Sarcopenia: European consensus on definition and diagnosis: Report of the European Working Group on Sarcopenia in Older People

Sarcopenia, dynapenia, and the impact of advancing age on human skeletal muscle size and strength; a quantitative review

Changing demographics make it ever more important to understand the modifiable risk factors for disability and loss of independence with advancing age. For more than two decades there has been increasing interest in the role of sarcopenia, the age-related loss of muscle or lean mass, in curtailing active and healthy aging. There is now evidence to suggest that lack of strength, or dynapenia, is a more constant factor in compromised wellbeing in old age and it is apparent that the decline in muscle mass and the decline in strength can take quite different trajectories. This demands recognition of the concept of muscle quality; that is the force generating per capacity per unit cross-sectional area (CSA). An understanding of the impact of aging on skeletal muscle will require attention to both the changes in muscle size and the changes in muscle quality. The aim of this review is to present current knowledge of the decline in human muscle mass and strength with advancing age and the associated risk to health and survival and to review the underlying changes in muscle characteristics and the etiology of sarcopenia. Cross-sectional studies comparing young (18–45 years) and old (>65 years) samples show dramatic variation based on the technique used and population studied. The median of values of rate of loss reported across studies is 0.47% per year in men and 0.37% per year in women. Longitudinal studies show that in people aged 75 years, muscle mass is lost at a rate of 0.64–0.70% per year in women and 0.80–00.98% per year in men. Strength is lost more rapidly. Longitudinal studies show that at age 75 years, strength is lost at a rate of 3–4% per year in men and 2.5–3% per year in women. Studies that assessed changes in mass and strength in the same sample report a loss of strength 2–5 times faster than loss of mass. Loss of strength is a more consistent risk for disability and death than is loss of muscle mass.

A prospective study of frailty in nephrology-referred patients with CKD

BACKGROUND

Frailty is a construct developed to characterize a state of reduced functional capacity in older adults. However, there are limited data describing the prevalence or consequences of frailty in middle-aged patients with chronic kidney disease (CKD).

STUDY DESIGN

Observational study.

SETTING & PARTICIPANTS

336 non-dialysis-dependent patients with stages 1-4 CKD with estimated glomerular filtration rate (eGFR) <90 mL/min/1.73 m(2) (by the CKD-EPI [CKD Epidemiology Collaboration] serum creatinine-based equation) or evidence of microalbuminuria enrolled in the Seattle Kidney Study, a clinic-based cohort study. Findings were compared with community-dwelling older adults in the Cardiovascular Health Study.

OUTCOME

Prevalence and determinants of frailty in addition to its association with the combined outcome of all-cause mortality or renal replacement therapy.

MEASUREMENTS

We defined frailty according to established criteria as 3 or more of the following characteristics: slow gait, weakness, unintentional weight loss, exhaustion, and low physical activity. We estimated kidney function using serum cystatin C concentrations (eGFR(cys)) to minimize confounding due to relationships of serum creatinine levels with muscle mass and frailty.

RESULTS

The mean age of the study population was 59 years and mean eGFR(cys) was 51 mL/min/1.73 m(2). The prevalence of frailty (14.0%) was twice that of the much older non-CKD reference population (P < 0.01). The most common frailty components were physical inactivity and exhaustion. After adjustment including diabetes, eGFR(cys) categories of <30 and 30-44 mL/min/1.73 m(2) were associated with a 2.8- (95% CI, 1.3-6.3) and 2.1 (95% CI, 1.0-4.7)-fold greater prevalence of frailty compared with GFR(cys) ≥60 mL/min/1.73 m(2). There were 63 events during a median 987 days of follow-up. After adjustment, the frailty phenotype was associated with an estimated 2.5 (95% CI, 1.4-4.4)-fold greater risk of death or dialysis therapy.

LIMITATIONS

Cross-sectional study design obscures inference regarding temporal relationships between CKD and frailty.

CONCLUSIONS

Frailty is relatively common in middle-aged patients with CKD and is associated with lower eGFR(cys) and increased risk of death or dialysis therapy.

Mass spectrometry-based proteomic analysis of middle-aged vs. aged vastus lateralis reveals increased levels of carbonic anhydrase isoform 3 in senescent human skeletal muscle

The age-related loss of skeletal muscle mass and associated progressive decline in contractile strength is a serious pathophysiological issue in the elderly. In order to investigate global changes in the skeletal muscle proteome after the fifth decade of life, this study analysed total extracts from human vastus lateralis muscle by fluorescence difference in-gel electrophoresis. Tissue specimens were derived from middle-aged (47-62 years) vs. aged (76-82 years) individuals and potential changes in the protein expression profiles were compared between these two age groups by a comprehensive gel electrophoresis-based survey. Age-dependent alterations in the concentration of 19 protein spots were revealed and mass spectrometry identified these components as being involved in the excitation-contraction-relaxation cycle, muscle metabolism, ion handling and the cellular stress response. This indicates a generally perturbed protein expression pattern in senescent human muscle. Increased levels of mitochondrial enzymes and isoform switching of the key contractile protein, actin, support the idea of glycolytic-to-oxidative and fast-to-slow transition processes during muscle aging. Importantly, the carbonic anhydrase (CA)3 isoform displayed an increased abundance during muscle aging, which was independently verified by immunoblotting of differently aged human skeletal muscle samples. Since the CA3 isoform is relatively muscle-specific and exhibits a fibre type-specific expression pattern, this enzyme may represent an interesting new biomarker of sarcopenia. Increased levels of CA are indicative of an increased demand of CO₂-removal in senescent muscle, and also suggest age-related fibre type shifting to slower-contracting muscles during human aging.

Protein supplementation increases muscle mass gain during prolonged resistance-type exercise training in frail elderly people: a randomized, double-blind, placebo-controlled trial

OBJECTIVES

Protein supplementation has been proposed as an effective dietary strategy to augment the skeletal muscle adaptive response to prolonged resistance-type exercise training in elderly people. Our objective was to assess the impact of protein supplementation on muscle mass, strength, and physical performance during prolonged resistance-type exercise training in frail elderly men and women.

