Sarcopenia: current concepts

Postprandial lipemia in the elderly involves increased incorporation of ingested fat in plasma free fatty acids and small (Sf 20-400) triglyceride-rich lipoproteins

In the elderly, the rise in postprandial plasma triglyceride (TG) concentrations is increased, contributing to their increased risk of cardiovascular disease. We sought to determine the incorporation of ingested fat (whipping cream enriched with [1,1,1-(13)C]triolein) into plasma lipids during the postprandial period in six healthy elderly (67 ± 1 yr old) and six healthy young (23 ± 2 yr old) subjects. Blood and expired air samples were taken before and at 2-h intervals during the 8-h postprandial period. As expected, the area under the curve of postprandial plasma TG concentrations was larger in the elderly compared with the young subjects (152 ± 38 vs. 66 ± 27 mg·dl(-1)·h, P < 0.05). The incorporation of [(13)C]oleate in plasma free fatty acids (FFAs) and TG of the small (S(f) = 20-400) triglyceride-rich lipoprotein (TRL) fraction was significantly higher in the elderly compared with the young subjects, resulting in increased postprandial contributions of the ingested lipid to plasma FFAs (41 ± 3 vs. 26 ± 6%, P < 0.05) and the small TRL fraction (36 ± 5 vs. 21 ± 3%, P < 0.05) in elderly. Plasma apoB-100 concentration was higher, whereas the rate of oxidation of the ingested lipid was lower (P < 0.05) in the elderly. We conclude that increased postprandial lipemia in the elderly involves increased contribution of ingested lipid to the plasma small TRLs. This appears to be driven at least in part by increased appearance of the ingested fat as plasma FFA and increased availability of apo B-100 lipoproteins in the elderly.

Cytochrome c oxidase deficiency in human posterior cricoarytenoid muscle

BACKGROUND

Mitochondrial alterations occur in skeletal muscle fibers throughout the normal aging process, resulting from increased accumulation of reactive oxide species (ROS). These result in respiratory chain abnormalities, which decrease the oxidative capacity of muscle fibers, leading to decreased contractile force, sarcopenia, or fiber necrosis. Intrinsic laryngeal muscles are a cranial muscle group that possesses some distinctive genotypic, phenotypic, and physiologic properties. Their susceptibility to mitochondrial alterations resulting from biological processes that increase levels of oxidative stress may be one of these distinctive characteristics.

OBJECTIVES

The incidence of cytochrome c oxidase (COX) deficiency (COX(-)) was determined in human posterior cricoarytenoid (PCA) muscle when compared with the human thyrohyoid (TH) muscle, an extrinsic laryngeal muscle that served as "control" muscle. Ten PCA and 10 TH muscles were harvested postlaryngectomy from 10 subjects ranging in age from 55 to 86 years. Differences in COX(-) were compared within and between muscle types using tissue section staining and standard morphometric analysis.

RESULTS AND CONCLUSIONS

COX(-) fibers were identified in both the PCA and TH muscles. The PCA muscle had 10 times as may affected fibers as the TH muscle, with significant differences in COX(-) found between muscle type and fiber type (P=0.003). Almost all of this effect was the result of elevated levels of COX(-) in type I fibers from the PCA muscle (P=0.002) that showed a strong positive correlation with increased age. These results suggest that increased mitochondrial alterations may occur in the PCA muscle during normal aging.

Contractile and non-contractile tissue volume and distribution in ankle muscles of young and older adults

Magnetic resonance imaging (MRI) enables accurate in vivo quantification of human muscle volumes, which can be used to estimate subject-specific muscle force capabilities. An important consideration is the amount of contractile and non-contractile tissue in the muscle compartment, which will influence force capability. We quantified age-related differences in the proportion and distribution of contractile and non-contractile tissue in the dorsiflexor and plantar flexor (soleus, and medial and lateral heads of gastrocnemius) muscles, and examined how well these volumes can be estimated from single MRI cross-sections. Axial MRIs of the left leg for 12 young (mean age 27 years) and 12 older (72 years) healthy, active adults were used to compute muscle volumes. Contractile tissue distribution along the leg was characterized by mathematical functions to allow volume prediction from single-slice cross-sectional area (CSA) measurements. Compared to young, older adults had less contractile volume and a greater proportion of non-contractile tissue. In both age groups the proportion of non-contractile tissue increased distally, with the smallest proportion near the maximum compartment CSA. A single CSA measurement predicted contractile volume with 8-11% error, with older adults in the higher end of this range. Using multiple slices improved volume estimates by roughly 50%, with average errors of about 3-4%. These results demonstrate significant age-related differences in non-contractile tissue for the dorsi- and plantar-flexor muscles. Although estimates of contractile volume can be obtained from single CSA measurements, multiple slices are needed for increased accuracy due to inter-individual variations in muscle volume and composition.

Enhanced survival of skeletal muscle myoblasts in response to overexpression of cold shock protein RBM3

Cold-inducible RNA-binding protein (RBM3) is suggested to be involved in the regulation of skeletal muscle mass. Cell death pathways are implicated in the loss of muscle mass and therefore the role of RBM3 in muscle apoptosis in C(2)C(12) myoblasts was investigated in this study. RBM3 overexpression was induced by either cold shock (32°C exposure for 6 h) or transient transfection with a myc-tagged RBM3 expression vector. Cell death was induced by H(2)O(2) (1,000 μM) or staurosporine (StSp, 5 μM), and it was shown that cold shock and RBM3 transfection were associated with attenuation of morphological changes and an increase in cell viability compared with normal temperature or empty vector, respectively. No changes in proliferation were observed with either cold shock or RBM3 transfection. DNA fragmentation was not increased in response to H(2)O(2), and a cell permeability assay indicated that cell death in response to H(2)O(2) is more similar to necrosis than apoptosis. RBM3 overexpression reduced apoptosis and the collapse of the membrane potential in response to StSp. Moreover, the increase in caspase-3, -8, and -9 activities in response to StSp was returned to control levels with RBM3 overexpression. These results indicate that increased RBM3 expression decreases muscle cell necrosis as well as apoptosis and therefore RBM3 could potentially serve as an intervention for the loss of muscle cell viability during muscle atrophy and muscle diseases.

Identification of novel genes involved in sarcopenia through RNAi screening in Caenorhabditis elegans

BACKGROUND

Aging in humans is characterized by a progressive loss of muscle mass and strength known as sarcopenia. Although considered to be a normal aspect of aging, the loss of strength can have significant effects on the health, functioning, and independence of elderly individuals. Although these aspects of sarcopenia have been well studied, the molecular mechanisms leading to its development are still unclear. The nematode Caenorhabditis elegans might be a novel animal model for sarcopenia as worms experience sarcopenia during aging and mutations affecting the daf-2/insulin-like signaling pathway are able to delay this process.

METHODS

Via the use of RNA interference, we screened a total of 43 genes, most of which have been shown to be required for the enhanced longevity of daf-2 mutants, to assess for the effects of these genes on muscle function and worm mobility during aging.

