Severe Hypoglycemia Increases Dementia Risk and Related Mortality: A Nationwide, Population-based Cohort Study

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.

Association of hypoglycemic events with cognitive impairment in patients with type 2 diabetes mellitus: Protocol for a dose-response meta-analysis

INTRODUCTION

With an incidence rate as high as 46%-58%, hypoglycemia is a common complication of glycemic management among those suffering from type 2 diabetes mellitus(T2DM). According to preclinical research, hypoglycemia episodes may impair cognition by harming neurons. However, there is still controversy regarding the clinical evidence for the relationship between hypoglycemic events and the likelihood of cognitive impairment. Furthermore, little research has been done on the dose-response association between hypoglycemia incidents and the possibility of cognitive impairment. To address these knowledge gaps, the present research intends to update the comprehension of the association among hypoglycemic events and the risk of cognitive impairment and to clarify the correlation between dose and response by incorporating the most recent investigations.

METHOD AND ANALYSIS

This work has developed a protocol for a systematic review and meta-analysis that will examine, via a well-organized assessment of several databases, the relationship between the incidence of hypoglycemia and the probability of cognitive impairment. Observational studies investigating the connection between hypoglycemia episodes and cognitive impairment will be included. The databases that will be searched are PubMed, Web of Science, the Chinese Biomedical Literature Database (CBM), Cochrane Library, Embase, the China National Knowledge (CNKI), Wan Fang, the Chinese Science and Technology Periodical Database (VIP), and Du Xiu. Literature from the establishment of each database to December 2023 will be included in the search. Two researchers will independently screen the studies that satisfy the requirements for both inclusion and exclusion. A third researcher will be asked to mediate any disputes. The methodological caliber of the studies included will be assessed utilizing the Newcastle-Ottawa Scale (NOS) or the Joanna Briggs Institute (JBI) critical appraisal method. With regard to GRADE, which stands for Grading of Recommendations, Assessment, Development, and Evaluation, the quality of the evidence will be evaluated. ROBIS Tool will be used to evaluate the risk of bias in the development of the systematic review. If the data is accessible, meta-analysis and dose-response curve analysis will be employed by Stata software. However, if the data does not allow for such analysis, a descriptive review will be performed.

DISCUSSION AND CONCLUSION

Hypoglycemic episodes may raise the likelihood of cognitive impairment, according to earlier investigations. This study will update the relevant evidence and explore the dose-response connection between hypoglycemic episodes and cognitive impairment. The results of this review will have significant effects on decision-making by individuals with diabetes, healthcare providers, and government policy institutions.

TRIAL REGISTRATION

Prospero registration number: CRD42023432352.

Improving Care for People Living With Dementia and Diabetes: Applying the Human-Centered Design Process to Continuous Glucose Monitoring

People with Alzheimer's disease or related dementias and diabetes mellitus (ADRD-DM) are at high risk for hypoglycemic events. Their cognitive impairment and psychosocial situation often hinder detection of hypoglycemia. Extending use and benefits of continuous glucose monitoring (CGM) to people with ADRD-DM could improve hypoglycemia detection, inform care, and reduce adverse events. However, cognitive impairment associated with ADRD presents unique challenges for CGM use. This commentary proposes applying the human-centered design process to CGM, investigating design solutions or interventions needed to integrate CGM into the health care of patients with ADRD-DM. With this process, we can identify and inform CGM designs for people with ADRD-DM, broadening CGM access, increasing detection and treatment of the silent threat posed by hypoglycemia.

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.

The Current Place of DPP4 Inhibitors in the Evolving Landscape of Type 2 Diabetes Management: Is It Time to Bid Adieu?