DESIGN/SETTING/PARTICIPANTS

A randomized, double-blind, placebo-controlled trial with 2 arms in parallel among 62 frail elderly subjects (78 ± 1 year). These elderly subjects participated in a progressive resistance-type exercise training program (2 sessions per week for 24 weeks) during which they were supplemented twice daily with either protein (2 * 15 g) or a placebo.

MEASUREMENTS

Lean body mass (DXA), strength (1-RM), and physical performance (SPPB) were assessed at baseline, and after 12 and 24 weeks of intervention.

RESULTS

Lean body mass increased from 47.2 kg (95% CI, 43.5-50.9) to 48.5 kg (95% CI, 44.8-52.1) in the protein group and did not change in the placebo group (from 45.7 kg, 95% CI, 42.1-49.2 to 45.4 kg, 95% CI, 41.8-48.9) following the intervention (P value for treatment × time interaction = .006). Strength and physical performance improved significantly in both groups (P = .000) with no interaction effect of dietary protein supplementation.

CONCLUSIONS

Prolonged resistance-type exercise training represents an effective strategy to improve strength and physical performance in frail elderly people. Dietary protein supplementation is required to allow muscle mass gain during exercise training in frail elderly people.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT01110369.

The effects of exercise on strength and physical performance in frail older people: a systematic review

The proportion of older people becoming frail will increase with the expanding older population. Apart from poor health, frailty is associated with loss of strength and functional dependency. Building on previous work in this area, this review investigates the effectiveness, sustainability and adverse effects of exercise interventions on muscle strength and physical performance in frail older people. Randomized controlled trials reporting physical outcomes in frail older people were identified from seven electronic databases. Thirteen trials involving 1652 participants met the inclusion criteria. There was wide heterogeneity in degree of frailty, types of intervention, outcome measures and results. However, evidence from this review suggests that exercise and some physical activity programmes, particularly moderate intensity and multi-component programmes, are safe and can improve strength and function in the majority of frail older people except highly frail individuals with multiple co-morbidities. There was limited evidence on transferability of improvements into everyday life, and sustainability could not be determined.

Sarcopenic indices in community-dwelling older adults

BACKGROUND

Sarcopenic (SP) indices are used to estimate loss of skeletal lean mass and function and to determine the prevalence of SP in older adults. It is believed that older women and men with lower skeletal lean mass will be weaker and have more functional limitations.

PURPOSE

(1) To classify community-dwelling older adults using 2 common SP indices: appendicular lean mass/height² (ALM/ht²) and skeletal muscle index (SMI), and (2) to determine each indices value as indicators of lower extremity strength and physical function.

METHODS

The sample consisted of 154 community-dwelling older adults (111 women and 43 men; mean age = 82.4, SD = 3.6 years; mean body mass index = 25.8, SD = 4.4 kg/m). Each underwent whole-body dual-energy x-ray absorptiometry to assess lean mass. The 9-item modified Physical Performance Test and self-selected walking speed were used to evaluate function. Lower extremity strength was measured bilaterally using isokinetic dynamometry.

RESULTS

The ALM/ht² index classified 75 participants (49%) as SP and 79 (51%) as nonsarcopenic (NSP). The SMI classified 129 participants (84%) as SP and 25 (16%) as NSP. There were no differences in functional measures between groups by gender using either index after classification. The ALM/ht index was more strongly correlated with peak torque of all lower extremity muscle groups (r = 0.276-0.487) compared with the SMI (r = 0.103-0.344). There was no relationship between SP index and physical function.

DISCUSSION

There were marked differences in how 2 SP indices classified community-dwelling older adults. Lower extremity strength was lower in older women classified as SP than NSP using the ALM/ht index, but LE strength was not different in older men. However, no lower extremity strength differences were observed between SP and NSP men or women using the SMI classification. None of the SP index uniformly identified community-dwelling older adults with functional or strength deficits.

CONCLUSIONS

Detection of strength deficits using SP indices alone may be gender-specific and may not reflect strength or functional decline in community-dwelling men aged 80 years or older. Given associations between lower extremity strength and physical function, strength measures remain a better predictor of physical performance than SP indices for community-dwelling older men and women.

Prevalence rate and associated factors of sarcopenic obesity in korean elderly population

This study was conducted to estimate the prevalence rates and to explore associated factors of sarcopenic obesity (SO) in 2,221 Koreans over 60 yr-of age from the Fourth Korea National Health and Nutrition Examination Survey (2009). Participants were assessed by dual energy X-ray absorptiometry. Appendicular skeletal muscle mass divided by body weight was used to define sarcopenia and waist circumference was used to define obesity. We estimated the prevalence rates of SO according to age-groups, sex and region. In addition, each group was compared by demographic characteristics, metabolic status, nutrition, and physical activity. The prevalence rates of SO were 6.1% (95% confidential interval [CI] = 6.1-6.2) for men and 7.3% (95% CI = 7.3-7.3) for women, respectively. SO was positively associated with no current working and the number of combined medical conditions. High serum insulin level was positively associated with SO, whereas vitamin D was negatively associated with SO in both men and women. In conclusion, the prevalence rates of SO are 6.1% in men and 7.3% in women. SO is associated with insulin resistance, inappropriate nutrition, and low physical activity.

Frailty and sarcopenia: definitions and outcome parameters

An operational definition of musculoskeletal decline in older people is needed to allow development of interventions for prevention or treatment, as was developed for the treatment of osteoporosis. Frailty and sarcopenia are linked, but distinct, correlates of musculoskeletal aging that have many causes, including age-related changes in body composition, inflammation, and hormonal imbalance. With the emergence of a number of exciting candidate therapies to retard the loss of muscle mass with aging, the derivation of a consensual definition of sarcopenia and physical frailty becomes an urgent priority. Although several consensual definitions have been proposed, these require clinical validation. An operational definition, which might provide a threshold for treatment/trial inclusion, should incorporate a loss of muscle mass as well as evidence of a decrease in muscle strength and/or physical activity. Evidence is required for a link between improvements in the measures of muscle strength and/or physical activity and clinical outcomes to allow development of interventions to improve clinical outcomes in frail older patients.

