High Hemoglobin A1c and Diabetes Predict Memory Decline in the Health and Retirement Study

Effects of glycaemic control on memory performance, hippocampal volumes and depressive symptomology

BACKGROUND

Diabetes and poor glycaemic control have been shown to negatively impact cognitive abilities, while also raising risk of both mood disorders and brain structural atrophy. Sites of atrophy include the hippocampus, which has been implicated in both memory performance and depression. The current study set out to better characterise the associations between poor glycaemic control, memory performance, and depression symptoms, and investigate whether loss of hippocampal volume could represent a neuropathological mechanism underlying these.

METHODS

1331 participants (60.9% female, age range 18-88 (Mean = 44.02), 6.5% with likely diabetes) provided HbA1c data (as an index of glycaemic control), completed a word list learning task, and a validated depression scale. A subsample of 392 participants underwent structural MRI; hippocampal volumes were extracted using FreeSurfer.

RESULTS

Partial correlation analyses (controlling for age, gender, and education) showed that, in the full sample, poorer glycaemic control was related to lower word list memory performance. In the MRI sub-sample, poorer glycaemic control was related to higher depressive symptoms, and lower hippocampal volumes. Total hippocampus volume partially mediated the association between HbA1c levels and depressive symptoms.

CONCLUSIONS

Results emphasise the impact of glycaemic control on memory, depression and hippocampal volume and suggest hippocampal volume loss could be a pathophysiological mechanism underlying the link between HbA1c and depression risk; inflammatory and stress-hormone related processes might have a role in this.

Longitudinal study of cognitive decline among women with and without urinary incontinence

BACKGROUND

Cross-sectional and short-term cohort studies have demonstrated an association between urinary incontinence and dementia, as well as lower performance on cognitive testing. The Health and Retirement Study, a longitudinal study of community-dwelling older adults, offers an opportunity to assess the temporal association between these conditions because it included an assessment of incontinence symptoms and biennial assessments of cognitive function.

OBJECTIVE

This study aimed to evaluate if urinary incontinence before the age of 70 years had an effect on changes in cognitive function among women participating in the Health and Retirement Study.

STUDY DESIGN

This secondary analysis included data from female respondents in the Health and Retirement Study aged 58 to 67 years with ≥2 cognitive assessments. Urinary incontinence was defined as any involuntary loss of any urine in the preceding 12 months. A control group without incontinence was reweighted for better comparability using coarsened exact matching for age and comorbidities. Validated methods, including neuropsychological test data, estimated a memory score and dementia probability for each participant biennially. Coprimary outcomes were the changes in memory score and dementia probability. Linear regression models were used to estimate the association of urinary incontinence with change in memory score and dementia probability, adjusting for baseline demographics and comorbidities. A subgroup analysis was performed to assess the effects of urinary incontinence frequency on these outcomes. The infrequent subgroup reported <15 days of leakage per month and the frequent subgroup reported ≥15 days of leakage per month.

RESULTS

Among eligible female respondents, 40.6% reported urinary incontinence between the ages of 58 and 69 years. Baseline memory scores and dementia probability were similar between those with urinary incontinence (n=1706) and controls (n=2507). Memory score declined significantly in both cohorts, indicating poorer memory over time (-0.222 among those with incontinence [95% confidence interval, -0.245 to -0.199] vs -0.207 in controls [95% confidence interval, -0.227 to -0.188]). The decline of memory score was not statistically significantly different between cases and controls (mean difference, -0.015; 95% confidence interval, -0.045 to 0.015). Dementia probability increased significantly in both groups, indicating a greater probability of developing dementia by 0.018 among those with incontinence (95% confidence interval, 0.015-0.020) and by 0.020 among controls (95% confidence interval, 0.017-0.022). The change in dementia probability was not significantly different between groups (mean difference, -0.002; 95% confidence interval, -0.006 to 0.002). Frequent urinary incontinence was reported in 105 of 1706 (6%) of those with urinary incontinence. Memory score declined and dementia probability increased with time (P<.001) in frequent and infrequent urinary incontinence subgroups. There was no dose-response relationship.

CONCLUSION

Measures of cognitive performance declined during approximately 10 years of observation. The changes in performance were not associated with the presence of urinary incontinence in the participants' younger years.

Study of cognitive functions and their association with depression in type II diabetes mellitus

Introduction

Individuals with diabetes have higher risk of developing depression, cognitive impairment, and dementia compared to those who do not have diabetes. The present study aims to assess the level of cognitive functions and the presence of depression in diabetes patients and healthy controls. The study also explores the level of cognition among the normal control, diabetes without depression, and diabetes with depression.

Methods

In the present study, the presence of depression and the level of cognitive functions of 59 cases of diabetes mellitus type-2 were compared with an age- and gender-matched control group of 40 individuals. Clinical and demographic details were recorded on a semi-structured performa. Montreal Cognitive Assessment (MoCA) and Patient Health Questionnaire-9 (PHQ-9) were applied to both diabetes patients and healthy controls to assess the level of cognitive functions and the presence of depression, respectively.

Results

On applying odds ratio (OR), it was observed in the present study that there were 93.50% more chances [OR 1.935 with 95% confidence interval (CI) being 0.481-7.789] of depression among diabetic cases as compared to the control group. Similarly, the chance of MoCA score being less than 26 was twice among the diabetic group as compared to the control group (OR 2.208 with 95% CI being 0.702-6.946). On application of the Chi-square test, the association of depression was significant with HBA1C level, level of education, and presence of complications.

Conclusions

Patients with diabetes had almost double the risk of developing depression and poor cognitive functions as compared to the healthy control. High HbA1C level, level of education, and presence of complication in diabetes had a positive statistical association with depression. Thus, it is advisable to investigate patients with diabetes for the presence of depression and cognitive dysfunction by applying simple tools.

Depressive Symptoms Longitudinally Mediate the Effect of Hyperglycemia on Memory Decline in Type 2 Diabetes

OBJECTIVE

We sought to examine the mediating role of changes in depressive symptoms in the association between chronic hyperglycemia and longitudinal cognition in a sample of older adults with type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

We conducted a longitudinal mediation analysis using structural equation modeling of observational data collected over 6 years from 2,155 participants with T2D (aged ≥51 years) in the U.S.-wide Health and Retirement Study. T2D was defined using self-reported diagnosis, and HbA1c was assessed at study baseline. Self-reported depressive symptoms were assessed at two time points 4 years apart. Episodic memory was measured using a list-learning test administered at three time points over 6 years. We adjusted for sociodemographics, chronic health comorbidities, medication adherence, study enrollment year, and prior years' depressive symptoms and memory scores.

