Subclinical carotid artery atherosclerosis and cognitive function in older adults

The molecular mechanisms of steroid hormone effects on cognitive function

OBJECTIVE

There is a lack of information on the molecular mechanisms by which steroid hormones (testosterone, estrogen, and progesterone) regulate cognitive impairment. Thus, we aimed to identify the protective effects of steroid hormones on cognitive function.

METHODS

We analyzed the literature on the molecular mechanisms, biological activities, physicochemical properties, and pharmacokinetics of steroid hormones.

RESULTS

Steroid hormones can protect against cognitive impairment by regulating key genes (INS, TNF, STAT3, ESR1). Specific microRNAs, namely hsa-miR-335-5p, hsa-miR-16-5p, and hsa-miR-26b-5p, along with transcription factors NFKB1, PPARG, NR3C1, GATA2, EGR1, ATF3, and CEBPA, play a significant role in this protective mechanism. The involvement in cognitive processes, regulation of phosphorylation, neuronal apoptosis, and signaling pathways related to Alzheimer's disease significantly influence the protein-protein interaction network underlying these effects. Additionally, steroid hormones exhibit anti-hypercholesterolemic properties, anti-inflammatory activity, antitoxic properties, and function as inhibitors of acetylcholine neuromuscular transmission. They also hold promise as therapeutic agents for the treatment of dementia. Promising therapeutic interventions for cognitive impairment include the use of miRNA sponges targeting hsa-miR-16-5p, along with the administration of capsaicin, minocycline, dopamine, sertraline, and minaprine. The gut microbiota species Lactobacillus amylovorus, Paraprevotella clara, Libanicoccus massiliensis, Prevotella oris, Turicibacter sanguinis, and Dubosiella newyorkensis were identified as significant contributors to cognitive impairment and altered levels of steroid hormones.

CONCLUSION

Steroid hormones are promising compounds for improving cognitive function. Further research is needed to validate these findings through focused investigations into apoptosis, regulation of neuronal cell death, miRNA sponges, interactions with gut microbiota, and the potential efficacy of pharmaceutical agents.

The Effect of Zeolite Zinc on Memory Performance and Hippocampal Cell Death in a Rat Model of Alzheimer's-like Disease Induced by Aβ1-42

Alzheimer's disease (AD) is one of the most common neurodegenerative disorders, characterized by the slow and progressive loss of brain structure and function, primarily affecting older individuals. Evidence has shown that disruption of zinc homeostasis in the brain contributes to synaptic dysfunction, as well as impairments in learning and memory. In this study, we evaluated the effect of zeolite zinc on memory performance and hippocampal cell death in a rat model of Alzheimer's disease (AD) induced by intracerebroventricular administration of Aβ1-42. We employed the Morris water maze, shuttle box, and open field tests to assess spatial memory, passive avoidance memory, and anxiety-like behavior, respectively. P-Tau and the amyloid precursor protein (APP) expression, along with hippocampal cell death, were also evaluated. Both Aβ1-42 and zeolite zinc were injected intracerebroventricularly. The results showed that zeolite zinc partially reversed Aβ1-42-induced impairments in memory performance and mitigated the effects of Aβ1-42 on locomotor activity, although it did not fully restore baseline levels. In addition, Aβ1-42 increased the expression of APP and P-Tau, as well as the number of dead cells, whereas zeolite zinc reduced these effects. In conclusion, our findings suggest that while zeolite zinc plays a role in modulating the pathophysiology of AD, its therapeutic effects only partially reverse the progression or symptoms of AD, indicating the need for further investigation into optimal dosing or combination therapies.

Associations Between Atherosclerosis and Subsequent Cognitive Decline: A Prospective Cohort Study

BACKGROUND

This study aimed to examine whether baseline atherosclerosis was associated with subsequent short-term domain-specific cognitive decline.

