Low-Dose Aspirin Use and Cognitive Function in Older Age: A Systematic Review and Meta-analysis

Exploring the Intersection of Dementia and Myocardial Infarction: Vascular Perspectives

Emerging evidence underscores the relationship between myocardial infarction and dementia, implicating a profound influence on patient health. The bidirectional relationship between myocardial infarction and dementia is highlighted by pathophysiological changes in vasculature function, lifestyle factors, and environmental influences. Our literature review aims to explore the complex relationship between these 2 pathologies and highlight the pathways by which they mutually influence each other.

Association of Aspirin with Dementia or Mild Cognitive Impairment: A Systematic Review and Meta-Analysis of Randomized Trials

BACKGROUND

At present, the effect of aspirin in preventing dementia or mild cognitive impairment (MCI) is controversial. Clarifying their association is of interest for subsequent relevant clinical trials.

METHODS

Four databases (PubMed, Embase, Web of Science, and the Cochrane Library) were searched from inception to May 12, 2023, for randomized controlled trials (RCTs) that explored the effects between aspirin and dementia or MCI. Two reviewers independently extracted and analyzed data using Stata software. Discrepancy was resolved by a third reviewer. The primary outcomes were dementia and MCI. The secondary outcomes were cognitive decline and changes in cognitive scores.

RESULTS

Five RCTs with 46,804 participants at randomization were included. For the primary outcomes, low-certainty evidence showed that aspirin was not associated with dementia (odds ratio [OR] = 0.93, 95% confidence interval [CI]: [0.85, 1.03], p > 0.05, I2 = 0%) or MCI (OR = 1.00, 95% CI: [0.88, 1.14], p > 0.05, I2 = 3.3%). For the secondary outcomes, moderate-certainty evidence showed that aspirin was not associated with cognitive decline (OR = 1.02, 95% CI: [0.93, 1.11], p > 0.05, I2 = 0%) and a change in global cognitive score (standard mean difference [SMD] = -0.01, 95% CI: [-0.03, 0.02], p > 0.05, I2 = 0%). Low-certainty evidence showed that aspirin was not associated with a change in verbal learning memory score (SMD = -0.04, 95% CI: [-0.09, 0.01], p > 0.05; I2 = 72.5%).

CONCLUSIONS

Low- and moderate-certainty evidence showed that aspirin was not associated with dementia, MCI, cognitive decline, or better cognitive scores. Future research may need to focus more on subtypes of dementia, mainly vascular dementia or other vascular neurocognitive diseases, and assess whether aspirin has long-term clinical benefits in a large sample of patients with dementia or MCI.

Neurotrophic fragments as therapeutic alternatives to ameliorate brain aging

Aging is a global phenomenon and a complex biological process of all living beings that introduces various changes. During this physiological process, the brain is the most affected organ due to changes in its structural and chemical functions, such as changes in plasticity and decrease in the number, diameter, length, and branching of dendrites and dendritic spines. Likewise, it presents a great reduction in volume resulting from the contraction of the gray matter. Consequently, aging can affect not only cognitive functions, including learning and memory, but also the quality of life of older people. As a result of the phenomena, various molecules with notable neuroprotective capacity have been proposed, which provide a therapeutic alternative for people under conditions of aging or some neurodegenerative diseases. It is important to indicate that in recent years the use of molecules with neurotrophic activity has shown interesting results when evaluated in in vivo models. This review aims to describe the neurotrophic potential of molecules such as resveratrol (3,5,4′-trihydroxystilbene), neurotrophins (brain-derived neurotrophic factor), and neurotrophic-type compounds such as the terminal carboxyl domain of the heavy chain of tetanus toxin, cerebrolysin, neuropeptide-12, and rapamycin. Most of these molecules have been evaluated by our research group. Studies suggest that these molecules exert an important therapeutic potential, restoring brain function in aging conditions or models of neurodegenerative diseases. Hence, our interest is in describing the current scientific evidence that supports the therapeutic potential of these molecules with active neurotrophic.

Improving the effectiveness of anti-aging modalities by using the constrained disorder principle-based management algorithms

Aging is a complex biological process with multifactorial nature underlined by genetic, environmental, and social factors. In the present paper, we review several mechanisms of aging and the pre-clinically and clinically studied anti-aging therapies. Variability characterizes biological processes from the genome to cellular organelles, biochemical processes, and whole organs' function. Aging is associated with alterations in the degrees of variability and complexity of systems. The constrained disorder principle defines living organisms based on their inherent disorder within arbitrary boundaries and defines aging as having a lower variability or moving outside the boundaries of variability. We focus on associations between variability and hallmarks of aging and discuss the roles of disorder and variability of systems in the pathogenesis of aging. The paper presents the concept of implementing the constrained disease principle-based second-generation artificial intelligence systems for improving anti-aging modalities. The platform uses constrained noise to enhance systems' efficiency and slow the aging process. Described is the potential use of second-generation artificial intelligence systems in patients with chronic disease and its implications for the aged population.

