Sex differences in risk factors for cognitive decline and dementia, including death as a competing risk, in individuals with diabetes: Results from the ADVANCE trial

Risk factors for mild cognitive impairment in type 2 diabetes mellitus older adult: a systematic review and meta-analysis

AIMS

Numerous of evidence suggest that older adults with diabetes are more likely to experience mild cognitive impairment (MCI), therefore identifying risk factors is crucial. Thus, the purpose of this study was to investigate the risk factors for the development of MCI in older diabetics.

METHODS

The MEDLINE, Web of Science, Scopus, and Embase databases were searched for pertinent research on the risk factors for the beginning of MCI. The remaining studies were assessed using predetermined inclusion and exclusion criteria after duplicate studies were eliminated. The Comprehensive Meta-Analysis software (version 2) was used to analyze the data. The Egger test was used to examine publication bias, while the I-square statistic was used to evaluate study heterogeneity. 95 % confidence limits and odds ratios were used in the analysis.

RESULTS

Thirty studies were authorized for assessment and statistical analysis using the systematic review procedure. These studies' findings indicate that, using both univariate and multivariate analyses, the odds ratio for the occurrence of MCI in older people with diabetes is higher for factors like low educational attainment (univariate analysis: OR = 0.706, CI95 %: 0.622-0.801, P ≤ 0.001 and multivariate analysis: OR = 0.753, CI95 %: 0.637-0.831, P = 0.001), duration of diabetes (univariate analysis: OR = 1.249, CI95 %: 1.111-1.405, P ≤ 0.001 and multivariate analysis: OR = 1.174, CI95 %: 1.006-1.370, P = 0.042), abnormal Hemoglobin A1c (HbA1C) levels (univariate analysis: OR = 1.744, CI95 %: 1.277-2.383, P ≤ 0.001 and multivariate analysis: OR = 1.248, CI95 %: 1.091-1.427, P ≤ 0.001), retinopathy(OR = 2.163, CI95 %: 1.686-2.776, P ≤ 0.001), nephropathy(OR = 1.568, CI95 %: 1.151-2.135, P = 0.004), neuropathy(OR = 1.334, CI95 %: 0.686-2.591, P = 0.396), depression(univariate analysis: OR = 1.649, CI95 %: 1.016-2.841, P = 0.046, and multivariate analysis: OR = 1.957, CI95 %: 1.322-2.856, P ≤ 0.001), and stroke(univariate analysis: OR = 1.820, CI95 %: 1.172-2.827, P = 0.008. multivariate analysis: OR = 1.496, CI95 %: 1.184-1.899, P = 0.001). Furthermore, univariate data analysis revealed that age(OR = 1.067, CI95 %: 1.011-1.126, P = 0.019), high total cholesterol(OR = 0.934, CI95 %: 0.866-1.008, P = 0.076), fasting blood sugar(OR = 1.129, CI95 %: 1.017-1.254, P = 0.023), the presence of hypertension(OR = 1.572, CI95 %: 1.147-2.155, P = 0.005), and kidney disease(OR = 1.676, CI95 %: 0.972-2.89, P = 0.063), all affect the odds ratio for the development of MCI in older adults with diabetes.

CONCLUSION

factors like low education, long-term diabetes, abnormal HbA1C levels, retinopathy, nephropathy, depression, and stroke, as well as high total cholesterol, fasting blood glucose, high blood pressure, and kidney disease, increase the risk of developing MCI in older diabetics. These cases in diabetic patients require special attention.

Risk factors for cognitive decline in type 2 diabetes mellitus adults: a systematic review and meta-analysis

Cognitive decline (CD) is a common disorder in patients with type 2 diabetes mellitus (T2DM), which is affected by various factors. The present study aimed to investigate the factors affecting its occurrence CD in patients T2DM. The PubMed, Web of Science, Scopus, and Embase databases were searched for pertinent research on the risk factors for the beginning of CD. The remaining studies were assessed using predetermined inclusion and exclusion criteria after duplicate studies were eliminated. The Comprehensive Meta-Analysis software (version 2) was used to analyze the data. The Egger test and Begg and Mazumdar test was used to examine publication bias, while the I-square statistic was used to evaluate study heterogeneity. 95% confidence limits and odds ratios were used in the analysis. 40 studies were authorized for assessment and statistical analysis using the systematic review procedure. These studies' findings indicate that, using both crude and adjusted analyses, the odds ratio for the occurrence of CD in people with diabetes is higher for factors like low educational attainment, men, abnormal Hemoglobin A1c (HbA1C) levels, physical inactivity, depression, and stroke. Factors like low education, abnormal HbA1C levels, depression, and stroke as well increase the risk of developing CD in diabetic patients. These cases in diabetic patients require special attention.