RESULTS

We identified 17 novel genes that are essential for the delay in the onset of sarcopenia in daf-2 mutants. The identified genes include splicing factors, vacuolar sorting proteins, transcription factors, and metabolic enzymes. Using a transgenic strain that only responds to RNA interference in the body wall muscle, we also found that most of the identified genes act in muscle to prevent the onset of sarcopenia.

CONCLUSIONS

Our results demonstrate that at least in worms, specific genetic pathways that modify the development of sarcopenia can be identified. Interestingly, almost all the identified genes also have a known human homolog, and hence, our findings may offer significant leads toward the identification of genes involved in sarcopenia in people.

Does the amount of fat mass predict age-related loss of lean mass, muscle strength, and muscle quality in older adults?

BACKGROUND

An excessive amount of adipose tissue may contribute to sarcopenia and may be one mechanism underlying accelerated loss of muscle mass and strength with aging. We therefore examined the association of baseline total body fat with changes in leg lean mass, muscle strength, and muscle quality over 7 years of follow-up and whether this link was explained by adipocytokines and insulin resistance.

METHODS

Data were from 2,307 men and women, aged 70-79 years, participating in the Health, Aging, and Body Composition study. Total fat mass was acquired from dual energy X-ray absorptiometry. Leg lean mass was assessed by dual energy X-ray absorptiometry in Years 1, 2, 3, 4, 5, 6, and 8. Knee extension strength was measured by isokinetic dynamometer in Years 1, 2, 4, 6, and 8. Muscle quality was calculated as muscle strength divided by leg lean mass.

RESULTS

Every SD greater fat mass was related to 1.3 kg more leg lean mass at baseline in men and 1.5 kg in women (p < .01). Greater fat mass was also associated with a greater decline in leg lean mass in both men and women (0.02 kg/year, p < .01), which was not explained by higher levels of adipocytokines and insulin resistance. Larger fat mass was related to significantly greater muscle strength but significantly lower muscle quality at baseline (p < .01). No significant differences in decline of muscle strength and quality were found.

CONCLUSIONS

High fatness was associated with lower muscle quality, and it predicts accelerated loss of lean mass. Prevention of greater fatness in old age may decrease the loss of lean mass and maintain muscle quality and thereby reducing disability and mobility impairments.

Poor physical function in elderly women in low-level aged care is related to muscle strength rather than to measures of sarcopenia

Purpose:

To determine the prevalence of sarcopenia and investigate relationships among body composition, muscle strength, and physical function in elderly women in low-level aged care.

Subjects and methods:

Sixty-three ambulatory women (mean age 86 years) participated in this cross-sectional study where body composition was determined by dual energy X-ray absorptiometry (DXA); ankle, knee, and hip strength by the Nicholas Manual Muscle Tester; and physical function by ‘timed up and go’ (TUG) and walking speed (WS) over 6 meters. Body composition data from a female reference group (n = 62, mean age 29 years) provided cut-off values for defining sarcopenia.

Results:

Elderly women had higher body mass index (P < 0.001), lower lean mass (P < 0.001), and higher fat mass (P < 0.01) than the young reference group. Only a small proportion (3.2%) had absolute sarcopenia (defined by appendicular skeletal muscle mass/height squared) whereas 37% had relative sarcopenia class II (defined by percentage skeletal muscle mass). Scores for TUG and WS indicated relatively poor physical function, yet these measures were not associated with muscle mass or indices of sarcopenia. In multivariate analysis, only hip abductor strength predicted both TUG and WS (both P = 0.01).

Conclusion:

Hip strength is a more important indicator of physical functioning than lean mass. Measurement of hip strength may therefore be a useful screening tool to detect those at risk of functional decline and requirement for additional care. Further longitudinal studies with a range of other strength measures are warranted.

Body composition, muscle strength, functional capacity, and physical disability risk in liver transplanted familial amyloidotic polyneuropathy patients

BACKGROUND

Familial amyloidotic polyneuropathy (FAP) is a neurodegenerative disease leading to sensory and motor polyneuropathies, and functional limitations. Liver transplantation is the only treatment for FAP, requiring medication that negatively affects bone and muscle metabolism. The aim of this study was to compare body composition, levels of specific strength, level of physical disability risk, and functional capacity of transplanted FAP patients (FAPTx) with a group of healthy individuals (CON).

METHODS

A group of patients with 48 FAPTx (28 men, 20 women) was compared with 24 CON individuals (14 men, 10 women). Body composition was assessed by dual-energy X-ray absorptiometry, and total skeletal muscle mass (TBSMM) and skeletal muscle index (SMI) were calculated. Handgrip strength was measured for both hands as was isometric strength of quadriceps. Muscle quality (MQ) was ascertained by the ratio of strength to muscle mass. Functional capacity was assessed by the six-minute walk test.

RESULTS

Patients with FAPTx had significantly lower functional capacity, weight, body mass index, total fat mass, TBSMM, SMI, lean mass, muscle strength, MQ, and bone mineral density.

CONCLUSION

Patients with FAPTx appear to be at particularly high risk of functional disability, suggesting an important role for an early and appropriately designed rehabilitation program.

Declines in physical performance by sex and age among nondisabled community-dwelling older Japanese during a 6-year period

Background

Few studies have examined whether declines over time in hand-grip strength (HGS) and fast walking speed (FWS) differ by sex and age among non-Western community-dwelling older adults. This study aimed to quantify changes in HGS and FWS over the 6-year period from 1994 to 2000 and examine whether these changes differed by sex and baseline age among older individuals in a Japanese community.

Methods

We conducted a community-based prospective cohort study. The participants were 513 nondisabled men and women aged 67 to 91 years at the 1994 survey. Independent variables regarding time since baseline, in addition to various time-dependent and time-independent covariates, were obtained in 1994, 1996, 1998, and 2000. The outcome variables were HGS and FWS assessed at each survey. All data on independent and dependent variables that were collected at each survey were simultaneously analyzed using a linear mixed-effects model.

Results

The linear mixed-effects model revealed significant declines in both HGS (−0.70 kg/year, P < 0.001) and FWS (−0.027 m/sec/year, P < 0.001) among nondisabled older participants who had analyzable data in any survey during the 6-year period. Sex was significantly associated with the rate of decline in HGS (P < 0.001), but not FWS (P = 0.211).

Conclusions

In this analysis of nondisabled older Japanese, a mixed-effects model confirmed a significant effect of aging on declines in HGS and FWS and showed that men had a significantly steeper decline in HGS than did women during a 6-year period.

Menopause and sarcopenia: A potential role for sex hormones

Menopause is associated with a decline in estrogen levels, which could lead to an increase in visceral adiposity as well as a decrease in bone density, muscle mass and muscle strength. This decline in muscle mass, known as sarcopenia, is frequently observed in postmenopausal women. Potential causes of sarcopenia include age-related changes in the hormonal status, low levels of physical activity, reduced protein intake and increased oxidative stress. However, the role of sex hormones, specifically estrogens, on the onset of sarcopenia is controversial. Preventing sarcopenia and preserving muscle strength are highly relevant in order to prevent functional impairment and physical disability. To date, resistance training has been shown to be effective in attenuating age-related muscle loss and strength. However, results on the effect of hormonal supplementation to treat or prevent sarcopenia are contradictory. Further research is needed to identify other potential mechanisms of sarcopenia as well as effective interventions for the prevention and treatment of sarcopenia. Therefore, the purpose of this review will be to examine the role of sex hormonal status in the development of sarcopenia. We will also overview the physical as well as metabolic consequences of sarcopenia and the efficiency of different interventions for the prevention and treatment of sarcopenia.

