Normal Aging Process Research Articles

Can the balance evaluation systems test be used to identify system-specific postural control impairments in older adults with chronic neck pain?

Older adults with chronic neck pain (CNP) demonstrate impaired postural control. The Balance Evaluation Systems Test (BESTest) is used to assess systems underlying postural control impairments, but its use in CNP has not been reported. This study assessed whether the BESTest can identify postural control impairments in CNP as well as the level of BESTest item difficulty by Rasch analysis. This cross-sectional study recruited thirty young adults (YOUNG) aged 20-40 years and eighty older adults aged 60 years or older [without neck pain (OLD) = 60, with chronic neck pain (CNP) = 20]. Questionnaires were administered to collect demographic data, intensity of neck pain (VAS), patient's self-rated neck pain and disability (NDI), and balance confidence in daily activities (ABC). The BESTest was used to assess postural control. The CNP group showed the lowest ABC scores. Compared to the YOUNG group, the BESTest score was significantly lower in the OLD group, while the CNP group showed the lowest score, suggesting that balance control deteriorated from the normal aging process and further declined in the CNP group, especially in biomechanical constraints, transitions-anticipatory postural adjustment, and reactive postural response (p < 0.05). Using scores from these three sections, the BESTest was accurate at the cutoff score of 48.5 out of 51 for differentiating the older adults whose daily life are affected by neck problems (using the NDI as a reference) with a high AUC (0.79), sensitivity (72%), and specificity (69%). The Rasch analysis revealed that the Timed Up and Go with dual task test was the most difficult BESTest item for all groups, whereas 14 items showed more difficulty for the CNP group. The BESTest can be used to identify postural control impairments in CNP patients, even those with moderate pain and mild disability with a high level of physical functioning. The combined score of biomechanical constraints, transitions-anticipatory postural adjustment, and reactive postural response domains was suggested for the detection of older adults whose daily lives are affected by neck problems. This will also help clinicians consider the management of neck pain to prevent falls in CNP.

Structural basis for the interaction between unfarnesylated progerin and the Ig-like domain of lamin A/C in premature aging disorders

Hutchinson–Gilford progeria syndrome (HGPS) is a premature aging disorder caused by C-terminally truncated lamin A, termed as the pre-progerin product. Progerin is a C-terminally farnesylated protein derived from pre-progerin, which causes nuclear deformation at the inner-nuclear membrane. As an alternative or additional mechanism, a farnesylation-independent abnormal interaction between the C-terminus of progerin and Ig-like domain has been proposed. However, the molecular mechanism underlying the role of unfarnesylated C-terminus of pre-progerin in HGPS remains largely unknown. In this study, we determined the crystal structures of C-terminal peptide of progerin and Ig-like domain of lamin A/C. Results showed that the C-terminal cysteine residue of progerin forms a disulfide bond with the only cysteine residue of the Ig-like domain. This finding suggested that unfarnesylated progerin can form a disulfide bond with the Ig-like domain in the lamin meshwork. The Alphafold2-assisted docking structure showed that disulfide bond formation was promoted by a weak interaction between the groove of Ig-like domain and the unfarnesylated C-terminal tail region of progerin. Our results provide molecular insights into the normal aging process as well as premature aging of humans.

Relationships between Inflammation and Age-Related Neurocognitive Changes.

The relationship between inflammation and age-related neurocognitive changes is significant, which may relate to the age-related immune dysfunctions characterized by the senescence of immune cells and elevated inflammatory markers in the peripheral circulation and the central nervous system. In this review, we discuss the potential mechanisms, including the development of vascular inflammation, neuroinflammation, organelle dysfunctions, abnormal cholesterol metabolism, and glymphatic dysfunctions as well as the role that the key molecules play in the immune-cognition interplay. We propose potential therapeutic pharmacological and behavioral strategies for ameliorating age-related neurocognitive changes associated with inflammation. Further research to decipher the multidimensional roles of chronic inflammation in normal and pathological aging processes will help unfold the pathophysiological mechanisms underpinning neurocognitive disorders. The insight gained will lay the path for developing cost-effective preventative measures and the buffering or delaying of age-related neurocognitive decline.

Age-Related Learning and Working Memory Impairment in the Common Marmoset.