Latent profiles of modifiable dementia risk factors in later midlife: relationships with incident dementia, cognition, and neuroimaging outcomes

In 2020, the Lancet Commission identified 12 modifiable factors that increase population-level dementia risk. It is unclear if these risk factors co-occur among individuals in a clinically meaningful way. Using latent class analysis, we identified profiles of modifiable dementia risk factors in dementia-free adults aged 60-64 years from the UK Biobank. We then estimated associations between these profiles with incident dementia, cognition, and neuroimaging outcomes, and explored the differences across profiles in the effects of a polygenic risk score for Alzheimer's disease on outcomes. In 55,333 males and 63,063 females, three sex-specific latent profiles were identified: cardiometabolic risk, substance use-related risk, and low risk. The cardiometabolic risk profile in both males and females was associated with greater incidence of all-cause dementia (male: OR [95% CI] = 2.33 [2.03, 2.66]; female: OR [95% CI] = 1.44 [1.24, 1.68]), poorer cognitive performance, greater brain atrophy, and greater white matter hyperintensity volume compared to the low risk profile. The substance use-related risk profile in males was associated with poorer cognitive performance and greater white matter hyperintensities compared to the low risk profile, but no difference in all-cause dementia incidence was observed (OR [95% CI] = 1.00 [0.95, 1.06]). In females, the substance use-related risk profile demonstrated increased dementia incidence (OR [95% CI] = 1.58 [1.57, 1.58]) and greater brain atrophy but smaller white matter hyperintensity volume compared to the low risk profile. The polygenic risk score had larger effects among females, and differentially influenced outcomes across profiles; for instance, there were larger effects of the polygenic risk score on atrophy in the cardiometabolic profile vs. the low risk profile among males, and larger effects of the polygenic risk score on loss of white matter integrity in the cardiometabolic profile vs. the low risk profile among females. These results reveal three modifiable dementia risk profiles, their unique cognitive/neuroimaging outcomes, and their interactions with genetic risk for Alzheimer's disease. These differences highlight the need to consider population heterogeneity in risk prediction tools and in planning personalized prevention strategies.

Effect of randomised blood pressure lowering treatment and intensive glucose control on dementia and cognitive decline according to baseline cognitive function and other subpopulations of individuals with type 2 diabetes: Results from the ADVANCE trial

Background and aims

Accumulating evidence indicates that reducing high blood pressure (BP) prevents dementia and mild cognitive impairment (MCI). Furthermore, although diabetes is a risk factor for dementia and MCI, there is uncertainty of the effect of intensive glucose control on these endpoints. This study aimed to determine the effects of BP-lowering (vs placebo) and intensive glucose-lowering (vs standard control) treatments according to baseline cognition and other characteristics on dementia and cognitive decline (CD) in people with type 2 diabetes mellitus (T2DM).

Methods

The Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) trial involved 11,140 individuals with T2DM. The effects of BP-lowering and intensive glucose-lowering treatments were explored in subgroups of baseline Mini-Mental State Examination (MMSE), categorised as cognitively normal (scores ≥28) and cognitive impairment (scores <28). The primary outcome was a composite of dementia/CD that accounted for the competing risk of death. Multinomial regression models, adjusted for common cardiovascular risk factors, were used to estimate odds ratios (OR) with 95 % confidence intervals (CI) of the effects of the treatments on dementia/CD. Homogeneity of effects by subgroups were evaluated using interaction terms in the models. A two-sided p value <0.05 was regarded as statistically significant.