Clinical observations in total body DXA: technical aspects of positioning and analysis

Total body (TB) dual-energy X-ray absorptiometry (DXA) can assess regional body composition, which may necessitate greater attention to patient positioning and analysis than required for whole body assessment. This report describes technical challenges experienced in performing TB DXA, explores the frequency with which autoanalysis inaccuracies occur, assesses their effect on regional body composition results, and describes a uniform clinical approach for TB DXA positioning and analysis. Patient positioning followed manufacturer recommendations with additional facility-imposed procedures. On visual inspection, it was apparent that automated analysis often did not meet manufacturer guidelines, thus requiring manual alteration. To explore the frequency with which manual adjustments were needed, and the impact on results, TB scans were obtained in 20 men and 20 women aged 18-93 yr. The head line was altered in 98%, one or both shoulder lines in 93%, and the lateral hip boundary in 40%. Manual and automated TB analyses were highly correlated (r(2)=0.98-1.00). However, regional result correlation was less robust, that is, automated and manual appendicular lean mass differed by more than our least significant change in 33%. In conclusion, manual correction of automated TB DXA scan analysis is often needed. Such alterations do not affect TB measures but may affect regional body composition results.

Automated rodent in situ muscle contraction assay and myofiber organization analysis in sarcopenia animal models

Age-related sarcopenia results in frailty and decreased mobility, which are associated with increased falls and long-term disability in the elderly. Given the global increase in lifespan, sarcopenia is a growing, unmet medical need. This report aims to systematically characterize muscle aging in preclinical models, which may facilitate the development of sarcopenia therapies. Naïve rats and mice were subjected to noninvasive micro X-ray computed tomography (micro-CT) imaging, terminal in situ muscle function characterizations, and ATPase-based myofiber analysis. We developed a Definiens (Parsippany, NJ)-based algorithm to automate micro-CT image analysis, which facilitates longitudinal in vivo muscle mass analysis. We report development and characterization of translational in situ skeletal muscle performance assay systems in rat and mouse. The systems incorporate a custom-designed animal assay stage, resulting in enhanced force measurement precision, and LabVIEW (National Instruments, Austin, TX)-based algorithms to support automated data acquisition and data analysis. We used ATPase-staining techniques for myofibers to characterize fiber subtypes and distribution. Major parameters contributing to muscle performance were identified using data mining and integration, enabled by Labmatrix (BioFortis, Columbia, MD). These technologies enabled the systemic and accurate monitoring of muscle aging from a large number of animals. The data indicated that longitudinal muscle cross-sectional area measurement effectively monitors change of muscle mass and function during aging. Furthermore, the data showed that muscle performance during aging is also modulated by myofiber remodeling factors, such as changes in myofiber distribution patterns and changes in fiber shape, which affect myofiber interaction. This in vivo muscle assay platform has been applied to support identification and validation of novel targets for the treatment of sarcopenia.

Effects of meal frequency on metabolic profiles and substrate partitioning in lean healthy males

Introduction

The daily number of meals has an effect on postprandial glucose and insulin responses, which may affect substrate partitioning and thus weight control. This study investigated the effects of meal frequency on 24 h profiles of metabolic markers and substrate partitioning.

Methods

Twelve (BMI:21.6±0.6 kg/m²) healthy male subjects stayed after 3 days of food intake and physical activity standardization 2×36 hours in a respiration chamber to measure substrate partitioning. All subjects randomly received two isoenergetic diets with a Low meal Frequency (3×; LFr) or a High meal Frequency (14×; HFr) consisting of 15 En% protein, 30 En% fat, and 55 En% carbohydrates. Blood was sampled at fixed time points during the day to measure metabolic markers and satiety hormones.

Results

Glucose and insulin profiles showed greater fluctuations, but a lower AUC of glucose in the LFr diet compared with the HFr diet. No differences between the frequency diets were observed on fat and carbohydrate oxidation. Though, protein oxidation and RMR (in this case SMR + DIT) were significantly increased in the LFr diet compared with the HFr diet. The LFr diet increased satiety and reduced hunger ratings compared with the HFr diet during the day.

Conclusion

The higher rise and subsequently fall of insulin in the LFr diet did not lead to a higher fat oxidation as hypothesized. The LFr diet decreased glucose levels throughout the day (AUC) indicating glycemic improvements. RMR and appetite control increased in the LFr diet, which can be relevant for body weight control on the long term.

Trial Registration

ClinicalTrails.gov NCT01034293

Sarcopenia and mortality among older nursing home residents

BACKGROUND AND AIMS

Sarcopenia has been indicated as a reliable marker of frailty and poor prognosis among the oldest individuals. At present, no data are available on sarcopenia in the nursing home population. The aim of the current study was to explore the relationship between sarcopenia and all-cause mortality in a population of elderly persons aged 70 years and older living in a nursing home in Italy.

METHODS

This study was conducted among all subjects (n = 122) aged 70 years and older who lived in the teaching nursing home of Catholic University of Rome between August 1, 2010, and September 30, 2010. According to the European Working Group on Sarcopenia in Older People (EWGSOP), sarcopenia was diagnosed in presence of low muscle mass plus either low muscle strength or low physical performance. The primary outcome measure was survival after 6 months.

RESULTS

Forty residents (32.8%) were indentified as affected by sarcopenia. This condition was more common in men (68%) than in women (21%). During the follow-up period, 26 (21.3%) patients died. After adjusting for age, gender, cerebrovascular diseases, osteoarthritis, chronic obstructive pulmonary disease, activity of daily living impairment, and body mass index, residents with sarcopenia were more likely to die compared with those without sarcopenia (adjusted hazard ratio 2.34; 95% confidence interval 1.04-5.24).

CONCLUSIONS

The present study suggests that among subjects living in a nursing home, sarcopenia is highly prevalent and is associated with a significantly increased risk of all-cause death. The current findings support the possibility that sarcopenia has an independent effect on survival among nursing home residents.