Neuroinflammation in Dementia—Therapeutic Directions in a COVID-19 Pandemic Setting

Although dementia is a heterogenous group of diseases, inflammation has been shown to play a central role in all of them and provides a common link in their pathology. This review aims to highlight the importance of immune response in the most common types of dementia. We describe molecular aspects of pro-inflammatory signaling and sources of inflammatory activation in the human organism, including a novel infectious agent, SARS-CoV-2. The role of glial cells in neuroinflammation, as well as potential therapeutic approaches, are then discussed. Peripheral immune response and increased cytokine production, including an early surge in TNF and IL-1β concentrations activate glia, leading to aggravation of neuroinflammation and dysfunction of neurons during COVID-19. Lifestyle factors, such as diet, have a large impact on future cognitive outcomes and should be included as a crucial intervention in dementia prevention. While the use of NSAIDs is not recommended due to inconclusive results on their efficacy and risk of side effects, the studies focused on the use of TNF antagonists as the more specific target in neuroinflammation are still very limited. It is still unknown, to what degree neuroinflammation resulting from COVID-19 may affect neurodegenerative process and cognitive functioning in the long term with ongoing reports of chronic post-COVID complications.

Effects of aspirin on dementia and cognitive function in diabetic patients: the ASCEND trial

AIMS

Aspirin is widely used in cardiovascular disease prevention but is also associated with an increased risk of bleeding. The net effect of aspirin on dementia and cognitive impairment is uncertain.

METHODS AND RESULTS

In the ASCEND trial, 15 480 people from the UK with diabetes and no history of cardiovascular disease were randomized to aspirin 100 mg daily or matching placebo for a mean of 7.4 years. The 15 427 ASCEND participants with no recorded dementia prior to baseline were included in this cognitive study with a primary pre-specified outcome of 'broad dementia', comprising dementia, cognitive impairment, or confusion. This was ascertained through participant, carer, or general practitioner report or hospital admission diagnosis, by 31 March 2019 (∼2 years beyond the scheduled treatment period). The broad dementia outcome occurred in a similar percentage of participants in the aspirin group and placebo group: 548 participants (7.1%) vs. 598 (7.8%), rate ratio 0.91 [95% confidence interval (CI), 0.81-1.02]. Thus, the CI excluded proportional hazards of >2% and proportional benefits of >19%.

CONCLUSION

Aspirin does not have a large proportional effect on the risk of dementia. Trials or meta-analyses with larger total numbers of incident dementia cases to increase statistical power are needed to assess whether any modest proportional 10-15% benefits of 5-7 years of aspirin use on dementia exist.

CLINICAL TRIAL REGISTRATION

Current Controlled Trials number, ISRCTN60635500; ClinicalTrials.gov number: NCT00135226.

Long-term low-dose acetylsalicylic use shows protective potential for the development of both vascular dementia and Alzheimer's disease in patients with coronary heart disease but not in other individuals from the general population: results from two large cohort studies

BACKGROUND

No population-based cohort study investigated a potential inverse association between long-term low-dose acetylsalicylic acid (ASA) use and all-cause dementia and its two most common sub-types Alzheimer's disease (AD) and vascular dementia (VD) so far.

METHODS

Cox regression models with inverse probability of treatment weighting to model the underlying cardiovascular risk were used to assess the associations of low-dose ASA use with all-cause dementia, AD, and VD incidence in community-dwelling older adults from the German ESTHER study (N = 5258) and the UK Biobank (N = 305,394). Inclusion criteria were age of 55 years or older and completed drug assessment. Meta-analyses of the individual participant data from the two prospective cohort studies were performed.

RESULTS

Four hundred seventy-six cases of all-cause dementia, 157 cases of AD, and 183 cases of VD were diagnosed over a median of 14.3 years of follow-up in ESTHER. In the UK Biobank, 5584 participants were diagnosed with all-cause dementia, 2029 with AD, and 1437 with VD over a median of 11.6 years. The meta-analysis of both cohorts revealed a weak reduction in hazards for all-cause dementia (hazard ratio (HR) [95% confidence interval (CI)]: 0.96 [0.93 to 0.99]). The strongest protective effect of low-dose ASA was observed in participants with coronary heart disease (CHD) in both cohorts, and a significant interaction was detected. In particular, in meta-analysis, a 31% reduction in hazard for AD, 69% for VD and 34% for all-cause dementia were observed (HR [95% CI]: 0.69 [0.59 to 0.80], 0.31 [0.27 to 0.35], 0.46 [0.42 to 0.50], respectively). Furthermore, compared to non-users, users of low-dose ASA for 10 years or longer (who likely use it because they have CHD or a related diagnosis putting them at an increased risk for cardiovascular events) demonstrated a strong protective effect on all dementia outcomes, especially for VD (HR [95% CI]: 0.48 [0.42 to 0.56]) whereas no protective associations were observed with shorter low-dose ASA use.

CONCLUSIONS

The protective potential of low-dose ASA for all-cause dementia, AD, and VD seems to strongly depend on pre-existing CHD and the willingness of patients to take it for a minimum of ten years.