Results

BP-lowering treatment (vs. placebo) was associated with a lower odds of dementia/CD in participants with cognitive impairment (OR 0.76, 95 % CI (0.59-0.99)) but not in those cognitively normal (OR 1.05, 95 % CI (0.92-1.21); p for interaction 0.03). Those with a history of cardio-renal-metabolic syndrome did not experience a benefit of active BP lowering treatment compared with placebo on dementia/CD. There were no further subgroup effects of BP-lowering treatment. The effect of intensive glucose lowering (vs standard control) on the odds of dementia/CD did not vary by baseline cognition subgroup. However, it did vary by level of blood glucose at baseline (<7.9 mmol/L OR 1.12, 95 % CI (0.96-1.30) vs ≥ 7.9 mmol/L 0.87 (0.75-1.00); p for interaction 0.02) and duration of T2DM (<10 years OR 0.92 (0.81-1.05) vs ≥10 years 1.16 (0.97-1.38); p for interaction 0.04).

Conclusions

This study suggests greater effects of BP-lowering treatment in those with early loss of cognitive function than in those cognitively normal. There were also differential effects of intensive glucose-lowering on dementia and CD according to levels of blood glucose and duration of diabetes in people with T2DM.

Clinical trial registration

ADVANCE is registered with ClinicalTrials.gov: number NCT00145925.

Association between Age at Diagnosis of Type 2 Diabetes and Subsequent Risk of Dementia and Its Major Subtypes

Background/Objectives: Type 2 diabetes mellitus (T2DM) is a major contributor to cognitive decline and dementia in older adults; however, the role of the age of onset of T2DM in younger patients remains uncertain. We explored the association between the risk of dementia and its subtypes in relation to the age at T2DM diagnosis. Methods: This population cohort study included a total of 612,201 newly diagnosed T2DM patients. The controls were randomly selected from the general population and matched at a 1:2 ratio based on the propensity score. The outcomes of interest were all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VD). The association of T2DM with dementia was stratified by the age at diagnosis of T2DM. Results: The mean ages of the subjects in the T2DM and control groups were 55.7 ± 13.0 and 55.7 ± 13.0. The patients with T2DM diagnosed at <50 years had the highest excess risk for most outcomes relative to the controls, with a hazard ratio (HR) (95% CI) of 3.29 (3.11-3.49) for all-cause dementia, 4.08 (3.18-5.24) for AD, and 5.82 (3.84-8.81) for VD. All risks were attenuated progressively with each increasing decade at the diagnostic age, but remained significant; for T2DM diagnosed at ≥80 years, the HR (95% CI) was 1.38 (1.34-1.41) for all-cause dementia, 1.35 (1.31-1.40) for AD, and 1.98 (1.70-2.30) for VD. Conclusions: We need to stratify T2DM management according to the age of diagnosis. Physicians should closely monitor cognitive function in patients with T2DM, especially in younger individuals.

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.

Race and sex differences in the association between lifespan glycemic status and midlife cognitive function: the Bogalusa heart study

Introduction

Glycemic markers throughout life are associated with increased risk of midlife cognitive decline, yet it is unclear whether these associations differ by race and sex.

Methods

This study used cross-sectional analysis of prospectively maintained cohort. 1,295 participants in the Bogalusa Heart Study, a biracial epidemiological cohort located in a micropolitan area core setting, provided fasting plasma insulin (FPI) and glucose (FPG) biannually from 1973 to 2016. Memory, executive function (EF), attention, working memory (WM), and global cognition (GC), collected 2013-2016. Glycemic markers (i.e., FPG, FPI, and HOMA-IR) averaged within lifespan epochs (≤ 20 years, childhood/adolescence (C/A); 21-40 years, early adulthood (EA); and 40-58 years, midlife). Linear regression models were analyzed for each epoch and separate models were analyzed with sex and race, education as a covariate.

Results

Sample was 59% women, 34% African American (AA). Among women, higher C/A FPG was associated with poorer memory and poorer GC. Higher EA FPG was associated with poorer WM. Among men, higher EA HOMA-IR was associated with worse attention. Higher C/A HOMA-IR and FPI were associated with better memory, as was higher EA FPI. Among AA, higher C/A FPG was associated with worse attention, EF, and GC. Higher EA HOMA-IR was associated with worse attention. Higher midlife FPI and C/A HOMA-IR were associated with worse WM and EF among White Americans (WAs).

Discussion

Markers indicative of hyperglycemia at different epochs were associated with worse midlife cognition in women, AAs, and WAs; but not in men. Differences in the relationship between lifespan glycemic exposures and midlife cognition could reflect broader health disparities.