Age-related changes in speed and mechanism of adult skeletal muscle stem cell migration

Skeletal muscle undergoes a progressive age-related loss in mass and function. Preservation of muscle mass depends in part on satellite cells, the resident stem cells of skeletal muscle. Reduced satellite cell function may contribute to the age-associated decrease in muscle mass. Here, we focused on characterizing the effect of age on satellite cell migration. We report that aged satellite cells migrate at less than half the speed of young cells. In addition, aged cells show abnormal membrane extension and retraction characteristics required for amoeboid-based cell migration. Aged satellite cells displayed low levels of integrin expression. By deploying a mathematical model approach to investigate mechanism of migration, we have found that young satellite cells move in a random "memoryless" manner, whereas old cells demonstrate superdiffusive tendencies. Most importantly, we show that nitric oxide, a key regulator of cell migration, reversed the loss in migration speed and reinstated the unbiased mechanism of movement in aged satellite cells. Finally, we found that although hepatocyte growth factor increased the rate of aged satellite cell movement, it did not restore the memoryless migration characteristics displayed in young cells. Our study shows that satellite cell migration, a key component of skeletal muscle regeneration, is compromised during aging. However, we propose clinically approved drugs could be used to overcome these detrimental changes.

A moderate acute increase in physical activity enhances nutritive flow and the muscle protein anabolic response to mixed nutrient intake in older adults

BACKGROUND

Nutrient stimulation of muscle protein anabolism is blunted with aging and may contribute to the development and progression of sarcopenia in older adults. This is likely due to insulin resistance of protein metabolism and/or endothelial dysfunction with a reduction in nutritive flow, both of which can be improved by aerobic exercise.

OBJECTIVE

Our objective was to determine whether increasing physical activity can enhance the muscle protein anabolic effect of essential amino acid (EAA) + sucrose intake in older subjects by improving nutritive flow and/or insulin signaling.

DESIGN

Using a randomized crossover design, we measured in older subjects [n = 6, 70 ± 3 y of age, BMI (in kg/m2) of 25 ± 1] the acute effects of increasing physical activity with aerobic exercise, as compared with normal sedentary lifestyle, on the response of blood flow, microvascular perfusion, insulin signaling, and muscle protein kinetics to EAA+sucrose intake.

RESULTS

No differences between treatment groups were found in the basal state. The change from the basal state in blood flow, muscle perfusion, phenylalanine delivery, net balance, and muscle protein synthesis during the consumption of EAA+sucrose was significantly higher after the exercise than after the control treatment (P < 0.05). Insulin signaling increased during EAA+sucrose ingestion in both groups (P < 0.05).

CONCLUSIONS

Our data indicate that a prior bout of aerobic exercise increases the anabolic effect of nutrient intake in older adults. This effect appears to be mediated by an exercise-induced improvement in nutrient-stimulated vasodilation and nutrient delivery to muscle rather than to improved insulin signaling. This trial was registered at clinicaltrials.gov as NCT00690534.

Sarcopenia predicts early dose-limiting toxicities and pharmacokinetics of sorafenib in patients with hepatocellular carcinoma

BACKGROUND

Sorafenib induces frequent dose limiting toxicities (DLT) in patients with advanced hepatocellular carcinoma (HCC). Sarcopenia has been associated with poor performance status and shortened survival in cancer patients.

PATIENTS AND METHODS

The characteristics of Child Pugh A cirrhotic patients with HCC receiving sorafenib in our institution were retrospectively analyzed. Sorafenib plasma concentrations were determined at each visit. Toxicities were recorded during the first month of treatment, and sarcopenia was determined from baseline CT-scans.

RESULTS

Forty patients (30 males) were included. Eleven (27.5%) were sarcopenic. Eighteen patients (45%) experienced a DLT during the first month of treatment. Sarcopenic patients experienced significantly more DLTs than non-sarcopenic patients did (82% versus 31%, p = 0.005). Grade 3 diarrhea was significantly more frequent in sarcopenic patients than in non-sarcopenic patients (45.5% versus 6.9%, p = 0.01), but not grade 3 hand foot syndrome reaction (9% versus 17.2%, p = 1). On day 28, median sorafenib AUC (n = 17) was significantly higher in sarcopenic patients (102.4 mg/l.h versus 53.7 mg/l.h, p = 0.013).

CONCLUSIONS

Among cirrhotic Child Pugh A patients with advanced HCC, sarcopenia predicts sorafenib exposure and the occurrence of DLT within the first month of treatment.

Low-grade chronic inflammation and superoxide anion production by NADPH oxidase are the main determinants of physical frailty in older adults

BACKGROUND

Physical performance measured by gait speed is being recognized as a major instrument for clinical evaluation in older adults, because it predicts physical frailty, loss of autonomy, hospitalization and decreased survival. Low-grade chronic inflammation and oxidative stress, mediated partly by the superoxide anion produced by NADPH oxidase, are closely linked and could be involved in age-related physical decline.

OBJECTIVE

To determine whether slow gait speed is associated with superoxide anion overproduction by NADPH oxidase and low-grade chronic inflammation.

DESIGN AND SETTING

Observational study among the 280 elderly of an ambulatory geriatric care unit (191 women, 89 men, 79.9 ± 6.1 years old).

METHODS

Gait speed was evaluated by walking at self-chosen usual pace. Usual gait speed < 0.8 m/s was defined as slow gait speed. Superoxide anion production was evaluated using a lucigenin-based chemiluminescence method. Inflammation was evaluated by CRP, fibrinogen and leukocyte count.

RESULTS

Among the 280 participants, 179 (63.9%) walked with a gait speed < 0.8 m/s (slow walkers) and 101 (36.1%) with a gait speed ≥ 0.8 m/s. Superoxide production and inflammation markers, such as fibrinogen, were more important in slow walkers (p = 0.004 and p = 0.006, respectively). In multivariate analysis, superoxide anion overproduction and fibrinogen were independently associated with physical frailty assessed by slow gait speed (p = 0.028 and p = 0.007, respectively).