Rhythm Control Better Prevents Dementia than Rate Control Strategies in Patients with Atrial Fibrillation-A Nationwide Cohort Study

Background: Atrial fibrillation (AF) increases the risk of dementia. Whether the pharmacological rhythm control of AF can reduce the risk of dementia compared to the rate control strategy remains unclear. We hypothesize that the rhythm control strategy is better than the rate control strategy in preventing dementia. Methods: AF patients aged ≥65 years were identified from the Taiwan National Health Insurance Database. Patients receiving anti-arrhythmic drugs at a cumulative defined daily dose (cDDD) of >30 within the first year of enrollment constituted the rhythm control group. Patients who used rate control medications for a cDDD of >30 constituted the rate control group. A multivariate Cox hazards regression model was used to determine the hazard ratio (HR) for dementia. Results: A total of 3382 AF patients (698 in the rhythm control group; 2684 in the rate control group) were analyzed. During a 4.86 ± 3.38 year follow-up period, 414 dementia events occurred. The rhythm control group had a lower rate of dementia than the rate control group (adjust HR: 0.75, p = 0.031). The rhythm control strategy reduced the risk of dementia particularly in those receiving aspirin (p = 0.03). Conclusions: In patients with AF, pharmacological rhythm control was associated with a lower risk of dementia than rate control over a long-term follow-up period, particularly in patients receiving aspirin treatment.

Acetylsalicylic Acid Suppresses Alcoholism-Induced Cognitive Impairment Associated with Atorvastatin Intake by Targeting Cerebral miRNA155 and NLRP3: In Vivo, and In Silico Study

Alcoholism is one of the most common diseases that can lead to the development of several chronic diseases including steatosis, and cognitive dysfunction. Statins are lipid-lowering drugs that are commonly prescribed for patients with fatty liver diseases; however, the exact effect of statins on cognitive function is still not fully understood. In the present study, we have investigated the molecular and microscopic basis of cognitive impairment induced by alcohol and/or Atorvastatin (ATOR) administration to male Wistar albino rats and explored the possible protective effect of acetylsalicylic acid (ASA). The biochemical analysis indicated that either alcohol or ATOR or together in combination produced a significant increase in the nucleotide-binding domain–like receptor 3 (NLRP3), interleukin-1β (IL-1β) miRNA155 expression levels in the frontal cortex of the brain tissue. The histological and morphometric analysis showed signs of degeneration in the neurons and the glial cells with aggregations of inflammatory cells and a decrease in the mean thickness of the frontal cortex. Immunohistochemical analysis showed a significant increase in the caspase-8 immunoreaction in the neurons and glial cells of the frontal cortex. Interestingly, administration of ASA reversed the deleterious effect of the alcohol and ATOR intake and improved the cognitive function as indicated by biochemical and histological analysis. ASA significantly decreased the expression levels of miRNA155, NLRP3, and IL1B, and produced a significant decrease in caspase-8 immunoreaction in the neurons and glial cells of the frontal cortex with a reduction in the process of neuroinflammation and neuronal damage. To further investigate these findings, we have performed an extensive molecular docking study to investigate the binding affinity of ASA to the binding pockets of the NLRP3 protein. Our results indicated that ASA has high binding scores toward the active sites of the NLRP3 NACHT domain with the ability to bind to the NLRP3 pockets by a set of hydrophilic and hydrophobic interactions. Taken together, the present study highlights the protective pharmacological effect of ASA to attenuate the deleterious effect of alcohol intake and long term ATOR therapy on the cognitive function via targeting miRNA155 and NLRP3 proteins.

Three-year trajectories in functional limitations and cognitive decline among Dutch 75+ year olds, using nine-month intervals

Background

Using longitudinal panel data, we aimed to identify three-year trajectories in cognitive and physical functioning among Dutch older adults, and the characteristics associated with these trajectories.

Methods

We used Group-based Trajectory Modelling with mortality jointly estimated to identify trajectories, using a scale composed of 6 Activities of Daily Living (ADL) as a measure of physical functioning, and the short mini mental status examination (sMMSE) or the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) as a measure of cognitive functioning. Data came from 574 Dutch adults aged 75+, collected in five nine-month measurement waves (2015–2018) for the Longitudinal Aging Study Amsterdam.

Results

For physical functioning five trajectories were identified: ‘high’, ‘moderate’, ‘steeply declining’, ‘gradually declining’, and ‘continuously low’; and for cognitive functioning: ‘high’, ‘moderate’, ‘declining’, and ‘low’. Living in an institution, and being lower educated increased the probability of the two continuously low functioning trajectories, whereas old age and multimorbidity increased the probability of low physical functioning, but multimorbidity decreased the probability of low cognitive functioning. Associations for steeply declining physical functioning were absent. Being older and having multimorbidity increased the probability of gradually declining physical functioning and declining cognitive functioning. A higher prevalence of lung- and heart disease, cancer, and rheumatic disease was found in the gradually declining physical functioning group; and a higher prevalence of diabetes, cerebrovascular accidents, and cancer was found in the declining cognitive functioning group. High and moderate physical functioning and high cognitive functioning were characterized by being younger, community-dwelling, and higher educated. Having multimorbidity negatively predicted high and moderate physical functioning, but was not associated with high and moderate cognitive functioning.

Conclusions

This study identified trajectories comparable to studies that used longer time intervals, showing the consistent presence of heterogeneity in both physical and cognitive trajectories. Co-modelling mortality resulted in bigger group sizes for the more adverse trajectories. The favourable trajectories, containing most of the participants, were mostly characterized by absence of disease. The prevalence of chronic diseases differed between the declining trajectories, suggesting that certain diseases tend to induce cognitive decline rather than physical decline, and vice versa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02720-x.