Use of knee height for the estimation of stature in elderly Turkish people and their relationship with cardiometabolic risk factors

The determination of the approximately truest value in height measurement is important in many fields, but it is difficult to perform true measurements, especially in the elderly individuals. We planned to investigate the following items in geriatric Turkish population: to calculate the decrease in height with advancing age by using the standing height measurement and estimated height derived from the knee height; to evaluate the significance of difference between the two measurement methods in the calculation of body mass index (BMI) and waist/height ratio (WHtR); to determine the cut-off value of WHtR according to estimated height in elderly individuals. We studied 551 cases aged between 19 and 97 years. Knee height was measured using a sliding caliper in a sitting position. Linear regression analysis was carried out to derive predictive equations for the estimation of stature with adults (≤ 50 years of age) according to the gender. This equation was then used to estimate height among elderly subjects. Of the cases, 60.3% were <60 years (mean: 48.75 ± 7.50); 39.7% of the cases were >60 years (mean: 69.51 ± 7.12). Estimated BMI (EBMI) measurements in the females and males >60 years were in average 1.23 kg/m(2) and 0.92 kg/m(2) higher than their real BMIs, respectively. EBMI measurements in the females <60 years were 0.32 kg/m(2) higher than their real BMIs (p<0.01). There is a statistically significant difference between WHtR in the females of both age groups, and in the males >60 years, as compared to our estimated WHtR (EWHtR) measurements (p<0.01). The cut-off point of WHtR was 0.61 and 0.58 in the female and male cases of >60 years in our study, respectively. WHtR seemed to be a better anthropometric index that could predict most cardiometabolic risk factors in our study. EWHtR emerged to be a better cardiometabolic risk index especially in the elderly group.

Obesity, sarcopenia and their functional consequences in old age

The prevalence of obesity is high in older persons and recent trends show a rapid increase in this prevalence. Results from observational and intervention studies (i.e. weight loss studies) show the strong negative impact of obesity on functional status in old age. There are different potential pathways through which obesity may lead to functional decline in older persons. Furthermore, the presence of overweight and obesity during the life course and trends in medical care are likely to influence the impact of obesity on disability. The concepts sarcopenia (age-related loss of muscle mass) and dynapenia (age-related loss of muscle strength) receive a lot of research attention as potential determinants of functional decline in old age. There is no consensus on the definitions of these concepts. Recent studies conducted in large cohort studies of mainly community-dwelling older persons show that poor muscle strength is strongly associated with functional decline compared to low muscle mass. In several studies, no association between muscle mass and functional status was observed. Current research on the combination of obesity with poor muscle strength (dynapenic-obesity) suggests a potential additive effect of both components on poor functional status in old age which seems independent of the level of physical activity.

The association between the ratio of visceral fat to thigh muscle area and metabolic syndrome: the Korean Sarcopenic Obesity Study (KSOS)

OBJECTIVE

A relationship between visceral fat accumulation and metabolic syndrome (MetS) has been established. However, the effect of a relative increase in visceral fat and a decrease in muscle mass on metabolic disorders has not been investigated. The aim of the present study was to examine the association between the ratio of visceral fat to thigh muscle area (VMR) and MetS in Korean adults. STUDY SUBJECT/MEASUREMENTS: A total of 264 age-and gender-matched subjects recruited from the Korean Sarcopenic Obesity Study (KSOS), an ongoing prospective observational cohort study, were categorized into four groups based on their body mass index (BMI) and VMR. We measured visceral fat area and thigh muscle area using computed tomography.

RESULTS

Subjects with MetS showed a significantly higher VMR than those without MetS. In both obese and nonobese groups, the subjects with a higher VMR had a higher prevalence of MetS than those in the lower VMR groups. VMR was significantly related to components of the metabolic syndrome, especially in women, and was positively correlated with a number of MetS components in both men and women. In multiple logistic regression analysis, the odds ratio for MetS was 6·72 (highest vs lowest quartile, 95% confidence interval, 1·60-28·14) after an adjustment of potential confounders, including BMI and waist-to-hip ratio.

CONCLUSION

VMR is significantly increased in subjects with MetS and independently associated with MetS. These results suggest that the VMR may be a potential indicator for MetS risk in Korean adults.

Effect of standing posture during whole body vibration training on muscle morphology and function in older adults: a randomised controlled trial

BACKGROUND

Whole body vibration (WBV) is a novel modality of exercise shown to improve musculoskeletal function. This study aims to examine the effects of standing posture during low magnitude WBV training on muscle function and muscle morphology in older adults.

METHODS

Nineteen men and women (50-80 years) were recruited to a three month randomised controlled trial and allocated to one of three groups: WBV with flexed knees (FK), WBV with locked knees (LK), or sham WBV with flexed knees (CON). Exposure was intermittent (1 min WBV:1 min rest) for 20 min, three times per week for 13 weeks. Measurements were taken at baseline and at three months. Primary outcomes included upper and lower body muscle function (strength, power and velocity). Secondary outcomes were muscle morphology, balance, habitual and maximal gait velocity, stair climb power, and chair stand performance.

RESULTS

Sixteen subjects completed the study. Relative (%) upper body contraction velocity improved significantly after WBV with FK compared to LK (FK 16.0%, LK -7.6%, CON 4.7, p = 0.01). Relative upper body strength (LK 15.1%, p = 0.02; FK 12.1%, p = 0.04; CON 4.7%) increased significantly following WBV compared to control. Absolute (p = 0.05) and relative (p = 0.03) lower leg strength significantly improved with both standing postures (LK 14.4%; FK 10.7%; CON 1.3%). Only the LK group differed significantly from CON in relative leg strength gains (p = 0.02). Potentially clinically meaningful but statistically non-significant improvements in lower leg muscle cross-sectional area (LK 3.7 cm², FK 2.4 cm², CON 2.2 cm² p = 0.13) were observed after WBV with LK compared to the other groups. No significant effects of WBV on any functional performance tests were observed.

CONCLUSIONS

Our results suggest that WBV may improve muscle strength and contraction velocity in some muscle groups in older adults. However, hypothesised differential adaptation to standing posture (FK > LK) was observed only for upper body contraction velocity, making recommendations regarding this prescriptive element inconclusive. The efficacy, mechanism of action and long term feasibility of WBV for musculoskeletal health in older adults warrants continued investigation in robustly designed, sufficiently powered future studies.

TRIAL REGISTRATION

ACTRN12609000353291.