CONCLUSION

Physical frailty in older people is associated with superoxide anion overproduction by NADPH oxidase and low-grade chronic inflammation.

Sarcopenia during androgen-deprivation therapy for prostate cancer

PURPOSE

To characterize changes in lean body mass (LBM) in men with prostate cancer receiving androgen-deprivation therapy (ADT).

PATIENTS AND METHODS

We prospectively evaluated LBM in a prespecified substudy of a randomized controlled trial of denosumab to prevent fractures in men receiving ADT for nonmetastatic prostate cancer. LBM was measured by total-body dual-energy x-ray absorptiometry at study baseline and at 12, 24, and 36 months. The analyses included 252 patients (132, denosumab; 120, placebo) with a baseline and at least one on-study LBM assessment. Patients were stratified by age (< 70 v ≥ 70 years) and by ADT duration (≤ 6 v > 6 months).

RESULTS

Median ADT duration was 20.4 months at study baseline. Mean LBM decreased significantly from baseline, by 1.0% at month 12 (95% CI, 0.4% to 1.5%; P < .001; n = 248), by 2.1% at month 24 (95% CI, 1.5% to 2.7%; P < .001; n = 205), and by 2.4% at month 36 (95% CI, 1.6% to 3.2%; P < .001; n = 168). Men age ≥ 70 years (n = 127) had significantly greater changes in LBM at all measured time points than younger men. At 36 months, LBM decreased by 2.8% in men age ≥ 70 years and by 0.9% in younger men (P = .035). Men with ≤ 6 months of ADT at study entry (n = 36) had a greater rate of decrease in LBM compared with men who had received more than 6 months of ADT at study entry (3.7% v 2.0%; P = .0645).

CONCLUSION

In men receiving ADT, LBM decreased significantly after 12, 24, and 36 months.

Adverse effects of coexistence of sarcopenia and metabolic syndrome in Japanese women

BACKGROUND/OBJECTIVES

Little information is available regarding the interactions of sarcopenia and metabolic syndrome (MetS) in the risks of these age-associated diseases in women. The present cross-sectional study was performed to investigate whether the coexistence of sarcopenia and MetS further increases the risks of lifestyle-related diseases in Japanese women.

SUBJECTS/METHODS

Healthy Japanese women (n=533) aged 30-84 participated in this study. MetS was defined as higher body mass index, fasting plasma glucose, systolic or diastolic blood pressure and blood lipid abnormalities. Appendicular muscle mass and bone mineral density (BMD) were measured using dual-energy X-ray absorptiometry. The criterion of low muscle mass and strength defined median skeletal muscle index (appendicular muscle mass/height², kg/m²) and handgrip strength.

RESULTS

Two-way ANCOVA with adjustment for age, body fat percentage and whole-body lean tissue mass indicated that sarcopenia and MetS interacted to produce a significant effect on HbA1c, systolic blood pressure, triglycerides and brachial-ankle pulse wave velocity in Japanese women. The systolic blood pressure, triglycerides and brachial-ankle pulse wave velocity were significantly higher in women with coexisting sarcopenia and MetS than in healthy controls or in those with sarcopenia or MetS alone. The HbA1c in the coexisting sarcopenia and MetS group was higher than in healthy controls and sarcopenia subjects.

CONCLUSIONS

The coexistence of sarcopenia and MetS further increases the risks of cardiovascular diseases, such as type 2 diabetes mellitus, hypertension, arterial stiffness and hyperlipidemia even adjustment of age and body composition in adult Japanese women.

Exercise training attenuates MuRF-1 expression in the skeletal muscle of patients with chronic heart failure independent of age: the randomized Leipzig Exercise Intervention in Chronic Heart Failure and Aging catabolism study

BACKGROUND

Muscle wasting occurs in both chronic heart failure (CHF) and normal aging and contributes to exercise intolerance and increased morbidity/mortality. However, the molecular mechanisms of muscle atrophy in CHF and their interaction with aging are still largely unknown. We therefore measured the activation of the ubiquitin-proteasome system and the lysosomal pathway of intracellular proteolysis in muscle biopsies of CHF patients and healthy controls in two age strata and assessed the age-dependent effects of a 4-week endurance training program on the catabolic-anabolic balance.

METHODS AND RESULTS

Sixty CHF patients (30 patients aged ≤55 years, mean age 46±5 years; 30 patients aged ≥65 years, mean age 72±5 years) and 60 healthy controls (30 subjects aged ≤55 years, mean age 50±5 years; 30 subjects aged ≥65 years, mean age 72±4 years) were randomized to 4 weeks of supervised endurance training or to a control group. Before and after the intervention, vastus lateralis muscle biopsies were obtained. The expressions of cathepsin-L and the muscle-specific E3 ligases MuRF-1 and MAFbx were measured by real-time polymerase chain reaction and confirmed by Western blot. At baseline, MuRF-1 expression was significantly higher in CHF patients versus healthy controls (mRNA: 624±59 versus 401±25 relative units; P=0.007). After 4 weeks of exercise training, MuRF-1 mRNA expression was reduced by -32.8% (P=0.02) in CHF patients aged ≤55 years and by -37.0% (P<0.05) in CHF patients aged ≥65 years.

CONCLUSIONS

MuRF-1, a component of the ubiquitin-proteasome system involved in muscle proteolysis, is increased in the skeletal muscle of patients with heart failure. Exercise training results in reduced MuRF-1 levels, suggesting that it blocks ubiquitin-proteasome system activation and does so in both younger and older CHF patients.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00176319.

Instrumental activities of daily living performance in healthy and cognitively intact seniors from a Brazilian sample and its relation to age and other socio-demographic variables

BACKGROUND

Studies on functional capacity in community-dwelling older people have shown associations between declines in instrumental activities of daily living (IADL) and several factors. Among these, age has been the most consistently related to functional capacity independent of other variables. We aimed at evaluating the performance of a sample of healthy and cognitively intact Brazilian older people on activities of daily living and to analyze its relation to social-demographic variables.