RESULTS

At baseline, participants' mean age was 69.4 (SD = 9.1), mean HbA1c was 7.2% (SD = 1.4%), 55.0% were women, 19.3% were non-Latinx Black, and 14.0% were Latinx. Higher baseline levels of HbA1c were associated with increases in depressive symptoms over 4 years, which, in turn, were associated with poorer memory 2 years later. Depressive symptoms accounted for 19% of the longitudinal effect of HbA1c on memory over the 6-year period. Sensitivity analyses ruled out alternative directions of associations.

CONCLUSIONS

Incident elevations in depressive symptoms mediated the longitudinal association between hyperglycemia and 6-year episodic memory scores. For older adults with T2D, interventions to prevent HbA1c-related incident depressive symptoms may be beneficial in reducing the neurotoxic effects of chronic hyperglycemia on cognition.

Diabetes, Edentulism, and Cognitive Decline: A 12-Year Prospective Analysis

Diabetes mellitus (DM) is a recognized risk factor for dementia, and increasing evidence shows that tooth loss is associated with cognitive impairment and dementia. However, the effect of the co-occurrence of DM and edentulism on cognitive decline is understudied. This 12-y cohort study aimed to assess the effect of the co-occurrence of DM and edentulism on cognitive decline and examine whether the effect differs by age group. Data were drawn from the 2006 to 2018 Health and Retirement Study. The study sample included 5,440 older adults aged 65 to 74 y, 3,300 aged 75 to 84 y, and 1,208 aged 85 y or older. Linear mixed-effect regression was employed to model the rates of cognitive decline stratified by age cohorts. Compared with their counterparts with neither DM nor edentulism at baseline, older adults aged 65 to 74 y (β = -1.12; 95% confidence interval [CI], -1.56 to -0.65; P < 0.001) and those aged 75 to 84 y with both conditions (β = -1.35; 95% CI, -2.09 to -0.61; P < 0.001) had a worse cognitive function. For the rate of cognitive decline, compared to those with neither condition from the same age cohort, older adults aged 65 to 74 y with both conditions declined at a higher rate (β = -0.15; 95% CI, -0.20 to -0.10; P < 0.001). Having DM alone led to an accelerated cognitive decline in older adults aged 65 to 74 y (β = -0.09; 95% CI, -0.13 to -0.05; P < 0.001); having edentulism alone led to an accelerated decline in older adults aged 65 to 74 y (β = -0.13; 95% CI, -0.17 to -0.08; P < 0.001) and older adults aged 75 to 84 (β = -0.10; 95% CI, -0.17 to -0.03; P < 0.01). Our study finds the co-occurrence of DM and edentulism led to a worse cognitive function and a faster cognitive decline in older adults aged 65 to 74 y.

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.

Evaluation of retinal nerve fibre layer thickness as a possible measure of diabetic retinal neurodegeneration in the EPIC-Norfolk Eye Study

BACKGROUND/AIMS

Markers to clinically evaluate structural changes from diabetic retinal neurodegeneration (DRN) have not yet been established. To study the potential role of peripapillary retinal nerve fibre layer (pRNFL) thickness as a marker for DRN, we evaluated the relationship between diabetes, as well as glycaemic control irrespective of diabetes status and pRNFL thickness.

METHODS

Leveraging data from a population-based cohort, we used general linear mixed models (GLMMs) with a random intercept for patient and eye to assess the association between pRNFL thickness (measured using GDx) and demographic, systemic and ocular parameters after adjusting for typical scan score. GLMMs were also used to determine: (1) the relationship between: (A) glycated haemoglobin (HbA1c) irrespective of diabetes diagnosis and pRNFL thickness, (B) diabetes and pRNFL thickness and (2) which quadrants of pRNFL may be affected in participants with diabetes and in relation to HbA1c.

RESULTS

7076 participants were included. After controlling for covariates, inferior pRNFL thickness was 0.94 µm lower (95% CI -1.28 µm to -0.60 µm), superior pRNFL thickness was 0.83 µm lower (95% CI -1.17 µm to -0.49 µm) and temporal pRNFL thickness was 1.33 µm higher (95% CI 0.99 µm to 1.67 µm) per unit increase in HbA1c. Nasal pRNFL thickness was not significantly associated with HbA1c (p=0.23). Similar trends were noted when diabetes was used as the predictor.

CONCLUSION

Superior and inferior pRNFL was significantly thinner among those with higher HbA1c levels and/or diabetes, representing areas of the pRNFL that may be most affected by diabetes.

Effects of Intermittent Hypoxia and Electrical Muscle Stimulation on Cognitive and Physiological Metrics

OBJECTIVES

This study describes the effects of interval hypoxic training and electrical muscle stimulation (EMS) technology on human productivity with the following metrics: biochemical indices, cognitive abilities, changes in oxygenated (HbO) and deoxygenated (Hb) hemoglobin concentrations over the prefrontal cortex, and functional connectivity via electroencephalography (EEG).

METHODS

All measurements according to the described technology were made before the start of training and one month later, right after it ended. The study involved middle-aged Indo-European men. Specifically, there were 14, 15, and 18 participants in the control, hypoxic, and EMS groups, respectively.

RESULTS

EMS training improved reactions and nonverbal memory but decreased attention scores. Functional connectivity decreased in the EMS group while it increased in the hypoxic group. A result of the interval normobaric hypoxic training (IHT) was significantly improved contextual memory, with a p-value = 0.08.

CONCLUSIONS

It was found that EMS training is more likely to cause stress on the body than positively affect cognitive functions. At the same time, interval hypoxic training can be considered a promising direction for increasing human productivity. The data obtained during the study can also help in the timely diagnosis of insufficient or overestimated indicators of biochemistry.

Inflammation, metabolic dysregulation and environmental neurotoxins and risk of cognitive decline and impairment in midlife

BACKGROUND

Age-related declines in cognitive function may begin in midlife.

PURPOSE

To determine whether blood-based biomarkers of inflammation, metabolic dysregulation and neurotoxins are associated with risk of cognitive decline and impairment.

