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The European Journal of Neuroscience Mar 2009The age of an experimental animal can be a critical variable, yet age matters are often overlooked within neuroscience. Many studies make use of young animals, without... (Review)
Review
The age of an experimental animal can be a critical variable, yet age matters are often overlooked within neuroscience. Many studies make use of young animals, without considering possible differences between immature and mature subjects. This is especially problematic when attempting to model traits or diseases that do not emerge until adulthood. In this commentary we discuss the reasons for this apparent bias in age of experimental animals, and illustrate the problem with a systematic review of published articles on long-term potentiation. Additionally, we review the developmental stages of a rat and discuss the difficulty of using the weight of an animal as a predictor of its age. Finally, we provide original data from our laboratory and review published data to emphasize that development is an ongoing process that does not end with puberty. Developmental changes can be quantitative in nature, involving gradual changes, rapid switches, or inverted U-shaped curves. Changes can also be qualitative. Thus, phenomena that appear to be unitary may be governed by different mechanisms at different ages. We conclude that selection of the age of the animals may be critically important in the design and interpretation of neurobiological studies.
Topics: Age Factors; Aging; Animals; Behavior; Hippocampus; Humans; Long-Term Potentiation; Neurons; Neurosciences; Research Design
PubMed: 19291226
DOI: 10.1111/j.1460-9568.2009.06648.x -
Frontiers in Endocrinology 2023Neurodegenerative diseases often cause motor and cognitive deterioration that leads to postural instability and motor impairment, while aging-associated frailty... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Neurodegenerative diseases often cause motor and cognitive deterioration that leads to postural instability and motor impairment, while aging-associated frailty frequently results in reduced muscle mass, balance, and mobility. These conditions increase the risk of falls and injuries in these populations. This study aimed to determine the effects of exercise on falls and consequent injuries among individuals with neurodegenerative diseases and frail aging people.
METHODS
Electronic database searches were conducted in PubMed, Cochrane Library, SportDiscus, and Web of Science up to 1 January 2023. Randomized controlled trials that reported the effects of exercise on falls and fall-related injuries in neurodegenerative disease and frail aging people were eligible for inclusion. The intervention effects for falls, fractures, and injuries were evaluated by calculating the rate ratio (RaR) or risk ratio (RR) with 95% confidence interval (CI).
RESULTS
Sixty-four studies with 13,241 participants met the inclusion criteria. Exercise is effective in reducing falls for frail aging people (RaR, 0.75; 95% CI, 0.68-0.82) and participants with ND (0.53, 0.43-0.65) [dementia (0.64, 0.51-0.82), Parkinson's disease (0.49, 0.39-0.69), and stroke survivors (0.40, 0.27-0.57)]. Exercise also reduced fall-related injuries in ND patients (RR, 0.66; 95% CI, 0.48-0.90) and decreased fractures (0.63, 0.41-0.95) and fall-related injuries (0.89, 0.84-0.95) among frail aging people. For fall prevention, balance and combined exercise protocols are both effective, and either short-, moderate-, or long-term intervention duration is beneficial. More importantly, exercise only induced a very low injury rate per participant year (0.007%; 95% CI, 0-0.016) and show relatively good compliance with exercise (74.8; 95% CI, 69.7%-79.9%).
DISCUSSION
Exercise is effective in reducing neurodegenerative disease- and aging-associated falls and consequent injuries, suggesting that exercise is an effective and feasible strategy for the prevention of falls.