METHODS

We conducted a secondary analysis of data collected for previous epidemiological studies with community-dwelling subjects aged 60 years or more. We selected subjects who did not have dementia or depression, and with no history of neurological diseases, heart attack, HIV, hepatitis or arthritis (n = 1,111). Functional capacity was assessed using the Brazilian version of the Older American Resources and Services Questionnaire (BOMFAQ). ADL performance was analyzed according to age, gender, education, and marital status (Pearson's χ2, logistic regression).

RESULTS

IADL difficulties were present in our sample, especially in subjects aged 80 years or more, with lower levels of education, or widowed. The logistic regression analysis results indicated that "higher age" and "lower education" (p ≤ 0.001) remained significantly associated with IADL difficulty.

CONCLUSIONS

Functional decline was present in older subjects even in the absence of medical conditions and cognitive impairment. Clinicians and researchers could benefit from knowing what to expect from older people regarding IADL performance in the absence of medical conditions.

Malnutrition, fatigue, frailty, vulnerability, sarcopenia and cachexia: overlap of clinical features

PURPOSE OF REVIEW

Malnutrition, fatigue, frailty, vulnerability, sarcopenia and cachexia all phenotypically present with the same features because they are subject to the operation of similar mechanistic factors. However, the conditions referred to above differ by which mechanism dominates the cause of the clinical condition. This review discusses the overlap and differences, which distinguish as well as unite these different conditions and allow a rationale for treatment.

RECENT FINDINGS

In the continuum of malnutrition, cachexia, sarcopenia and frailty the recent activities focus on two areas. The first is a better understanding of the mechanisms of cachexia and sarcopenia and frailty. In particular, the differential effects of cytokines on muscle and on the hypothalamic system. The effects of inactivity promoting the loss of body mass in cachexia and sarcopenia as well as the positive effects of exercise. The second is the development of a synthesis of available literature to develop consensus documents about the definition, causes, diagnosis and treatment of cachexia, sarcopenia and frailty.

SUMMARY

Loss of body tissues resulting in wasting is a common phenotype for several different conditions which can be caused by a combination of reduced food intake, excessive requirements, altered metabolism, sepsis, trauma, ageing and inactivity. They have been referred to loosely as malnutrition but in not all will respond to simply providing nutrients. In this review the common features and the differences as they relate to cause and response to treatment are discussed.

Plasma heat shock protein 72 as a biomarker of sarcopenia in elderly people

Sarcopenia is a geriatric syndrome in which there is a decrease of muscle mass and strength with aging. In age-related loss of muscle strength, there are numerous observations supporting the assertion that neural factors mediate muscle strength. A possible contributing cause may be that aging changes systemic extracellular heat shock protein (eHsp)72 activity. The present study was designed to assess the plasma levels of eHsp72 in elderly people and to investigate its potential interaction with components of sarcopenia. A total of 665 men and women participated in an official medical health examination and an integrated health examination, including psychological and physical fitness tests. Blood samples were assayed for levels of plasma Hsp72, serum C-reactive protein, interleukin 6, tumor necrosis factor α, and regular biomedical parameters. We found that higher Hsp72 in plasma is associated with lower muscle mass, weaker grip strength, and slower walking speed, and may be a potential biomarker of sarcopenia in elderly people. This finding was supported by other results in the present study: (1) older age and shrinking body and lower hemoglobin levels, all of which characterize sarcopenia, were related to higher eHsp72 tertiles and (2) the ORs of the highest tertile of eHsp72 for the lowest tertiles of muscle mass, grip strength, and walking speed were 2.7, 2.6, and 1.8, respectively. These ORs were independent of age, sex, and the incidence of related diseases. Our results would reveal that eHsp72 in plasma is linked to sarcopenia factors and is a potential biomarker or predictor of sarcopenia.

Sarcopenia in the elderly: basic and clinical issues

The original definition of sarcopenia refers to the age-related loss of muscle mass. The literature suggests that the prevalence of sarcopenia in 60- to 70-year-olds is in the range of 5-13%. Prevalence estimates increase to 11-50% for the population aged 80 years or older. Estimates by the World Health Organization suggest that there were 600 million people aged 60 years or older in the year 2000, and that this number will increase to 1.2 billion by the year 2025. There are, however, limited published data on serial measures of muscle mass in older subjects to establish the age-related changes in muscle mass and to relate this change with adverse health consequences. This review is focused on the definition, prevalence, symptoms, pharmacy and physical therapy of sarcopenia in older subjects with the aim of promoting the recognition and treatment of age-related sarcopenia in the clinical setting.

Consensus statement of the Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition: characteristics recommended for the identification and documentation of adult malnutrition (undernutrition)

The Academy of Nutrition and Dietetics (Academy) and the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) recommend that a standardized set of diagnostic characteristics be used to identify and document adult malnutrition in routine clinical practice. An etiologically based diagnostic nomenclature that incorporates a current understanding of the role of the inflammatory response on malnutrition's incidence, progression, and resolution is proposed. Universal use of a single set of diagnostic characteristics will facilitate malnutrition's recognition, contribute to more valid estimates of its prevalence and incidence, guide interventions, and influence expected outcomes. This standardized approach will also help to more accurately predict the human and financial burdens and costs associated with malnutrition's prevention and treatment, and further ensure the provision of high quality, cost effective nutritional care.

Leg strength is associated with ventilatory efficiency in older women

The aim of the present study was to determine if leg function is associated with ventilatory efficiency during exercise in healthy older adults. 24 women and 18 men aged 60-80 years performed treadmill exercise to fatigue for calculation of ventilatory efficiency using the ratio of ventilation to carbon dioxide at the anaerobic threshold (VE/VCO₂@AT). On a separate day, participants performed leg strength testing and graded single-leg knee extension exercise. The VE/VCO₂@AT was higher in women than men (33±3 vs. 30±3; p=0.03). After adjustment for age and VO(₂max), leg strength (knee extensor isometric force) was inversely associated with VE/VCO₂@AT in women (r= - 0.44, p=0.03) while no relationships were found for men. Strength-matched women and men had similar VE/VCO₂@AT indicating that the correlation between leg strength and VE/VCO₂@AT was strength- but not sex-specific. During knee extensor exercise, women with lower leg strength had increased VE/VCO₂ slope across 0-15 W as compared to higher strength women (38±8 vs. 31±3; p<0.05), while no differences were found for men. These results find leg strength to be associated with ventilatory responses to exercise in healthy older women, a finding that might be related to lower leg strength in women than men.