Aspirin in people with dementia, long-term benefits, and harms: a systematic review

PURPOSE

People with dementia may have indications for aspirin prescription and clinicians are asked to balance the potential risks against benefits. This review examines the evidence for the risk and benefit of long-term aspirin use in people with dementia aged over 65 years, including randomised controlled trials and observational studies.

METHODS

We searched three databases for research published between 2007 and 2020. Each eligible article was assessed for risk of bias, and confidence in findings was rated using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Four papers met inclusion criteria: one randomised controlled trial, two cohort studies, and one with pooled data. All looked only at dementia of Alzheimer's type, and none addressed myocardial or cerebral infarction as outcomes. Dementia progression was reported by two studies, with conflicting results. The trial found no significant effect of aspirin on mortality (odds ratio aspirin vs. no aspirin 1.07, 95% confidence interval 0.58-1.97) but found more events of severe bleeding with aspirin (OR aspirin vs. no aspirin 6.9, 1.5-31.2). An excess in intracranial haemorrhage in the aspirin group was judged plausible based on two non-randomised studies.

CONCLUSIONS

The review findings are limited because studies include only people with Alzheimer's-type dementia and lack confirmatory studies, although an increased risk of bleeding events is recognised. Further research that addresses the benefits and risks of aspirin in more representative groups of people with dementia is needed to guide prescribing decisions.

Impact of age and cyclooxygenase inhibition on the hemodynamic response to acute cognitive challenges

Structural and functional changes in the cerebral vasculature occur with advancing age, which may lead to impaired neurovascular coupling (NVC) and cognitive decline. Cyclooxygenase (COX) inhibition abolishes age-related differences in cerebrovascular reactivity, but it is unclear if COX inhibition impacts NVC. The purpose of this study was to examine the influence of aging on NVC before and after COX inhibition. Twenty-three young (age = 25 ± 4 yr) and 21 older (age = 64 ± 5 yr) adults completed two levels of difficulty of the Stroop and n-back tests before and after COX inhibition. Middle cerebral artery blood velocity (MCAv) was measured using transcranial Doppler ultrasound and mean arterial blood pressure (MAP) was measured using a finger cuff. Hemodynamic variables were measured at rest and in response to cognitive challenges. During the Stroop test, older adults demonstrated a greater increase in MCAv (young: 2.2 ± 6.8% vs. older: 5.9 ± 5.8%; P = 0.030) and MAP (young: 2.0 ± 4.9% vs. older: 4.8 ± 4.9%; P = 0.036) compared with young adults. There were no age-related differences during the n-back test. COX inhibition reduced MCAv by 30% in young and 26% in older adults (P < 0.001 for both). During COX inhibition, there were no age-related differences in the percent change in MCAv or MAP in response to the cognitive tests. Our results show that older adults require greater increases in MCAv and MAP during a test of executive function compared with young adults and that any age-related differences in NVC were abolished during COX inhibition. Collectively, this suggests that aging is associated with greater NVC necessary to accomplish a cognitive task.

Aspirin using was associated with slower cognitive decline in patients with Alzheimer's disease

We aimed to examine whether the use of aspirin is associated with change in cognitive performance over time, and whether this association is modified by the cognitive stages. This study included a total of 1866 subjects, including 509 subjects with normal cognition (NC), 985 subjects with mild cognitive impairment (MCI), and 372 patients with Alzheimer’s disease (AD). In each group, we further categorized our subjects into two groups based on their aspirin using conditions: Aspirin users and non-aspirin users. Mini-Mental State Examination (MMSE) was the cognitive outcome. Linear mixed models were conducted to examine the longitudinal relationship between the use of aspirin and cognitive performance in each diagnostic group. In the cross-sectional analysis, there were no significant differences in MMSE scores between non-aspirin users and aspirin users in subjects with NC, subjects with MCI or patients with AD. In the longitudinal analysis, we detected an association of the baseline use of aspirin with cognitive decline (MMSE) over time in patients with AD, but not in the NC group or MCI group. Specifically, in AD patients, the use of aspirin at baseline was associated with slower cognitive decline over time. Our data may support an association between the use of aspirin and slower cognitive decline, while this association may be dependent on the clinical stages.

Improve cognitive impairment using mefenamic acid non-steroidal anti-inflammatory therapy: additional beneficial effect found in a controlled clinical trial for prostate cancer therapy

Inflammation is an essential component of prostate cancer (PCa), and mefenamic acid has been reported to decrease its biochemical progression. The current standard therapy for PCa is androgen deprivation therapy (ADT), which has side effects such as cognitive dysfunction, risk of Alzheimer's disease, and dementia. Published results of in vitro tests and animal models studies have shown that mefenamic acid could be used as a neuroprotector. Objective: Examine the therapeutic potential of mefenamic acid in cognitive impairment used in a controlled clinical trial. Clinical trial phase II was conducted on patients undergoing ADT for PCa. Two groups of 14 patients were included. One was treated with a placebo, while the other received mefenamic acid 500 mg PO every 12hrs for six months. The outcome was evaluated through the Mini-Mental State Examination (MMSE) score at six months. At the beginning of the study, both groups had similar MMSE scores (mefenamic acid vs. placebo: 26.0±2.5 vs. 27.0±2.6, P=0.282). The mefenamic acid group improved its MMSE score after six months compared with the placebo group (27.7±1.8 vs. 25.5±4.2, P=0.037). Treatment with mefenamic acid significantly increases the probability of maintained or raised cognitive function compared to placebo (92% vs. 42.9%, RR=2.2, 95% CI: 1.16-4.03, NNT=2.0, 95% CI: 1.26-4.81, P=0.014). Furthermore, 42.9% of the placebo group patients had relevant cognitive decline (a 2-point decrease in the MMSE score), while in patients treated with mefenamic acid, cognitive impairment was not present. This study is the first conducted on humans that suggests that mefenamic acid protects against cognitive decline.