METHODS

Baseline blood samples from the longitudinal Beaver Dam Offspring Study (2005-2008) were assayed for markers of inflammation, metabolic dysregulation, and environmental neurotoxins. Cognitive function was measured at baseline, 5-year (2010-2013) and 10-year (2015-2017) examinations. Participants without cognitive impairment at baseline and with cognitive data from at least one follow-up were included. Cox proportional hazards models were used to evaluate associations between baseline blood biomarkers and the 10-year cumulative incidence of cognitive impairment. Poisson models were used to estimate the relative risk (RR) of 5-year decline in cognitive function by baseline blood biomarkers. Models were adjusted for age, sex, education, and cardiovascular related risk factors.

RESULTS

Participants (N = 2421) were a mean age of 49 years and 55% were women. Soluble vascular cell adhesion molecule-1 (sVCAM-1Tertile(T)3 vs T1-2 hazard ratio (HR) = 1.72, 95% confidence interval (CI) = 1.05,2.82) and hemoglobin A1C (HR = 1.75, 95% CI = 1.18,2.59, per 1% in women) were associated with the 10-year cumulative incidence of cognitive impairment. sVCAM-1 (RRT3 vs T1-2 = 1.45, 95% CI = 1.06,1.99) and white blood cell count (RR = 1.10, 95% CI = 1.02,1.19, per 103/μL) were associated with 5-year cognitive decline.

CONCLUSIONS

Biomarkers related to inflammation and metabolic dysregulation were associated with an increased risk of developing cognitive decline and impairment. These results extend previous research in cognitive aging to early markers of cognitive decline in midlife, a time when intervention methods may be more efficacious.

Associations Between Midlife Menopausal Hormone Therapy Use, Incident Diabetes, and Late Life Memory in the Wisconsin Longitudinal Study

BACKGROUND

Prior research suggests a link between menopausal hormone therapy (MHT) use, memory function, and diabetes risk. The menopausal transition is a modifiable period to enhance long-term health and cognitive outcomes, although studies have been limited by short follow-up periods precluding a solid understanding of the lasting effects of MHT use on cognition.

OBJECTIVE

We examined the effects of midlife MHT use on subsequent diabetes incidence and late life memory performance in a large, same-aged, population-based cohort. We hypothesized that the beneficial effects of MHT use on late life cognition would be partially mediated by reduced diabetes risk.

METHODS

1,792 women from the Wisconsin Longitudinal Study (WLS) were included in analysis. We employed hierarchical linear regression, Cox regression, and causal mediation models to test the associations between MHT history, diabetes incidence, and late life cognitive performance.

RESULTS

1,088/1,792 women (60.7%) reported a history of midlife MHT use and 220/1,792 (12.3%) reported a history of diabetes. MHT use history was associated with better late life immediate recall (but not delayed recall), as well as a reduced risk of diabetes with protracted time to onset. Causal mediation models suggest that the beneficial effect of midlife MHT use on late life immediate recall were at least partially mediated by diabetes risk.

CONCLUSION

Our data support a beneficial effect of MHT use on late life immediate recall (learning) that was partially mediated by protection against diabetes risk, supporting MHT use in midlife as protective against late life cognitive decline and adverse health outcomes.

Can probiotics mitigate age-related neuroinflammation leading to improved cognitive outcomes?

Changes in brain structure and cognitive function are a natural part of aging; however, in some cases these changes are more severe resulting in mild cognitive impairment (MCI) or Alzheimer's disease (AD). Evidence is mounting to show that neuroinflammation is an underlying risk factor for neurodegenerative disease progression. Age-related neuroinflammation does not appear to occur in isolation and is part of increased systemic inflammation, which may in turn be triggered by changes in the gut associated with aging. These include an increase in gut permeability, which allows immune triggering compounds into the body, and alterations in gut microbiota composition leading to dysbiosis. It therefore follows that, treatments that can maintain healthy gut function may reduce inflammation and protect against, or improve, symptoms of age-associated neurodegeneration. The aim of this mini review was to evaluate whether probiotics could be used for this purpose. The analysis concluded that there is preliminary evidence to suggest that specific probiotics may improve cognitive function, particularly in those with MCI; however, this is not yet convincing and larger, multilocation, studies focus on the effects of probiotics alone are required. In addition, studies that combine assessment of cognition alongside analysis of inflammatory biomarkers and gut function are needed. Immense gains could be made to the quality of life of the aging population should the hypothesis be proven to be correct.

Glucose-lowering drugs, cognition, and dementia: The clinical evidence

Type 2 diabetes mellitus (T2DM) is an important risk factor for dementia. The possibility to mitigate this risk by controlling T2DM is compelling; however, different glucose-lowering drugs have different effects on the brain by virtue of their different mechanisms of action. The clinical and epidemiological data appear mixed, warranting careful critical evaluation of the human studies. Here we examine the evidence in the context of dementia prevention and treatment, both for people with and without T2DM. We discuss the evidence on this scaffold of research directions, identifying methodological complexities in the extant literature (e.g. comparator discrepancies, changes in the therapeutic landscape), and the implications of different outcome measures (e.g. neuropsychological). We consider possible implications of cerebrovascular protection vs. effects on progression of neurodegenerative proteinopathy, and we present a research roadmap for glucose-lowering drugs in cognitive neurology, including neuroimaging, and fluid biomarkers. We conclude that there is great potential to advance personalized strategies to prevent and treat dementia with glucose-lowering drugs.

High sensitivity C-reactive protein and glycated hemoglobin levels as dominant predictors of all-cause dementia: a nationwide population-based cohort study

BACKGROUND

Chronic inflammation might play a major role in the pathogenesis linking diabetes mellitus (DM) to cognition. In addition, DM might be the main driver of dementia risk. The purpose of the present study was to evaluate whether inflammation, glycation, or both are associated with the risk of developing all-cause dementia (ACD).

METHODS

A nationwide population-based cohort study was conducted with 4113 participants. The data were obtained from the Taiwanese Survey on Prevalence of Hypertension, Hyperglycemia, and Hyperlipidemia (TwSHHH) in 2007, which was linked with the Taiwan National Health Insurance Research Database (NHIRD). The markers of inflammation, expressed as hs-CRP, and glycation, presented as HbA1c, were measured. High levels of hs-CRP and HbA1c were defined as values greater than or equal to the 66th percentile. Developed ACD was identified based on the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes.

