2023. Articles were rigorously assessed using specific inclusion and exclusion criteria. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the studies. Data analysis was performed with STATA 15.0.

RESULTS

The study analyzed 15 articles, covering 10,103,868 patients, with 8,821,516 diagnosed with diabetes. The meta-analysis reveals a substantial association between diabetes and an increased risk of dementia [RR: 1.59, 95%CI (1.40-1.80), P < 0.01, I²=96.4%]. A diabetes duration of less than five years is linked to a higher dementia risk [RR: 1.29, 95%CI (1.20-1.39), P < 0.01, I²=92.6%]. Additionally, hypoglycemia significantly raises dementia risk [RR: 1.56, 95%CI (1.13-2.16), P < 0.01, I²=51.5%]. Analyses of blood sugar control, glycated hemoglobin, and fasting blood sugar indicated no significant effects on the onset of dementia.

CONCLUSION

Diabetes notably increases dementia risk, particularly where diabetes duration is under five years or hypoglycemia is present.

REGISTRATION

The research protocol was registered with PROSPERO and assigned the registration number CRD42023394942.

Acute and Chronic Exposure to Linagliptin, a Selective Inhibitor of Dipeptidyl Peptidase-4 (DPP-4), Has an Effect on Dopamine, Serotonin and Noradrenaline Level in the Striatum and Hippocampus of Rats

Linagliptin is a selective dipeptidyl peptidase-4 (DPP-4) inhibitor that indirectly elevates the glucagon-like peptide-1 (GLP-1) level. The aim of the present study was to check whether linagliptin has an influence on neurotransmission in rat brain. Rats were acutely and chronically exposed to linagliptin (10 and 20 mg/kg, intraperitoneally (i.p.)). Twenty-four hours later, the striatum and hippocampus were selected for further studies. In neurochemical experiments, using high-performance liquid chromatography with electrochemical detection (HPLC-ED), the concentrations of three major neurotransmitters-dopamine, serotonin and noradrenaline-and their metabolites were measured. The analysis of mRNA expression of dopamine (D1 and D2), serotonin (5-HT-1 and 5-HT-2) and noradrenaline (α1 and α2a) receptors was also investigated using real-time quantitative reverse transcription polymerase chain reaction (RQ-PCR) in the same brain areas. Linagliptin has the ability to influence the dopaminergic system. In the striatum, the elevation of dopamine and its metabolites was observed after repeated administration of that linagliptin, and in the hippocampus, a reduction in dopamine metabolism was demonstrated. Acute linagliptin exposure increases the serotonin level in both areas, while after chronic linagliptin administration a tendency for the mRNA expression of serotoninergic receptors (5-HT1A and 5-HT2A) to increase was observed. A single instance of exposure to linagliptin significantly modified the noradrenaline level in the striatum and intensified noradrenaline turnover in the hippocampus. The recognition of the interactions in the brain between DPP-4 inhibitors and neurotransmitters and/or receptors is a crucial step for finding novel discoveries in the pharmacology of DPP-4 inhibitors and raises hope for further applications of DPP-4 inhibitors in clinical practices.

Diabetes: a tipping point in neurodegenerative diseases

Diabetes is associated with an increased risk and progression of Alzheimer's (AD) and Parkinson's (PD) diseases. Conversely, diabetes may confer neuroprotection against amyotrophic lateral sclerosis (ALS). It has been posited that perturbations in glucose and insulin regulation, cholesterol metabolism, and mitochondrial bioenergetics defects may underlie the molecular underpinnings of diabetes effects on the brain. Nevertheless, the precise molecular mechanisms remain elusive. Here, we discuss the evidence from molecular, epidemiological, and clinical studies investigating the impact of diabetes on neurodegeneration and highlight shared dysregulated pathways between these complex comorbidities. We also discuss promising antidiabetic drugs, molecular diagnostics currently in clinical trials, and outstanding questions and challenges for future pursuit.

Pioglitazone Use and Reduced Risk of Dementia in Patients With Diabetes Mellitus With a History of Ischemic Stroke

BACKGROUND AND OBJECTIVES

Previous studies have reported the protective effect of pioglitazone on dementia in patients with type 2 diabetes mellitus (DM). Recent studies have shown that pioglitazone also lowers the risk of primary and recurrent stroke. Understanding the characteristics of patients particularly associated with the benefits of pioglitazone would facilitate its personalized use by specifying subpopulations during routine clinical care. The aim of this study was to examine the effects of pioglitazone use on dementia in consideration of stroke occurrence.

METHODS

Using nationwide longitudinal data of patients with DM from the Korean National Health Insurance Service DM cohort (2002-2017), we investigated the association of pioglitazone use with incident dementia in patients with new-onset type 2 DM. The heterogeneity of the treatment effect was examined using exploratory analyses. Using a multistate model, we assessed the extent to which incident stroke affects the association between pioglitazone use and dementia.