Workshop on idiopathic pulmonary fibrosis in older adults

Idiopathic pulmonary fibrosis (IPF), a heterogeneous disease with respect to clinical presentation and rates of progression, disproportionately affects older adults. The diagnosis of IPF is descriptive, based on clinical, radiologic, and histopathologic examination, and definitive diagnosis is hampered by poor interobserver agreement and lack of a consensus definition. There are no effective treatments. Cellular, molecular, genetic, and environmental risk factors have been identified for IPF, but the initiating event and the characteristics of preclinical stages are not known. IPF is predominantly a disease of older adults, and the processes underlying normal aging might significantly influence the development of IPF. Yet, the biology of aging and the principles of medical care for this population have been typically ignored in basic, translational, or clinical IPF research. In August 2009, the Association of Specialty Professors, in collaboration with the American College of Chest Physicians, the American Geriatrics Society, the National Institute on Aging, and the National Heart, Lung, and Blood Institute, held a workshop, summarized herein, to review what is known, to identify research gaps at the interface of aging and IPF, and to suggest priority areas for future research. Efforts to answer the questions identified will require the integration of geriatrics, gerontology, and pulmonary research, but these efforts have great potential to improve care for patients with IPF.

Associations between energy demands, physical activity, and body composition in adult humans between 18 and 96 y of age

BACKGROUND

Associations between body composition and the energy expended on basal metabolism and activity are complex and age dependent.

OBJECTIVE

The objective was to examine associations between body composition and daily (DEE), basal (BEE), and activity energy expenditure (AEE) throughout the adult life span.

DESIGN

A cross-sectional study was conducted in 529 adults aged 18-96 y. DEE was measured by using doubly labeled water, BEE by using respirometry, and body composition by isotope dilution. AEE was calculated as DEE - BEE, and physical activity level (PAL) was calculated as DEE/BEE.

RESULTS

Up to age 52 y, fat-free mass (FFM) and fat mass (FM) were positively associated with age in men, but no significant effect was observed in women. No effects of age on DEE and AEE were observed. The average DEE in men (14.1 MJ/d) was 27% greater than that in women (10.7 MJ/d). PAL averaged 1.84 in men and 1.75 in women. Above and including the age of 52 y, FFM, FM, DEE, BEE, and AEE were all negatively associated with greater age. The effect of age on AEE was greater than on BEE; consequently, PAL by the age of 95 y was only 1.36. PAL and AEE were both unrelated to FFM (both age adjusted).

CONCLUSIONS

PAL and AEE were not associated with age in subjects aged <52 y. AEE, BEE, and PAL were all negatively associated with age in subjects aged ≥52 y. An absence of a relation between age-adjusted PAL and FFM suggested that greater physical activity was not associated with higher FFM in the elderly.

Models of accelerated sarcopenia: critical pieces for solving the puzzle of age-related muscle atrophy

Sarcopenia, the age-related loss of skeletal muscle mass, is a significant public health concern that continues to grow in relevance as the population ages. Certain conditions have the strong potential to coincide with sarcopenia to accelerate the progression of muscle atrophy in older adults. Among these conditions are co-morbid diseases common to older individuals such as cancer, kidney disease, diabetes, and peripheral artery disease. Furthermore, behaviors such as poor nutrition and physical inactivity are well-known to contribute to sarcopenia development. However, we argue that these behaviors are not inherent to the development of sarcopenia but rather accelerate its progression. In the present review, we discuss how these factors affect systemic and cellular mechanisms that contribute to skeletal muscle atrophy. In addition, we describe gaps in the literature concerning the role of these factors in accelerating sarcopenia progression. Elucidating biochemical pathways related to accelerated muscle atrophy may allow for improved discovery of therapeutic treatments related to sarcopenia.

Sarcopenia, cardiopulmonary fitness, and physical disability in community-dwelling elderly people

BACKGROUND

Sarcopenia refers to the loss of skeletal muscle mass with aging. It is believed to be associated with functional impairment and physical disability.

OBJECTIVE

The purposes of this study were: (1) to compare the physical activity, muscle strength (force-generating capacity), cardiopulmonary fitness, and physical disability in community-dwelling elderly people with sarcopenia, borderline sarcopenia, and normal skeletal muscle mass in Taiwan and (2) to test the hypothesis that sarcopenia is associated with physical disability and examine whether the association is mediated by decreased muscle strength or cardiopulmonary fitness.

DESIGN

This was a cross-sectional investigation.

METHODS

Two hundred seventy-five community-dwelling elderly people (148 men, 127 women) aged > or =65 years participated in the study. The participants were recruited from communities in the district of Zhongzheng, Taipei. Predicted skeletal muscle mass was estimated using a bioelectrical impedance analysis equation. The skeletal muscle mass index (SMI) was calculated by dividing skeletal muscle mass by height squared. Physical disability was assessed using the Groningen Activity Restriction Scale. Physical activity was assessed using a 7-day recall physical activity questionnaire. Cardiopulmonary fitness was assessed using a 3-minute step test, and grip strength was measured to represent muscle strength.

RESULTS

Cardiopulmonary fitness was significantly lower in elderly people with sarcopenia than in those with normal SMIs. Grip strength and daily energy expenditure (kcal/kg/day) were not significantly different between the participants with sarcopenia and those with normal SMIs. The odds ratio for physical disability between the participants with sarcopenia and those with normal SMIs was 3.03 (95% confidence interval=1.21-7.61). The odds ratio decreased and the significant difference diminished after controlling for cardiopulmonary fitness.

LIMITATIONS

A causal relationship between sarcopenia and physical activity, cardiopulmonary fitness, and physical disability cannot be established because of the cross-sectional nature of study design.

CONCLUSIONS

Sarcopenia was associated with physical disability in elderly men. The association between sarcopenia and physical disability was mediated to a large extent by decreased cardiopulmonary fitness.

Exercise attenuates the weight-loss-induced reduction in muscle mass in frail obese older adults

PURPOSE

To evaluate the effect of adding exercise to a hypocaloric diet on changes in appendicular lean mass and strength in frail obese older adults undergoing voluntary weight loss.

METHODS

Thirty frail older (age, 70 +/- 5 yr) obese (body mass index, 37 +/- 5 kg.m) adults were randomly assigned to 6 months of diet/behavioral therapy (diet group, n = 15) or diet or behavioral therapy plus exercise that incorporated progressive resistance training (PRT; diet + exercise group; n = 15). Body composition was assessed using dual-energy x-ray absorptiometry, and muscle strength was assessed using one-repetition maximum. The volume of upper extremity (UE) and lower extremity (LE) exercise training was determined by multiplying the average number of repetitions performed by the average weight lifted during the first three exercise sessions and during the last three exercise sessions of the study.

RESULTS

The diet and the diet + exercise groups had similar (P > 0.05) decreases in weight (10.7 +/- 4.5 vs 9.7 +/- 4.0 kg) and fat mass (6.8 +/- 3.7 vs 7.7 +/- 2.9 kg). However, the diet + exercise group lost less fat-free mass (FFM; 1.8 +/- 1.5 vs 3.5 +/- 2.1 kg), LE lean mass (0.9 +/- 0.8 vs 2.0 +/- 0.9 kg), and UE lean mass (0.1 +/- 0.2 vs 0.2 +/- 0.2 kg) than the diet group (P < 0.05). The diet + exercise group had greater increases in percent of weight as FFM (FFM / weight x 100) than the diet group (7.9 +/- 3.3 vs 5.4 +/- 3.7%; P < 0.05). Despite lean mass losses, the diet + exercise group increased UE and LE strength in response to exercise (17-43%), whereas the diet group maintained strength. The volume of UE and LE exercises correlated with the amount of UE and LE lean mass (r = 0.64-0.84; P < 0.05).