During the last decade, the landscape of type 2 diabetes (T2D) management has been completely transformed, moving from a glucose-centric perspective to a holistic approach that also takes into account weight control and organ protection. Dipeptidyl peptidase-4 inhibitors (DPP4i) are oral agents that have been used for the treatment of T2D for almost 20 years. Although they present an excellent safety profile, including the risk of hypoglycemia, they lack the spectacular cardiorenal benefits and weight-loss effects of the newer antidiabetic agents. This poses the question of whether they still deserve a place in the arsenal of drugs against T2D. In this article, we use a hypothetical case scenario to illustrate possible patient profiles where DPP4i could prove useful in the clinical setting. We discuss the advantages and disadvantages of the category, focusing on glycemic control, weight management, and cardiorenal protection, which are the pillars of modern T2D management, also considering its safety profile and cost-effectiveness. We conclude that in most cases, DPP4i present a more favorable risk-benefit ratio compared to sulfonylureas, which are still widely prescribed throughout the world. We also suggest that future research should clarify the reasons behind the contradictory findings between human and animal studies on cardiorenal effects of the class and identify subgroups of patients who would derive most benefit with DPP4i treatment.

Metabolic Profile of Alzheimer's Disease: Is 10-Hydroxy-2-decenoic Acid a Pertinent Metabolic Adjuster?

Alzheimer's disease (AD) represents a significant public health concern in modern society. Metabolic syndrome (MetS), which includes diabetes mellitus (DM) and obesity, represents a modifiable risk factor for AD. MetS and AD are interconnected through various mechanisms, such as mitochondrial dysfunction, oxidative stress, insulin resistance (IR), vascular impairment, inflammation, and endoplasmic reticulum (ER) stress. Therefore, it is necessary to seek a multi-targeted and safer approach to intervention. Thus, 10-hydroxy-2-decenoic acid (10-HDA), a unique hydroxy fatty acid in royal jelly, has shown promising anti-neuroinflammatory, blood-brain barrier (BBB)-preserving, and neurogenesis-promoting properties. In this paper, we provide a summary of the relationship between MetS and AD, together with an introduction to 10-HDA as a potential intervention nutrient. In addition, molecular docking is performed to explore the metabolic tuning properties of 10-HDA with associated macromolecules such as GLP-1R, PPARs, GSK-3, and TREM2. In conclusion, there is a close relationship between AD and MetS, and 10-HDA shows potential as a beneficial nutritional intervention for both AD and MetS.

Association of hypoglycaemia with the risks of arrhythmia and mortality in individuals with diabetes - a systematic review and meta-analysis

Background

Hypoglycaemia has been linked to an increased risk of cardiac arrhythmias by causing autonomic and metabolic alterations, which may be associated with detrimental outcomes in individuals with diabetes(IWD), such as cardiovascular diseases (CVDs) and mortality, especially in multimorbid or frail people. However, such relationships in this population have not been thoroughly investigated. For this reason, we conducted a systematic review and meta-analysis.

Methods

Relevant papers published on PubMed, Embase, Cochrane, Web of Knowledge, Scopus, and CINHAL complete from inception to December 22, 2022 were routinely searched without regard for language. All of the selected articles included odds ratio, hazard ratio, or relative risk statistics, as well as data for estimating the connection of hypoglycaemia with cardiac arrhythmia, CVD-induced death, or total death in IWD. Regardless of the heterogeneity assessed by the I2 statistic, pooled relative risks (RRs) and 95% confidence intervals (CI) were obtained using random-effects models.

Results

After deleting duplicates and closely evaluating all screened citations, we chose 60 studies with totally 5,960,224 participants for this analysis. Fourteen studies were included in the arrhythmia risk analysis, and 50 in the analysis of all-cause mortality. Hypoglycaemic patients had significantly higher risks of arrhythmia occurrence (RR 1.42, 95%CI 1.21-1.68), CVD-induced death (RR 1.59, 95% CI 1.24-2.04), and all-cause mortality (RR 1.68, 95% CI 1.49-1.90) compared to euglycaemic patients with significant heterogeneity.

Conclusion

Hypoglycaemic individuals are more susceptible to develop cardiac arrhythmias and die, but evidence of potential causal linkages beyond statistical associations must await proof by additional specifically well planned research that controls for all potential remaining confounding factors.

Relationship between key continuous glucose monitoring-derived metrics and specific cognitive domains in patients with type 2 diabetes mellitus

BACKGROUND

Continuous glucose monitoring (CGM)-derived time in range (TIR) is closely associated with micro- and macrovascular complications in type 2 diabetes mellitus (T2DM). This study was performed to investigate the relationship between key CGM-derived metrics and specific cognitive domains in patients with T2DM.