RESULTS

During 32,926.90 person-years, 106 individuals developed ACD in up to 8 years of follow-up. The study participants were separated into four categories by the top tertiles of hs-CRP and HbA1c based on the 66th percentile: high levels of both hs-CRP and HbA1c, only high levels of hs-CRP, only high levels of HbA1c, and non-high levels of hs-CRP nor HbA1c. Those who with a high level of only hs-CRP had the higher hazard for developing ACD (adjusted HR = 2.58; 95% CI = 1.29 ~ 5.17; P = 0.007), followed by the group with a high level of only HbA1c (adjusted HR = 2.52; 95% CI = 1.34 ~ 4.74; P = 0.004) and the group with high levels of both hs-CRP and HbA1c (adjusted HR = 2.36; 95% CI = 1.20 ~ 4.62; P = 0.012). Among those aged less than 65 years, hs-CRP was the only significant predictor of ACD risk (P = 0.046), whereas it did not yield any significant result in the elderly.

CONCLUSIONS

A higher risk of developing ACD was found not only in patients with high levels of inflammation but also high levels of glycated hemoglobin. Future studies should focus on the clinical implementation of hs-CRP or HbA1c to monitor cognitive deficits.

Secondary Prevention of Dementia: Combining Risk Factors and Scalable Screening Technology

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that is the most common cause of dementia. Over a third of dementia cases are estimated to be due to potentially modifiable risk factors, thus offering opportunities for both identification of those most likely to be in early disease as well as secondary prevention. Diabetes, hypertension and chronic kidney failure have all been linked to increased risk for AD and dementia and through their high prevalence are particularly apt targets for initiatives to reduce burden of AD. This can take place through targeted interventions of cardiovascular risk factors (shown to improve cognitive outcomes) or novel disease modifying treatments in people with confirmed AD pathology. The success of this approach to secondary prevention depends on the availability of inexpensive and scalable methods for detecting preclinical and prodromal dementia states. Developments in blood-based biomarkers for Alzheimer's disease are rapidly becoming a viable such method for monitoring large at-risk groups. In addition, digital technologies for remote monitoring of cognitive and behavioral changes can add clinically relevant data to further improve personalisation of prevention strategies. This review sets the scene for this approach to secondary care of dementia through a review of the evidence for cardiovascular risk factors (diabetes, hypertension and chronic kidney disease) as major risk factors for AD. We then summarize the developments in blood-based and cognitive biomarkers that allow the detection of pathological states at the earliest possible stage. We propose that at-risk cohorts should be created based on the interaction between cardiovascular and constitutional risk factors. These cohorts can then be monitored effectively using a combination of blood-based biomarkers and digital technologies. We argue that this strategy allows for both risk factor reduction-based prevention programmes as well as for optimisation of any benefits offered by current and future disease modifying treatment through rapid identification of individuals most likely to benefit from them.

Cognitive function among older adults with diabetes and prediabetes, NHANES 2011-2014

AIMS

To determine the association between diabetes status, glycemia, and cognitive function among a national U.S. sample of older adults in the 2011-2014 National Health and Nutrition Examinations Surveys.

METHODS

Among 1,552 adults age ≥ 60 years, linear and multivariable logistic regressions were used to determine the association between diabetes status (diabetes, prediabetes, normoglycemia) and cognitive function [Consortium to Establish a Registry for Alzheimer's Disease-Word Learning (CERAD W-L), Animal Fluency test, Digit Symbol Substitution Test (DSST)].

RESULTS

Overall, diabetes was associated with mild cognitive dysfunction. In age-adjusted models, adults with diabetes had significantly poorer performance on the delayed and total word recalls (CERAD W-L) compared to those with normoglycemia (5.8 vs. 6.8 words; p = 0.002 and 24.5 vs. 27.6 words; p < 0.001, respectively); the association was non-significant after adjusting for cardiovascular disease. Among all adults, cognitive function scores decreased with increasing HbA1c for all assessments, but remained significant in the fully adjusted model for the Animal Fluency and DSST [beta coefficient = -0.44;-1.11, p < 0.05, respectively]. As measured by the DSST, the proportion with cognitive impairment was significantly higher for older adults with HbA1c ≥ 8.0% (≥64 mmol/mol) vs. HbA1c < 7.0% (<53 mmol/mol) (14.6% vs. 6.3%, p = 0.04).

CONCLUSIONS

Dysglycemia, as measured by HbA1c, was associated with poorer executive function and processing speed.

Physical Activity in Early- and Mid-Adulthood Are Independently Associated With Longitudinal Memory Trajectories in Later Life

BACKGROUND

Physical activity (PA) in later life may reduce dementia risk, but little is known regarding long-term cognitive effects of PA that occurred earlier in adulthood or mechanisms underlying associations. PA patterns at different ages may independently contribute to dementia risk, which would implicate multiple critical periods for intervention. The current study tested whether retrospective reports of PA in early and mid-adulthood were independently associated with later-life longitudinal memory outcomes and whether associations were mediated by late-life cardiometabolic diseases.

METHOD

Participants comprised 5200 Health and Retirement Study Life History Mail Survey respondents. Latent growth curves estimated independent associations between retrospectively reported PA in early adulthood (age 18-29) and mid-adulthood (age 40-49) and 16-year episodic memory trajectories. Indirect pathways involving the maintenance of PA from early- to mid-adulthood and the influence of PA on later-life cardiometabolic diseases (hypertension, diabetes, and heart disease) were also estimated.

RESULTS

PA in early- and mid-adulthood independently predicted higher initial memory level and slower memory decline in later life, respectively. Early-adulthood PA was indirectly associated with later-life memory level through higher mid-adulthood PA and lower rates of later-life hypertension, as well as with subsequent memory decline through higher mid-adulthood PA.

CONCLUSIONS

The current findings highlight the importance of PA throughout adulthood, such that initiating and/or maintaining exercise in early- or mid-adulthood may be protective for later-life cognitive health, and hypertension appears to represent a key mediator of these effects.