Design and validation of a novel method to measure cross-sectional area of neck muscles included during routine MR brain volume imaging

Introduction

Low muscle mass secondary to disease and ageing is an important cause of excess mortality and morbidity. Many studies include a MR brain scan but no peripheral measure of muscle mass. We developed a technique to measure posterior neck muscle cross-sectional area (CSA) on volumetric MR brain scans enabling brain and muscle size to be measured simultaneously.

Methods

We performed four studies to develop and test: feasibility, inter-rater reliability, repeatability and external validity. We used T1-weighted MR brain imaging from young and older subjects, obtained on different scanners, and collected mid-thigh MR data.

Results

After developing the technique and demonstrating feasibility, we tested it for inter-rater reliability in 40 subjects. Intraclass correlation coefficients (ICC) between raters were 0.99 (95% confidence intervals (CI) 0.98–1.00) for the combined group (trapezius, splenius and semispinalis), 0.92 (CI 0.85–0.96) for obliquus and 0.92 (CI 0.85–0.96) for sternocleidomastoid. The first unrotated principal component explained 72.2% of total neck muscle CSA variance and correlated positively with both right (r = 0.52, p = .001) and left (r = 0.50, p = .002) grip strength. The 14 subjects in the repeatability study had had two MR brain scans on three different scanners. The ICC for between scanner variation for total neck muscle CSA was high at 0.94 (CI 0.86–0.98). The ICCs for within scanner variations were also high, with values of 0.95 (CI 0.86–0.98), 0.97 (CI 0.92–0.99) and 0.96 (CI 0.86–0.99) for the three scanners. The external validity study found a correlation coefficient for total thigh CSA and total neck CSA of 0.88.

Discussion

We present a feasible, valid and reliable method for measuring neck muscle CSA on T1-weighted MR brain scans. Larger studies are needed to validate and apply our technique with subjects differing in age, ethnicity and geographical location.

Efficacy of a home-based intervention programme on the physical activity level and functional ability of older people using domestic services: a randomised study

OBJECTIVE

Our main objective was to assess whether a home-based program supervised by home helpers (HH) during their normal working hours can prevent excessive sedentariness (mainly maximum walking time and distance) and preserve functional status in elderly people at risk for frailty or disability and using domestic services.

DESIGN

A four-month, open label, randomised trial with two groups called "prevention" and "control".

SETTING

In the homes of study participants.

PARTICIPANTS

The participants were all over 78 years old, lived independently at home, and received the visits of HHs at least once a week.

INTERVENTION

The intervention combined a self-administered exercise program, with 10 g amino-acid supplementation under the supervision of HHs.

MEASUREMENTS

Main outcome measures included physical activity (the PASE questionnaire), functional tests, nutritional and autonomy scores, and compliance (50% or more was considered satisfactory). Non-parametric methods were used for comparisons between the two groups. A linear regression model was fitted to assess the effect of the intervention on the relative variation of outcomes, adjusted for unbalanced baseline co-variables.

RESULTS

One hundred and two persons (prevention n=53, control n=49) with a median age of 85 years were included. Their median Activities of Daily Living and Instrumental Activities of Daily Living (IADL) scores were 6 and 7 respectively. Twenty-three (44%) were good compliers for both interventions. The maximum walking time remained stable while decreasing by 25% in the control group (p=0.0015); and fewer participants had a worsened IADL score in the prevention group (p=0.05). The baseline IADL Score was significantly associated with good compliance to the prevention program (p=0.0011). In good compliers, maximum walking distance and maximum walking time increased by 29.15% (0.0 to 66.7) and 33.3% (-20.0 to 50.0) respectively.

CONCLUSION

This study confirms the feasibility of a prevention program supervised by HHs, and some benefit from the intervention and identifies predictors for better compliance. It will help in the design of prevention trials for elderly people at risk for frailty.

Sarcopenia in the elderly

Sarcopenia is the age-related loss of muscle. It leads to loss of muscle power, which in the end results in frailty and disability. There are numerous causes of sarcopenia. Treatment consists of resistance exercise and a leucine-enriched essential amino acid protein supplement. There is an emerging role for testosterone and other anabolic steroids. An activin II receptor soluble fusion protein is showing great potential to increase muscle mass and bone mineral density.

Chronology of age-related disease definitions: osteoporosis and sarcopenia

Low muscle mass at older age has been associated with functional impairments, cognitive decline and mortality. The term sarcopenia, coined in 1988, has been used interchangeably to describe low muscle mass, strength, and function. Without a well defined definition, results of studies using the term sarcopenia cannot be compared. Difficulties in defining sarcopenia parallel the history of defining osteoporosis. To understand critical steps that are needed to reach consensus in defining age-related diseases, we have identified milestones in the history of defining osteoporosis and compared these to sarcopenia. As a result, the main missing steps in the process of defining sarcopenia are: specific treatment options, pharmaceutical interest, and public awareness. Similar to osteoporosis being defined as 'low bone mineral density', the term sarcopenia should be reserved for 'low muscle mass'. Consensus must be reached regarding the diagnostic criteria to quantify muscle mass, correction factors, and reference populations used to define cut-off values of muscle mass.