Association of geriatric measures and global frailty with cognitive decline after allogeneic hematopoietic cell transplantation in older adults

INTRODUCTION

Allogeneic hematopoietic cell transplantation (alloHCT) is increasingly offered to older adults, and its potential impact on cognition in this population is understudied. This work aims to evaluate the ability of cancer-specific geriatric assessments (cGA) and a global frailty index based on accumulation of deficits identified in the cGA to predict the risk of cognitive decline after alloHCT in older adults.

MATERIALS AND METHODS

AlloHCT recipients aged 50 years or older completed a cGA, including a cognitive evaluation by the Blessed Orientation Memory Concentration (BOMC) test, at baseline prior to alloHCT and then at 3, 6, and 12 months after transplant. Baseline frailty was assessed using a deficit accumulation frailty index (DAFI) calculated from the cGA. A multinomial logit model was used to examine the association between predictors (individual cGA measures, DAFI) and the following three outcomes: alive with stable or improved cognition, alive with cognitive decline, and deceased. In post-hoc analyses, analysis of variance was used to compare BOMC scores at baseline, 3, 6, and 12 months across frailty categories.

RESULTS

In total, 148 participants were included, with a median age of 62 (range 50-76). At baseline, 12% had cognitive impairment; at one year, 29% of survivors had improved BOMC scores, 33% had stable BOMC, and 37% had worse BOMC. Prior to transplant, 25% were pre-frail and 11% were frail. Individual baseline cGA measures were not associated with cognitive change at one year as assessed by BOMC. Adjusting for age, sex, and education, those who were frail at baseline were 7.4 times as likely to develop cognitive decline at one year than those who were non-frail, although this finding did not reach statistical significance (95% confidence interval [CI] 0.74-73.8, p = 0.09). The probability of being alive with stable/improved cognition at 12 months for the non-frail, pre-frail, and frail groups was 43%, 34%, and 8%, respectively.

DISCUSSION

Baseline geriatric measures and frailty were not significantly associated with cognitive change as assessed by BOMC in adults aged 50 or older after alloHCT. However, the study was underpowered to detect clinically meaningful differences, and future work to elucidate potential associations between frailty and cognitive outcomes is warranted.

Diabetes and factors associated with cognitive and functional decline. The screening for CKD among older people across Europe (SCOPE) study

BACKGROUND

Type 2 diabetes mellitus (DM) in older people is a heterogeneous condition that exhibits differential characteristics in comparison with younger adults. DM increases the risk of disability, is associated with dementia and loss of function, and cognition may often be interrelated and more pronounced in older patients with DM than in those without.

AIMS

Our aim was to evaluate the incidence of functional and/or cognitive impairment in older adults with and without DM, and its associated factors in DM participants.

METHODS

A 2-year prospective analysis was conducted in a European multicenter prospective cohort (SCOPE study). Older community-dwelling adults (aged ≥ 75 years) underwent a comprehensive geriatric assessment. New functional and/or cognitive decline was explored.

RESULTS

Of 1611 participants, 335 (22.0%) had DM at baseline. The percentage of participants scoring at least one ADL impairment and/or cognitive impairment (MMSE < 24) was similar in both groups (9.6%). Factors associated with any new disability in participants with DM in the multivariate analysis were female sex (OR 3.28, 95% CI 1.42-7.56), history of stroke (OR 4.58, 95% CI 1.64-12.7), and greater IADL dependency (OR 1.08 95% CI 1.02-1.15).

DISCUSSION

Association between DM and cognitive or functional decline in outpatients of 75 years and older was not found, but factors such as female gender, history of stroke, and IADL dependency could be related.

CONCLUSION

Decline in functional and cognitive status of community-dwelling older adults with DM was similar to participants without DM in a short period of 2 years of follow-up, though several clinical factors may increase its risk in this population.

Differential Associations of 6 Adiposity Indices With Dementia in Older Adults: The MIND-China Study

OBJECTIVES

The cross-sectional association between late-life obesity and dementia is often explained by the obesity paradox. We assessed the potential differential associations of various adiposity indices with dementia and subtypes of dementia in rural Chinese older adults.

DESIGN

A population-based cross-sectional study.

SETTING AND PARTICIPANTS

A total of 5277 participants (age ≥60 years; 57.23% female) who were living in rural communities and were examined in March-September 2018 for MIND-China.