Socioeconomic and psychosocial mechanisms underlying racial/ethnic disparities in cognition among older adults

Objective: Racial/ethnic disparities in cognitive aging are only partly attributable to socioeconomic indicators. Psychosocial factors, such as discrimination and perceived control, also differ across racial/ethnic groups, and emerging literature highlights their potential role in contributing to cognitive disparities in addition to socioeconomic status. Method: 1,463 older adults (51% Hispanic, 27% non-Hispanic Black, and 22% non-Hispanic White) in the Washington Heights-Inwood Columbia Aging Project completed cognitive and psychosocial measures, including a comprehensive neuropsychological battery, Everyday and Major Experiences of Lifetime Discrimination scales, and the Perceived Control scale. Mediation models quantified separate indirect effects of Black race and Hispanic ethnicity on global cognitive composite scores through education, income, discrimination, and external perceived control. Results: Educational attainment, income, and perceived control each mediated racial/ethnic disparities in global cognition. Socioeconomic indicators (i.e., lower education and lower income) explained approximately 50% of the Black-White and Hispanic-White disparities in global cognition, and more external perceived control explained an additional 5%-8%. Hispanics reported the lowest levels of discrimination, while non-Hispanic Blacks reported the highest levels. However, neither everyday nor major lifetime discrimination was associated with global cognition. Significant racial/ethnic disparities in global cognition remained after accounting for the included socioeconomic and psychosocial factors. Conclusions: This study suggests that psychosocial factors may explain racial/ethnic disparities in cognitive aging above and beyond socioeconomic indicators. More external perceived control, which could reflect chronic exposure to interpersonal and institutional marginalization, may be a particularly salient psychosocial risk factor for poorer cognitive aging among non-Hispanic Black and Hispanic older adults. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Association of Coronary Artery Bypass Grafting vs Percutaneous Coronary Intervention With Memory Decline in Older Adults Undergoing Coronary Revascularization

IMPORTANCE

It is uncertain whether coronary artery bypass grafting (CABG) is associated with cognitive decline in older adults compared with a nonsurgical method of coronary revascularization (percutaneous coronary intervention [PCI]).

OBJECTIVE

To compare the change in the rate of memory decline after CABG vs PCI.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of community-dwelling participants in the Health and Retirement Study, who underwent CABG or PCI between 1998 and 2015 at age 65 years or older. Data were modeled for up to 5 years preceding and 10 years following revascularization or until death, drop out, or the 2016-2017 interview wave. The date of final follow-up was November 2017.

EXPOSURES

CABG (including on and off pump) or PCI, ascertained from Medicare fee-for-service billing records.

MAIN OUTCOMES AND MEASURES

The primary outcome was a summary measure of cognitive test scores and proxy cognition reports that were performed biennially in the Health and Retirement Study, referred to as memory score, normalized as a z score (ie, mean of 0, SD of 1 in a reference population of adults aged ≥72 years). Memory score was analyzed using multivariable linear mixed-effects models, with a prespecified subgroup analysis of on-pump and off-pump CABG. The minimum clinically important difference was a change of 1 SD of the population-level rate of memory decline (0.048 memory units/y).

RESULTS

Of 1680 participants (mean age at procedure, 75 years; 41% female), 665 underwent CABG (168 off pump) and 1015 underwent PCI. In the PCI group, the mean rate of memory decline was 0.064 memory units/y (95% CI, 0.052 to 0.078) before the procedure and 0.060 memory units/y (95% CI, 0.048 to 0.071) after the procedure (within-group change, 0.004 memory units/y [95% CI, -0.010 to 0.018]). In the CABG group, the mean rate of memory decline was 0.049 memory units/y (95% CI, 0.033 to 0.065) before the procedure and 0.059 memory units/y (95% CI, 0.047 to 0.072) after the procedure (within-group change, -0.011 memory units/y [95% CI, -0.029 to 0.008]). The between-group difference-in-differences estimate for memory decline for PCI vs CABG was 0.015 memory units/y (95% CI, -0.008 to 0.038; P = .21). There was statistically significant increase in the rate of memory decline after off-pump CABG compared with after PCI (difference-in-differences: mean increase in the rate of decline of 0.046 memory units/y [95% CI, 0.008 to 0.084] after off-pump CABG), but not after on-pump CABG compared with PCI (difference-in-differences: mean slowing of decline of 0.003 memory units/y [95% CI, -0.024 to 0.031] after on-pump CABG).

CONCLUSIONS AND RELEVANCE

Among older adults undergoing coronary revascularization with CABG or PCI, the type of revascularization procedure was not significantly associated with differences in the change of rate of memory decline.

Increased resting state functional irregularity of T2DM brains with high HbA1c: sign for impaired verbal memory function?

Glycosylated hemoglobin A1c (HbA1c) has been considered as a key contributor to impaired cognition in type 2 diabetes mellitus (T2DM) brains. However, how does it affect the brain and whether the glucose controlling can slow down the process are still unknown. In the current study, T2DM patients with high glycosylated hemoglobin level (HGL) and controls with normal glycosylated hemoglobin level (NGL) were enrolled to investigate the relationships between HbA1c, brain imaging characteristics and cognitive function. First, a series of cognitive tests including California Verbal Learning Test (CVLT) were conducted. Then, the functional irregularity based on resting state functional magnetic resonance imaging data was evaluated via a new data-driven brain entropy (BEN) mapping analysis method. We found that the HGLs exhibited significantly increased BEN in the right precentral gyrus (PreCG.R), the right middle frontal gyrus (MFG.R), the triangular and opercular parts of the right inferior frontal gyrus (IFGtriang.R and IFGoperc.R). The strengths of the functional connections of PreCG.R with the brainstem/cerebellum were decreased. Partial correlation analysis showed that HbA1c had a strong positive correlation to regional BEN and negatively correlated with some CVLT scores. Negative correlations also existed between the BEN of PreCG.R/IFGoperc.R and some CVLT scores, suggesting the correspondence between higher HbA1c, increased BEN and decreased verbal memory function. This study demonstrated the potential of BEN in exploring the functional alterations affected by HbA1c and interpreting the verbal memory function decline. It will help understanding the neurophysiological mechanism of T2DM-induced cognitive decline and taking effective prevention or treatment measures.

The Effect of Diabetes on the Cognitive Trajectory of Older Adults in Mexico and the United States

OBJECTIVES

To study the impact of diabetes on the long-term cognitive trajectories of older adults in 2 countries with different socioeconomic and health settings, and to determine whether this relationship differs by cognitive domains. This study uses Mexico and the United States to confirm if patterns hold in both populations, as these countries have similar diabetes prevalence but different socioeconomic conditions and diabetes-related mortality.

METHODS

Two nationally representative cohorts of adults aged 50 years or older are used: the Mexican Health and Aging Study for Mexico and the Health and Retirement Study for the United States, with sample sizes of 18,810 and 26,244 individuals, respectively, followed up for a period of 14 years. The outcome is cognition measured as a total composite score and by domain (memory and nonmemory). Mixed-effect linear models are used to test the effect of diabetes on cognition at 65 years old and over time in each country.

RESULTS

Diabetes is associated with lower cognition and nonmemory scores at baseline and over time in both countries. In Mexico, diabetes only predicts lower memory scores over time, whereas in the United States it only predicts lower memory scores at baseline. Women have higher total cognition and memory scores than men in both studies. The magnitude of the effect of diabetes on cognition is similar in both countries.