METHODS AND RESULTS

This research was based on the BRAVE (Beijing Research on Aging and Vessel) study, a population-based prospective cohort study of adults aged 40 to 80 years, free of dementia. At baseline (wave 1, 2019), cognitive assessments and atherosclerosis measures, including carotid intima-media thickness, carotid plaques, coronary artery calcification, and brachial-ankle pulse wave velocity were conducted. Cognitive function was reassessed in wave 2 (2022-2023) using linear mixed models for analysis. A total of 932 participants (63.7% women; mean age, 60.0±6.9 years) were included. Compared with the lowest tertile of carotid intima-media thickness, carotid plaques, and brachial-ankle pulse wave velocity, or a coronary artery calcification score=0, the highest tertile of carotid intima-media thickness (β=-0.065 SD/y [95% CI, -0.112 to -0.017]; P=0.008), carotid plaques (β=-0.070 SD/y [95% CI, -0.130 to -0.011]; P=0.021), and brachial-ankle pulse wave velocity (β=-0.057 SD/y [95% CI, -0.105 to -0.010]; P=0.018), and a coronary artery calcification score≥400 (β=-0.081 SD/y [95% CI, -0.153 to -0.008]; P=0.029) were significantly associated with a faster decline in semantic fluency after multivariable adjustment. Moreover, greater carotid intima-media thickness, coronary artery calcification, and brachial-ankle pulse wave velocity were significantly associated with a faster decline in global cognition.

CONCLUSIONS

More significant atherosclerosis was associated with faster semantic fluency and global cognition declines.

The relationship between atherosclerosis and dementia

OBJECTIVE

The main objective is to confirm a hypothesis that atherosclerosis, through various mechanisms, considerably influences cognitive impairment and significantly increases the risk for developing dementia. Complete sample should be 920 individuals. The present study aimed to analyse epidemiological data from a questionnaire survey.

METHODS

The work was carried out in the form of an epidemiological case control study. Subjects are enrolled in the study based on results of the following examinations carried out in neurology departments and outpatient centres during the project NU20-09-00119 from 2020 to 2023. Respondents were divided into four research groups according to the results of clinical examination for the presence of atherosclerosis and dementia. The survey was mainly concerned with risk factors for both atherosclerosis and dementia. It contained questions on lifestyle factors, cardiovascular risk factors, leisure activities, and hobbies.

RESULTS

Analysis of the as yet incomplete sample of 877 subjects has yielded the following selected results: on average, 16% of subjects without dementia had primary education while the proportion was 45.2% in the group with both dementia and atherosclerosis. Subjects with dementia did mainly physical work. Low physical activity was more frequently noted in dementia groups (Group 2 - 54.4% and Group 3 - 47.2%) than in subjects without dementia (Group 1 - 19.6% and Group 4 - 25.8%). Coronary heart disease was more frequently reported by dementia patients (33.95%) than those without dementia (16.05%).

CONCLUSION

Cognitively impaired individuals, in particular those with vascular cognitive impairment, have poorer quality of life and shorter survival. Risk factors contributing to such impairment are similar to those for ischaemic or haemorrhagic stroke. It may be concluded that most of the analysed risk factors play a role in the development of both atherosclerosis and dementia.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

The Protective Effects of Zeaxanthin on Amyloid-β Peptide 1–42-Induced Impairment of Learning and Memory Ability in Rats

Background and Objectives

Zeaxanthin (ZEA) as one of the biologically active phytochemicals presents a neuroprotective effect. Since ZEA may play its anti-oxidative role in neurodegenerative diseases including Alzheimer’s disease (AD), we hypothesized cognitive defects could be prevented or deferred by ZEA pre-treatment.

Methods and Study Design

All the rats were randomly divided into four groups (control, Aβ1–42, ZEA, and ZEA + Aβ groups). Learning and memory ability of rats, cerebrovascular ultrastructure changes, the redox state, endothelin-1 (ET-1) level, and amyloid-β peptide (Aβ) level in plasma and the Aβ transport receptors which are advanced glycation end products (RAGEs) and LDL receptor-related protein-1 (LRP-1) and interleukin-1β (IL-1β) expressions in the cerebrovascular tissue were measured in the present study.

Results

The escape latency and frequency of spanning the position of platform showed significant differences between the Aβ group and ZEA treatment groups. ZEA could prevent the ultrastructure changes of cerebrovascular tissue. In addition, ZEA also showed the protective effects on regulating redox state, restraining ET-1 levels, and maintaining Aβ homeostasis in plasma and cerebrovascular. Moreover, the disordered expressions of RAGE and LRP-1 and IL-1β induced by Aβ1–42 could be prevented by the pre-treatment of ZEA.

Conclusion

ZEA pre-treatment could prevent learning and memory impairment of rats induced by Aβ1–42. This neuroprotective effect might be attributable to the anti-oxidative and anti-inflammatory effects of ZEA on maintaining the redox state and reducing the Aβ level through regulating the Aβ transport receptors and inflammatory cytokine of the cerebrovascular tissue.