Topics: Humans; Accidental Falls; Neurodegenerative Diseases; Exercise; Fractures, Bone; Aging
PubMed: 37534209
DOI: 10.3389/fendo.2023.1187325 -
Nutrients Jan 2022Despite the increasing life expectancy, an individual's later years tends to be accompanied by a decrease in the quality of life. Though biological changes that occur... (Review)
Review
Despite the increasing life expectancy, an individual's later years tends to be accompanied by a decrease in the quality of life. Though biological changes that occur through the natural process of aging cannot be controlled, the risk factors associated with lifestyle can. Thus, the main goal of this systematic review was to evaluate how nutrition can modulate aging. For this purpose, thirty-six studies were selected on (i) the efficiency of nutrition's effect on aging, (ii) the evaluation of biomarkers that promote healthy aging, and (iii) how to increase longevity through nutrition, and their quality was assessed. The results showed that choosing low carbohydrate diets or diets rich in vegetables, fruits, nuts, cereals, fish, and unsaturated fats, containing antioxidants, potassium, and omega-3 decreased cardiovascular diseases and obesity risk, protected the brain from aging, reduced the risk of telomere shortening, and promoted an overall healthier life. With this study, the conclusion is that since the biological processes of aging cannot be controlled, changing one's nutritional patterns is crucial to prevent the emergence and development of diseases, boost longevity, and, mostly, to enhance one's quality of life and promote healthy aging.
Topics: Aging; Animals; Biomarkers; Longevity; Nutritional Status; Quality of Life
PubMed: 35276919
DOI: 10.3390/nu14030554 -
Experimental Gerontology Jun 2023Frailty is a geriatric syndrome whose frequency is increasing in parallel with population aging and is of great interest due to its dire consequences: increased... (Meta-Analysis)
Meta-Analysis
Frailty is a geriatric syndrome whose frequency is increasing in parallel with population aging and is of great interest due to its dire consequences: increased disability, hospitalizations, falls and fractures, institutionalization, and mortality. Frailty is multifactorial but nutritional factors, which are modifiable, play a crucial role in its pathogenesis. Epidemiologic evidence supports that high-quality dietary patterns can prevent, delay or even reverse the occurrence of frailty. In order to add new knowledge bridging the gap as the main purpose of the present article we performed a comprehensive review of the rationale behind the association of MedDiet with frailty and a systematic review and meta-analysis updating the latest ones published in 2018 specifically examining the relationship of Mediterranean diet (MedDiet) and incident frailty. Adding the updated information, our results confirmed a robust association of a higher adherence to MedDiet with reduced incident frailty. Key components of the MedDiet, i.e., abundant consumption of vegetables and fruit as well as the use of olive oil as the main source of fat, all of which have been associated with a lower incidence of frailty, may help explain the observed benefit. Future well-designed and sufficiently large intervention studies are needed to confirm the encouraging findings of the current observational evidence. Meanwhile, based on the existing evidence, the promotion of MedDiet, a high-quality dietary pattern, adapted to the conditions and traditions of each region, and considering lifelong and person-tailored strategies, is an open opportunity to reduced incident frailty. This could also help counteract the worrying trend towards the spread of unhealthy eating and lifestyle models such as those of Western diets that greatly contribute to the genesis of chronic non-communicable diseases and disability.
Topics: Humans; Aged; Frailty; Diet, Mediterranean; Aging; Fruit; Vegetables; Diet
PubMed: 37087024
DOI: 10.1016/j.exger.2023.112180 -
Maturitas Dec 2023Aging is associated with a loss of skeletal muscle mass and function that negatively impacts the independence and quality of life of older individuals. Females... (Review)
Review
Aging is associated with a loss of skeletal muscle mass and function that negatively impacts the independence and quality of life of older individuals. Females demonstrate a distinct pattern of muscle aging compared to males, potentially due to menopause, when the production of endogenous sex hormones declines. This systematic review aims to investigate the current knowledge about the role of estrogen in female skeletal muscle aging. A systematic search of MEDLINE Complete, Global Health, Embase, PubMed, SPORTDiscus, and CINHAL was conducted. Studies were considered eligible if they compared a state of estrogen deficiency (e.g. postmenopausal females) or supplementation (e.g. estrogen therapy) to normal estrogen conditions (e.g. premenopausal females or no supplementation). Outcome variables of interest included measures of skeletal muscle mass, function, damage/repair, and energy metabolism. Quality assessment was completed with the relevant Johanna Briggs critical appraisal tool, and data were synthesized in a narrative manner. Thirty-two studies were included in the review. Compared to premenopausal women, postmenopausal women had reduced muscle mass and strength, but the effect of menopause on markers of muscle damage and expression of the genes involved in metabolic signaling pathways remains unclear. Some studies suggest a beneficial effect of estrogen therapy on muscle size and strength, but evidence is largely conflicting and inconclusive, potentially due to large variations in the reporting and status of exposure and outcomes. The findings from this review point toward a potential negative effect of estrogen deficiency on aging skeletal muscle, but further mechanistic evidence is needed to clarify its role.