RESULTS

Pioglitazone use was associated with a reduced risk of dementia, compared with nonuse (adjusted hazard ratio [aHR] = 0.84, 95% CI 0.75-0.95); the risk reduction in dementia was greater among patients with a history of ischemic heart disease or stroke before DM onset (aHR = 0.46, 95% CI 0.24-0.90; aHR = 0.57, 95% CI 0.38-0.86, respectively). The incidence of stroke was also reduced by pioglitazone use (aHR = 0.81, 95% CI 0.66-1.00). However, when the stroke developed during the observation period of pioglitazone use, such lowered risk of dementia was not observed (aHR = 1.27, 95% CI 0.80-2.04).

DISCUSSION

Pioglitazone use is associated with a lower risk of dementia in patients with DM, particularly in those with a history of stroke or ischemic heart disease, suggesting the possibility of applying a personalized approach when choosing pioglitazone to suppress dementia in patients with DM.

Lung function and risk of incident dementia: A prospective cohort study of 431,834 individuals

BACKGROUND

Whether lung function prospectively affects cognitive brain health independent of their overlapping factors remains largely unknown. This study aimed to investigate the longitudinal association between decreased lung function and cognitive brain health and to explore underlying biological and brain structural mechanisms.

METHODS

This population-based cohort included 43,1834 non-demented participants with spirometry from the UK Biobank. Cox proportional hazard models were fitted to estimate the risk of incident dementia for individuals with low lung function. Mediation models were regressed to explore the underlying mechanisms driven by inflammatory markers, oxygen-carrying indices, metabolites, and brain structures.

FINDINGS

During a follow-up of 3,736,181 person-years (mean follow-up 8.65 years), 5,622 participants (1.30 %) developed all-cause dementia, which consisted of 2,511 Alzheimer's dementia (AD) and 1,308 Vascular Dementia (VD) cases. Per unit decrease in lung function measure was each associated with increased risk for all-cause dementia (forced expiratory volume in 1 s [liter]: hazard ratio [HR, 95 %CI], 1.24 [1.14-1.34], P = 1.10 × 10^-07; forced vital capacity [liter]: 1.16 [1.08-1.24], P = 2.04 × 10^-05; peak expiratory flow [liter/min]: 1.0013 [1.0010-1.0017], P = 2.73 × 10^-13). Low lung function generated similar hazard estimates for AD and VD risks. As underlying biological mechanisms, systematic inflammatory markers, oxygen-carrying indices, and specific metabolites mediated the effects of lung function on dementia risks. Besides, brain grey and white matter patterns mostly affected in dementia were substantially changed with lung function.

INTERPRETATION

Life-course risk for incident dementia was modulated by individual lung function. Maintaining optimal lung function is useful for healthy aging and dementia prevention.

Diabetes and cognitive function: An evidence-based current perspective

Several epidemiological studies have clearly identified diabetes mellitus (DM) as a major risk factor for cognitive dysfunction, and it is going to be a major public health issue in the coming years because of the alarming rise in diabetes prevalence across the world. Brain and neural tissues predominantly depend on glucose as energy substrate and hence, any alterations in carbohydrate meta-bolism can directly impact on cerebral functional output including cognition, executive capacity, and memory. DM affects neuronal function and mental capacity in several ways, some of which include hypoperfusion of the brain tissues from cerebrovascular disease, diabetes-related alterations of glucose transporters causing abnormalities in neuronal glucose uptake and metabolism, local hyper- and hypometabolism of brain areas from insulin resistance, and recurrent hypoglycemic episodes inherent to pharmacotherapy of diabetes resulting in neuronal damage. Cognitive decline can further worsen diabetes care as DM is a disease largely self-managed by patients. Therefore, it is crucial to understand the pathobiology of cognitive dysfunction in relation to DM and its management for optimal long-term care plan for patients. A thorough appraisal of normal metabolic characteristics of the brain, how alterations in neural metabolism affects cognition, the diagnostic algorithm for patients with diabetes and dementia, and the management and prognosis of patients when they have this dangerous combination of illnesses is imperative in this context. This evidence-based narrative with the back-up of latest clinical trial reviews elaborates the current understanding on diabetes and cognitive function to empower physicians to manage their patients in day-to-day clinical practice.

Perception of benefits and barriers associated with dementia prevention behaviors among people with diabetes

Type 2 diabetes mellitus is a risk factor for developing dementia and a public health concern around the world. Identifying any predictive factors associated with diabetes-related dementia prevention behaviors are of value in helping to prevent dementia. From six community hospitals in Chiang Mai, Thailand, 182 people aged 30-60 years were enrolled in a cross-sectional study and completed a written questionnaire on dementia prevention behaviors and perceptions of health beliefs. Multiple linear regression analysis was applied to determine possible associations between dementia prevention behaviors and health belief perceptions. A high level of preventive behavior was associated with high perceptions of the benefits of, and barriers to, dementia prevention and longer duration of patients' diabetes. Findings indicate the predictive role of the two factors in the perception of health beliefs about dementia prevention behaviors among the participants. Although further testing with different samples and in different locations is warranted, education programs for health practitioners that integrate the findings of this study would be beneficial to improvement of dementia prevention behaviors in people with diabetes.

