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I am currently investigating skeletal muscle ageing for my PhD.

PINBOARD SUMMARY

Sarcopenia is attributed to a loss in independence, how can exercise ensure healthy ageing?

What is sarcopenia? The age-related loss of muscle mass and function has been extensively studied, but the term sarcopenia was first coined by Rosenberg in 1989 which means in literal terms loss of flesh. It is expected that by 2045 the number of adults aged 65 – 100 years with sarcopenia will rise by 72.4%..

How does sarcopenia affect my muscles? As we all age, our muscle volume, mass and the speed at which they contract declines. As there is less lean tissue we are con subsequently unable to produce as much force or power making everyday living difficult and thus reduce our quality of life. It is thought that this process affects males to a greater extent than females, at least until the menopause in women.

What about my ability to move? As a direct result of reduced force and power production, we are as a consequence less mobile. Moreover, older adults are at much greater risk of falls as a result of muscle wasting. The combination of the two leads to reduced physical activity levels thus creating a negative cycle of activity leading to further functional loss.

What can I do to prevent this from happening to me? Unfortunately like all good things in life, they must eventually come to a gradual end and this is no different for our muscles. However, engaging in regular physical activity can reduce the speed of the decline in muscle function, as found in a study comparing older males who completed lifelong football training to age-matched sedentary counterparts. Even if you have not engaged in physical activity all your life then all is not lost. Men aged 83-94 years old completing 12 weeks of resistance training 3 times a week resulted in a significant increase in muscle size and a staggering 91% increase in one-repetition max!

To ensure maintenance of muscle function with age exercise really is the best medicine.

12 ITEMS PINNED

Muscle function and postural balance in lifelong trained male footballers compared with sedentary elderly men and youngsters.

Abstract: The present study investigated whether elderly subjects exposed to lifelong football training have better rapid muscle force characteristics, body composition and postural stability in comparison with untrained elderly. Ten elderly men exposed to lifelong football training (FTE; 69.6 +/- 1.4 years) and eight age-matched untrained elderly men (UE; 70.5 +/- 1.0 years) were studied and 49 untrained young men (UY; 32.4 +/- 0.9 years) served as a reference group. FTE showed an elevated rate of force development (RFD) and impulse at 0-30, 100 and 200 ms (relative RFD at 1/6 MVC: 567 +/- 39 vs 353 +/- 42% MVC/s), higher total lean body mass (56.9 +/- 0.8 vs 52.7 +/- 2.2 kg) and better postural stability (Flamingo test: 15 +/- 1 vs 33 +/- 2 falls) compared with UE (P<0.05), with no difference between FTE and UY. The proportion of type IIA fibers was higher and the area percentage of type IIX fibers was lower in FTE than in UE (P<0.05). Rapid muscle force characteristics and postural stability were consistently higher in elderly subjects exposed to lifelong football training, providing an enhanced ability to counteract unexpected perturbations in postural balance. The superior RFD and balance in elderly footballers were of such a magnitude that no deficit could be observed when compared with young untrained individuals.

Pub.: 10 Mar '10, Pinned: 14 Apr '17

The Future Prevalence of Sarcopenia in Europe: A Claim for Public Health Action.

Abstract: Sarcopenia is a major public health issue. To convince health policy makers of the emergency to invest in the sarcopenia field, it is of critical importance to produce reliable figures of the expected burden of sarcopenia in the coming years. Age- and gender-specific population projections were retrieved until 2045 from the Eurostat online database (28 European countries). Age- and gender-specific prevalences of sarcopenia were interpolated from a study that compared prevalence estimates according to the different diagnostic cutoffs of the EWGSOP proposed definition. The reported prevalence estimates were interpolated between 65 and 100 years. Interpolated age- and gender-specific estimates of sarcopenia prevalence were then applied to population projections until 2045. Using the definition providing the lowest prevalence estimates, the number of individuals with sarcopenia would rise in Europe from 10,869,527 in 2016 to 18,735,173 in 2045 (a 72.4% increase). This corresponds to an overall prevalence of sarcopenia in the elderly rising from 11.1% in 2016 to 12.9% in 2045. With the definition providing the highest prevalence estimates, the number of individuals with sarcopenia would rise from 19,740,527 in 2016 to 32,338,990 in 2045 (a 63.8% increase), corresponding to overall prevalence rates in the elderly of 20.2% and 22.3% for 2016 and 2045, respectively. We showed that the number of sarcopenic patients will dramatically increase in the next 30 years, making consequences of muscle wasting a major public health issue.

Pub.: 25 Dec '16, Pinned: 14 Apr '17

Relationships Between Performance on Assessments of Executive Function and Fall Risk Screening Measures in Community-Dwelling Older Adults.