Aging is the greatest risk factor for the development of neurodegenerative diseases, yet we still do not understand how the aging process leads to pathologic vulnerability. The research community has relied heavily on mouse models, but the considerable anatomic, physiological, and cognitive differences between mice and humans limit their translational relevance. Ultimately, these barriers necessitate the development of novel aging models. As a nonhuman primate (NHP), the common marmoset (Callithrix jacchus) shares many features in common with humans and yet has a significantly shorter lifespan (10 years) than other primates, making it ideally suited to longitudinal studies of aging. Our objective was to evaluate the marmoset as a model of age-related cognitive impairment. To do this, we used the Delayed Recognition Span Task (DRST) to characterize age-related changes in working memory capacity in a cohort of sixteen marmosets, of both sexes, varying in age from young adult to geriatric. These monkeys performed thousands of trials over periods of time ranging up to 50% of their adult lifespan. To our knowledge, this represents the most thorough cognitive profiling of any marmoset aging study conducted to date. By analyzing individual learning curves, we found that aged animals exhibited delayed onset of learning, slowed learning rate after onset, and decreased asymptotic working memory performance. These findings are not accounted for by age-related impairments in motor speed and motivation. This work firmly establishes the marmoset as a model of age-related cognitive impairment.SIGNIFICANCE STATEMENT Understanding the normal aging process is fundamental to identifying therapeutics for neurodegenerative diseases for which aging is the biggest risk factor. Historically, the aging field has relied on animal models that differ markedly from humans, constraining translatability. Here, we firmly establish a short-lived nonhuman primate (NHP), the common marmoset, as a key model of age-related cognitive impairment. We demonstrate, through continuous testing over a substantial portion of the adult marmoset lifespan, that aging is associated with both impaired learning and working memory capacity, unaccounted for by age-related changes in motor speed and motivation. Characterizing individual cognitive aging trajectories reveals inherent heterogeneity, which could lead to earlier identification of the onset of impairment, and extended timelines during which therapeutics are effective.

Verbal intelligence and leisure activities are associated with cognitive performance and resting-state electroencephalogram.

Cognitive reserve (CR) is the adaptability of cognitive processes that helps to explain differences in the susceptibility of cognitive or daily functions to resist the onslaught of brain-related injury or the normal aging process. The underlying brain mechanisms of CR studied through electroencephalogram (EEG) are scarcely reported. To our knowledge, few studies have considered a combination of exclusively dynamic proxy measures of CR. We evaluated the association of CR with cognition and resting-state EEG in older adults using three of the most frequently used dynamic proxy measures of CR: verbal intelligence, leisure activities, and physical activities. Multiple linear regression analyses with the CR proxies as independent variables and cognitive performance and the absolute power (AP) on six resting-state EEG components (beta, alpha1, alpha2, gamma, theta, and delta) as outcomes were performed. Eighty-eight healthy older adults aged 60–77 (58 female) were selected from previous study data. Verbal intelligence was a significant positive predictor of perceptual organization, working memory, processing speed, executive functions, and central delta power. Leisure activities were a significant positive predictor of posterior alpha2 power. The dynamic proxy variables of CR are differently associated with cognitive performance and resting-state EEG. Implementing leisure activities and tasks to increase vocabulary may promote better cognitive performance through compensation or neural efficiency mechanisms.

Dynamic features of human mitochondrial DNA maintenance and transcription.

Mitochondria are the primary sites for cellular energy production and are required for many essential cellular processes. Mitochondrial DNA (mtDNA) is a 16.6 kb circular DNA molecule that encodes only 13 gene products of the approximately 90 different proteins of the respiratory chain complexes and an estimated 1,200 mitochondrial proteins. MtDNA is, however, crucial for organismal development, normal function, and survival. MtDNA maintenance requires mitochondrially targeted nuclear DNA repair enzymes, a mtDNA replisome that is unique to mitochondria, and systems that control mitochondrial morphology and quality control. Here, we provide an overview of the current literature on mtDNA repair and transcription machineries and discuss how dynamic functional interactions between the components of these systems regulate mtDNA maintenance and transcription. A profound understanding of the molecular mechanisms that control mtDNA maintenance and transcription is important as loss of mtDNA integrity is implicated in normal process of aging, inflammation, and the etiology and pathogenesis of a number of diseases.