Short-term air pollution, cognitive performance and nonsteroidal anti-inflammatory drug use in the Veterans Affairs Normative Aging Study

Air pollution, especially the fine particulate matter (PM_2.5), may impair cognitive performance^1-3, but its short-term impact remains poorly understood. We investigated the short-term associations of PM_2.5 with the cognitive performances of 954 white males measured as the global cognitive function (GCF) and Mini-Mental State Examination (MMSE) scores, and further explored whether taking nonsteroidal anti-inflammatory drugs (NSAIDs) could modify their relationships. Higher short-term exposure to PM_2.5 demonstrated non-linear negative associations with cognitive function. Compared with the lowest quartile of the 28-day average PM_2.5 concentration, the 2^nd, 3^rd, and 4^th quartiles were associated with 0.378-, 0.376-, and 0.499-unit decreases in GCF score, 0.484-, 0.315-, and 0.414-unit decreases in MMSE score, and 69%, 45%, and 63% greater odds of low MMSE scores (≤25), respectively. Such adverse effects were attenuated among NSAIDs users compared to non-users. This study elucidates the short-term impacts of air pollution on cognition and warrants further investigations on the modifying effects of NSAIDs.

Novel Strategies for Healthy Brain Aging

One of the best strategies for healthy brain aging is regular aerobic exercise. Commonly studied "anti-aging" compounds may mimic some effects of exercise on the brain, but novel approaches that target energy-sensing pathways similar to exercise probably will be more effective in this context. We review evidence in support of this hypothesis by focusing on biological hallmarks of brain aging.

Static Stretching Reduces Motoneuron Excitability: The Potential Role of Neuromodulation

Prolonged static muscle stretching transiently reduces maximal muscle force, and this force loss has a strong neural component. In this review, we discuss the evidence suggesting that stretching reduces the motoneuron's ability to amplify excitatory drive. We propose a hypothetical model in which stretching causes physiological relaxation, reducing the brainstem-derived neuromodulatory drive necessary to maximize motoneuron discharge rates.

Aspirin Use on Incident Dementia and Mild Cognitive Decline: A Systematic Review and Meta-Analysis

Background: More people with cognitive dysfunction and dementia also fall into the category of high vascular risk, for which aspirin is one of the most frequently used drugs. However, previous studies reporting that aspirin buffers against mild cognitive decline (MCI) and dementia remain controversial. We thus conducted an updated systematic review and meta-analysis to evaluate the association of aspirin use with the risk of MCI and dementia in older adults. Methods: Data sources from PubMed, Embase, Web of Science, and the Cochrane Database for randomized controlled trails (RCTs) and cohort studies (published between January 1, 2000 and April 11, 2020). Relative risks (RRs) and 95% confidence intervals (95% CIs) were used to pool data on the occurrence of dementia and MCI with random-effects models. Results: Of 3,193 identified articles, 15 studies (12 cohort studies and three RCTs) were eligible and were included in our analysis, which involved a total of 100,909 participants without cognitive dysfunctions or dementia at baseline. In pooled cohort studies, aspirin use did not reduce the incidence of MCI and dementia (the pooled RR = 0.97; 95% CI = 0.85-1.11;I for heterogeneity 2 = 65%) compared with non-users. However, low-dose aspirin (75-100 mg/day) was associated with a decreased likelihood of developing dementia or MCI (the pooled RR = 0.75; 95% CI = 0.63-0.9;I for heterogeneity 2 = 50.5%). This association existed in studies including all-cause dementia (the pooled RR = 0.82; 95% CI = 0.71-0.96) and Alzheimer's disease (AD) (the pooled RR = 0.54; 95% CI = 0.33-0.89), but not in MCI (the pooled RR = 0.58; 95% CI = 0.31-1.08). In RCTs, low-dose aspirin use was not significantly associated with less prevalence of dementia or MCI (RR = 0.94; 95% CI = 0.84-1.05;I for heterogeneity 2 = 0.0%). Conclusions: In cohort studies, we found that low-dose aspirin use had a higher likelihood of reducing the incidence of dementia, which was not supported by RCTs. The evidence was insufficient to fully evaluate the effect of aspirin on cognitive function and dementia. Well-designed studies and innovative approaches are therefore needed to clarify whether the use of aspirin improves cognitive function and reduces the risk of dementia.

Aspirin in the Prevention of Cardiovascular Disease and Cancer

More than a century after its synthesis, daily aspirin, given at a low dose, is a milestone treatment for the secondary prevention of cardiovascular disease (CVD). Its role in primary prevention of CVD is still debated. Older randomized controlled trials showed that aspirin reduced the low incidence of myocardial infarction but correspondingly increased the low incidence of serious gastrointestinal bleeds without altering mortality. More recent trials see the benefit attenuated, perhaps obscured by other cardioprotective practices, while the bleeding risk remains, especially in older patients. Indirect evidence, both preclinical and clinical, suggests that aspirin may protect against sporadic colorectal cancer and perhaps other cancers. However, further studies are still necessary to warrant the consumption of aspirin for primary prevention of CVD and cancer by apparently healthy individuals.