Abstract: Fall-related injuries are a leading cause of institutionalization and morbidity in older adults. Limitations in cognition, including deficits in higher cognitive processes, like executive function (EF), contribute to a higher risk of falling in older adults. Specifically, declines in EF have been associated with changes in gait, limited mobility, and an increased frequency of falling. It is unknown whether associations between performance on commonly used clinical assessments of EF and performance on commonly used physical performance measures of fall risk are present. The purpose of this study was to examine the relationship between a clinical measure of EF, the Trail Making Test Part B (TMT-B), and 3 physical performance measures of fall risk: the Timed Up and Go (TUG) test, gait speed, and the Five Times Sit to Stand (FTSTS) test, in a group of community-dwelling older adults.Forty-seven community-dwelling older adults met the inclusion/exclusion criteria. Demographic information was obtained and measures of fall risk and cognition were performed. Correlations and linear regression analyses to assess relationships between measures were completed. To account for the high prevalence of mild cognitive impairment (MCI) in this population, the sample was screened and stratified for MCI in post hoc analyses.The EF performance was not significantly correlated with performance on the FTSTS test (ρ = 0.26, P > .05) but was significantly correlated with the TUG test (ρ = 0.31, P < .05) and gait speed (r = -0.36, P < .05). These relationships remained after adjusting for age and education in multivariate models. Results from post hoc analyses demonstrated that only those with MCI had significant relationships between EF and physical performance measures. TMT-B scores in the MCI group were significantly correlated with gait speed (ρ = -0.51, P < .05) and TUG test (ρ = 0.58, P < .05).A significant relationship exists between performance on clinical assessments of EF and fall risk assessments that integrate a mobility task for those individuals who screen positive for MCI. For those who screened negative, no significant relationship exists. Given the large prevalence of undiagnosed MCI in community-dwelling older adults, this finding could be used as an indication to screen older adults for MCI.Screening tools that require cognitive resources such as gait speed appear to have significant relationships with performance of EF for those who screen positive for MCI. This information could be used clinically to identify older adults with cognitive limitations, which could put them at higher risk for falling.

Pub.: 08 Jun '15, Pinned: 14 Apr '17

Innervation and neuromuscular control in ageing skeletal muscle

Abstract: Changes in the neuromuscular system affecting the ageing motor unit manifest structurally as a reduction in motor unit number secondary to motor neuron loss; fibre type grouping due to repeating cycles of denervation‐reinnervation; and instability of the neuromuscular junction that may be due to either or both of a gradual perturbation in postsynaptic signalling mechanisms necessary for maintenance of the endplate acetylcholine receptor clusters or a sudden process involving motor neuron death or traumatic injury to the muscle fibre. Functionally, these changes manifest as a reduction in strength and coordination that precedes a loss in muscle mass and contributes to impairments in fatigue. Regular muscle activation in postural muscles or through habitual physical activity can attenuate some of these structural and functional changes up to a point along the ageing continuum. On the other hand, regular muscle activation in advanced age (>75 years) loses its efficacy, and at least in rodents may exacerbate age‐related motor neuron death. Transgenic mouse studies aimed at identifying potential mechanisms of motor unit disruptions in ageing muscle are not conclusive due to many different mechanisms converging on similar motor unit alterations, many of which phenocopy ageing muscle. Longitudinal studies of ageing models and humans will help clarify the cause and effect relationships and thus, identify relevant therapeutic targets to better preserve muscle function across the lifespan.

Pub.: 21 Dec '15, Pinned: 13 Apr '17

Interventions for sarcopenia and muscle weakness in older people.

Abstract: three major strategies have been tested for combating the losses in muscle mass and strength that accompany ageing. Those strategies are testosterone replacement for men, growth hormone replacement and resistance exercise training. This review will cover the risks and benefits associated with each of these interventions.searches of PubMed and Web of Science through May 2004 yielded 85 relevant citations for the following descriptors: sarcopenia, aging/ageing, elderly, testosterone, hormone replacement, growth hormone, resistance training, exercise, muscle mass, nutrition and strength.testosterone replacement in elderly hypogonadal men produces only modest increases in muscle mass and strength, which are observed in some studies and not in others. Higher doses have not been given for fear of accelerating prostate cancer. Growth hormone replacement in elderly subjects produces a high incidence of side-effects, does not increase strength and does not augment strength gains resulting from resistance training. Some alternate strategies for stimulating the growth hormone/insulin-like growth factor (IGF) pathway continue to hold promise. The latter include growth hormone releasing hormone (GHRH) and the complex of IGF-I with its major circulating binding protein (IGF-I/IGFBP-3). Resistance training remains the most effective intervention for increasing muscle mass and strength in older people. Elderly people have reduced food intake and increased protein requirements. As a result, adequate nutrition is sometimes a barrier to obtaining full benefits from resistance training in this population.

Pub.: 24 Sep '04, Pinned: 13 Apr '17

Loss of muscle strength, mass (sarcopenia), and quality (specific force) and its relationship with functional limitation and physical disability: the Concord Health and Ageing in Men Project.

Abstract: To determine the association between loss of muscle strength, mass, and quality and functional limitation and physical disability in older men.Cross-sectional study of older men participating in the Concord Health and Ageing in Men Project (CHAMP).Elderly men living in a defined geographical region in Sydney, Australia.One thousand seven hundred five community-dwelling men aged 70 and older who participated in the baseline assessments of CHAMP.Upper and lower extremity strength were measured using dynamometers for grip and quadriceps strength. Appendicular skeletal lean mass was assessed using dual X-ray absorptiometry. Muscle quality was defined as the ratio of strength to mass in upper and lower extremities. For each parameter, subjects in the lowest 20% of the distribution were defined as below normal. Functional limitation was assessed according to self-report and objective lower extremity performance measures. Physical disability was measured according to self-report questionnaire.After adjusting for important confounders, the prevalence ratio (PR) for poor quadriceps strength and self-reported functional limitation was 1.91 (95% confidence interval (CI) = 1.10-2.40); for performance-based functional limitation the PR was 1.81 (95% CI = 1.45-2.24). The adjusted PR for poor grip strength and physical disability in instrumental activities of daily living (IADLs) was 1.37 (95% CI = 1.20-1.56). The adjusted PR for low skeletal lean mass (adjusted for fat mass) and physical disability in basic activities of daily living was 2.08 (95% CI = 1.37-3.15). For muscle quality, the PR for lower extremity specific force and functional limitation and physical disability was stronger than upper extremity specific force.Muscle strength is the single best measure of age-related muscle change and is associated with physical disability in IADLs and functional limitation.

Pub.: 09 Nov '10, Pinned: 13 Apr '17