A Review Article: Fall Incidents and Interior Architecture— Influence of Executive Function in Normal Ageing

Many ageing people are staying at home, whether they are self-isolating or social distancing, because of the current Covid-19 situation. Fall incidents at home among the ageing are significantly associated with a high level of mortality. Bathrooms are frequently reported as a major environmental hazard in connection with falls. This serious health risk raises the matter of interior architecture. In terms of preventing falls, more architectural research focuses on interior elements e.g., handrail design, and non-slip mat, whilst less attention is paid to the issue of how ageing causes falls. Therefore, this article sheds light on the normal ageing process through an executive function that helps in the fall prevention of ageing people via decision-making and problem-solving. Normal ageing gradually results in declining executive function, including cognitive and motor functions, which limits and reduces day to day activities. The cognitive function (as a system) involves processing speed, accuracy in response, and error response whereas the motor function (as a mechanism) defines both gross and fine motor functions. A combination of cognitive and motor functions reflects conditions that may lead to a fall. Regarding the executive function, interior architecture for preventing falls in normal ageing people is strongly encouraged e.g., clear layout, timesaving activity, simplicity of design, lighting uniformity, short walking distance, cased opening, lightweight fixtures, and fine texture flooring. This article reviews the literature to address the knowledge gaps between interior architecture and human-centred design through ageing ergonomics, and employs a behaviour-focused aspect to interpret results for interior architects. Electronic databases, including Scopus, PubMed, and Google Scholar, were searched to specify appropriate papers, which were restricted to those in the English language. To improve the quality of the elderly’s life, this article provides recommendations that could assist interior architects in this challenge.

Automatic Diagnosis of Mild Cognitive Impairment Based on Spectral, Functional Connectivity, and Nonlinear EEG-Based Features.

Accurate and early diagnosis of mild cognitive impairment (MCI) is necessary to prevent the progress of Alzheimer's and other kinds of dementia. Unfortunately, the symptoms of MCI are complicated and may often be misinterpreted as those associated with the normal ageing process. To address this issue, many studies have proposed application of machine learning techniques for early MCI diagnosis based on electroencephalography (EEG). In this study, a machine learning framework for MCI diagnosis is proposed in this study, which extracts spectral, functional connectivity, and nonlinear features from EEG signals. The sequential backward feature selection (SBFS) algorithm is used to select the best subset of features. Several classification models and different combinations of feature sets are measured to identify the best ones for the proposed framework. A dataset of 16 and 18 EEG data of normal and MCI subjects is used to validate the proposed system. Metrics including accuracy (AC), sensitivity (SE), specificity (SP), F1-score (F1), and false discovery rate (FDR) are evaluated using 10-fold crossvalidation. An average AC of 99.4%, SE of 98.8%, SP of 100%, F1 of 99.4%, and FDR of 0% have been provided by the best performance of the proposed framework using the linear support vector machine (LSVM) classifier and the combination of all feature sets. The acquired results confirm that the proposed framework provides an accurate and robust performance for recognizing MCI cases and outperforms previous approaches. Based on the obtained results, it is possible to be developed in order to use as a computer-aided diagnosis (CAD) tool for clinical purposes.

Interrelating differences in structural and functional connectivity in the older adult's brain.

In the normal aging process, the functional connectome restructures and shows a shift from more segregated to more integrated brain networks, which manifests itself in highly different cognitive performances in older adults. Underpinnings of this reorganization are not fully understood, but may be related to age-related differences in structural connectivity, the underlying scaffold for information exchange between regions. The structure-function relationship might be a promising factor to understand the neurobiological sources of interindividual cognitive variability, but remain unclear in older adults. Here, we used diffusion weighted and resting-state functional magnetic resonance imaging as well as cognitive performance data of 573 older subjects from the 1000BRAINS cohort (55-85 years, 287 males) and performed a partial least square regression on 400 regional functional and structural connectivity (FC and SC, respectively) estimates comprising seven resting-state networks. Our aim was to identify FC and SC patterns that are, together with cognitive performance, characteristic of the older adults aging process. Results revealed three different aging profiles prevalent in older adults. FC was found to behave differently depending on the severity of age-related SC deteriorations. A functionally highly interconnected system is associated with a structural connectome that shows only minor age-related decreases. Because this connectivity profile was associated with the most severe age-related cognitive decline, a more interconnected FC system in older adults points to a process of dedifferentiation. Thus, functional network integration appears to increase primarily when SC begins to decline, but this does not appear to mitigate the decline in cognitive performance.