CONCLUSION

Exercise added to diet reduces muscle mass loss during voluntary weight loss and increases muscle strength in frail obese older adults. Regular exercise that incorporates PRT should be used to attenuate muscle mass loss in frail obese older adults on weight-loss therapy.

Subclinical hypothyroidism has little influences on muscle mass or strength in elderly people

Sarcopenia, the age-related decline in muscle mass, affects the muscle strength and muscle quality, and these changes decrease functional capacity. The prevalence of thyroid dysfunction increases with age, and changes in thyroid hormone level lead to neuromuscular deficits. We investigated the effects of subclinical hypothyroidism on the muscle mass, strength or quality in elderly people. One thousand one hundred eighteen subjects aged > or = 65 yr were randomly selected from a local population and classified into a euthyroid (280 men and 358 women), subclinically hypothyroid (61 men and 75 women), or overtly hypothyroid (7 men and 16 women) group. Although women with subclinical hypothyroidism had a higher prevalence of sarcopenia, defined according to the ratio of appendicular skeletal muscle mass to the square of height, muscle mass, strength or quality did not differ in relation to thyroid status in men or in women. Multivariate analysis including age, diabetes, hypertension, acute coronary event, alcohol, smoking, presence of pain, physical activity score, and lipid profile, showed that thyroid-stimulating hormone level was not associated with muscle mass, strength or quality. In conclusion, subclinical hypothyroidism has little influences on muscle mass, strength or quality, and may not be associated with sarcopenia.

Nutritional recommendations for the management of sarcopenia

The Society for Sarcopenia, Cachexia, and Wasting Disease convened an expert panel to develop nutritional recommendations for prevention and management of sarcopenia. Exercise (both resistance and aerobic) in combination with adequate protein and energy intake is the key component of the prevention and management of sarcopenia. Adequate protein supplementation alone only slows loss of muscle mass. Adequate protein intake (leucine-enriched balanced amino acids and possibly creatine) may enhance muscle strength. Low 25(OH) vitamin D levels require vitamin D replacement.

BsmI polymorphism in the vitamin D receptor gene is associated with leg extensor muscle strength in elderly men

BACKGROUND AND AIMS

Sarcopenia is defined as a reduction in skeletal muscle mass, strength, and endurance observed with advancing age. Although Vitamin D receptor (VDR) polymorphism is reported to be associated with muscle mass and strength, evidence for this is limited and conflicting. In this study, we examined the association between the polymorphisms of VDR gene BsmI, TaqI and FokI and muscular mass and strength in elderly men.

METHODS

This is a cross-sectional study conducted in a university hospital. One hundred and twenty men over 65 years of age participated, all participants were active men living independently in Istanbul, who were followed as outpatients in geriatric polyclinics. Most common diagnoses were hypertension, hyperlipidemia, and mild to moderate osteoarthritis. Morbid obese patients were not included in the study. Genomic DNA was extracted from peripheral blood, and VDR genotypes were determined by the polymerase chain reaction. The peak torque of the knee flexors and extensors was measured on a Cybex 350 dynamometer. Body muscle mass was calculated by using bioelectric impedance analysis.

RESULTS

The extensor strength of the knee was higher in BB homozygotic men than in the Bb/bb group. No significant association was found with TaqI and FokI haplotypes. There was no significant association between muscle mass and strength, or between muscle mass and VDR genotype.

CONCLUSION

Our data suggest that VDR gene BsmI polymorphism is associated with muscular strength in elderly men.

Falls Clinics: an opportunity to address frailty and improve health outcomes (preliminary evidence)

BACKGROUND AND AIM

Currently the operational model of a Falls Clinic is not clearly defined making it difficult to assess outcomes. Predominantly referrals are for older, frail adults and while there is merit in current interventions prescribed the effect on falls and other outcomes over time are unclear. The aim of this pilot study is to describe 12 month health outcomes of community-dwelling older adults who have attended a multi-disciplinary Falls Clinic.

METHODS

A sequential sample of 90 community-dwelling older adults (> or =65 years) attending a Falls and Injury Risk Assessment Clinic between April and October 2001 was followed-up at 12 months. Outcomes included grip strength, Timed- Up and Go, body weight, number of fallers, and change in accommodation. Data are summarised as mean (SD) and n (%) with change over time tested using paired sample t-tests (continuous data) and chi-square (categorical data).

RESULTS

Sixty-five participants were available at 12 months. Mean (SD) age of participants was 80 (6) years and 30 of 65 (46%) were males. At 12 months, 62 (96%) remained in the same accommodation, 37 out of 65 (57%) reported >1 fall in the previous year, compared to 72% (n=47) on average at baseline (p=0.21). Grip strength (p=0.006), TUG (p=0.001) and body weight (p=0.033) all declined between baseline and 12 months.

CONCLUSIONS

This pilot study found a trend for reduction in falls, but this was accompanied with a significant decline in measures of frailty, including outcomes of nutritional status, strength and mobility. Evaluation of more targeted multi-disciplinary frailty interventions in this at risk group are required.

Overview of the physiological changes and optimal diet in the golden age generation over 50

Basically, our lifespan is determined genetically. However, several other parameters such as the environment, lifestyle and diet have a high impact on living in the best of health. Many older persons suffer from various diseases, which often cannot be avoided; however, their development can be postponed and symptoms can be mitigated by a balanced diet, moderate physical activity as well as a healthy lifestyle. These diseases are, for example, sarcopenia (degenerative loss of muscle mass), osteoporosis (decomposition of bone structure), digestive restrictions, sensory impairment, water imbalance or a compromised immune system. Psychological modifications, obesity and loss of weight also commonly occur in older adults. To define an adequate diet for elderly between the ages 50 and 80 is difficult, even impossible, because the nutritional requirements differ between the dynamic quinquagenarian and the frailer eighty-year-old. However, several studies have shown that sufficient consumption of high-quality proteins, calcium, vitamin D, anti-oxidative food compounds, water as well as adapted energy values and nourishment with high-nutrient density in combination with physical activity especially help one to remain healthy to a great age. The cornerstone of healthy ageing is the maintenance of normal bodyweight in order to prevent the development of diseases such as osteoporosis, coronary heart disease or diabetes type 2. This publication will review the physiological changes that occur with advanced age and consequential nutritional recommendations for elderly persons.