METHODS

We used weight, height, and waist circumference (WC) to calculate 6 adiposity indices: body mass index (BMI), waist-to-height ratio (WHtR), weight-adjusted-waist index (WWI), A Body Shape Index (ABSI), body roundness index (BRI), and Conicity Index (ConI). Dementia, Alzheimer's disease (AD), and vascular dementia (VaD) were clinically diagnosed following the international criteria. Data were analyzed with logistic regression models.

RESULTS

Of the 5277 participants, 303 were diagnosed with dementia, including 193 with AD and 99 with VaD. The multivariable-adjusted odds ratio (95% CI) of dementia associated with the highest (vs lowest) quintile of adiposity index was 2.32 (1.40-3.85) for WWI, 1.56 (1.03-2.36) for ABSI, and 1.40 (0.92-2.11) for ConI. Similarly, higher levels of these 3 adiposity indices were significantly associated with an increased likelihood of AD, whereas a higher BMI was associated with a decreased likelihood of AD. None of the 6 examined adiposity indices was significantly associated with VaD when adjusting for multiple confounders.

CONCLUSIONS AND IMPLICATIONS

The adiposity index WWI is linearly associated with the likelihood of dementia and AD. An increased WWI may be a clinical marker for the dementia syndrome and Alzheimer's dementia.

Relationships Between Body Composition and Cognitive Impairment in Hospitalised Middle-Aged Type 2 Diabetic Patients

Objective

The aim of this study was to elucidate the relationship between specific body composition and the risk of Cognitive Impairment (CI) in middle-aged Type 2 Diabetes Mellitus (T2DM) patients.

Methods

This cross-sectional study included 504 hospitalized patients with T2DM from the Department of Endocrinology and Metabolism of the Tianjin Union Medical Center. Subjects were grouped by sex, and cognitive status was assessed using the Montreal Cognitive Assessment (MoCA). The relationship between body composition and cognitive ability was investigated with the use of linear regression analysis. The association between body composition and CI risk was determined by logistic regression analysis.

Results

The prevalence of CI was 39.3% in middle-aged T2DM patients. After adjusting for age, education, marriage status, carotid atherosclerosis, cerebrovascular disease and hemoglobin, multiple linear regression analysis showed that lean mass index (LMI), body mass index (BMI) and appendicular skeletal muscle index (SMI) were significant predictors for the MoCA scores in men (p < 0.05). In addition, BMI (OR 0.913, 95% CI 0.840-0.992) and LMI (OR 0.820, 95% CI 0.682-0.916) were independent protective factors for CI in males. After adjusted for age, education, marriage status, dietary control of diabetes and cerebrovascular disease, visceral obesity (VO, OR 1.950, 95% CI 1.033-3.684) and abdominal obesity (AO, OR 2.537, 95% CI 1.191-5.403) were risk factors for CI in female patients.

Conclusion

The results suggest that there may be different mechanisms underlying the relationship of body compositions and cognitive performance between middle-aged male and female patients with T2DM. In addition, our finding of potential determinants of cognitive impairment may facilitate the development of intervention programs for middle-aged type 2 diabetic patients. Nevertheless, more large prospective studies looking at cognition and changes in body composition over time are needed in the future to further support their association.

Ranking the risk factors for Alzheimer's disease; findings from the UK Biobank study

Background

The cause of the most common form of dementia, sporadic Alzheimer's disease (AD), remains unknown. This may reflect insufficiently powered studies to date for this multi-factorial disorder. The UK Biobank dataset presents a unique opportunity to rank known risk factors and determine novel variables.

Methods

A custom machine learning approach for high dimensionality data was applied to explore prospectively associations between AD in a sub-cohort of 156,209 UK Biobank participants aged 60-70 including more than 2,090 who were subsequently diagnosed with AD.

Results

After the possession of the APOE4 allele, the next highest ranked risk factors were other genetic variants within the TOMM40-APOE-APOC1 locus. When stratified by their apolipoprotein epsilon 4 (APOE4) carrier status, the most prominent risk factors in carriers were AST:ALT ratio, the "number of treatments/ medications" taken as well as "time spent in hospital" while protection was conferred by "Sleeplessness/Insomnia". In non-APOE carriers, lower socioeconomic status and fewer years of education were highly ranked but effect sizes were small relative to APOE4 carriers.

