Prevalence of cognitive impairment and associated factors in older people

BACKGROUND

Older people are the fastest-growing age group, with the highest risk of cognitive impairment. This study assessed the prevalence and associated factors with cognitive impairment in community-dwelling older people.

METHODS

Older people were interviewed and accomplished through sociodemographic and health questionnaires. The quantitative variables were described by mean and standard deviation or median and interquartile range. The significance level adopted was 5 % (p < 0.05). The association between the quantitative variables was evaluated using the Pearson or Spearman correlation coefficients.

RESULTS

The research population comprised 165 long-lived adults aged ≥80. The youngest one was 80, and the oldest one was 94 years old. The participants were 84.8 ± 3.6 years old, female (63 %) with a mean of education of 2.9 ± 1.8 years. A poor performance in the Mini-Mental State Examination (MMSE) was found in 58 (35.2 %) individuals when adjusted for educational level. After adjustment for confounding factors, body mass index (BMI) (p = 0.09), total older adults' income (up to 1 minimum wage [mw], p = 0.023; over 1 to 2 mw, p = 0.023), functional disability (Moderate dependence 75 %, p = 0.038; Moderate dependence 50 %, p = 0.081; Moderate dependence 25 %, p = 0.054), and the anxiety scale (p = 0.032), remained associated with cognitive impairment.

CONCLUSIONS

This study showed that BMI, total older adults' income, functional disability, and anxiety are related to cognitive impairment in long-lived adults. This study has some limitations, such as the fact that it is a cross-sectional study, the reduced number of individuals, and the fact that there were no comparisons among different ages and populations.

Neuroprotective effects of combined therapy with memantine, donepezil, and vitamin D in ovariectomized female mice subjected to dementia model

Women older than 60 have a higher risk of dementia, aging-related cognitive decline, and Alzheimer's Disease (AD) than the rest of the population. The main reason is hormonal senescence after menopause, a period characterized by a decline in estrogen levels. Since the effectiveness of drugs currently approved for the treatment of AD is limited, it is necessary to seek the development of new therapeutic strategies. Vitamin D deficiency is prevalent in AD patients and individuals with dementia in general. The supplementation of this vitamin in dementia patients might be an interesting approach for increasing the effectiveness of pre-existing medications for dementia treatment. Thus, the present study aims to investigate the effect of vitamin D treatment associated with memantine and donepezil in female mice submitted to ovariectomy (OVX) for five months and subjected to a dementia animal model induced by intracerebroventricular injection of aggregated amyloid βeta (Aβ_1-42). For this purpose, Balb/c mice were divided into five experimental groups, which received 17 days of combined therapy with vitamin D, donepezil, and memantine. Then, animals were subjected to behavioral tests. OVX groups exhibited reduced levels of estradiol (E2) in serum, which was not altered by the combined therapy. Higher levels of vitamin D3 were found in the OVX animals submitted to the triple-association treatment. Mice exposed to both OVX and the dementia animal model presented impairment in short and long-term spatial and habituation memories. Also, female mice exposed to Aβ and OVX exhibited a reduction in brain-derived neurotrophic factor (BDNF) and interleukin-4 (IL-4) levels, and an increase in tumor necrose factor-α (TNFα) levels in the hippocampus. Besides, increased levels of IL-1β in the hippocampus and cerebral cortex were observed, as well as a significant increase in immunoreactivity for glial fibrillary acidic protein (GFAP), an astrocytes marker, in the hippocampus. Notably, triple-association treatment reversed the effects of the exposition of mice to Aβ and OVX in the long-term spatial and habituation memories impairment, as well as reversed changes in TNFα, IL-1β, IL-4, and GFAP immunoreactivity levels in the hippocampus of treated animals. Our results indicate that the therapeutic association of vitamin D, memantine, and donepezil has beneficial effects on memory performance and attenuated the neuroinflammatory response in female mice subjected to OVX associated with a dementia animal model.

COVID-19 and brain aging: what are the implications of immunosenescence?

The human lifespan is increasing, and mankind is aging. It is estimated that, until the year 2050, this population worldwide will reach 22% of the total world population. Along with aging, the human immunologic system changes, a process called immunosenescence or even inflammaging. The aging immune system increases mortality and morbidity in the elderly mainly because it loses its capacity to react against internal and external aggressions. There is a decrease in B and T lymphocytes and CD4+ lymphocytes lose the CD28 protein expression that is needed for co-stimulation, leading to reduced response to viral infections. This could be responsible for more deleterious consequences of coronavirus disease infection in the elderly. Besides that, the human brain ages, being more susceptible to damage and viral infections, such as COVID-19 infection. There are several pathways that could explain the susceptibility to the COVID-19 infection in the elderly brain, one of them is binding to ACE 2 receptors in cerebral cells through the spike protein. It has been reported that glial cells and neurons, in addition to endothelial and arterial smooth muscle cells in the brain, express the ACE 2 receptor, which would justify the neurological symptoms and consequences of the disease. This infection can have several clinical manifestations such as hemorrhagic stroke, delirium and long-term cognitive complaints, such as brain fog, polyneuropathies, short time memory complaints and insomnia. Although none of the studies could prove that there is a long-term neuronal damage, there are clinical sequelae that should be taken into account and more studies are necessary to know the consequences of the infection in the elderly brain.