Remodeling of the neuromuscular junction precedes sarcopenia related alterations in myofibers

Several mechanisms contributing to the etiology of sarcopenia (age-related loss of muscle size) have been postulated. One of these attributes the loss of muscle mass to a preceding age-related denervation of myofibers. The aim of this study was to determine if signs of denervation were apparent at the neuromuscular junction (NMJ) before fiber atrophy, or fiber type conversion could be documented, and to reveal if a muscle's activity level impacts its sensitivity to age-related denervation. Plantaris and soleus muscles were obtained from young adult (10 months) and early aged (21 months) rats. Pre- and post-synaptic NMJ morphology was quantified with cytofluorescent staining of nerve terminal branches and endplate regions, respectively. Myofiber profiles (fiber size and fiber type composition) were assessed with histochemical procedures. Results show that in the lightly recruited plantaris, significant (P<0.05) signs of denervation were noted in aged rats, while the same muscles displayed no change in myofiber profile. In the heavily recruited soleus, however, there was little evidence of denervation, and again no alterations in myofiber profile. These results indicate that age-related denervation occurs before myofiber atrophy, and that high amounts of neuromuscular activity may delay the onset of age-related denervation and sarcopenia.

Exercise, body composition, and functional ability: a randomized controlled trial

CONTEXT

In women, age and the menopausal transition contribute to an increase of body fat and a reduction of lean body mass associated with functional decline, affecting independent living.

BACKGROUND

Sarcopenia and adiposity in the elderly has been associated with increased mortality and functional decline affecting independent living.

PURPOSE

This study was conducted to determine the effect of a multipurpose exercise program on the body composition and functional ability of elderly women living in a community.

DESIGN

An 18-month single-blinded RCT comparing participants in an exercise program with an active control group was conducted from May 2005 through December 2007. Analyses were conducted from January 2008 to July 2008.

SETTING/PARTICIPANTS

Two hundred forty-six women (aged 69.1+/-4.0 years) living independently in the area of Erlangen-Nürnberg (Germany) participated in the study.

INTERVENTION

Subjects (n=123) performed a multipurpose exercise program with special emphasis on exercise intensity but with low-level requirements for training facilities and materials. The 123 women in the control group focused primarily on well-being.

MAIN OUTCOME MEASURES

Body composition was assessed by dual-energy x-ray absorptiometry. Further, strength was evaluated using isometric techniques for the back and legs. Aerobic fitness was determined from a progressive-intensity treadmill test.

RESULTS

After 18 months, significant effects in favor of the exercise program for body composition were increases in appendicular skeletal muscle mass and lean body mass along with reductions in abdominal fat and total body fat. Significant performance effects also favored the exercise program and included enhanced isometric maximum trunk-extensor and leg press strength, leg press power, timed up-and-go test, and aerobic fitness.

CONCLUSIONS

A high-intensity multipurpose exercise program produced significant improvements in body composition and functional ability in a cohort of elderly women living in a community.

The effect of whole body vibration exposure on muscle or bone morphology and function in older adults: a systematic review of the literature

CONTEXT AND OBJECTIVE

The aim of this study was to examine the effect of whole body vibration (WBV), a novel exercise modality, on muscle or bone morphology and function in older adults.

METHODS

A literature search of published randomised controlled trials (RCTs) was conducted using multiple databases and hand searching for study designs reporting the effects of WBV in older adults on any outcomes related to muscle function, or muscle or bone morphology. Concomitant exercise was only included if the control group performed the same exercise as the active WBV group, but without vibration.

RESULTS

Six RCTs met the inclusion criteria of this review, three reporting measures of muscle only, two assessing bone measures only and one detailing measures of both bone and muscle. Study design varied greatly across the six trials and only six of 35 musculoskeletal outcomes analysed were statistically significant. All statistically significant improvements were of muscle function.

CONCLUSIONS

The published literature to date provides only weak support for the efficacy of WBV exposure for muscle function, muscle morphology, or bone architecture in older adults. Irregularities in study design and WBV protocols across the literature and poor quality trials contribute to this inconsistency, revealing the need for more uniformity in future trials. Future research should be more robust in design, include larger cohorts, longer interventions and standardisation of protocols. They should also investigate the optimal dose-response relationships and variation in vibration characteristics, to determine the true efficacy, clinical relevance, and underlying mechanisms of muscle and bone adaptations.

Handgrip strength and mortality in the oldest old population: the Leiden 85-plus study

BACKGROUND

Poor muscular strength has been shown to be associated with increased morbidity and mortality in diverse samples of middle-aged and elderly people. However, the oldest old population (i.e., over 85 years) is underrepresented in such studies. Our objective was to assess the association between muscular strength and mortality in the oldest old population.

METHODS

We included 555 participants (65% women) from the Leiden 85-plus study, a prospective population-based study of all 85-year-old inhabitants of Leiden, Netherlands. We measured the handgrip strength of participants at baseline and again at age 89 years. We collected baseline data on comorbidities, functional status, levels of physical activity, and adjusted for potential confounders. During the follow-up period, we collected data on mortality.

RESULTS

During a follow-up period of 9.5 years (range 8.5-10.5 years), 444 (80%) participants died. Risk for all-cause mortality was elevated among participants in the lowest tertile of handgrip strength at age 85 years (hazard ratio [HR] 1.35, 95% confidence interval [CI] 1.00-1.82, p = 0.047) and the lowest two tertiles of handgrip strength at age 89 years (HR 2.04, CI 1.24-3.35, p = 0.005 and HR 1.73, CI 1.11-2.70, p = 0.016). We also observed significantly increased mortality among participants in the tertile with the highest relative loss of handgrip strength over four years (HR 1.72, CI 1.07-2.77, p = 0.026).

INTERPRETATION

Handgrip strength, a surrogate measurement of overall muscular strength, is a predictor of all-cause mortality in the oldest old population and may serve as a convenient tool for prognostication of mortality risk among elderly people.

Testosterone supplementation reverses sarcopenia in aging through regulation of myostatin, c-Jun NH2-terminal kinase, Notch, and Akt signaling pathways

Aging in rodents and humans is characterized by loss of muscle mass (sarcopenia). Testosterone supplementation increases muscle mass in healthy older men. Here, using a mouse model, we investigated the molecular mechanisms by which testosterone prevents sarcopenia and promotes muscle growth in aging. Aged mice of 22 months of age received a single sc injection of GnRH antagonist every 2 wk to suppress endogenous testosterone production and were implanted subdermally under anesthesia with 0.5 or 1.0 cm testosterone-filled implants for 2 months (n = 15/group). Young and old mice (n = 15/group), of 2 and 22 months of age, respectively, received empty implants and were used as controls. Compared with young animals, a significant (P < 0.05) increase in muscle cell apoptosis coupled with a decrease in gastrocnemius muscles weight (by 16.7%) and muscle fiber cross-sectional area, of both fast and slow fiber types, was noted in old mice. Importantly, such age-related changes were fully reversed by higher dose (1 cm) of testosterone treatment. Testosterone treatment effectively suppressed age-specific increases in oxidative stress, processed myostatin levels, activation of c-Jun NH(2)-terminal kinase, and cyclin-dependent kinase inhibitor p21 in aged muscles. Furthermore, it restored age-related decreases in glucose-6-phosphate dehydrogenase levels, phospho-Akt, and Notch signaling. These alterations were associated with satellite cell proliferation and differentiation. Collectively these results suggest involvement of multiple signal transduction pathways in sarcopenia. Testosterone reverses sarcopenia through stimulation of cellular metabolism and survival pathway together with inhibition of death pathway.

