Article

Functional consequences of sarcopenia and dynapenia in the elderly

Institute for Neuromusculoskeletal Research, Department of Biomedical Sciences, Ohio University, Athens, Ohio, USA.
Current opinion in clinical nutrition and metabolic care 02/2010; 13(3):271-6. DOI: 10.1097/MCO.0b013e328337819e
Source: PubMed

ABSTRACT

The economic burden due to the sequela of sarcopenia (muscle wasting in the elderly) are staggering and rank similarly to the costs associated with osteoporotic fractures. In this article, we discuss the societal burden and determinants of the loss of physical function with advancing age, the physiologic mechanisms underlying dynapenia (muscle weakness in the elderly), and provide perspectives on related critical issues to be addressed.
Recent epidemiological findings from longitudinal aging studies suggest that dynapenia is highly associated with both mortality and physical disability even when adjusting for sarcopenia indicating that sarcopenia may be secondary to the effects of dynapenia. These findings are consistent with the physiologic underpinnings of muscle strength, as recent evidence demonstrates that alterations in muscle quantity, contractile quality and neural activation all collectively contribute to dynapenia.
Although muscle mass is essential for regulation of whole body metabolic balance, overall neuromuscular function seems to be a critical factor for maintaining muscle strength and physical independence in the elderly. The relative contribution of physiologic factors contributing to muscle weakness are not fully understood and further research is needed to better elucidate these mechanisms between muscle groups and across populations.