Stenotic aortic valves have high metal and lack selenium: A new toxic inflammation hypothesis?

Background and Aims : Aortic valve stenosis is the most common valvular problem and is generally assumed to be a normal aging process. Trace element alterations and chronic heavy metal exposure are related with inflammation and different atherosclerotic events. We evaluated and compared elemental composition calcific aortic valves and normal valves from autopsies

The age differences and effect of mild cognitive impairment on perceptual-motor and executive functions.

It is unclear whether the decline in executive function (EF) and perceptual-motor function (PMF) found in older adults with mild cognitive impairment (MCI) is the result of a normal aging process or due to MCI. This study aimed to determine age-related and MCI-related cognitive impairments of the EF and PMF. The EF and PMF were investigated across four groups of 240 participants, 60 in each group, including early adult, middle adult, older adult, and older adult with probable MCI. The EF, working memory, inhibition, and cognitive flexibility were evaluated using digit span backward tasks, the Stroop color-word test, and the modified switching verbal fluency test, respectively. The PMF, visual perception, visuoconstructional reasoning, and perceptual-motor coordination were evaluated using the clock reading test, stick design test, and stick catching test, respectively. Group differences were found for all subdomains of EF and PMF (p < 0.05), except for perceptual-motor coordination, indicating that this subdomain could be maintained in older adults and was not affected by MCI. For the age difference, working memory, cognitive flexibility, visual perception, and visuoconstructional reasoning remained stable across middle adults and started to decline in older adults, while cognitive inhibition began to decrease in middle adults and it further declined in older adults. To control the confounding effect of education level, the results showed that only cognitive flexibility was further decreased in older adults with probable MCI compared to those without MCI (p < 0.05). In conclusion, cognitive inhibition decreased earlier in middle adults, whereas EF and PMF started to decline in older adults. Cognitive flexibility was the only MCI-sensitive cognitive function.

Changes in the Relative Displacement between the Supra-Aortic Branches with Age

This study aimed to determine the normal ranges for the height and deflection angle of the aortic arch and the displacement distances between the supra-aortic branches in relation to age, sex, body mass index (BMI), and body surface area (BSA) in adults without aortic disease using non-contrast chest computed tomography (CT). The CT scans of 700 patients were analyzed. We measured the height and deflection angle of the aortic arch based on the lower level of the pulmonary artery bifurcation. The displacement distances between the supra-aortic branches in the coronal and sagittal planes were measured, and the deflection angles between these branches were calculated. Multiple linear regression analysis was used to investigate the associations of age, sex, BMI, and BSA with these aortic arch parameters. The height of the aortic arch was significantly higher (74±15mm vs. 65±12mm, P<0.001) and the left-posterior displacement distance of the left subclavian artery (LSA) to the innominate artery (IA) was greater in men than that in women. The height and deflection angle of the aortic arch increased with age. The distance by which the LSA was shifted to the left posterior of the left common carotid artery and to the left of the IA increased with age. The normal aging process is accompanied by morphological changes in the aortic arch and relative displacement between the supra-aortic branches. Identifying these parameters could lead to a comprehensive understanding of the anatomy and morphology of the aortic arch.

Polygenic score for Alzheimer's disease identifies differential atrophy in hippocampal subfield volumes.