Association between fitness and changes in body composition and muscle strength

OBJECTIVES

To examine the association between physical fitness, assessed according to ability and time to complete a 400-m walk, on changes in body composition and muscle strength over a 7-year period.

DESIGN

Prospective observational cohort study.

SETTING

Memphis, Tennessee, and Pittsburgh, Pennsylvania.

PARTICIPANTS

Two thousand nine hundred forty-nine black and white men and women aged 70 to 79 participating in the Health, Aging and Body Composition Study.

MEASUREMENTS

Body composition (fat and bone-free lean mass) was assessed using dual-energy X-ray absorptiometry in Years 1 to 6 and 8. Knee extension strength was measured using isokinetic dynamometry and grip strength using isometric dynamometry in Years 1, 2, 4, 6, and 8.

RESULTS

Less fit people weighed more and had a higher total percentage of fat and a lower total percentage of lean mass than very fit men and women at baseline (P<.001). Additionally, the least fit lost significantly more weight, fat mass, and lean mass over time than the very fit (all P<.01). Very fit people had the highest grip strength and knee extensor strength at baseline and follow-up; decline in muscle strength was similar in every fitness group.

CONCLUSION

Low fitness in old age was associated with greater weight loss and loss of lean mass than with high fitness. Despite having lower muscle strength, the rate of decline in the least fit persons was similar to that in the most fit. In clinical practice, a long-distance walk test as a measure of fitness might be useful to identify people at risk for these adverse health outcomes.

The effects of supplementation with creatine and protein on muscle strength following a traditional resistance training program in middle-aged and older men

OBJECTIVES

Creatine and protein supplementation can enhance the training outcomes of young subjects, but it is not clear if there are benefits for older individuals. Therefore, the purpose of this study was to determine the effects of creatine and protein supplementation on strength gains following a traditional resistance training program for middle-aged and older men.

DESIGN, SETTING, PARTICIPANTS

This study assessed changes in strength of men aged 48-72 years following 14 weeks of resistance training supplemented with creatine and/or protein. A double-blind, randomized, placebo-controlled design placed 42 males into one of four groups: Resistance Trained Placebo (RTP, n=10); Resistance Trained Creatine (RTCr, 5g Cr, n=10); Resistance Trained Protein (RTPr, 35g whey Pr, n=11); or Resistance Trained Creatine and Protein (RTCrPr, 5g Cr and 35g Pr, n=11).

INTERVENTION

All groups trained 3 days per week for 14 weeks. The resistance training program was based on progressive overload. Training loads corresponded to 80% 1 RM (one repetition maximum strength), 3 sets of 8 repetitions for the following exercises: knee extension/knee flexion; bicep curl/tricep extension; military press; lat pull down; seated leg press; and bench press.

MEASUREMENTS

1 RM for each exercise and measures of lean body mass were assessed prior to and following the 14 week program.

RESULTS

Each group significantly (p < 0.05) increased strength and lean body mass, however, there were no significant group effects or group X trial interactions.

CONCLUSION

Resistance training in middle-aged and older men significantly increased muscular strength and added muscle mass with no additional benefits from creatine and/or protein supplementation.

Understanding sarcopenia as a geriatric syndrome

PURPOSE OF REVIEW

Highly prevalent in the population older than 65 years and leading to poor outcomes (functional decline and its related consequences), sarcopenia does not benefit yet either of a clear understanding of its pathophysiology or of precise clinical or biological markers allowing its identification.

RECENT FINDINGS

The new scientific definition of 'geriatric syndromes' challenges the authors to review the current sarcopenia literature, allowing them to affirm that sarcopenia cannot be considered as an age-related disease but as a true 'geriatric syndrome'. More than 50% of the population older than 80 years suffer from this medical condition, which is linked to multiple causations: the ageing process itself, genetic susceptibility, certain life habits, changes in living conditions and a number of chronic diseases. Moreover, sarcopenia favours poor outcomes such as mobility disorders, disability, poor quality of life and death.

SUMMARY

Considering sarcopenia as a geriatric syndrome allows us to request its recognition and assess its multiple risk factors, to implement a clinical and public health approach to the management of sarcopenic patients and population at risk and to disentangle the links among sarcopenia, frailty, disability and mortality.

Arquitetura muscular e envelhecimento: adaptação funcional e aspectos clínicos; revisão da literatura

O envelhecimento é associado a um progressivo declínio na massa muscular, conhecido como sarcopenia, que afeta diretamente a arquitetura e a capacidade de produção de força muscular. O objetivo deste artigo foi revisar a literatura sobre os efeitos do envelhecimento sobre a arquitetura muscular, bem como revisar as principais evidências dos efeitos de programas de treinamento de força nas propriedades morfológicas da musculatura esquelética, discutindo as implicações clínicas da adaptação funcional na população idosa. Foram selecionados 42 artigos publicados entre 1993 e 2008 nas bases de dados Pubmed, Science Direct e Scopus, utilizando os descritores aging, older adults, elderly, muscle architecture, strength training e resistance training. Os artigos revisados suportam a idéia de que existem diferenças na arquitetura do músculo esquelético de idosos acometidos por sarcopenia quando comparados a adultos jovens saudáveis. As evidências parecem ser unânimes quanto à redução no volume, área de seção transversa fisiológica e ângulo de penação do músculo esquelético de idosos. Além disso, também há evidências de que o envelhecimento determina uma redução do comprimento fascicular e da espessura muscular, o que gera uma redução também da área de seção transversa anatômica. Programas terapêuticos de treinamento de força têm sido utilizados com o objetivo de retardar e até mesmo reverter os efeitos do envelhecimento sobre a musculatura dos idosos.

Epidemiology and consequences of sarcopenia

Sarcopenia is an evolving concept and the current definition of sarcopenia includes both a loss of muscle strength and loss of muscle mass. However, despite the increasing knowledge and improved technology, a worldwide operational definition of sarcopenia applicable across racial/ethnic groups and populations lacks consensus. As a result the prevalence of sarcopenia (8 to 40% of older people over 60 years) varies depending on the study sample (namely the age of the sample), the definition, and the assessment tool used. DXA is the main assessment method used to evaluate muscle mass, which is further adjusted to height, weight fat mass, or BMI to obtain an index of sarcopenia. Cross-sectional analyses seemed to prove an association between low muscle mass and functional decline, but these results were not consistent when analysed longitudinally over time. This inconsistency could be due to methodological issues as the selected populations in the cohorts where autonomous, community-dwelling, older people. In this highly active population decreases in muscle mass might be not as important as decreases in strength to predict functional decline. The aim of the present paper was to perform a comprehensive review of the literature on the epidemiology of sarcopenia and its consequences to be presented on November 13th and 14th 2008, at the Carla Workshop.

Towards a definition of sarcopenia--results from epidemiologic studies

The age-related loss of muscle mass, also called sarcopenia, is receiving increasing attention in aging research. While the concept is frequently being used in research settings and introduced to clinical settings, thus far no consensus on its definition has been established. This article provides an overview of the history of sarcopenia definitions proposed in the literature thus far. It will describe the methodology used to develop the cutpoints for low muscle mass (or strength) in large epidemiological studies, how sarcopenia based on these cutpoints relates to functional outcomes, and the advantages and disadvantages of the different definitions. This overview will contribute to the current need to develop a consensus definition of sarcopenia which can be used in all relevant settings.