Conclusions

Possession of the APOE4 allele was confirmed as the most important risk factor in AD. Other TOMM40-APOE-APOC1 locus variants further moderate the risk of AD in APOE4 carriers. Liver pathology is a novel risk factor in APOE4 carriers while "Sleeplessness/Insomnia" is protective in AD irrespective of APOE4 status. Other factors such as "Number of treatments/ medications" suggest that multimorbidity is an important risk factor for AD. Future treatments aimed at co-morbidities, including liver disease, may concomitantly lower the risk of sporadic AD.

Prevalence of Dementia among Patients Hospitalized with Type 2 Diabetes Mellitus in Spain, 2011-2020: Sex-Related Disparities and Impact of the COVID-19 Pandemic

(1) Background: To assess changes in the prevalence of dementia among patients hospitalized with type 2 diabetes (T2DM), to analyze the effects of dementia on in-hospital mortality (IHM) in this population, to evaluate sex differences, and to determine the impact of the COVID-19 pandemic on these parameters. (2) Methods: We used a nationwide discharge database to select all patients with T2DM aged 60 years or over admitted to Spanish hospitals from 2011 to 2020. We identified those with all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VaD). The effect of sex, age, comorbidity, and COVID-19 on the prevalence of dementia subtypes and on IHM was assessed using multivariable logistic regression. (3) Results: We identified 5,250,810 hospitalizations with T2DM. All-cause dementia was detected in 8.31%, AD in 3.00%, and VaD in 1.55%. The prevalence of all subtypes of dementia increased significantly over time. After multivariable adjustment, higher values were observed in women for all-cause dementia (OR 1.34; 95% CI 1.33-1.35), AD (OR 1.6; 95% CI 1.58-1.62), and VaD (OR 1.12; 95% CI 1.11-1.14). However, female sex was a protective factor for IHM in patients with all-cause dementia (OR 0.90; 95% CI 0.89-0.91), AD (OR 0.89; 95% CI 0.86-0.91), and VaD (OR 0.95; 95% CI 0.91-0.99). IHM among patients with dementia remained stable over time, until 2020, when it increased significantly. Higher age, greater comorbidity, and COVID-19 were associated with IHM in all dementia subtypes. (4) Conclusions: The prevalence of dementia (all-cause, AD, and VaD) in men and women with T2DM increased over time; however, the IHM remained stable until 2020, when it increased significantly, probably because of the COVID-19 pandemic. The prevalence of dementia is higher in women than in men, although female sex is a protective factor for IHM.

PTP1B Inhibitor Claramine Rescues Diabetes-Induced Spatial Learning and Memory Impairment in Mice

Accumulating clinical and epidemiological studies indicate that learning and memory impairment is more prevalent among people with diabetes mellitus (DM). PTP1B is a member of protein tyrosine phosphatase family and participates in a variety of pathophysiological effects including inflammatory, insulin signaling pathway, and learning and memory. This study was aimed to investigate the effects of CA, a specific inhibitor of PTP1B, on spatial learning and memory impairment in diabetic mice caused by high-fat diet and injection of streptozotocin. We found that the protein expressions of PTP1B increased in hippocampal CA1, CA3, and PFC regions of diabetic mice. Network pharmacology results showed that PTP1B might be one of the key targets between diabetes and cognitive dysfunction, and CA might alleviate DM-induced cognitive dysfunction. Animal experiments showed that CA ameliorated DM-induced spatial learning and memory impairment, and improved glucose and lipid metabolic disorders. Moreover, administration of CA alleviated hippocampal structure damage and enhanced the expressions of synaptic proteins, including PSD-95, SYN-1, and SYP in diabetic mice. Furthermore, CA treatment not only significantly down-regulated the expressions of PTP1B and NLRP3 inflammatory related proteins (NLRP3, ASC, Caspase-1, COX-2, IL-1β, and TNF-α), but also significantly up-regulated the expressions of insulin signaling pathway-related proteins (p-IRS1, p-PI3K, p-AKT, and p-GSK-3β) in diabetic mice. Taken together, these results suggested that PTP1B might be a targeted strategy to rescue learning and memory deficits in DM, possibly through inhibition of NLRP3 inflammasome and regulation of insulin signaling pathway.