Hippocampal subfield atrophy is a prime structural change in the brain, associated with cognitive aging and neurodegenerative diseases such as Alzheimer’s disease. Recent developments in genome-wide association studies (GWAS) have identified genetic loci that characterize the risk of hippocampal volume loss based on the processes of normal and abnormal aging. Polygenic risk scores are the genetic proxies mimicking the genetic role of the pre-existing vulnerabilities of the underlying mechanisms influencing these changes. Discriminating the genetic predispositions of hippocampal subfield atrophy between cognitive aging and neurodegenerative diseases will be helpful in understanding the disease etiology. In this study, we evaluated the polygenic risk of Alzheimer’s disease (AD PGRS) for hippocampal subfield atrophy in 1,086 individuals (319 cognitively normal (CN), 591 mild cognitively impaired (MCI), and 176 Alzheimer’s disease dementia (ADD)). Our results showed a stronger association of AD PGRS effect on the left hemisphere than on the right hemisphere for all the hippocampal subfield volumes in a mixed clinical population (CN+MCI+ADD). The subfields CA1, CA4, hippocampal tail, subiculum, presubiculum, molecular layer, GC-ML-DG, and HATA showed stronger AD PGRS associations with the MCI+ADD group than with the CN group. The subfields CA3, parasubiculum, and fimbria showed moderately higher AD PGRS associations with the MCI+ADD group than with the CN group. Our findings suggest that the eight subfield regions, which were strongly associated with AD PGRS are likely involved in the early stage ADD and a specific focus on the left hemisphere could enhance the early prediction of ADD.

Facial skin ageing: Key concepts and overview of processes.

IntroductionThe face is a cosmetically sensitive region where the process of ageing is most clearly manifested. With increased focus on anti‐ageing and longevity, more anti‐senescent treatments are being proposed despite limited evidence. This study outlines the pathways and mechanisms underpinning the biological process of ageing in the face.MethodsComprehensive searches of MEDLINE, EMBASE, Cochrane Library and CINAHL from inception to 2020. Inclusion criteria included all empirical human research studies specific to facial ageing features, written in the English language.ResultsA total of 65 papers met inclusion criteria for analysis. Pathways were subdivided into intrinsic and extrinsic senescence mechanisms. Intrinsic pathways included genetics, generation of reactive oxygen species and hormonal changes. Extrinsic pathways included photoageing and damage to skin layers. The combined intrinsic and extrinsic pathway alterations result in wrinkles, higher laxity, slackness and thinning of the skin. Skin functions such as barrier immune function, wound healing, thermoregulation and sensory function are also impaired.ConclusionThe ageing process is unique to the individual and depends on the interplay between an individual's genetics and external environmental factors. Through understanding the molecular and cellular mechanisms, an appreciation of the consequent structural and functional changes can be achieved. Based on this knowledge, further research can focus on how to slow or impede the ageing process and identify specific targets to develop and evolve new treatment strategies.

Galectin-3 Involvement in Cognitive Processes for New Therapeutic Considerations.

Cognitive impairment may be a consequence of the normal aging process, but it may also be the hallmark of various neurodegenerative and psychiatric diseases. Early identification of individuals at particular risk for cognitive decline is critical, as it is imperative to maintain a cognitive reserve in these neuropsychiatric entities. In recent years, galectin-3 (Gal-3), a member of the galectin family, has received considerable attention with respect to aspects of neuroinflammation and neurodegeneration. The mechanisms behind the putative relationship between Gal-3 and cognitive impairment are not yet clear. Intrigued by this versatile molecule and its unique modular architecture, the latest data on this relationship are presented here. This mini-review summarizes recent findings on the mechanisms by which Gal-3 affects cognitive functioning in both animal and human models. Particular emphasis is placed on the role of Gal-3 in modulating the inflammatory response as a fine-tuner of microglia morphology and phenotype. A review of recent literature on the utility of Gal-3 as a biomarker is provided, and approaches to strategically exploit Gal-3 activities with therapeutic intentions in neuropsychiatric diseases are outlined.

Role of Chaperone-Mediated Autophagy in Ageing Biology and Rejuvenation of Stem Cells.

What lies at the basis of the mechanisms that regulate the maintenance and self-renewal of pluripotent stem cells is still an open question. The control of stemness derives from a fine regulation between transcriptional and metabolic factors. In the last years, an emerging topic has concerned the involvement of Chaperone-Mediated Autophagy (CMA) as a key mechanism in stem cell pluripotency control acting as a bridge between epigenetic, transcriptional and differentiation regulation. This review aims to clarify this new and not yet well-explored horizon discussing the recent studies regarding the CMA impact on embryonic, mesenchymal, and haematopoietic stem cells. The review will discuss how CMA influences embryonic stem cell activity promoting self-renewal or differentiation, its involvement in maintaining haematopoietic stem cell function by increasing their functionality during the normal ageing process and its effects on mesenchymal stem cells, in which modulation of CMA regulates immunosuppressive and differentiation properties. Finally, the importance of these new discoveries and their relevance for regenerative medicine applications, from transplantation to cell rejuvenation, will be addressed.