The Impact of Disease Registries on Advancing Knowledge and Understanding of Dementia Globally

To help address the increasing challenges related to the provision of dementia care, dementia registries have emerged around the world as important tools to gain insights and a better understanding of the disease process. Dementia registries provide a valuable source of standardized data collected from a large number of patients. This review explores the published research relating to different dementia registries around the world and discusses how these registries have improved our knowledge and understanding of the incidence, prevalence, risk factors, mortality, diagnosis, and management of dementia. A number of the best-known dementia registries with high research output including SveDem, NACC, ReDeGi, CREDOS and PRODEM were selected to study the publication output based on their data, investigate the key findings of these registry-based studies. Registries data contributed to understanding many aspects of the disease including disease prevalence in specific areas, patient characteristics and how they differ in populations, mortality risks, as well as the disease risk factors. Registries data impacted the quality of patients’ lives through determining the best treatment strategy for a patient based on previous patient outcomes. In conclusion, registries have significantly advanced scientific knowledge and understanding of dementia and impacted policy, clinical practice care delivery.

Glucose-Lowering Medications and Post-Dementia Survival in Patients with Diabetes and Dementia

BACKGROUND

The effectiveness of glucose-lowering drugs (GLDs) is unknown among patients with dementia.

OBJECTIVE

To analyze all-cause mortality among users of six GLDs in dementia and dementia-free subjects, respectively.

METHODS

This was a longitudinal open-cohort registry-based study using data from the Swedish Dementia Registry, Total Population Register, and four supplemental registers providing data on dementia status, drug usage, confounders, and mortality. The cohort comprised 132,402 subjects with diabetes at baseline, of which 11,401 (8.6%) had dementia and 121,001 (91.4%) were dementia-free. Subsequently, comparable dementia - dementia-free pairs were sampled. Then, as-treated and intention-to-treat exposures to metformin, insulin, sulfonylurea, dipeptidyl-peptidase-4 inhibitors, glucagon-like peptide-1 analogues (GLP-1a), and sodium-glucose cotransporter-2 inhibitors (SGLT-2i) were analyzed in the parallel dementia and dementia-free cohorts. Confounding was addressed using inverse-probability weighting and propensity-score matching, and flexible parametric survival models were used to produce hazard ratios (HR) and 95% confidence intervals (CI) of the association between GLDs and all-cause mortality.

RESULTS

In the as-treated models, increased mortality was observed among insulin users with dementia (HR 1.34 [95%CI 1.24-1.45]) as well as in dementia-free subjects (1.54 [1.10-1.55]). Conversely, sulfonylurea was associated with higher mortality only in dementia subjects (1.19 [1.01-1.42]). GLP-1a (0.44 [0.25-0.78]) and SGLT-2i users with dementia (0.43 [0.23-0.80]) experienced lower mortality compared to non-users.

CONCLUSION

Insulin and sulfonylurea carried higher mortality risk among dementia patients, while GLP-1a and SGLT-2i were associated with lower risk. GLD-associated mortality varied between dementia and comparable dementia-free subjects. Further studies are needed to optimize GLD use in dementia patients.

Factors Affecting Rapid Cognitive Decline in Patients with Alzheimer's Disease: A Longitudinal Follow-Up Study

We investigated the preventive and risk factors of rapid cognitive decline in patients with Alzheimer’s disease (AD). Using the Chang Gung Research Database (CGRD), we enrolled patients with AD aged over 65 years between 1 January 2001 and 30 May 2019, and followed up for at least two years. Rapid cognitive decline was defined by a Mini-Mental State Examination (MMSE) score decline of ≥4 in 2 years. A longer prescription of acetylcholinesterase inhibitors (AChEIs) was defined as 22 months based on the median treatment duration of the cohorts. The Cox proportional hazards regression model adjusted for age, sex, medication, and physical comorbidities was used to examine the candidate risk and protective factors. We analyzed data from 3846 patients with AD (1503 men, 2343 women) with a mean age and percentage of females of 77.8 ± 6.2 years and 60.9%, respectively. The mean duration of patients with AD receiving AChEIs was 658.7 ± 21.9 days. In general, 310 patients with AD showed a rapid cognitive decline, accounting for 8.1%. Treatment of a consecutive AChEI prescription for >22 months in patients with AD was a protective factor against rapid cognitive decline (adjusted hazard ratio (aHR) = 0.41, 95% confidence interval (CI) = 0.33–0.52, p < 0.001). Patients with AD aged >85 years (aHR = 0.53, 95% CI = 0.36–0.79, p < 0.01) and aged 75–85 years (aHR = 0.73, 95% CI = 0.57–0.93, p < 0.05) had a significantly lower risk of rapid cognitive decline than those aged 65–75 years. Additionally, patients with mild and moderate AD (clinical dementia rating (CDR = 1, aHR = 1.61, 95% CI = 1.26–2.07, p < 0.001; CDR = 2, aHR = 2.64, 95% CI = 1.90–3.65, p < 0.001) were more likely to have rapid cognitive decline than those with early AD (CDR = 0.5). Sex, medication with different types of AChEIs, and physical comorbidities were not associated with rapid cognitive decline. These findings indicate that it is important to maintain longer consecutive AChEI prescriptions in patients with AD to prevent cognitive decline.