DISCUSSION

Despite the overall lower cognition in Mexico and different socioeconomic characteristics, the impact of diabetes on cognitive decline and the main risk and protective factors for poor cognition are similar in both countries.

Vascular mild cognitive impairment and its relationship to hemoglobin A1c levels and apolipoprotein E genotypes in the Dominican Republic

Dementia and vascular mild cognitive impairment (VaMCI) currently impose a tremendous human and economic burden on patients from aging populations and their families worldwide. Understanding the interplay of cardiometabolic risk factors and apolipoprotein E (APOE) may direct us to a more personalized medicine and preventative care in MCI and dementia.

Glucose-Dementia Association Is Consistent Over Blood Pressure/Antihypertensive Groups

BACKGROUND

Higher glucose levels are associated with dementia risk in people with and without diabetes. However, little is known about how this association might vary by hypertension status and antihypertensive treatment. Most studies on modifiable dementia risk factors consider each factor in isolation.

OBJECTIVE

To test the hypothesis that hypertension and antihypertensive treatments may modify associations between glucose levels and dementia.

METHODS

Analyses of data generated from a research study and clinical care of participants from a prospective cohort of dementia-free older adults, including glucose measures, diabetes and antihypertensive treatments, and blood pressure data. We defined groups based on blood pressure (hypertensive versus not, ≥140/90 mmHg versus <140/90 mmHg) and antihypertensive treatment intensity (0, 1, or ≥2 classes of antihypertensives). We used Bayesian joint models to jointly model longitudinal exposure and time to event data.

RESULTS

A total of 3,056 participants without diabetes treatment and 480 with diabetes treatment were included (mean age at baseline, 75.1 years; mean 7.5 years of follow-up). Higher glucose levels were associated with greater dementia risk among people without and with treated diabetes. Hazard ratios for dementia were similar across all blood pressure/antihypertensive treatment groups (omnibus p = 0.82 for people without and p = 0.59 for people with treated diabetes).

CONCLUSION

Hypertension and antihypertensive treatments do not appear to affect the association between glucose and dementia risk in this population-based longitudinal cohort study of community-dwelling older adults. Future studies are needed to examine this question in midlife and by specific antihypertensive treatments.

Association of Plasma Hemoglobin A1c with Improvement of Cognitive Functions by Probiotic Bifidobacterium breve Supplementation in Healthy Adults with Mild Cognitive Impairment

We demonstrated the benefit of the probiotic strain, Bifidobacterium breve MCC1274 (synonym B. breve A1), at improving cognition in our previous double-blind, placebo-controlled clinical study. Analysis of the association of blood parameters changes with the improvement of cognitive function revealed an inverse correlation of HbA1c with total RBANS score amelioration after the study only in the probiotic group (ρ= -0.4218, p = 0.0067). A stratified analysis based on baseline HbA1c with a median value showed a more remarkable benefit by the probiotic supplementation in the higher median subgroup. These data support the mechanism of anti-inflammation in improving cognition by the probiotic strain.

Cognitive impairment among patients with diabetes in Saudi Arabia: a cross-sectional study

Background

The incidence of cognitive impairment (CI) is higher in patients with diabetes mellitus (DM). The association between DM and CI and the risk factors for CI need to be addressed to estimate the prevalence of cognitive impairment in patients with DM and to identify the potential risk factors. The study is a cross-sectional study using a convenient sample of 269 subjects. Sociodemographic diabetes-related variables including biochemical markers were collected. CI and diabetes-related distress (DRD) were assessed using the Arabic version of Montreal Cognitive Assessment scale (MoCA) and the Diabetes Distress Screening Scale respectively.

Results

Overall, 80.3% had cognitive impairment while 33.8% had severe impairment. Older age, female gender, low level of education, and low income were associated with CI; duration of diabetes and DRD were associated with CI while ophthalmic complications were associated with severe CI. Duration of diabetes was inversely associated with CI. Level of HbA1c was significantly higher in patients with severe CI, and the probability of CI increased as the level of HbA1c increased. Low level of education was associated with severe CI, and CI was two times more likely among patients with DRD.

Conclusion

CI was higher than worldwide figures. Elderly females with low educational level, long duration of DM, and low socioeconomic status are at more risk. The probability of severe CI increased with increased level of HbA1c. Screening for CI in patients with diabetes along with intervention programs while considering the DRD and the level of HbA1c is crucial.

The Relation of Diabetes to Memory Function

PURPOSE OF REVIEW

Research has consistently shown that type 2 diabetes (T2D) is associated with increased risk of all-cause dementia. Because one of the most common clinical presentations of early stage dementia is memory impairment, we examined the relationship of T2D with memory function, using the recently published scientific literature.

RECENT FINDINGS

We conducted a structured review to identify studies of "T2D and memory" published since 2015. After review of the 129 articles retrieved, we identified 14 studies meeting the inclusion and exclusion criteria. Among the eight studies with a single assessment of memory function in time (mostly cross-sectional), six found an association of T2D with lower memory function, but mostly in select subgroups of persons. Separately, six studies included repeated measures of memory (longitudinal design). Four out of six longitudinal studies found that T2D was related with a faster decline in memory, while two did not. Among the four studies showing a relation with memory decline, two had sample sizes of 9000-10,000 persons. Further, three longitudinal studies controlled for hypertension and stroke as covariates, and results suggested that common vascular risk factors and diseases do not account for the relation. While mechanistic studies clearly support a role for cerebrovascular disease in the relation of T2D with cognition, emerging data suggest that insulin resistance in the brain itself may also play a role. Most, but not all, recently published studies suggest that T2D is associated with a lower level and faster decline in memory function. This association does not appear to be fully accounted for by common vascular processes. More research will clarify the mechanisms linking T2D to memory and dementia.

Glycated Haemoglobin Is Associated With Poorer Cognitive Performance in Patients With Recent-Onset Psychosis

BACKGROUND

Glucose abnormalities and cognitive alterations are present before the onset of schizophrenia. We aimed to study whether glucose metabolism parameters are associated with cognitive functioning in recent-onset psychosis (ROP) patients while adjusting for hypothalamic-pituitary adrenal (HPA) axis measures.