METHODS

Outpatients with T2DM who were otherwise healthy were recruited for this study. A battery of neuropsychological tests was performed to evaluate cognitive function, including memory, executive functioning, visuospatial ability, attention, and language. Participants wore a blinded flash continuous glucose monitoring (FGM) system for 72 h. The key FGM-derived metrics were calculated, including TIR, time below range (TBR), time above range (TAR), glucose coefficient of variation (CV), and mean amplitude of glycemic excursions (MAGE). Furthermore, the glycemia risk index (GRI) was also calculated by the GRI formula. Binary logistic regression was used to assess risk factors for TBR, and we further analysed the associations between neuropsychological test results and key FGM-derived metrics with multiple linear regressions.

RESULTS

A total of 96 outpatients with T2DM were recruited for this study, with 45.8% experiencing hypoglycemia (TBR^{< 3.9 mmol/L}). Spearman analysis results revealed that a higher TBR^{< 3.9 mmol/L} was correlated with worse performance on the Trail Making Test A (TMTA), Clock Drawing Test (CDT), and cued recall scores (P < 0.05). Logistic regression analysis results indicated that the TMTA (OR = 1.010, P = 0.036) and CDT (OR = 0.429, P = 0.016) scores were significant factors influencing the occurrence of TBR^{< 3.9 mmol/L}. Multiple linear regressions further demonstrated that TBR^{< 3.9 mmol/L} (β = -0.214, P = 0.033), TAR^{> 13.9 mmol/L} (β = -0.216, P = 0.030) and TAR^{10.1-13.9 mmol/L} (β = 0.206, P = 0.042) were significantly correlated with cued recall scores after adjusting for confounding factors. However, TIR, GRI, CV and MAGE showed no significant correlation with the results of neuropsychological tests (P > 0.05).

CONCLUSIONS

A higher TBR^{< 3.9 mmol/L} and TAR^{> 13.9 mmol/L} were associated with worse cognitive functions (memory, visuospatial ability, and executive functioning). Conversely, a higher TAR of 10.1-13.9 mmol/L was associated with better memory performance in memory tasks.

The effects of long-term cumulative HbA1c exposure on the development and onset time of dementia in the patients with type 2 diabetes mellitus: hospital based retrospective study (2005-2021)

AIMS

We examine cumulative effect of long-term glycemic exposure in patients with type 2 diabetes mellitus (T2DM) on the development of dementia.

METHODS

The study involved 20,487 records of patients with T2DM identified in the electronic medical record at Severance Hospital, Korea. Cumulative HbA1c (AUC_HbA1c) and mean HbA1c over time (HbA1c_avg) as measures of long-term glycemic exposure were compared for the development of dementia and the time to dementia.

RESULTS

AUC_HbA1c and HbA1c_avg were significantly higher in patients who later developed dementia than in those who did not dementia (AUC_HbA1c: 56.2 ± 26.4 vs. 52.1 ± 26.1 %*Year; HbA1c_avg: 7.0 ± 1.0 vs. 7.3 ± 1.0 %). Odds ratio of dementia increased when HbA1c_avg was 7.2% (55 mmol/mol) or above, and when AUC_HbA1c was 42 %*Year (e.g., HbA1c 7.0% maintained for 6 years) or above. Among those who developed dementia, as HbA1c_avg increased, the time to dementia onset decreased (β = -380.6 days, 95% confidence interval [CI]: -416.2 to -345.0).

CONCLUSIONS

Our results indicate poorly controlled T2DM was associated with an increased risk of developing dementia, as measured by AUC_HbA1c and HbA1c_avg. Higher cumulative glycemic exposure may lead to developing dementia in a shorter time.