Dementia Diagnosis Is Associated with Changes in Antidiabetic Drug Prescription: An Open-Cohort Study of ∼130,000 Swedish Subjects over 14 Years

BACKGROUND

Care individualization dominates in clinical guidelines for cognitively impaired patients with diabetes; however, few studies examined such adaptations.

OBJECTIVE

Describe long-term pharmacological changes in diabetes treatment in subjects with and without dementia.

METHODS

We performed a registry-based cohort study on 133,318 Swedish subjects (12,284 [9.2%] with dementia) with type 2 or other/unspecified diabetes. Dementia status originated from the Swedish Dementia Registry, while the National Patient Register, Prescribed Drug Register, and Cause of Death Register provided data on diabetes, comorbidities, drug dispensation, and mortality. Drug dispensation interval comprised years between 2005 and 2018 and the dispensation was assessed relative to index date (dementia diagnosis) in full cohort and propensity-score (PS) matched cohorts. Annual changes of drug dispensation were analyzed by linear regression, while Cox and competing-risk regression were used to determine the probability of drug dispensation after index date in naïve subjects. Studied medications included insulin, metformin, sulfonylureas, thiazolidinediones, dipeptidyl-peptidase-4 inhibitors (DPP-4i), glucagon-like peptide-1 agonists (GLP-1a), and sodium-glucose cotransporter-2 inhibitors (SGLT-2i).

RESULTS

Dementia patients had higher probability of insulin dispensation (hazard ratio 1.21 [95% CI 1.11-1.31] and lower probability of DPP-4i (0.72 [0.66-0.79]), GLP-1a (0.51 [0.41-0.63]), and SGLT-2i dispensation (0.44 [0.36-0.54]) after index date. PS-matched analyses showed increased annual insulin dispensation (β difference 0.97%) and lower increase in DPP-4i (-0.58%), GLP-1a (-0.13%), and SGLT-2i (-0.21%) dispensation in dementia patients compared to dementia-free controls.

CONCLUSION

Dementia patients had lower probability of receiving newer antidiabetic drugs, with simultaneous higher insulin dispensation compared to dementia-free subjects.

Comprehensive Management of Daily Living Activities, behavioral and Psychological Symptoms, and Cognitive Function in Patients with Alzheimer's Disease: A Chinese Consensus on the Comprehensive Management of Alzheimer's Disease

Alzheimer's disease (AD) is the most common cognitive disorder in the elderly. Its main clinical manifestations are cognitive decline (C), behavioral and psychological symptoms (B), and a decline in the activities of daily living (A), also known as ABC symptoms. Early identification and evaluation of ABC symptoms are helpful for establishing the accurate diagnosis, comprehensive treatment, and prognosis of AD. To guide Chinese clinical practice for optimization of the comprehensive management of AD, in 2018, The Academy of Cognitive Disorder of China gathered 22 neurologists and gerontologists in China to build a consensus on the comprehensive management of AD. Based on a review of the evidence, the consensus summarizes the pathogenesis, pathological changes, clinical manifestations, evaluation, diagnosis, drug and non-drug treatment, and patient care for AD. Focus group discussion was used to establish a flowchart of comprehensive ABC management for AD patients. The new consensus provides a feasible AD management process for clinicians.

Changes in Cognitive Impairment in the Czech Republic

BACKGROUND

Studies from North America and Western Europe suggest stable or declining trends in impaired cognition across birth cohorts.

OBJECTIVE

We aimed to examine changes in the age-specific prevalence of cognitive impairment in the Czech Republic.

METHODS

The study used two samples from the population-based Czech Survey on Health, Ageing and Retirement in Europe. Age-specific prevalence of cognitive impairment (defined based on scores in verbal fluency, immediate recall, delayed recall, and temporal orientation) was compared between participants in wave 2 (2006/2007; n = 1,107) and wave 6 (2015; n = 3,104). Logistic regression was used to estimate the association between the wave and cognitive impairment, step-wise adjusting for sociodemographic and clinical characteristics. Multiple sensitivity analyses, focusing on alternative operationalizations of relative cognitive impairment, impact of missing cognitive data, and survival bias, were carried out.

RESULTS

The most conservative estimate suggested that the age-specific prevalence of cognitive impairment declined by one fifth, from 11% in 2006/2007 to 9% in 2015. Decline was observed in all sensitivity analyses. The change was associated with differences in physical inactivity, management of high blood cholesterol, and increases in length education.