Metabolic syndrome predictors of brain gray matter volume in an age-stratified community sample of 776 Mexican- American adults: Results from the genetics of brain structure image archive

Introduction

This project aimed to investigate the association between biometric components of metabolic syndrome (MetS) with gray matter volume (GMV) obtained with magnetic resonance imaging (MRI) from a large cohort of community-based adults (n = 776) subdivided by age and sex and employing brain regions of interest defined previously as the "Neural Signature of MetS" (NS-MetS).

Methods

Lipid profiles, biometrics, and regional brain GMV were obtained from the Genetics of Brain Structure (GOBS) image archive. Participants underwent T1-weighted MR imaging. MetS components (waist circumference, fasting plasma glucose, triglycerides, HDL cholesterol, and blood pressure) were defined using the National Cholesterol Education Program Adult Treatment Panel III. Subjects were grouped by age: early adult (18-25 years), young adult (26-45 years), and middle-aged adult (46-65 years). Linear regression modeling was used to investigate associations between MetS components and GMV in five brain regions comprising the NS-MetS: cerebellum, brainstem, orbitofrontal cortex, right insular/limbic cluster and caudate.

Results

In both men and women of each age group, waist circumference was the single component most strongly correlated with decreased GMV across all NS-MetS regions. The brain region most strongly correlated to all MetS components was the posterior cerebellum.

Conclusion

The posterior cerebellum emerged as the region most significantly associated with MetS individual components, as the only region to show decreased GMV in young adults, and the region with the greatest variance between men and women. We propose that future studies investigating neurological effects of MetS and its comorbidities-namely diabetes and obesity-should consider the NS-MetS and the differential effects of age and sex.

Diastolic Blood Pressure Variability in Later Life May Be a Key Risk Marker for Cognitive Decline

BACKGROUND

There is an increasing awareness of the need to understand the interaction between long-term blood pressure patterns and their impact on the brain and cognition.

METHODS

Our aim was to investigate the relationship between repeated blood pressure measures and change in cognitive performance over 12 years and imaging data at 12 years using a longitudinal population study. The data consisted of 2 cohorts, one midlife and one later life. Using linear regression, we examined the relationship between blood pressure (systolic, diastolic, change in blood pressure between visits, and visit-to-visit variability), change in cognitive performance and imaging at 12 years.

RESULTS

Data on cognitive change were available in 1054 at midlife, baseline age 42.7 (SD 1.5) and 1233 in later life, 62.5 (1.5) years. Imaging data were available in 168 and 233, respectively. After adjustment for multiple comparisons greater diastolic blood pressure variability in later life was associated with a -1.95 point decline (95% CI, -2.89 to -1.01) on an attention-based task and a -0.42 point (95% CI, -0.68 to -0.15) decline in performance on a psychomotor task. A higher SD in diastolic pressure across follow-up was associated with greater white matter hyperintensity volume (%increase per 10 mm Hg increase in the SD [1.50 (95% CI, 1.16-1.94]).

CONCLUSIONS

In a largely normotensive/mildly hypertensive population, our analyses reported no relationships between blood pressure and cognition in midlife but a potential role for diastolic blood pressure variability in later life as a risk marker for cognitive decline. This may indicate an at-risk period or a means to identify an at-risk population at the age where diastolic pressure is starting to decline.

Female specific risk factors for the development of Alzheimer's disease neuropathology and cognitive impairment: Call for a precision medicine approach

Alzheimer's disease (AD) includes a long asymptomatic stage, which precedes the formal diagnosis of dementia. AD biomarker models provide a framework for precision medicine approaches during this stage. However, such approaches have ignored the possible influence of sex on cognition and brain health, despite female sex noted as a major risk factor. Since AD-related changes may emerge in midlife, intervention efforts are being redirected around this period. Midlife coincides with several endocrinological changes, such as the menopausal transition experienced by women. In this narrative review, we discuss evidence for sex-differences in AD neuropathological burden and outline key endocrinological mechanisms for both sexes, focussing on hormonal events throughout the lifespan that may influence female susceptibility to AD neuropathology and dementia onset. We further consider common non-modifiable (genetic) and modifiable (lifestyle and health) risk factors, highlighting possible sex-dependent differential effects for the AD disease course. Finally, we evaluate the studies selected for this review demonstrating sex-differences in cognitive, pathological and health factors, summarising the state of sex differences in AD risk factors. We further provide recommendations for targeted research on female-specific risk factors, to inform personalised strategies for AD-prevention and the promotion of female brain health.