Influência da ordem dos exercícios sobre o número de repetições e percepção subjetiva do esforço em mulheres jovens e idosas

Estudos sobre a influência da ordem de execução dos exercícios no desempenho da força em idosos são escassos. O objetivo do presente estudo foi comparar a influência da ordem de execução dos exercícios sobre o número de repetições e percepção de esforço de oito idosas (69 ± 7 anos) e 12 jovens (22 ± 2 anos) praticantes de treinamento resistido. As voluntárias executaram sessões com três séries até a exaustão com cargas estabelecidas em 10 repetições máximas (RM), em sequências invertidas de exercícios: sequência A - supino horizontal (SH), desenvolvimento em pé (DP) e rosca tríceps no pulley baixo (TP); sequência B - TP, DP e SH. A ANOVA de duas entradas com medidas repetidas revelou que o número de repetições no grupo de jovens foi sempre menor no último exercício, independentemente da sequência ou grupamento muscular envolvido (p < 0,05). O número de repetições permaneceu estável na sequência A para grupo de idosas, mas declinou significativamente na sequência B (p < 0,05). Não houve diferenças para a percepção de esforço ao final das sequências no grupo de jovens, mas no grupo de idosas a PSE foi significativamente maior em na sequência B (p < 0,05). Conclui-se que a ordem dos exercícios foi indiferente para o desempenho do grupo jovem, mas influenciou o número máximo de repetições em cada exercício e a percepção de esforço ao final das sequências no grupo de idosas.

Whole-body vibration augments resistance training effects on body composition in postmenopausal women

Age-related changes in body composition are well-documented with a decrease in lean body mass and a redistribution of body fat generally observed. Resistance training alone has been shown to have positive effects on body composition, however, these benefits may be enhanced by the addition of a vibration stimulus.

OBJECTIVE

The purpose of this study was to determine the effects of 8 months of resistance training with and without whole-body vibration (WBV) on body composition in sedentary postmenopausal women.

METHODS

Fifty-five women were assigned to resistance only (RG, n=22), vibration plus resistance (VR, n=21) or non-exercising control (CG, n=12) groups. Resistance training (3 sets 10 repetitions 80% strength) was performed using isotonic weight training equipment and whole-body vibration was done with the use of the power plate (Northbrooke, IL) vibration platform for three times per week for 8 months. Total and regional body composition was assessed from the total body DXA scans at baseline (pre) and after 8 months (post) of training.

RESULTS

In the VR group, total % body fat decreased from pre- to post-time points (p<0.05), whereas, the CG group had a significant increase in total % body fat (p<0.05). Both training groups exhibited significant increases in bone free lean tissue mass for the total body, arm and trunk regions from pre to post (p<0.05). CG did not show any changes in lean tissue.

CONCLUSION

In older women, resistance training alone and with whole-body vibration resulted in positive body composition changes by increasing lean tissue. However, only the combination of resistance training and whole-body vibration was effective for decreasing percent body fat.

Chronic inflammation is associated with low physical function in older adults across multiple comorbidities

BACKGROUND

Chronic subclinical inflammation may contribute to impaired physical function in older adults; however, more data are needed to determine whether inflammation is a common mechanism for functional decline, independent of disease or health status.

METHODS

We examined associations between physical function and inflammatory biomarkers in 542 older men and women enrolled in four clinical studies at Wake Forest University between 2001 and 2006. All participants were at least 55 years and had chronic obstructive pulmonary disease, congestive heart failure, high cardiovascular risk, or self-reported physical disability. Uniform clinical assessments were used across studies, including grip strength; a Short Physical Performance Battery (SPPB; includes balance, 4-m walk, and repeated chair stands); inflammatory biomarker assays for interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), and C-reactive protein (CRP); and anthropometric measures.

RESULTS

Higher levels of CRP and IL-6, but not TNF-alpha, were associated with lower grip strength and SPPB scores and longer times to complete the 4-m walk and repeated chair stands tests, independent of age, gender, and race. More importantly, these relationships were generally independent of disease status. Further adjustment for fat mass, lean mass, or percent body fat altered some of these relationships but did not significantly change the overall results.

CONCLUSIONS

Elevated CRP and IL-6 levels are associated with poorer physical function in older adults with various comorbidities, as assessed by a common battery of clinical assessments. Chronic subclinical inflammation may be a marker of functional limitations in older persons across several diseases/health conditions.

Metabolic syndrome and risk factors for cardiovascular disease: are nonagenarians protected?

This study assessed cardiovascular disease risk factors in three groups of human subjects aged 20-34 [young, 20 male (M)/33 female (F)], 60-74 (aged, 29M/29F), and > 90 years (nonagenarian, 47M/50F). Components of the metabolic syndrome, cardiovascular disease, and markers of inflammation and oxidative stress were assessed. Nonagenarians weighed less than the two other groups (P < 0.001); however, there was no difference in percent fat among the three groups. Aged individuals had the highest prevalence of the metabolic syndrome (P < 0.001) according to the Adult Treatment Panel III classification. Both fibrinogen and homocysteine concentrations were significantly higher in the nonagenarians compared to younger groups. However, there were no significant differences between groups in fasting insulin, high sensitive C-reactive protein, and plasminogen activator inhibitor 1 concentrations. There were also no relationships between inflammation/ oxidative stress and the metabolic syndrome or cardiovascular disease although nonagenarians appear to be protected from oxidative damage to DNA.

Skeletal muscle and mortality results from the InCHIANTI Study

BACKGROUND

Sarcopenia, the age-related loss of muscle mass, may not be an isolated process but is associated with an increase in fat mass. The aim of this study was to estimate the mortality risk of sarcopenia in the presence or absence of obesity.

METHODS

Data are from 934 participants aged 65 years or older, enrolled in the "Invecchiare in Chianti" study, and followed for 6 years. At baseline, a peripheral quantitative computerized tomography (pQCT) scan was performed on all participants to evaluate the muscle density, and the muscular and fat cross-sectional areas of the calf. Walking speed was measured on a 7-m track. Cox proportional hazard models were performed to estimate the association of pQCT measures (per 1 standard deviation increase) with mortality.

RESULTS

Unadjusted analyses showed significant associations of muscle density (hazard ratio [HR] 0.78, 95% confidence interval [CI] 0.69-0.88), muscle area (HR 0.75, 95% CI 0.66-0.86), and fat area (HR 0.82, 95% CI 0.73-0.92) with mortality. After adjustment for potential confounders, no body composition parameter was significantly associated with mortality. Walking speed (used as a reference measure to verify whether the negative results were due to peculiarities of the study sample) confirmed its well-established association with mortality risk (HR 0.73, 95% CI 0.60-0.88). These results did not change after the analyses were stratified according to sarcopenia and body mass index groups, and restricted to participants with frailty or a high inflammatory profile.

CONCLUSIONS

Calf skeletal muscle and fat mass are not significant risk factors for mortality in community-dwelling older adults. Walking speed confirmed to be a powerful predictor of health-related events.