Emerging Evidence for the Use of Antidiabetic Drugs, Glucagon-like Peptide 1 Receptor Agonists, for the Treatment of Alzheimer's Disease

From an epidemiological and pathophysiological point of view, Alzheimer's disease (AD) and type 2 diabetes (T2DM) should be considered 'sister' diseases. T2DM significantly increases the risk of developing AD, and the mechanisms of neuronal degeneration themselves worsen peripheral glucose metabolism in multiple ways. The pathophysiological links between the two diseases, particularly cerebral insulin resistance, which causes neuronal degeneration, are so close that AD is sometimes referred to as 'type 3 diabetes'. Although the latest news on the therapeutic front for AD is encouraging, no treatment has been shown to halt disease progression permanently. At best, the treatments slow down the progression; at worst, they are inactive, or cause worrying side effects, preventing their use on a larger scale. Therefore, it appears logical that optimizing the metabolic milieu through preventive or curative measures can also slow down the cerebral degeneration that characterizes AD. Among the different classes of hypoglycaemic drugs, glucagon-like peptide 1 receptor agonists, which are widely used in the treatment of T2DM, were shown to slow down, or even prevent, neuronal degeneration. Data from animal, preclinical, clinical phase II, cohort and large cardiovascular outcomes studies are encouraging. Of course, randomized clinical phase III studies, which are on-going, will be essential to verify this hypothesis. Thus, for once, there is hope for slowing down the neurodegenerative processes associated with diabetes, and that hope is the focus of this review.

Associations of Mid- and Late-Life Severe Hypoglycemic Episodes With Incident Dementia Among Patients With Type 2 Diabetes: A Population-Based Cohort Study

OBJECTIVE

Severe hypoglycemia is associated with an increased risk of dementia. We examined if the association is consistently present in mid- and late-life hypoglycemia.

RESEARCH DESIGN AND METHODS

Using health care data from Population Data BC, we created a base cohort of patients age ≥40 years with incident type 2 diabetes. Exposure was the first occurrence of severe hypoglycemia (hospitalization or physician visit). We assessed exposure versus no exposure in mid- (age 45-64 years) and late-life (age 65-84 years) cohorts. Index date was the later of the 45th birthday (midlife cohort), 65th birthday (late-life cohort), or diabetes diagnosis. Those with hypoglycemia or dementia before the index date were excluded. Patients were followed from index date until dementia diagnosis, death, emigration, or 31 December 2018. Exposure was modeled as time dependent. We adjusted for confounding using propensity score weighting. Dementia risk was estimated using cause-specific hazards models with death as a competing risk.

RESULTS

Of 221,683 patients in the midlife cohort, 1,793 experienced their first severe hypoglycemic event. Over a median of 9.14 years, 3,117 dementia outcomes occurred (32 among exposed). Of 223,940 patients in the late-life cohort, 2,466 experienced their first severe hypoglycemic event. Over a median of 6.7 years, 15,997 dementia outcomes occurred (158 among exposed). The rate of dementia was higher for those with (vs. without) hypoglycemia in both the mid- (hazard ratio 2.85; 95% CI 1.72-4.72) and late-life (2.38; 1.83-3.11) cohorts.

CONCLUSIONS

Both mid- and late-life hypoglycemia were associated with approximately double the risk of dementia, indicating the need for prevention throughout the life course of those with diabetes.

Effect of Comorbidities on Ten-Year Survival in Patients with Dementia

BACKGROUND

There is a verified association between comorbidity and survival in patients with dementia.

OBJECTIVE

To describe the ten-year survival probability of patients with dementia and to identify the impact of comorbidity.

METHODS

The prognostic retrospective cohort study was conducted using data from adults with dementia who had visited the outpatient departments at Maharaj Nakorn Chiang Mai hospital between 2006 and 2012. Dementia was verified in accordance with standard practice guidelines. Secondary data detailing about patient age, gender, date of dementia diagnosis and death, types of dementia, and comorbidities at the time of dementia diagnosis was obtained from electronic medical records. The association between comorbidity, patients' underlying disease at dementia diagnosis, and overall survival were analyzed using a multivariable Cox proportional hazard model adjusted for age, gender, types of dementia, and other comorbidities.