CONCLUSION

Older adults in the Czech Republic, a country situated in the Central and Eastern European region, have achieved positive developments in cognitive aging. Longer education, better management of cardiovascular factors, and reduced physical inactivity seem to be of key importance.

Carotid Intima-Media Thickness and Markers of Brain Health in a Biracial Middle-Aged Cohort: CARDIA Brain MRI Sub-study

BACKGROUND

We investigated whether carotid intima-media thickness is associated with measures of cerebral blood flow (CBF), white matter hyperintensities, and brain volume in a biracial cohort of middle-aged individuals.

METHODS

We performed a cross-sectional cohort study based on data from a multicenter, population-based study Coronary Artery Risk Development in Young Adults. Using linear and logistic regression, we estimated the association of the composite intima-media thickness measured in three segments of carotid arteries (common carotid artery, carotid artery bulb, and internal carotid artery) with volume (cm3) and CBF (mL/100 g/min) in the total brain and gray matter as well as volume of white matter hyperintensities (cm3).

RESULTS

In the analysis, 461 participants (54% women, 34% African Americans) were included. Greater intima-media thickness was associated with lower CBF in gray matter (β=-1.36; p = .04) and total brain (β=-1.26; p = .04), adjusting for age, sex, race, education, and total brain volume. The associations became statistically nonsignificant after further controlling for cardiovascular risk factors. Intima-media thickness was not associated with volumes of total brain, gray matter, and white matter hyperintensities.

CONCLUSIONS

This study suggests that lower CBF in middle age is associated with markers of atherosclerosis in the carotid arteries. This association may reflect early long-term exposure to traditional cardiovascular risk factors. Early intervention on atherosclerotic risk factors may modulate the trajectory of CBF as people age and develop brain pathology.

Socioeconomic position in childhood and depressive symptoms in later adulthood in the Czech Republic

BACKGROUND

Depression risk may partly originate from socioeconomic hardship in childhood. We investigated the association of childhood socioeconomic position with depressive symptoms in later adulthood in a Central and Eastern European country.

METHODS

We analyzed data from the Czech arm of the Health, Alcohol and Psychosocial factors In Eastern Europe (HAPIEE) study. We estimated the associations of three indicators of childhood socioeconomic position (access to household amenities at age of 10 years, father´s education and mother´s education) with high depressive symptoms, operationalized as ≥16 points on the Center for Epidemiological Studies - Depression 20 scale, controlling for age and sex, current socioeconomic position and other social and health-related factors.

RESULTS

The analytical sample included 4,213 individuals (mean age 58 years, 54% women). All three indicators of childhood socioeconomic position were inversely associated with depressive symptoms in age-sex adjusted models (p for trends: access to household amenities p<0.001; mother´s education p<0.001; father´s education p=0.03). Adjustment for current socioeconomic position attenuated the associations of depressive symptoms with access to household amenities (p for trend 0.04) and mother´s education (p for trend 0.05) and virtually eliminated the association with father´s education (p for trend 0.82).

LIMITATIONS

Individuals with higher depressive symptoms and more adverse socioeconomic position are likely to be underrepresented in the study sample. Data on childhood socioeconomic position may be reported inaccurately.

CONCLUSIONS

Socioeconomic hardship in childhood may have long-lasting consequences on mental health in later adulthood.

Using clinical registries, administrative data and electronic medical records to improve medication safety and effectiveness in dementia

PURPOSE OF REVIEW

Clinical registries, routinely collected administrative data and electronic medical records (EMRs) provide new opportunities to investigate medication safety and effectiveness. This review outlines the strengths and limitations of these data, and highlights recent research related to safe and effective medication use in dementia.

RECENT FINDINGS

Clinical registries, administrative data and EMRs facilitate observational research among people often excluded from randomized controlled trials (RCTs). Larger sample sizes and longer follow-up times permit research into less common adverse events not apparent in RCTs. The validity of diagnoses recorded in administrative data and EMRs remains variable, although positive predictive values are typically high and sensitivity is low. Dispensing records are a rich source of data for estimating medication exposure. Recent research has investigated medications and prescribing patterns as risk factors for incident dementia, strategies to alleviate behavioural symptoms and the management of comorbidity. Common study protocols and common data models are examples of distributed network approaches increasingly used to conduct large and generalizable multi-database studies across different countries.

SUMMARY

Greater availability of electronic health data provides important opportunities to address evidence-practice gaps in relation to medication use and safety in people with dementia.