Aspirin as a Potential Geroprotector: Experimental Data and Clinical Evidence

Aging is a biological process with effects at the molecular, cellular, tissue, organ, system, and organismal levels and is characterized by decline in physical function and higher risks of age-related diseases. The use of anti-aging drugs for disease prevention has become a high priority for science and is a new biomedicine trend. Geroprotectors are compounds which slow aging and increase lifespan of the organism in question. The common painkiller aspirin, a member of the non-steroidal anti-inflammatory drug (NSAID) family, is one of the potential geroprotective agents. Aspirin is often used in treatment of mild to moderate pain. It has anti-inflammatory and anti-pyretic properties and acts as an inhibitor of cyclooxygenase which results in inhibition of prostaglandin. Acetylsalicylic acid as an active compound of aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Aspirin has shown life-extending effects in numerous model organisms. This chapter reviews the evidence for clinical efficacy of aspirin including cardiovascular disease prevention, anti-cancer effects, and improvement of cognitive function. However, there are some limitations of these therapies, including the risk of excessive bleeding. We have also summarized numerous experimental and analytical data that support health and longevity benefits of aspirin treatment by affecting pro-longevity pathways.

PPARα Between Aspirin and Plaque Clearance

Mounting evidence has identified that impaired amyloid-β (Aβ) clearance might contribute to Alzheimer's disease (AD) pathology. The lysosome-autophagy network plays an important role in protein homeostasis and cell health by removing abnormal protein aggregates via intracellular degradation. Therefore, stimulation of cellular degradative machinery for efficient removal of Aβ has emerged as a growing field in AD research. However, mechanisms controlling such pathways and drugs to promote such mechanisms are poorly understood. Aspirin is a widely used drug throughout the world and recent studies have identified a new function of this drug. At low doses, aspirin stimulates lysosomal biogenesis and autophagy to clear amyloid plaques in an animal model of AD. This review delineates such functions of aspirin and analyzes underlying mechanisms that involve peroxisome proliferator-activated receptor alpha (PPARα)-mediated transcription of transcription factor EB (TFEB), the master regulator of lysosomal biogenesis.

Sex Difference in Effects of Low-Dose Aspirin on Prevention of Dementia in Patients With Type 2 Diabetes: A Long-term Follow-up Study of a Randomized Clinical Trial

OBJECTIVE

To evaluate and compare the efficacy of long-term use of low-dose aspirin for the prevention of dementia in men and women.

RESEARCH DESIGN AND METHODS

This study is a follow-up cohort study of the Japanese Primary Prevention of Atherosclerosis With Aspirin for Diabetes (JPAD) trial, which was a randomized, open-label, standard care-controlled trial examining the effects of low-dose aspirin on cardiovascular events. We followed up 2,536 Japanese patients with type 2 diabetes (T2D) enrolled in the JPAD trial from 2002 to 2017. The primary outcome of this post hoc analysis was the incidence of dementia, which was defined by the prescription of antidementia drugs or admission due to dementia.

RESULTS

Among the originally enrolled patients, 2,121 (84%) retained their original allocation. During a median follow-up of 11.4 years, 128 patients developed dementia. The overall effect of low-dose aspirin on the prevention of dementia adjusted for age, sex, and other established risk factors was not significant (hazard ratio [HR] 0.82, 95% CI 0.58-1.16). However, a significant reduction was seen in the risk of dementia in women (HR 0.58, 95% CI 0.36-0.95), but not in men (HR 1.27, 95% CI 0.75-2.13) (P _interaction = 0.03).

CONCLUSIONS

Long-term use of low-dose aspirin may reduce the risk for dementia in women with T2D.

PPARα serves as a new receptor of aspirin for neuroprotection

Acetyl salicylic acid, commonly known as aspirin, has been being widely used as an anti-inflammatory drug for almost 100 years. However, there was no receptor known for this popular drug. Recently, we have established that peroxisome proliferator-activated receptor alpha (PPARα) acts as a novel receptor of aspirin. Activation of PPARα by aspirin stimulated a series of downstream signaling pathways that could potentially ameliorate different Alzheimer's disease (AD)-related pathologies. In this mini-review, we have discussed how aspirin-PPARα interaction plays a pivotal role in the amelioration of AD pathology via the stimulation of neurotrophic factors, upregulation of plasticity-associated genes, and removal of plaque burden in hippocampal neurons.