RESULTS

Of the 702 patients, 56.9% were female. Alzheimer's disease (39.6%) was the most prevalent type of dementia. Median overall survival was 6.0 years (95% CI 5.5- 6.7). The comorbidities associated with a high risk of mortality included liver disease (aHR 2.70, 95% CI 1.46- 5.00), atrial fibrillation (aHR 2.15, 95% CI 1.29- 3.58), myocardial infarction (aHR 1.55, 95% CI 1.07- 2.26), and type 2 diabetes mellitus (aHR 1.40, 95% CI 1.13- 1.74).

CONCLUSION

Overall survival rate of patients with dementia in Thailand was comparable to previous studies. Several comorbidities were associated with a ten-year survival. The prognosis of patients with dementia may be improved by appropriate care of comorbidities.

Amyloid [Formula: see text] (1-42) peptide impairs mitochondrial respiration in primary human brain microvascular endothelial cells: impact of dysglycemia and pre-senescence

Diabetes increases the risk of Alzheimer's disease (AD). We investigated the impact of glucose concentrations on the β-amyloid (Aβ)-induced alteration of mitochondrial/cellular energetics in primary human brain microvascular endothelial cells (HBMECs). HBMECs were grown and passaged in media containing 15 mmol/l glucose (normal) based on which the glucose levels in the media were designated as high (25 mmol/L) or low (5 mmol/L). HBMECs were treated with Aβ (1-42) (5 µmol/l) or a scrambled peptide for 24 h and mitochondrial respiratory parameters were measured using Seahorse Mito Stress Test. Aβ (1-42) decreased the mitochondrial ATP production at normal glucose levels and decreased spare respiratory capacity at high glucose levels. Aβ (1-42) diminished all mitochondrial respiratory parameters markedly at low glucose levels that were not completely recovered by restoring normal glucose levels in the media. The addition of mannitol (10 mmol/l) to low and normal glucose-containing media altered the Aβ (1-42)-induced bioenergetic defects. Even at normal glucose levels, pre-senescent HMBECs (passage 15) displayed greater Aβ (1-42)-induced mitochondrial respiratory impairments than young cells (passages 7-9). Thus, hypoglycemia, osmolarity changes, and senescence are stronger instigators of Aβ (1-42)-induced mitochondrial respiration and energetics in HBMECs and contributors to diabetes-related increased AD risk than hyperglycemia.

Hypoglycaemia and the risk of dementia: a population-based cohort study using exposure density sampling

BACKGROUND

Previous studies have shown hypoglycaemia to be associated with an increased risk of dementia; however, there are several design challenges to consider. The objective of this study is to assess the association between hypoglycaemia and dementia while addressing these challenges using a lag period, exposure density sampling (EDS) and inverse probability of treatment weighting (IPTW).

METHODS

This was a population-based cohort using data (1996-2018) from British Columbia, Canada. From a cohort of incident type 2 diabetes patients aged 40-70 years, we created a dynamic sub-cohort of hypoglycaemia-exposed (≥1 episode requiring hospitalization or a physician visit) and unexposed individuals using EDS, in which four unexposed individuals per one exposed were randomly selected into risk sets based on diabetes duration and age. Follow-up was until dementia diagnosis, death, emigration or 31 December 2018. Those diagnosed with dementia within 2 years of follow-up were censored. We adjusted for confounding using IPTW and estimated the hazard ratio (HR, 95% CI) of dementia using weighted conditional cause-specific hazards risk models with death as a competing risk.

RESULTS

Among 13 970 patients with incident type 2 diabetes, 2794 experienced hypoglycaemia. There were 329 dementia events over a median (interquartile range: IQR) follow-up of 5.03 (5.7) years. IPTW resulted in well-balanced groups with weighted incidence rates (95% CI) of 4.59 (3.52, 5.98)/1000 person-years among exposed and 3.33 (2.58, 3.88)/1000 person-years among unexposed participants. The risk of dementia was higher among those with hypoglycaemia (HR, 1.83; 95% CI 1.31, 2.57).

CONCLUSIONS

After addressing several methodological challenges, we showed that hypoglycaemia contributes to an increased risk of all-cause dementia among patients with type 2 diabetes.