Soluble epoxide hydrolase inhibitor protects against blood-brain barrier dysfunction in a mouse model of type 2 diabetes via the AMPK/HO-1 pathway

Diabetes mellitus is a metabolic disorder that can lead to blood-brain barrier (BBB) disruption and cognitive decline. However, the mechanisms of BBB breakdown in diabetes are still unclear. Soluble epoxide hydrolase (sEH) is an enzyme that degrades epoxyeicosatrienoic acids (EETs), which have multiple protective effects on vascular structure and functions. In the current study, we showed increased vascular permeability of the BBB, which was accompanied by upregulation of sEH and downregulation of 14,15-EET. Moreover, the sEH inhibitor t-AUCB restored diabetic BBB integrity in vivo, and 14,15-EET prevented ROS accumulation and MEC injury in vitro. t-AUCB or 14,15-EET treatment provoked AMPK/HO-1 activation under diabetic conditions in vivo and in vitro. Thus, we suggest that decreased EET degradation by sEH inhibition might be a potential therapeutic approach to attenuate the progression of BBB injury in diabetic mice via AMPK/HO-1 pathway activation.

Cholinesterase inhibitors in patients with diabetes mellitus and dementia: an open-cohort study of ~23 000 patients from the Swedish Dementia Registry

OBJECTIVE

Cholinesterase inhibitors (ChEIs) and memantine are the only approved pharmacological treatments for Alzheimer's disease (AD). Recent literature suggests reductions in cardiovascular burden and risk of stroke in ChEI users. However, the clinical effectiveness of these drugs in patients with diabetes mellitus (DM) and dementia has not been evaluated.

RESEARCH DESIGN AND METHODS

We conducted a registry-based open-cohort study of 22 660 patients diagnosed with AD and mixed-pathology dementia registered in the Swedish Dementia Registry until December 2015. Information on drug use, comorbidity and mortality was extracted using the linkage with the National Patient Registry, the Prescribed Drug Registry and the Cause of Death Registry. In total, 3176 (14%) patients with DM and 19 484 patients without DM were identified. Propensity-score matching, Cox-regression and competing-risk regression models were applied to produce HRs with 95% CIs for differences in all-cause, cardiovascular and diabetes-related mortality rates in ChEI users and non-users.

RESULTS

After matching the ChEI use in patients with DM was associated with 24% all-cause mortality reduction (HR 0.76 (95% CI 0.67 to 0.86)), compared with 20% reduction (0.80 (0.75 to 0.84)) in non-DM users. Donepezil and galantamine use were associated with a reduced mortality in both patients with DM (0.84 (0.74 to 0.96); 0.80 (0.66 to 0.97)) and patients without DM (0.85 (0.80 to 0.90); 0.93 (0.86 to 0.99)). Donepezil was further associated with reduction in cardiovascular mortality, however only in patients without DM (0.84 (0.75 to 0.94)). Rivastigmine lowered mortality only in the whole-cohort analysis and in patients without DM (0.82 (0.75 to 0.89)). Moreover, ChEI use was associated with 48% reduction in diabetes-related mortality (HR 0.52 (0.32 to 0.87)) in the whole-cohort analysis. Last, low and high doses were associated with similar benefit.

CONCLUSIONS

We found reductions in mortality in patients with DM and AD or mixed-pathology dementia treated with ChEIs, specifically donepezil and galantamine were associated with largest benefit. Future studies should evaluate whether ChEIs help maintain self-management of diabetes in patients with dementia.

Stroke as a Cause of Death in Death Certificates of Patients with Dementia: A Cohort Study from the Swedish Dementia Registry

Introduction:

Patients with dementia may be at a higher risk for death from stroke. We aimed to describe characteristics of dementia patients that died from ischemic stroke (IS) in Sweden.

Methods:

A retrospective longitudinal analysis of prospectively collected data of patients registered into the Swedish Dementia Registry was conducted. Data on causes of death, drugs and comorbidities were acquired from the Swedish nationwide health registers. Deaths were attributed to stroke if the death certificate contained stroke as a cause of death and the patient had a stroke registered in Riksstroke, the Swedish Stroke Register, in the year preceding death. Demographic data at the time of dementia diagnosis was compared between patients dying from IS and registered in Riksstroke, patients dying from IS without being registered in Riksstroke and those dying from other causes.

Results:

Out of 49823 patients diagnosed with dementia between 2007 and 2014 in primary care or specialist clinics, 14170 (28.4%) had died by the end of 2014. Of these 1180 (8.3%) had IS in their death certificate, of which 459 (38.9%) had been registered in Riksstroke. In patients who died of IS the most common type of dementia was vascular dementia while those died from other causes were most often diagnosed with Alzheimer’s dementia (AD). Patients who died from IS and were registered in Riksstroke had higher MMSE score compared to other groups. Patients who died from IS took more cardiovascular medications. There were no differences in the use of antipsychotics, antidepressants, acetylcholinesterase inhibitors, memantine, anxiolytics, or hypnotics between the groups.

Conclusions:

There was a relatively high number of patients who died from IS as shown in their death certificate but had not been registered in Riksstroke in the year before death. This creates concerns on the accuracy of death certificate stroke diagnoses, particularly for deaths taking place outside hospitals.

Mental disorders and medical comorbidities: Association rule mining approach

PURPOSE

This study explored the medical comorbidities of mental disorders using association rule mining.

DESIGN AND METHODS

Patients diagnosed with mental disorders between 2002 and 2010 were identified. An equal number of nonmental disorder subjects were randomly selected and matched with case group by age and gender.

