9 research outputs found

    Aging under pressure:The roles of reactive oxygen and nitrogen species (rons) production and aging skeletal muscle in endothelial function and hypertension—from biological processes to potential interventions

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    The proportion of adults living with hypertension increases significantly with advancing age. It is therefore important to consider how health and vitality can be maintained by the aging population until end of life. A primary risk factor for the progression of cardiovascular diseases (CVD) is hypertension, so exploring the factors and processes central to this burden of disease is essential for healthy aging. A loss of skeletal muscle quantity and quality is characteristic in normal aging, with a reduction of vasodilatory capacity caused by endothelial dysfunction, and subsequent increase in peripheral resistance and risk for hypertension. Reactive Oxygen and Nitrogen Species (RONS) encompass the reactive derivatives of NO and superoxide, which are continuously generated in contracting skeletal muscle and are essential mediators for cellular metabolism. They act together as intra and intercellular messengers, gene expression regulators, and induce programmed cell death. In excessive amounts RONS can inflict damage to endothelial and skeletal muscle cells, alter signaling pathways or prematurely promote stress responses and potentially speed up the aging process. The age-related increase in RONS by skeletal muscle and endothelial mitochondria leads to impaired production of NO, resulting in vascular changes and endothelial dysfunction. Changes in vascular morphology is an early occurrence in the etiology of CVDs and, while this is also a normal characteristic of aging, whether it is a cause or a consequence of aging in hypertension remains unclear. This review serves to focus on the roles and mechanisms of biological processes central to hypertension and CVD, with a specific focus on the effects of aging muscle and RONS production, as well as the influence of established and more novel interventions to mediate the increasing risk for hypertension and CVD and improve health outcomes as we age

    The Physiological Effects of Amino Acids Arginine and Citrulline: Is There a Basis for Development of a Beverage to Promote Endurance Performance? A Narrative Review of Orally Administered Supplements

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    Nutritional and ergogenic aid supplementation is prevalent within athletic or general fitness populations, and is only continuing to gain momentum. Taken in isolation or as a combination, amino acid (AA) supplementation has the potential to increase endurance performance among other benefits. L-Arginine (L-Arg) and L-Citrulline (L-Cit) are two AAs proposed to increase endothelial nitric oxide (NO) synthesis, with potential additional physiological benefits, and therefore may contribute to enhanced performance outcomes such as increased power output, or time to exhaustion. However, the appropriate dose for promoting physiological and performance benefits of these AAs, and their potential synergistic effects remains to be determined. Therefore, the aim of this review was to evaluate the varied concentrations used in the current literature, assess the effects of L-Arg and L-Cit in combination on physiological responses and endurance performance, and consider if there is a fundamental basis for providing these supplements in the form of a beverage. A total of six studies were considered eligible for the review which utilized a range of 3–8 g of the AA constituents. The findings support the notion that supplementing with a combination of L-Arg and L-Cit may increase NO production, enhance vasodilation, and therefore increase performance capacity in athletes. A beverage as a carrier for the two AAs is worth considering; however, there remains limited research assessing these outcomes across a consistent range of concentrations in order to see their full potential

    Immunomodulatory effects of fucoidan in recreationally active adult males undertaking 3-weeks of intensified training

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    The aim of the current study was to determine whether daily fucoidan supplementation ( Undaria pinnatifida extract containing &gt;85% fucoidan, 1 g/day) for three-weeks in a double blind-placebo controlled cross-over trial (ACTRN12621000872831) could modulate alterations in faecal (calprotectin, lysozyme and IgA) and salivary (lactoferrin, lysozyme and IgA) markers of mucosal immune competence typically observed in response to both acute physical activity, and a period of intensified exercise training, in healthy recreationally active men ( n  = 12). Participants responded positively to the intensified training with 16-19% improvement in mean power that was not different between supplement groups. Faecal biomarkers and concentrations of lactoferrin, lysozyme and IgA from resting saliva samples were largely stable over the supplementation period. Concentrations of salivary biomarkers varied significantly over time in response to acute exercise, however differences between supplementation groups were modest. For salivary lysozyme, there was a trend for a lower magnitude of increase post-exercise ( p  = 0.08) and limited return towards pre-exercise in response to fucoidan. For salivary IgA, a greater acute exercise response was noted for IgA in response to fucoidan (~2.7-fold higher; p  = 0.02). Different dosage and supplementation protocols and inclusion of additional immune markers should be considered in subsequent assessments of any potential benefits of fucoidan supplementation in healthy active adults. </p

    Is A ‘One-size-fits-all’ Approach Suitable For Physical Activity And Exercise Prescription In Older People?