METHODS

Sixty ROP outpatients and 50 healthy subjects (HS) were studied. Cognitive function was assessed with the MATRICS Consensus Cognitive Battery. Glycated haemoglobin (HbA1_c), glucose, insulin, and C-peptide levels were determined in plasma. The HOMA-insulin resistance index was calculated. Salivary samples were obtained at home on another day to assess the cortisol awakening response and cortisol levels during the day. Univariate analyses were conducted to explore the association between glucose metabolism parameters and cognitive tasks. For those parameters that were more clearly associated with the cognitive outcome, multiple linear regression analyses were conducted to adjust for covariates. Each cognitive task was considered the dependent variable. Covariates were age, sex, education level, diagnosis, antipsychotic and benzodiazepine treatment, body mass index (BMI), smoking, and HPA axis measures. Potential interactions between diagnosis and glucose parameters were tested.

RESULTS

There were no significant differences in HPA axis measures or glucose parameters, with the exception of C-peptide (that was higher in ROP patients), between groups. ROP patients had a lower performance than HS in all cognitive tasks (p < 0.01 for all tasks). Of all glucose metabolism parameters, HbA1c levels were more clearly associated with cognitive impairment in cognitive tasks dealing with executive functions and visual memory in both ROP patients and HS. Multivariate analyses found a significant negative association between HbA1c and cognitive functioning in five cognitive tasks dealing with executive functions, visual memory and attention/vigilance (a ROP diagnosis by HbA1_c negative interaction was found in this latter cognitive domain, suggesting that HBA1_c levels are associated with impaired attention only in ROP patients).

CONCLUSIONS

Our study found that HbA1_c was negatively associated with cognitive functioning in both ROP patients and HS in tasks dealing with executive functions and visual memory. In ROP patients, HbA1_c was also associated with impaired attention. These results were independent of BMI and measures of HPA axis activity.

Association Between the Use of Antihyperglycemic Drugs and Dementia Risk: A Case-Control Study

BACKGROUND

There is a conflicting literature on the association between the use of antihyperglycemic drugs and dementia risk.

OBJECTIVE

The goal of this case-control study was to analyze the association between the use of antihyperglycemic drugs and dementia risk in patients followed in general practices in Germany.

METHODS

This study included patients with type 2 diabetes mellitus who had received a first dementia diagnosis in 972 general practices in Germany between January 2013 and December 2017 (index date). Controls without dementia were matched (1:1) to cases by age, gender, index year, and physician. Two multivariate regression models were used to study the association between the use of antihyperglycemic drugs and dementia risk. Model 1 included all antihyperglycemic drugs prescribed to patients regardless of the prescription duration, whereas Model 2 only included the longest therapy prescribed to each patient.

RESULTS

There were 8,276 diabetes patients with dementia and 8,276 diabetes patients without dementia included in this study. In Model 1, glitazones were associated with a decreased dementia risk (odds ratio [OR] = 0.80), whereas insulin was associated with an increased risk of developing the condition (OR = 1.34). In Model 2, metformin, prescribed as monotherapy (OR = 0.71) or as dual therapy with sulfonylureas (OR = 0.90), was associated with a decrease in the likelihood of subsequently being diagnosed with dementia. By contrast, the combination of basal insulin and bolus insulin (OR = 1.47) and premix insulin (OR = 1.33) were risk factors for dementia.

CONCLUSION

Metformin and glitazones were negatively associated with dementia, while insulin was positively associated with dementia.

The effect of mid-life insulin resistance and type 2 diabetes on older-age cognitive state: the explanatory role of early-life advantage

AIMS/HYPOTHESIS

Type 2 diabetes, hyperglycaemia and insulin resistance are associated with cognitive impairment and dementia, but causal inference studies using Mendelian randomisation do not confirm this. We hypothesised that early-life cognition and social/educational advantage may confound the relationship.

METHODS

From the population-based British 1946 birth cohort, a maximum number of 1780 participants had metabolic variables (type 2 diabetes, insulin resistance [HOMA2-IR] and HbA1c) assessed at age 60-64 years, and cognitive state (Addenbrooke's Cognitive Examination III [ACE-III]) and verbal memory assessed at age 69 years. Earlier-life measures included socioeconomic position (SEP), cognition at age 8 years and educational attainment. Polygenic risk scores (PRSs) for type 2 diabetes were calculated. We first used a PRS approach with multivariable linear regression to estimate associations between PRSs and metabolic traits and later-life cognitive state. Second, using a path model approach, we estimated the interrelationships between earlier-life measures, features of mid-life type 2 diabetes and cognitive state at age 69 years. All models were adjusted for sex.

RESULTS

The externally weighted PRS for type 2 diabetes was associated with mid-life metabolic traits (e.g. HOMA2-IR β = 0.08 [95% CI 0.02, 0.16]), but not with ACE-III (β = 0.04 [-0.02, 0.90]) or other cognitive outcomes. While there was an association between HOMA2-IR and subsequent ACE-III (β = -0.09 [-0.15, -0.03]), path modelling showed no direct effect (β = -0.01 [-0.06, 0.03]) after accounting for the association between childhood SEP and education with HOMA2-IR. The same pattern was observed for later-life verbal memory.

CONCLUSIONS/INTERPRETATION

Associations between type 2 diabetes and mid-life metabolic traits with subsequent cognitive state do not appear causal, and instead they may be explained by SEP in early life, childhood cognition and educational attainment. Therefore, glucose-lowering medication may be unlikely to combat cognitive impairment in older age.

Evaluation of Relation between HbA1c Level with Cognitive Disorders and Depression in Type 2 Diabetes Mellitus Patients

BACKGROUND:

The role of HbA1c level in cognition decline and depression in type 2 diabetic patients is reported in some studies.

AIM:

We evaluated the possible significant relationship between HbA1c level and cognition decline and depression in type 2 diabetic patients.

MATERIAL AND METHODS:

This descriptive-analytic study was performed on 512 patients with a different HbA1c level and ages range. All subjects were administered a structured clinical interview. Cognitive functions and depressive disorders were assessed through the Mini-Mental Status Exam (MMSE) and Patient Health Questionnaire-9 (PHQ-9) respectively. Chi-square test was used for relationships between variables.

RESULTS:

HbA1c mean in all patients was 7.58%. MMSE score mean in total was 27.28. 83.3% of patients had a depressive disorder, and 8.59% of patients had an MMSE score < 24. There was no significant relationship between HbA1c level and cognitive problems, but there was a significant relationship between recent memory declines with the level of HbA1c (P = 0.03). Also, there was no significant relationship between attention-deficit with HbA1c level.