FINDINGS

Sleep disorders and digestive diseases were frequent comorbidities among mental disorders. The specific medical comorbidities were diabetes mellitus, chronic liver disease, extrapyramidal diseases, disorders of stomach function, general symptoms, sleep disturbance, and family circumstances.

PRACTICE IMPLICATIONS

The results suggest that education of professional knowledge of comorbid conditions should be provided to nurses for caring patients with mental illnesses.

The treatment gap for mental disorders and associated factors in the Czech Republic

OBJECTIVES

To assess the extent of the treatment gap for mental disorders in the Czech Republic, determine factors associated with the utilization of mental health services and explore what influences willingness to seek mental health care.

METHODS

Data from the CZEch Mental health Study, a nationally representative study of community-dwelling adults in the Czech Republic were used. The Mini International Neuropsychiatric Interview assessed the presence of mental disorders. 659 participants with current affective, anxiety, alcohol use and substance use disorders were studied.

RESULTS

The treatment gap for mental disorders ranged from 61% for affective to 93% for alcohol use disorders. Mental health service use was associated with greater disability (OR 1.04; 95% CI 1.02-1.05; p < 0.001), female gender (OR 3.31; 95% CI 1.97-5.57; p < 0.001), urban residence (OR 1.84; 95% CI 1.12-3.04; p < 0.05) and a higher number of somatic diseases (OR 1.32; 95% CI 1.03-1.67; p < 0.05). Self-identification as having a mental illness was associated with greater willingness to seek a psychiatrist and a psychologist.

CONCLUSIONS

The treatment gap for mental disorders is alarmingly high in the Czech Republic. Interventions to decrease it should target in particular rural areas, men and people with low self-identification as having a mental illness.

Differences in cognitive performance and cognitive decline across European regions: a population-based prospective cohort study

BACKGROUND

A large variation in cognitive performance exists between European regions. However, it is unclear how older Europeans differ in the rate of cognitive decline.

METHODS

We analysed data from 22 181 individuals (54% women; median age 71) who participated in the Survey on Health, Ageing and Retirement in Europe. Cognition was measured using tests on verbal fluency, immediate and delayed recall. We used linear regression and linear mixed effects regression to examine regional differences in the level of cognitive performance and the rate of cognitive decline.

RESULTS

Scandinavians had the highest baseline cognitive scores (mean standardized overall cognitive score 0.3), followed by Western Europeans (mean 0.2), Central and Eastern Europeans (mean 0.1) and individuals from Mediterranean countries (mean -0.4). These differences persisted even after adjustment for sociodemographic and clinical characteristics. The annual cognitive decline in Scandinavia (0.59%) was approximately two times greater than in Western Europe (0.28%), Central and Eastern Europe (0.25%) and Mediterranean countries (0.23%).

DISCUSSION

There are substantial differences in cognitive performance as well as rates of cognitive decline among the elderly throughout European regions. This might be explained by differing levels of cognitive reserve.

Long-term liraglutide ameliorates nigrostriatal impairment via regulating AMPK/PGC-1a signaling in diabetic mice

Growing evidence indicates links between type 2 diabetes and Parkinson's disease. The glucagon-like peptide 1 analogue, liraglutide, a commonly used anti-diabetic drug, has protective effects on neurons. The goal of this study was to determine whether long-term liraglutide treatment could reduce the risk of adult type 2 diabetic mice developing Parkinson's disease. Male diabetic db/db mice (12 weeks old) were injected daily with liraglutide (n = 8), or saline (n = 8), and non-diabetic m/m littermates (n = 6) were included as controls. Motor function was assessed every 4 weeks and all mice were sacrificed after 8 weeks of drug intervention for further analysis. The results revealed that long-term treatment of liraglutide protected the db/db mice against the motor function decay and the dopaminergic neuron loss. Liraglutide also restored the impaired AMP kinase (AMPK)/peroxisome proliferator-activated receptor-γ coactivator 1a (PGC-1a) signaling in the striatum of db/db mice. Further experiments in SH-SY5Y cells supported that AMPK is involved in the neuroprotective effect of liraglutide. In summary, long-term liraglutide ameliorated motor dysfunction and dopaminergic neuron impairment in type 2 diabetic mice, probably via enhancing AMPK/PGC-1a signaling.

Impact of pharmacological treatment of diabetes mellitus on dementia risk: systematic review and meta-analysis

BACKGROUND

The association between diabetes mellitus (DM) treatment and dementia is not well understood.

OBJECTIVE

To investigate the association between treatment of diabetes, hypoglycemia, and dementia risk.

RESEARCH DESIGN AND METHODS

We performed a systematic review and meta-analysis of pharmacological treatment of diabetes and incident or progressive cognitive impairment. We searched Ovid MEDLINE, Embase, Cochrane Central Registry of Controlled Trials, and PsychINFO from inception to 18 October 2017. We included cross-sectional, case-control, cohort, and randomized controlled studies. The study was registered with PROSPERO (ID CRD42017077953).