Health Benefits of Anti-aging Drugs

Aging, as a physiological process mediated by numerous regulatory pathways and transcription factors, is manifested by continuous progressive functional decline and increasing risk of chronic diseases. There is an increasing interest to identify pharmacological agents for treatment and prevention of age-related disease in humans. Animal models play an important role in identification and testing of anti-aging compounds; this step is crucial before the drug will enter human clinical trial or will be introduced to human medicine. One of the main goals of animal studies is better understanding of mechanistic targets, therapeutic implications and side-effects of the drug, which may be later translated into humans. In this chapter, we summarized the effects of different drugs reported to extend the lifespan in model organisms from round worms to rodents. Resveratrol, rapamycin, metformin and aspirin, showing effectiveness in model organism life- and healthspan extension mainly target the master regulators of aging such as mTOR, FOXO and PGC1α, affecting autophagy, inflammation and oxidative stress. In humans, these drugs were demonstrated to reduce inflammation, prevent CVD, and slow down the functional decline in certain organs. Additionally, potential anti-aging pharmacologic agents inhibit cancerogenesis, interfering with certain aspects of cell metabolism, proliferation, angioneogenesis and apoptosis.

Measuring gait speed to better identify prodromal dementia

Slow gait speed has been shown to predict incident dementia and cognitive decline in older individuals. We aimed to summarize the evidence concerning the association of slow gait speed with cognitive decline and dementia, and discuss the possible shared pathways leading to cognitive and motor impairments, under the unifying hypothesis that body and mind are intimately connected. This is a scoping review supported by a systematic search of the literature, performed on PubMed and Web of Science. Longitudinal studies providing information on the role of gait speed in the prediction of cognitive decline and dementia in cognitively intact people and in those with initial cognitive impairment were eligible. Of 39 studies selected, including overall 57,456 participants, 33 reported a significant association between gait speed and cognitive outcomes, including dementia. Neurodegenerative pathology and cerebrovascular burden may damage cerebral areas involved in both cognitive functions and motor control. At the same time, systemic conditions, characterized by higher cardiorespiratory, and metabolic and inflammatory burden, can affect a number of organs and systems involved in motor functions, including the brain, having ultimately an impact on cognition. The interplay of body and mind seems relevant during the development of cognitive decline and dementia. The measurement of gait speed may improve the detection of prodromal dementia and cognitive impairment in individuals with and without initial cognitive deficits. The potential applicability of such a measure in both clinical and research settings points at the importance of expanding our knowledge about the common underlying mechanisms of cognitive and motor decline.

Correlation of Androgen Deprivation Therapy with Cognitive Dysfunction in Patients with Prostate Cancer: A Nationwide Population-Based Study Using the National Health Insurance Service Database

Purpose

The purpose of this study was to evaluate the association of androgen deprivation therapy (ADT) with cognitive dysfunction.

Materials and Methods

Using the National Health Insurance Service database of the entire Korean adult prostate cancer population (n=236,391), data on ADT and cognitive dysfunction between 2008 and 2015 were analyzed. We excluded patients previously diagnosed with cognitive dysfunction, dementia, or a cerebral event history. We tested the effect of ADT on the risk of cognitive dysfunction using propensity score–matched Cox proportional hazards regression models and Kaplan-Meier survival analysis. Our final cohort comprised of 35,401 individuals with prostate cancer, including 24,567 men (70.6%) who underwent ADT.

Results

During a mean follow-up period of 4.1 years, 4,741 patients were newly diagnosed with cognitive dysfunction. A statistically significant association was found between ADT and the risk of cognitive dysfunction (hazard ratio, 1.169; p=0.002). Meanwhile, age (≥ 70 years), diabetes, hypertension, cardiovascular history, and peripheral vascular disease were identified as factors that contribute to the increased risk of cognitive dysfunction. In contrast, the use of statins and aspirin was associated with a lower risk of cognitive dysfunction. Kaplan-Meier analysis demonstrated that patients aged 70 years or older who underwent ADT had the lowest cumulative probability of remaining cognitive dysfunction-free (log-rank p < 0.001).

Conclusion

Our results revealed an association between the use of ADT for the treatment of prostate cancer and an increased risk of cognitive dysfunction in a nationwide population-based study. This finding should be further evaluated in prospective studies.

Atrial Fibrillation, Cognitive Decline, and Dementia: an Epidemiologic Review

PURPOSE OF REVIEW

Atrial fibrillation (AF) and dementia are both prevalent diseases in aging societies, which exert a great economic burden worldwide. Although a handful of epidemiologic studies have indicated that AF is independently associated with faster cognitive decline and a higher risk of dementia, there is still a lack of comprehensive understanding of the observed association. In this review, we summarize evidence from major epidemiologic studies concerning AF-related cognitive decline and dementia, the potential mechanisms underlying their association, and the cognitive benefits of treatment options.

RECENT FINDINGS

A large majority of population-based longitudinal studies have consistently shown an independent association of AF with cognitive decline and dementia with varying effect sizes, depending on the age of the study population and the presence of clinical stroke. The underlying pathways linking AF to cognitive phenotypes may involve systemic inflammation, cerebral hypoperfusion, and cerebral small vessel disease and microemboli. However, current evidence is insufficient to support the potential benefits of AF treatment in reducing risk of cognitive decline and dementia.

SUMMARY

Current epidemiologic research suggests that AF contributes to cognitive decline and dementia, independent of a history of stroke. Further work is warranted to elucidate the potential mechanisms underlying this association, and more well-designed studies are needed to explore the possible cognitive benefits of different therapeutic options in patients with AF.