Topics: Male; Female; Humans; Quality of Life; Estrogens; Aging; Menopause; Muscle, Skeletal
PubMed: 37716136
DOI: 10.1016/j.maturitas.2023.107844 -
Molecular Ecology Dec 2022Human-driven environmental changes are affecting wildlife across the globe. These challenges do not influence species or populations to the same extent and therefore a... (Meta-Analysis)
Meta-Analysis Review
Human-driven environmental changes are affecting wildlife across the globe. These challenges do not influence species or populations to the same extent and therefore a comprehensive evaluation of organismal health is needed to determine their ultimate impact. Evidence suggests that telomeres (the terminal chromosomal regions) are sensitive to environmental conditions and have been posited as a surrogate for animal health and fitness. Evaluation of their use in an applied ecological context is still scarce. Here, using information from molecular and occupational biomedical studies, we aim to provide ecologists and evolutionary biologists with an accessible synthesis of the links between human disturbances and telomere length. In addition, we perform a systematic review and meta-analysis on studies measuring telomere length in wild/wild-derived animals facing anthropogenic disturbances. Despite the relatively small number of studies to date, our meta-analysis revealed a significant small negative association between disturbances and telomere length (-0.092 [-0.153, -0.031]; n = 28; k = 159). Yet, our systematic review suggests that the use of telomeres as a biomarker to understand the anthropogenic impact on wildlife is limited. We propose some research avenues that will help to broadly evaluate their suitability: (i) further causal studies on the link between human disturbances and telomeres; (ii) investigating the organismal implications, in terms of fitness and performance, of a given telomere length in anthropogenically disturbed scenarios; and (iii) better understanding of the underlying mechanisms of telomere dynamics. Future studies in these facets will help to ultimately determine their role as markers of health and fitness in wildlife facing anthropogenic disturbances.
Topics: Animals; Humans; Animals, Wild; Telomere Shortening; Anthropogenic Effects; Telomere; Biological Evolution
PubMed: 35080073
DOI: 10.1111/mec.16370 -
Nutrients Mar 2022Telomere length (TL) is a robust marker of biological aging, and increased telomere attrition is noted in adults with obesity. The primary objective of this systematic... (Review)
Review
OBJECTIVE
Telomere length (TL) is a robust marker of biological aging, and increased telomere attrition is noted in adults with obesity. The primary objective of this systematic review was to summarize current knowledge on the effects of childhood obesity in TL. The secondary objective was to assess the effect of weight management interventions in TL.
METHODS
The following databases were searched: PubMed, Scopus, Web of Science and Heal-link.gr from inception to September 2021. The search was performed using the following combinations of terms: "telomer*" [All Fields] AND ("length" [All Fields] OR "lengths" [All Fields]) AND "obes*" [All Fields] AND ("child*" [All Fields] OR "adolescen*" [All Fields]).
RESULTS
A total of 16 original articles were included in this systematic review. Eleven of them were cross-sectional and five were lifestyle interventions.
CONCLUSIONS
There was a tendency towards a negative association between childhood obesity and TL. Life-style interventions in children have been associated with increased TL peripherally, indicating a possible association of the redistribution of younger cells in the periphery with the favorable effect of these interventions. Further prospective studies with larger sample sizes that employ other markers of cell aging would potentially elucidate this important mechanistic relation.