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    Aging is a complex physiological process involving many variables that greatly influence the biological conditions in which we age. Increased lifespan and coincident increased prevalence of age-related diseases urges the need to identify and prescribe favourable lifestyle interventions that contribute to aging healthily, relative to a person’s existing health and fitness status.PURPOSE: This retrospective study determines the health and fitness status of a cohort of sedentary, older people living at home, as assessed before a physical activity intervention programme.METHODS: Data from a Comprehensive Geriatric Assessment Questionnaire conducted by a home care service agency in peri-urban Durban, KwaZulu-Natal, South Africa were analysed. The cohort consisted of older people aged 55 - 94, inclusive of 313 males (72 yrs ± 7.2) and 319 females (71 yrs ± 8.3). Fitness status was determined from cardiorespiratory (CR) fitness (6 min walk) and the Berg Balance Test. Health status was determined from body mass index, resting heart rate and blood pressure (BP), fasting glucose, haemoglobin (Hb) concentration and self-reported central nervous system, cardiorespiratory and musculoskeletal symptoms. Sex differences relating to fitness, health status and self-reported symptoms were examined using a two-sample Wilcoxon rank-sum (Mann-Whitney) test and Chi-Square tests, respectively. Fitness and health variables were examined using Spearman’s rank correlation test. All significance levels were set as α ≤ 0.05.RESULTS: Sex-specific differences were found for cardiorespiratory fitness (M; 275.13 m ± 188.9, F; 241.58 m ± 162.4, p = 0.02), diastolic BP (M; 82 mmHg ±12.4, F; 80 mmHg ±11.2, p = 0.04) and Hb concentration (M; 13.32 g/dL ± 1.7, F; 12.33 g/dL ± 1.4, p &lt; 0.0001), as well as self-reported symptoms. Significant moderate correlations were found between age and balance (r = -0.31), CR fitness and balance (r = 0.43), and CR fitness and Hb concentration (r = 0.43).CONCLUSIONS: Health and fitness status of older people is important to consider prior to implementation of an intervention programme. The results indicate sex-specific differences and functional decrements with age, which should be considered when prescribing exercise or physical activity to improve health and fitness in an aging population

    The long and the short of it: Salivary telomere length as a candidate biomarker for hypertension and age‐related changes in blood pressure

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    Abstract Hypertension becomes more prevalent with increasing age. Telomere length (TL) has been proposed as a candidate biomarker and can be accessibly extracted from saliva. However, clarity is needed to evaluate the suitability of using TL as a predictor in such instances. This study investigated salivary TL in a cohort of older adults from the 2008 Health and Retirement Study (n = 3329; F: 58%, mean age: 69.4, SD: 10.3 years) to examine any associations with blood pressure (BP). A Bayesian robust regression model was fit using weakly informative priors to predict the effects of TL with age, sex, systolic BP (SBP), diastolic BP (DBP), and treatment status. There were small effects of treatment (β: −0.07, 95% CrI [−0.33, 0.19], pd: 71.91%) and sex (β: −0.10, 95% CrI [−0.27, 0.07], pd: >86.78%). Population effects showed a reduction of 0.01 log2 units in TL with each year of advancing age (95% CrI [−0.01, −0.00]). Conditional posterior predictions suggest that females, and treated individuals, experience greater change in TL with increasing age. Bayes R2 was ~2%. TL declines with increasing age, differs between sexes, and appears to be influenced by antihypertensive drugs. Overall, all effects were weak. The data do not currently support the suitability of salivary TL as a biomarker to predict or understand any age‐related changes in BP

    Nutrition and Healthy Ageing Trajectories in Retirement Living in the Australian Capital Territory: Study Protocol

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    OBJECTIVES: There are a growing number of people aged over 55 years living in retirement communities in Australia. These communities typically consist of accommodation, services and community facilities which cater to older people and the desire to maintain independence. The Nutrition and Healthy Ageing Trajectories in Retirement Living (NutriHAT-RL) study aims to investigate the nutrition and lifestyle-based behaviours which contribute to healthy ageing and the maintenance of social and physical functioning among older people living in retirement communities. METHODS: This study will recruit a total of 2,770 people aged 55 years or over living in retirement communities in the Australian Capital Territory and southern New South Wales regions of Australia for a four-year prospective longitudinal study commencing in March 2021. A range of measures, including nutritional intake, health and lifestyle behaviours, cognitive and psychological function, and physical health, will be completed on three occasions over a total of four years. Participants will complete a face-to-face comprehensive, validated food frequency questionnaire at each time point. Risk of malnutrition and nutritional behaviour (emotional appetite and intuitive eating) will also be evaluated. Multiple mental, social, and physical health domains will be assessed at each time point. This will include cognitive and mental health (depression, anxiety, and loneliness) screening, social and occupational functioning questionnaires, self-reported and observed physical function assessments, and sleep quality. Bitter taste endophenotype, salivary C-reactive protein, telomere length, and blood biomarkers associated with healthy ageing will also be evaluated. RESULTS: Ethics approval has been obtained through the University of Canberra Human Ethics Research Committee (UCHREC-2306). To reduce risk of COVID-19 transmissions, a risk mitigation plan has been developed. CONCLUSIONS: The NutriHAT-RL study will be the first Australian longitudinal study with a focus on nutrition and healthy ageing in people living in retirement communities. Findings from this study will contribute to understanding of nutrition and healthy ageing in this growing population and will inform policy and practice related to nutrition and ageing in place. FUNDING SOURCES: N/A
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