Aspirin Induces Lysosomal Biogenesis and Attenuates Amyloid Plaque Pathology in a Mouse Model of Alzheimer's Disease via PPARα

Lysosomes play a central role in cellular homeostasis by regulating the cellular degradative machinery. Because aberrant lysosomal function has been associated with multiple lysosomal storage and neurodegenerative disorders, enhancement of lysosomal clearance has emerged as an attractive therapeutic strategy. Transcription factor EB (TFEB) is known as a master regulator of lysosomal biogenesis and, here, we reveal that aspirin, one of the most widely used medications in the world, upregulates TFEB and increases lysosomal biogenesis in brain cells. Interestingly, aspirin induced the activation of peroxisome proliferator-activated receptor alpha (PPARα) and stimulated the transcription of Tfeb via PPARα. Finally, oral administration of low-dose aspirin decreased amyloid plaque pathology in both male and female 5X familial Alzheimer's disease (5XFAD) mice in a PPARα-dependent fashion. This study reveals a new function of aspirin in stimulating lysosomal biogenesis via PPARα and suggests that low-dose aspirin may be used in lowering storage materials in Alzheimer's disease and lysosomal storage disorders.SIGNIFICANCE STATEMENT Developing drugs for the reduction of amyloid β containing senile plaques, one of the pathological hallmarks of Alzheimer's disease (AD), is an important area of research. Aspirin, one of the most widely used medications in the world, activates peroxisome proliferator-activated receptor alpha (PPARα) to upregulate transcription factor EB and increase lysosomal biogenesis in brain cells. Accordingly, low-dose aspirin decreases cerebral plaque load in a mouse model of Alzheimer's disease via PPARα. These results reveal a new mode of action of aspirin that may be beneficial for AD and lysosomal storage disorders.

Effect of long-term nutraceutical and dietary supplement use on cognition in the elderly: a 10-year systematic review of randomised controlled trials

Nutraceuticals have generated interest as a way to mitigate the cognitive decline in older adults. The aim of this systematic review was to determine the evidence for these claims from the scientific literature in randomised, double-blinded, controlled trials (duration: ≥1 year; participants: n≥100; age(mean): ≥65 years). Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched four electronic databases (PubMed, Scopus, CINAHL and Web of Science) and identified twenty-five studies published between the 15·June·2006 and 14·June·2016. Interventions included B-vitamins, n-3 fatty acids, antioxidant vitamins and herbs. Of the B-vitamin studies, four found benefits to cognition with supplementation. The first of these B-vitamin studies, in individuals with mild cognitive impairment (n 266; duration=2 years), included benefit to executive function (P=0·015) and improvements in the Mini-Mental State Examination (MMSE) among participants with baseline homocysteine above 11·3 µmol/l (P<0·001). In the same sample, the second study found cognitive benefits of B-vitamins dependent on the higher baseline plasma n-3 fatty acid status. The third B-vitamin study (n 900; duration=2 years) reported improved performance in immediate (P=0·046) and delayed recall (P=0·013), whereas the fourth study (n 856; duration=2 years) reported slower rate of cognitive decline in the MMSE (P=0·05). One study investigating DHA treatment (n 402; duration=1·5 years) revealed the slower rate of cognitive change in apoE e4 non-carriers (P=0·03). As only five included studies revealed notable benefits, presently based on the specific compounds explored here, there is not compelling evidence to support the use nutraceuticals to improve cognition in the elderly. Future long-term trials of nutraceuticals should investigate interactions with lifestyle, blood biomarkers and genetic risk factors.

The Study of Neurocognitive Outcomes, Radiological and Retinal Effects of Aspirin in Sleep Apnoea- rationale and methodology of the SNORE-ASA study

PURPOSE

Sleep disordered breathing (SDB) is highly prevalent in older adults. Increasing evidence links SDB to the risk of dementia, mediated via a number of pathways, some of which may be attenuated by low-dose aspirin. This study will evaluate, in a healthy older cohort, the prospective relationship between SDB and cognitive function, changes in retinal and cerebral microvasculature, and determine whether low-dose aspirin ameliorates the effects of SDB on these outcomes over 3years.

DESIGN

SNORE-ASA is a sub-study of the ASPirin in Reducing Events in the Elderly (ASPREE) randomised, multi-centre, placebo-controlled trial evaluating the effect of daily 100mg aspirin on disability-free and dementia-free survival in the healthy older adult aged 70 and over. At baseline, 1400 ASPREE participants successfully underwent a home sleep study with a home sleep study screening device for SDB; and 296 underwent both 1.5 Tesla brain magnetic resonance imaging (MRI) and retinal vascular imaging (RVI). Cognitive testing, brain MRI and RVI is being repeated after 3years.

PRIMARY OUTCOME MEASURES

Change in the modified mini-mental state examination score. Secondary outcome measures are changes in other cognitive tests, and changes in abnormal parameters on RVI and volume of white matter hyper-intensities on brain MRI.

CONCLUSION

Identifying preventive therapies for delaying the onset of dementia is of paramount importance. The results of this study will help clarify the impact of the SDB on risk of cognitive decline and cerebral small vessel disease, and whether low-dose aspirin can ameliorate cognitive decline in the setting of SDB.

SNORE-ASA TRIAL REGISTRATION

ACTRN12612000891820: The Principal ASPREE study is registered with the International Standardized Randomized Controlled Trials Register, ASPirin in Reducing Events in the Elderly, Number: ISRCTN83772183 and clinicaltrials.gov Number NCT01038583.