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Available from: Brian C. Clark, Jul 28, 2015
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    • "Older women are particularly at greater risk for muscular strength loss, since women have lower levels of muscular strength compared to men (Brady et al. 2014; Hughes et al. 2001). It is important to note that low levels of muscular strength have been shown to impact cardiovascular disease (Artero et al. 2011; Clark and Manini 2010; Ruiz et al. 2008). "
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    ABSTRACT: The aim of this study was to compare the effect of resistance training (RT) performed with different frequencies followed by a detraining period on muscular strength and oxidative stress (OS) biomarkers in older women. Twenty-seven physically independent women (68.8 ± 4.8 years, 69.1 ± 14.3 kg, 156.0 ± 6.5 cm, and 28.3 ± 4.9 kg.m-2) were randomly assigned to perform a RT program for two or three days per week (G2X = 13 vs. G3X = 14) for 12 weeks followed by 12 weeks of detraining period. One repetition maximum (1RM) tests were used as measures of muscular strength (3 exercises, 3 attempts for each exercise, 3-5 min of rest between attempts, and 5 min of rest between exercises). Advanced oxidized protein products (AOPP) and total radical-trapping antioxidant parameter (TRAP) were used as oxidative stress indicators. Both groups increased muscular strength after 12 weeks of training (P < 0.05) in chest press (G2X = +11.9% vs. G3X = +27.5%, P < 0.05), knee extension (G2X = +18.4% vs. G3X = +16.7%, P > 0.05), and preacher curl (G2X = +37.6% vs. G3X = +36.7%, P > 0.05). On the other hand, 12 weeks of detraining were not sufficient to eliminate the major effects produced by RT on muscular strength, although a significant decrease (P < 0.05) has been observed for chest press (G3X = -9.1% vs. G2X = -10.2%, P > 0.05), knee extension (G2X = -14.9% vs. G3X = -12.1%, P > 0.05), and preacher curl (G2X = -20.5% vs. G3X = -17.4%, P > 0.05). Pre- to post-training both groups showed significant (P < 0.05) increases in TRAP (G2X = +6.9% vs. G3X = +15.1%) with no statistical significant difference between the groups (P > 0.05), and the scores remained elevated compared to pre-training after 12-weeks of detraining. AOPP was not changed by RT or detraining (P > 0.05). The results suggest that a 12-week RT program with a frequency of two days per week may be sufficient to improve muscular strength and OS in older women and detraining for 12 weeks does not completely reverse the changes induced by RT.
    Full-text · Article · Oct 2015 · Age
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    • "Older women are particularly at greater risk for muscular strength loss, since women have lower levels of muscular strength compared to men (Brady et al. 2014; Hughes et al. 2001). It is important to note that low levels of muscular strength have been shown to impact cardiovascular disease (Artero et al. 2011; Clark and Manini 2010; Ruiz et al. 2008). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to compare the effect of resistance training (RT) performed with different frequencies followed by a detraining period on muscular strength and oxidative stress (OS) biomarkers in older women. Twenty-seven physically independent women (68.8±4.8 years, 69.1±14.3 kg, 156.0±6.5 cm, and 28.3±4.9 to kg.m −2) were randomly assigned to perform a RT program for 2 or 3 days per week (G2X=13 vs. G3X=14) for 12 weeks followed by 12 weeks of detraining period. One repetition maximum (1RM) tests were used as measures of muscular strength (three exercises , three attempts for each exercise, 3–5 min of rest between attempts, and 5 min of rest between exercises). Advanced oxidized protein products (AOPP) and total radical-trapping antioxidant parameter (TRAP) were used as oxidative stress indicators. Both groups increased muscular strength after 12 weeks of training (P<0.05) in chest press (G2X=+11.9 % vs. G3X=+27.5 %, P<0.05), knee extension (G2X=+18.4 % vs. G3X=+16.7 %, P > 0.05), and preacher curl (G2X = +37.6 % vs. G3X=+36.7 %, P>0.05). On the other hand, 12 weeks of detraining were not sufficient to eliminate the major effects produced by RT on muscular strength, although a significant decrease (P<0.05) has been observed for chest press (G3X = −9.1 % vs. G2X = −10.2 %, P>0.05), knee extension (G2X=−14.9 % vs. G3X= −12.1 %, P>0.05), and preacher curl (G2X=−20.5 % vs. G3X=−17.4 %, P>0.05). Pre-to post-training, both groups showed significant (P<0.05) increases in TRAP (G2X=+6.9 % vs. G3X=+15.1 %) with no statistical significant difference between the groups (P>0.05), and the scores remained elevated compared to pre-training after 12 weeks of detraining. AOPP was not changed by RT or detraining (P>0.05). The results suggest that a 12-week RT program with a frequency of 2 days per week may be sufficient to improve muscular strength and OS in older women and detraining for 12 weeks does not completely reverse the changes induced by RT.
    Full-text · Article · Oct 2015 · Journal of the American Aging Association
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    • "Sarcopenia commonly affects older people and is characterized by loss of both muscle mass and strength [1] [2]. Sarcopenia is associated with disability, a loss of independence, and reduced quality of life [3]. In one American study, sarcopenia and its consequences were estimated to cost the US healthcare system US$18 billion [4]. "
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    ABSTRACT: Background: Sarcopenia is the presence of low muscle mass and low muscle function. The aim of this study was to establish cutoffs for low muscle mass using three published methods and to compare the prevalence of sarcopenia in older Australians. Methods: Gender specific cutoffs levels were identified for low muscle mass using three different methods. Low grip strength was determined using established cutoffs of <30 kg for men and <20 kg for women to estimate the prevalence of sarcopenia. Results: Gender specific cutoffs levels for low muscle mass identified were (a) <6.89 kg/m(2) for men and <4.32 kg/m(2) for women, <2 standard deviation (SD) of a young reference population; (b) <7.36 kg/m(2) for men and <5.81 kg/m(2) for women from the lowest 20% percentile of the older group; and (c) <-2.15 for men and <-1.42 for women from the lowest 20% of the residuals of linear regressions of appendicular skeletal mass, adjusted for fat mass and height. Prevalence of sarcopenia in older (65 years and older) people by these three methods for men was 2.5%, 6.2%, and 6.4% and for women 0.3%, 9.3%, and 8.5%, respectively. Conclusions: Sarcopenia is common but consensus on the best method to confirm low muscle mass is required.
    Full-text · Article · Jul 2014 · BioMed Research International
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