Are Brain and Cognitive Reserve Shaped by Early Life Circumstances?

When growing older, many people are faced with cognitive deterioration, which may even amount to a form of dementia at some point in time. Although neuropathological signs of dementia disorders can often be demonstrated in brains of patients, the degree to which clinical symptoms are present does mostly not accurately reflect the amount of neuropathology that is present. Sometimes existent pathology even goes without any obvious clinical presentation. An explanation for this phenomenon may be found in the concept of reserve capacity. Reserve capacity refers to the ability of the brain to effectively buffer changes that are associated with normal aging processes and to cope with pathological damage. A larger reserve capacity has been suggested to increase resilience against age-associated cognitive deterioration and dementia disorders. Traditionally, a division has been made between brain reserve, which is based on morphological characteristics of the brain, and cognitive reserve, which is based on functional characteristics of the brain. The present review discusses the premises that brain and cognitive reserve capacity are shaped by prenatal and early postnatal factors. Evidence is accumulating that circumstances during the first 1,000 days of life are of the utmost importance for the lifelong health of an individual. Cognitive deterioration and dementia disorders may also have their origin in early life and a potentially important pathway by which the early environment affects the risk for neurodegenerative diseases is by developmental programming of the reserve capacity of the brain. The basic idea behind developmental programming of brain and cognitive reserve is explained and an overview of studies that support this idea is presented. The review is concluded by a discussion of potential mechanisms, synthesis of the evidence and relevance and future directions in the field of developmental origins of reserve capacity.

Abstract SY24-01: Changes in adaptive landscapes and somatic evolution as we age

Abstract Why do we get cancer? Why is cancer highly associated with old age, and why are insults like smoking, obesity, and sunlight associated with increased risk of cancers? Of course, these contexts all cause mutations, and some of these mutations can contribute to malignant phenotypes. But we now understand that carcinogenesis is much more complex than originally appreciated. In particular, there are microenvironmental forces that both impede and promote cancer evolution. Just as organismal evolution is known to be driven by environmental changes, somatic evolution in our bodies is similarly driven by changes in tissue environments, whether caused by the normal process of aging, by lifestyle choices or by extrinsic exposures. Environmental change promotes selection for new phenotypes that are adaptive to the new context. In our tissues, aging or insult-driven alterations in tissues drives selection for adaptive mutations, and some of these mutations can confer malignant phenotypes. We will discuss the evidence from many labs for microenvironmental change driven selection in the evolution of cancer, additional support from epidemiological and clinical studies, as well as the limitations, inconsistencies and unknowns that require the attention of cancer researchers. My own lab has been using mouse models of cancer initiation, mathematical models of clonal evolution, and analyses of human tissue samples to better understand the evolutionary forces that control somatic cell evolution and thus cancer risk. Using Monte Carlo modeling, we have explored the impact of key somatic evolutionary parameters on multi-stage carcinogenesis, revealing that two additional major mechanisms, aging-dependent somatic selection and life history-dependent evolution of species-specific tumor suppressor mechanisms, need to be incorporated into the multi-stage model of carcinogenesis to make it capable of generalizing cancer incidence across tissues and species. Using mouse models, we have shown that aging and inflammation dependent changes in tissue microenvironments dramatically impact the fitness impact of oncogenic mutations, leading to aging and inflammation driven clonal expansions in the hematopoietic compartment. These studies have also uncovered molecular mechanisms underlying oncogene-driven adaptation to aged and inflammatory tissue environments. In all, these studies indicate that strategies to prevent or treat cancers will need to incorporate interventions that alter tissue microenvironments. While we largely cannot prevent mutation accumulation through our lives, we do have the ability to manipulate tissue microenvironments so as to change the evolutionary trajectories of oncogenically-mutated cells. Citation Format: James V. DeGregori. Changes in adaptive landscapes and somatic evolution as we age [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr SY24-01.

Diadochokinetic rates in healthy young and elderly Greek-speaking adults: The effect of types of stimuli.