Predicting Hospice Transitions in Dementia Caregiving Dyads: An Exploratory Machine Learning Approach

Background and Objectives

Hospice programs assist people with serious illness and their caregivers with aging in place, avoiding unnecessary hospitalizations, and remaining at home through the end-of-life. While evidence is emerging of the myriad of factors influencing end-of-life care transitions among persons living with dementia, current research is primarily cross- sectional and does not account for the effect that changes over time have on hospice care uptake, access, and equity within dyads.

Research Design and Methods

Secondary data analysis linking the National Health and Aging Trends Study to the National Study of Caregiving investigating important social determinants of health and quality-of-life factors of persons living with dementia and their primary caregivers (n = 117) on hospice utilization over 3 years (2015-2018). We employ cutting-edge machine learning approaches (correlation matrix analysis, principal component analysis, random forest [RF], and information gain ratio [IGR]).

Results

IGR indicators of hospice use include persons living with dementia having diabetes, a regular physician, a good memory rating, not relying on food stamps, not having chewing or swallowing problems, and whether health prevents them from enjoying life (accuracy = 0.685; sensitivity = 0.824; specificity = 0.537; area under the curve (AUC) = 0.743). RF indicates primary caregivers' age, and the person living with dementia's income, census division, number of days help provided by caregiver per month, and whether health prevents them from enjoying life predicts hospice use (accuracy = 0.624; sensitivity = 0.713; specificity = 0.557; AUC = 0.703).

Discussion and Implications

Our exploratory models create a starting point for the future development of precision health approaches that may be integrated into learning health systems that prompt providers with actionable information about who may benefit from discussions around serious illness goals-for-care. Future work is necessary to investigate those not considered in this study-that is, persons living with dementia who do not use hospice care so additional insights can be gathered around barriers to care.

The Effectiveness of Antidiabetic Drugs in Treating Dementia: A Peek into Pharmacological and Pharmacokinetic Properties

Dementia dramatically affects the activities of daily living and quality of life; thus, many therapeutic approaches for overcoming dementia have been developed. However, an effective treatment regimen is yet to be developed. As diabetes is a well-known risk factor for dementia, drug repositioning and repurposing of antidiabetic drugs are expected to be effective dementia treatments. Several observational studies have been useful for understanding the effectiveness of antidiabetic drugs in treating dementia, but it is difficult to conclusively analyze the association between antidiabetic drug treatment and the risk of developing dementia after correcting for potential confounding factors. Mechanism-based approaches may provide a better understanding of the effectiveness of antidiabetic drugs for treating dementia. Since the peripheral circulation and the central nerve system are separated by the blood–brain barrier, it is important to understand the regulation of the central glucose metabolism. In this review, we discuss the pharmacological and pharmacokinetic properties of antidiabetic drugs in relation to treating dementia.

Diagnostic, Prognostic, and Mechanistic Biomarkers of Diabetes Mellitus-Associated Cognitive Decline

Cognitive dysfunctions such as mild cognitive impairment (MCI), Alzheimer’s disease (AD), and other forms of dementia are recognized as common comorbidities of type 2 diabetes mellitus (T2DM). Currently, there are no disease-modifying therapies or definitive clinical diagnostic and prognostic tools for dementia, and the mechanisms underpinning the link between T2DM and cognitive dysfunction remain equivocal. Some of the suggested pathophysiological mechanisms underlying cognitive decline in diabetes patients include hyperglycemia, insulin resistance and altered insulin signaling, neuroinflammation, cerebral microvascular injury, and buildup of cerebral amyloid and tau proteins. Given the skyrocketing global rates of diabetes and neurodegenerative disorders, there is an urgent need to discover novel biomarkers relevant to the co-morbidity of both conditions to guide future diagnostic approaches. This review aims to provide a comprehensive background of the potential risk factors, the identified biomarkers of diabetes-related cognitive decrements, and the underlying processes of diabetes-associated cognitive dysfunction. Aging, poor glycemic control, hypoglycemia and hyperglycemic episodes, depression, and vascular complications are associated with increased risk of dementia. Conclusive research studies that have attempted to find specific biomarkers are limited. However, the most frequent considerations in such investigations are related to C reactive protein, tau protein, brain-derived neurotrophic factor, advanced glycation end products, glycosylated hemoglobin, and adipokines.