RESULTS

We included 37 studies into our systematic review and 13 into our meta-analysis. Ten studies investigated any antidiabetic treatment compared with no treatment or as add-on therapy to prior care. Treatment with an antidiabetic agent, in general, was not associated with incident dementia (risk ratio (RR) 1.01; 95% CI 0.93 to 1.10). However, we found differential effects across drug classes, with a signal of harm associated with insulin therapy (RR 1.21; 95% CI 1.06 to 1.39), but potentially protective effects with thiazolidinedione exposure (RR 0.71; 95% CI 0.55 to 0.93). Severe hypoglycemic episodes were associated with a nearly twofold increased likelihood of incident dementia (RR 1.77; 95% CI 1.35 to 2.33). Most studies did not account for DM duration or severity.

CONCLUSIONS AND LIMITATIONS

The association between treatment for diabetes and dementia is differential according to drug class, which is potentially mediated by hypoglycemic risk. Not accounting for DM duration and/or severity is a major limitation in the available evidence base.

Socioeconomic position in childhood and cognitive aging in Europe

OBJECTIVES

We aimed to investigate whether socioeconomic position (SEP) in childhood has an effect on the level of cognitive performance and the rate of cognitive decline in older adults.

METHODS

We performed a prospective cohort study of individuals enrolled in a multicenter population-based study, SHARE (Survey of Health, Ageing and Retirement in Europe). Interviews were conducted in 6 waves at approximately 2-year intervals and included examinations of cognitive performance (memory, verbal fluency, delayed recall) and measurements of childhood SEP (participants' household characteristics at the age of 10 years). We estimated the associations of SEP with the level of cognitive performance using linear regression and the relation to the rate of cognitive decline with mixed-effects models.

RESULTS

This study included 20,244 participants from 16 European countries (median age at baseline 71 years, 54% women). Adverse childhood SEP was associated with a lower level of baseline cognitive performance. This association was attenuated after adjustment for clinical and social risk factors but remained statistically significant. Childhood SEP was not related to the rate of cognitive decline.

CONCLUSIONS

Variation in childhood SEP helps to explain differences in cognitive performance between older people, but not the rate of decline from their previous level of cognition. Strategies to protect cognitive aging should be applied early in life.

The Therapeutic Potential of Metformin in Neurodegenerative Diseases

The search for treatments for neurodegenerative diseases is a major concern in light of today's aging population and an increasing burden on individuals, families, and society. Although great advances have been made in the last decades to understand the underlying genetic and biological cause of these diseases, only some symptomatic treatments are available. Metformin has long since been used to treat Type 2 Diabetes and has been shown to be beneficial in several other conditions. Metformin is well-tested in vitro and in vivo and an approved compound that targets diverse pathways including mitochondrial energy production and insulin signaling. There is growing evidence for the benefits of metformin to counteract age-related diseases such as cancer, cardiovascular disease, and neurodegenerative diseases. We will discuss evidence showing that certain neurodegenerative diseases and diabetes are explicitly linked and that metformin along with other diabetes drugs can reduce neurological symptoms in some patients and reduce disease phenotypes in animal and cell models. An interesting therapeutic factor might be how metformin is able to balance survival and death signaling in cells through pathways that are commonly associated with neurodegenerative diseases. In healthy neurons, these overarching signals keep energy metabolism, oxidative stress, and proteostasis in check, avoiding the dysfunction and neuronal death that defines neurodegenerative disease. We will discuss the biological mechanisms involved and the relevance of neuronal vulnerability and potential difficulties for future trials and development of therapies.

The Therapeutic Potential of Metformin in Neurodegenerative Diseases

The search for treatments for neurodegenerative diseases is a major concern in light of today's aging population and an increasing burden on individuals, families, and society. Although great advances have been made in the last decades to understand the underlying genetic and biological cause of these diseases, only some symptomatic treatments are available. Metformin has long since been used to treat Type 2 Diabetes and has been shown to be beneficial in several other conditions. Metformin is well-tested in vitro and in vivo and an approved compound that targets diverse pathways including mitochondrial energy production and insulin signaling. There is growing evidence for the benefits of metformin to counteract age-related diseases such as cancer, cardiovascular disease, and neurodegenerative diseases. We will discuss evidence showing that certain neurodegenerative diseases and diabetes are explicitly linked and that metformin along with other diabetes drugs can reduce neurological symptoms in some patients and reduce disease phenotypes in animal and cell models. An interesting therapeutic factor might be how metformin is able to balance survival and death signaling in cells through pathways that are commonly associated with neurodegenerative diseases. In healthy neurons, these overarching signals keep energy metabolism, oxidative stress, and proteostasis in check, avoiding the dysfunction and neuronal death that defines neurodegenerative disease. We will discuss the biological mechanisms involved and the relevance of neuronal vulnerability and potential difficulties for future trials and development of therapies.