Diadochokinetic rates tasks are frequently used for the assessment of diadochokinesia (DKK) in young and elderly adults. However, there is scarce research on healthy elderly adults over 65 years old, and little is known about the effect of different types of stimuli (non-words/real words) in this specific population. Furthermore, the current research supports significant language variations, highlighting the need for language-specific norms. To investigate the effect of age, gender and type of stimuli (non-words versus real words) in DDK rates in healthy elderly adults of over 65 years of age, and to provide normative data for the Greek language. The participants were 791 healthy monolingual Greek-speaking adults (531 adults, aged 20-39 years; 157 participants aged 65-74 years; and 103 participants aged over 75 years). All participants were monolingual speakers of Greek and had normal hearing acuity, which allowed them to understand and follow instructions. Participants with a medical condition, which would affect DDK rates' performance, were excluded from the study. The time-by-count method was used, and all participants had to repeat as accurately and fast as possible: (1) four disyllabic non-words (/'gaba/, /'taka/, /'kata/, /'baga/); (2) four disyllabic real words (/'kapa/, /'tapa/, /ka'la/, /'paka/); and (3) two trisyllabic non-words (/'pataka/, /'badaga/). All responses were recorded and the speech samples that did not include at least 5 s of correct repetitions were excluded from the analysis. Age affected DDK rates significantly, with older adults achieving slower DDK rates for all speech stimuli (non-words/real words). Gender did not have an effect on the performance of DDK rates. The type of speech stimuli affected DDK rates significantly for all age groups. Analytically, trisyllabic non-word stimuli were articulated more slowly than disyllabic non-word stimuli, and real words were produced faster than non-words. A linear regression analysis revealed that only the repetition of non-words predicted 68.4% of the performance on the repetition of trisyllabic non-words. The above results complement prior research, which supports that real word stimuli yield faster performance than non-word stimuli. Clinicians should keep in mind that age, language and type of stimuli (non-words/real words) affect significantly the performance of DDK rates, as well as the fact that different types of stimuli tap distinct underlying levels of speech. The current research highlights the need for language-specific norms for different populations. What is already known on the subject DDK rates are significantly affected by the types of stimuli and language used. Moreover, the normal ageing process decreases performance in terms of DDK rates, but scarce evidence exists for healthy elderly adults over 65 years old. What this paper adds to existing knowledge Most studies have examined DDK rates in healthy elderly people with restricted samples and using non-word stimuli. The current study administered different types of stimuli (non-words/words) in a large sample of healthy elderly participants. This is also the first study to attempt to provide DDK normative data for this population in the Greek language. What are the potential or actual clinical implications of this work? The results of this study strongly suggest that clinicians should bear in mind the significant impact age and language have on performance in terms of DDK rates, especially when normative data are not available for a certain language or age group. Furthermore, non-word and real-word stimuli cannot be used interchangeably since they tap into distinct underlying levels of speech, thus providing clinicians with useful information about the level of breakdown and the proper treatment plan.

Impact of Hydrotherapy on Antioxidant Enzyme Activity in an Elderly Population.

Oxidative stress is defined as the imbalance between reactive species and antioxidant agents. One of the effects of oxidative stress is the normal process of cellular aging that stems from the accumulation of tissue damage. Epidemiological studies show that regular physical exercise prevents the injuries caused by aging. The objective was to evaluate whether the practice of hydrotherapy, in an elderly population, positively influenced the activity of the enzymes superoxide dismutase, glutathione peroxidase and reductase that act by reducing reactive species in the body. The study involved 37 participants aged ≥ 60 years, of both sexes, divided into experimental and control groups. The experimental group performed 15 hydrotherapy sessions. Enzyme activity was evaluated in two moments: T0-before the first session, and T1-after the last session, with blood collections conducted in both. In T1, there was a significant increase vs. T0 of glutathione peroxidase activity (57.72 ± 19.99 vs. 48.14 ± 17.22 U/g Hb) and glutathione reductase activity (100.18 ± 30.85 vs. 78.44 ± 21.26 U/L). Both sexes tended to show higher values at T1. We concluded that hydrotherapy proved to be a positive stimulus for the enzymatic antioxidant activity of the elderly, suggesting that a regular and moderate practice of physical exercise induces better and higher quality of life.