CONCLUSION:

Our finding provides that even though there is no significant difference between HbA1c level and cognitive problems and depression, recent memory state in these patients are more affected than the normal population and these patients have a worse state of depressive disorders.

Mitochondrial Dysfunctions: A Thread Sewing Together Alzheimer's Disease, Diabetes, and Obesity

Metabolic disorders are severe and chronic impairments of the health of many people and represent a challenge for the society as a whole that has to deal with an ever-increasing number of affected individuals. Among common metabolic disorders are Alzheimer's disease, obesity, and type 2 diabetes. These disorders do not have a univocal genetic cause but rather can result from the interaction of multiple genes, lifestyle, and environmental factors. Mitochondrial alterations have emerged as a feature common to all these disorders, underlining perhaps an impaired coordination between cellular needs and mitochondrial responses that could contribute to their development and/or progression.

Glycated Hemoglobin, but not Insulin Sensitivity, is Associated with Memory in Subjects with Obesity

OBJECTIVE

Obesity has been related to later-life dementia. Serum glucose levels and insulin resistance are known to influence cognition in individuals with diabetes. This study aimed to evaluate memory function in middle-aged individuals with obesity in association with glucose metabolism and brain iron content.

METHODS

This was a cross-sectional case-control study including 121 participants aged 27.2 to 66.6 years (56 without obesity, 65 with obesity) stratified according to sex and menopausal status. Insulin sensitivity, body composition, brain iron content, and memory function were evaluated by euglycemic hyperinsulinemic clamp, dual-energy x-ray absorptiometry, magnetic resonance relaxometry (R2*), and California Verbal Learning Test, respectively.

RESULTS

Women with obesity, but not men, had lower scores in some California Verbal Learning Tests in association with metabolic parameters and increased brain iron content compared with controls. Fasting plasma glucose, glycated hemoglobin (HbA1c; within normal range), and R2* were negatively associated with memory scores, whereas insulin sensitivity showed positive associations. Remarkably, only HbA1c levels and R2* in the right inferior fronto-orbital region remained significant after controlling for age, sex, education, and BMI.

CONCLUSIONS

Impairments in memory function in middle-aged women with obesity are associated with HbA1c levels and brain iron content independently of insulin sensitivity. These results may have implications in the design of therapeutic strategies in women with obesity.

Association between the Vicious Cycle of Diabetes-Associated Complications and Glycemic Control among the Elderly: A Systematic Review

Background and objectives: Improved quality of life (QoL) and life expectancy of elderly diabetic patients revolves around optimal glycemic control. Inadequate glycemic control may lead to the development of diabetes-associated complications (DAC), which not only complicate the disease, but also affect morbidity and mortality. Based on the available literature, the aim was to elucidate the vicious cycle underpinning the relationship between diabetes complications and glycemic control. Materials and Methods: A comprehensive literature search was performed to find eligible studies published between 1 January 2000 and 22 September 2018 pertaining to diabetes complications and glycemic control. Results: Initially, 261 studies were retrieved. Out of these, 67 were duplicates and therefore were excluded. From the 194 remaining articles, 85 were removed based on irrelevant titles and/or abstracts. Subsequently, the texts of 109 articles were read in full and 71 studies were removed at this stage for failing to provide relevant information. Finally, 38 articles were selected for this review. Depression, impaired cognition, poor physical functioning, frailty, malnutrition, chronic pain, and poor self-care behavior were identified as the major diabetes-associated complications that were associated with poor glycemic control in elderly diabetic patients. Conclusions: This paper proposes that diabetes-associated complications are interrelated, and that impaired glycemic control aggravates diabetes complications; as a result, patient’s self-care abilities are compromised. A schema is generated to reflect a synthesis of the literature found through the systematic review process. This not only affects patients’ therapeutic goals, but may also hamper their health-related quality of life (HRQoL) and financial status.

The Giant Geriatric Syndromes Are Intensified by Diabetic Complications

By 2015, diabetes has affected more than 415 million people over the world. It is anticipated that 640 million adults will suffer from diabetes in 2040. The elongation of the life expectancy, as the result of better general health care, extends also the time when diabetic complications may develop together with other senility-specific problems. The Giant Geriatric Syndromes (Geriatric Giants) have been qualified by the original Nascher's criteria defined more than 100 years ago, but they are becoming more and more relevant in connection with the aging of societies. The criteria comprise the older age, commonness of the health problem, multifactorial etiology, functional or cognitive impairment, worsened outcome, and increased morbidity and mortality. We described the impact of diabetes on Geriatric Giants including cognitive dysfunction, depression, malnutrition, incontinence, falls and fractures, chronic pain, and the loss of senses. The association of diabetes with Geriatric Giants reveals as a vicious circle with the background of neurovascular complications. However, diabetes influence on the incidence of cancer in elderly was also discussed, since neoplastic diseases associate with Geriatric Giants, for example, chronic pain and depression. The knowledge about these aspects of functional decline in geriatric population is crucial to improve patient care.

Macrophage migration inhibitory factor: A multifaceted cytokine implicated in multiple neurological diseases

Macrophage migration inhibitory factor (MIF) is a conserved cytokine found as a homotrimer protein. It is found in a wide spectrum of cell types in the body including neuronal and non-neuronal cells. MIF is implicated in several biological processes; chemo-attraction, cytokine activity, and receptor binding, among other functions. More recently, a chaperone-like activity has been added to its repertoire. In this review, we focus on the implication of MIF in the central nervous system and peripheries, its role in neurological disorders, and the mechanisms by which MIF is regulated. Numerous studies have associated MIF with various disease settings. MIF plays an important role in advocating tumorigenic processes, Alzheimer's disease, and is also upregulated in autism-spectrum disorders and spinal cord injury where it contributes to the severity of the injured area. The protective effect of MIF has been reported in amyotrophic lateral sclerosis by its reduction of aggregated misfolded SOD1, subsequently reducing the severity of this disease. Interestingly, a protective as well as pathological role for MIF has been implicated in stroke and cerebral ischemia, as well as depression. Thus, the role of MIF in neurological disorders appears to be diverse with both beneficial and adversary effects. Furthermore, its modulation is rather complex and it is regulated by different proteins, either on a molecular or protein level. This complexity might be dependent on the pathophysiological context and/or cellular microenvironment. Hence, further clarification of its diverse roles in neurological pathologies is warranted to provide new mechanistic insights which may lead in the future to the development of therapeutic strategies based on MIF, to fight some of these neurological disorders.