Topics: Adult; Aging; Child; Humans; Pediatric Obesity; Prospective Studies; Telomere; Telomere Homeostasis
PubMed: 35334902
DOI: 10.3390/nu14061244 -
Clinical Interventions in Aging 2018This review presents a critical examination of current knowledge of the impact of combined cognitive and physical training on cognition in healthy elderly subjects. The... (Review)
Review
This review presents a critical examination of current knowledge of the impact of combined cognitive and physical training on cognition in healthy elderly subjects. The objectives are to evaluate the contribution of cognitive and physical training to the enhancement of cognition, and to determine the interest of combining these two training types in one intervention in terms of the benefits for cognition (direct and transfer), long-term maintenance, and transfer to daily living. To do so, a systematic electronic search was conducted in PubMed and Google Scholar. Exclusion criteria were animal and pathological aging studies. We focused on the shared and different behavioral impacts of these two types of training on cognition, as well as their functional and structural impact on the brain. The review indicates that both cognitive and physical training have an impact on cognition and on the brain. However, each type of training seems to preferentially enhance different cognitive functions and specifically impact both brain structure and function. Even though some results argue in favor of a complementarity between cognitive and physical training and the superiority of combined cognitive and physical training, the current state of knowledge does not permit any definitive conclusion. Thus, the present review indicates the need for additional investigations.
Topics: Aged; Aging; Animals; Brain; Cognition; Cognition Disorders; Exercise; Humans; Learning
PubMed: 30057444
DOI: 10.2147/CIA.S165399 -
Neuroscience and Biobehavioral Reviews Mar 2017While gait variability may reflect subtle changes due to aging or cognitive impairment (CI), associated brain characteristics remain unclear. We summarize structural and... (Review)
Review
While gait variability may reflect subtle changes due to aging or cognitive impairment (CI), associated brain characteristics remain unclear. We summarize structural and functional neuroimaging findings associated with gait variability in older adults with and without CI and dementia. We identified 17 eligible studies; all were cross-sectional; few examined multiple brain areas. In older adults, temporal gait variability was associated with structural differences in medial areas important for lower limb coordination and balance. Both temporal and spatial gait variability were associated with structural and functional differences in hippocampus and primary sensorimotor cortex and structural differences in anterior cingulate cortex, basal ganglia, association tracts, and posterior thalamic radiation. In CI or dementia, some associations were found in primary motor cortex, hippocampus, prefrontal cortex and basal ganglia. In older adults, gait variability may be associated with areas important for sensorimotor integration and coordination. To comprehend the neural basis of gait variability with aging and CI, longitudinal studies of multiple brain areas are needed.
Topics: Aging; Brain; Cognitive Dysfunction; Cross-Sectional Studies; Dementia; Gait; Humans
PubMed: 28115194
DOI: 10.1016/j.neubiorev.2017.01.020 -
Current Cardiology Reviews 2017The concept of antioxidant therapies assumes high importance as oxidative stress is associated with cardiovascular aging via endothelial dysfunction. This review focuses... (Review)
Review
BACKGROUND
The concept of antioxidant therapies assumes high importance as oxidative stress is associated with cardiovascular aging via endothelial dysfunction. This review focuses on exploring the interaction between nrf-2 and ADMA in influencing the nitric oxide pathway and cardiovascular function.
OBJECTIVE
A systematic review of literature from 1990 to 2016 was conducted using Pubmed and Google Scholar. The literature suggests a strong influence of nrf-2 activation on up regulation of DDAH I which degrades ADMA, the endogenous inhibitor of nitric oxide synthase. The resulting decrease of ADMA would in turn enhance nitric oxide (NO) production. This would support endothelial function by adequate NO production and homeostasis of endothelial function.
CONCLUSION
As NO production has many positive pleiotropic effects in the cardiovascular system, such an interaction could be utilized for designing molecular therapeutics. The targets for therapy need not be limited to activation of nrf-2. Modulation of molecules downstream such as DDAH I can be used to regulate ADMA levels. Most current literature is supported by animal studies. The concept of antioxidant therapies needs to be tested in well-defined randomized control trials. The biochemical basis of nrf-2 activation needs to be substantiated in human studies.
Topics: Aging; Animals; Arginine; Cardiovascular Diseases; Endothelium, Vascular; Humans; NF-E2-Related Factor 2; Oxidative Stress; Signal Transduction
PubMed: 28215178
DOI: 10.2174/1573403X13666170216150955