The frequency of low muscle mass and its overlap with low bone mineral density and lipodystrophy in individuals with HIV--a pilot study using DXA total body composition analysis

As a result of the advances in antiretroviral therapy, the life span of human immunodeficiency virus (HIV)-infected patients has increased dramatically. Attendant to these effects are signs of premature aging with notable changes in the musculoskeletal system. Although changes in bone and fat distribution have been studied extensively, far less is known about changes in muscle. This study examined the extent of low muscle mass (LMM) and its relationship with low bone mineral density (BMD) and lipodystrophy (LD) in HIV-positive males. As such, HIV-positive males on therapy or treatment naive underwent dual-energy X-ray absorptiometry total body composition measurements. Appendicular lean mass/(height)2 and lowest 20% of residuals from regression analysis were used to define LMM. BMD criteria defined osteopenia/osteoporosis, and the percent central fat/percent lower extremity ratio defined LD. Several potential risk factors were assessed through chart review. Sixty-six males (57 with treatment and 9 treatment naive) volunteered. Treated individuals were older than naive (44 vs 34 yr) and had HIV longer (108 vs 14 mo). When definitions for sarcopenia (SP) in elderly individuals were applied, the prevalence of LMM was 21.9% and 18.8% depending on the definition used. Low BMD was present in 68.2% of participants. LD with a cutoff of 1.5 and 1.961 was present in 54.7% and 42.2% of participants, respectively. LMM and LD were negatively associated. In conclusion, this study shows that LMM is common in males with HIV and that SP affecting muscle function could be present in a substantial number of individuals. Future research needs to examine what impact decreased muscle mass and function has on morbidity, physical function, and quality of life in individuals with HIV.

Predicting cause-specific mortality of older men living in the Veterans home by handgrip strength and walking speed: a 3-year, prospective cohort study in Taiwan

OBJECTIVE

To determine prognostic value of handgrip strength (HGS) and walking speed (WS) in predicting the cause-specific mortality for older men.

DESIGN

Prospective cohort study.

SETTING

Banciao Veterans Care Home.

PARTICIPANTS

558 residents aged 75 years and older.

MEASUREMENTS

Anthropometric data, lifestyle factors, comorbid conditions, biomarkers, HGS, and WS at recruitment; all-cause and cause-specific mortality at 3 years after recruitment.

RESULTS

During the study period, 99 participants died and the baseline HGS and WS were significantly lower than survivors (P both <.001). Cox survival analysis showed that subjects with slowest quartile of WS were at significantly higher risk of all-cause mortality and cardiovascular mortality (hazard ratio [HR] 3.55, 95% confidence interval [CI] 1.69-7.43; HR 11.55, 95% CI 2.30-58.04, respectively), whereas the lowest quartile of HGS significantly predicted a higher risk of infection-related death (HR 5.53, 95% CI 1.09-28.09). Participants in the high-risk status with slowest quartile for WS but not those in the high-risk status with weakest quartile for HGS had similar high risk of all-cause mortality with the group with combined high-risk status (HR 2.96, 95% CI 1.68-5.23; HR 2.58, 95% CI 1.45-4.60, respectively) compared with the participants without high-risk status (reference group).

CONCLUSIONS

Slow WS predicted all-cause and cardiovascular mortality, whereas weak HGS predicted a higher risk of infection-related death among elderly, institutionalized men in Taiwan. Combining HGS with WS simultaneously had no better prognostic value than using WS only in predicting all-cause mortality.

Development and application of biological age prediction models with physical fitness and physiological components in Korean adults

BACKGROUND

Several biological age (BA) prediction models have been suggested with a variety of biomarkers. Valid models should be able to measure BA in a relatively short time period and predict subsequent physiological capability. Physiological and physical fitness variables have been shown to be distinctive markers for predicting BA and morbidity. The practical and noninvasive nature of such variables makes them useful as clinical assessment tools in estimating BA for in-depth diagnosis and corresponding intervention.

OBJECTIVE

To identify, develop and evaluate biomarkers and BA prediction models and validate their clinical usefulness for the practical diagnosis of functional aging.

METHODS

Fourteen variables were measured in 3,112 male and 1,233 female participants aged 30 and older between the years 2004 and 2007. Through a series of parsimonious stepwise elimination processes, two sets of 8 gender-specific variables were selected as candidate biomarkers for 1,604 men and 760 women. Principal component analysis, linear regression analysis and adjustment methods were further applied to obtain two sets of true BA (TBA) prediction models. The TBA models were examined for validity by comparing TBA to the corresponding chronological age (CA) with clinical risk factors.

RESULTS

TBA prediction models with r(2) values of 0.638 and 0.672 were developed, each unique to men and women, respectively. The overall mean TBA and CA of the participants were 53.9 and 51.8 years, respectively, with a marginal difference of -2.1 and -1.3 years. The regression slopes or rates of TBA as a function of CA were 1.00 and 1.28 for men and women with r values of 0.799 and 0.820 (p < 0.001), respectively. In comparing TBA to CA rates between healthy and clinical risk groups, both sarcopenic and obese groups showed significant increases in TBA.

CONCLUSIONS

The selected biomarkers encompass various complex physiopathological factors related to intrinsic and extrinsic physiological and functional aging. The BA prediction models based on the selected biomarkers could be practical in assessing BA for Korean adults.

Prevalence of sarcopenia and sarcopenic obesity in the Korean population based on the Fourth Korean National Health and Nutritional Examination Surveys

BACKGROUND

Sarcopenia is an important factor of functional impairment related to aging. This study is conducted to investigate the prevalence of sarcopenia and sarcopenic obesity in Korean population.

METHODS

Representative Korean men (4,486) and women (5,999) aged 20 years or older were analyzed from the Fourth Korean National Health and Nutritional Examination Surveys. Sarcopenia was classified into Class I defined relative skeletal muscle mass loss within 1-2 SD of the gender-specific mean for healthy young adults and Class II below 2 SD. Relative skeletal muscle mass was represented by the appendicular skeletal muscle mass adjusted by height and body weight. Sarcopenic obesity was considered present in Class II sarcopenic participants whose waist circumference was more than or equal to 90 cm for men and more than or equal to 85 cm for women, respectively.

RESULTS

The prevalence of Class II sarcopenia in the Korean elderly population was 12.4% for men and 0.1% for women by height-adjusted definition and 9.7% for men and 11.8% for women by weight-adjusted definition. The prevalence of sarcopenic obesity was 7.6% for men and 9.1% for women by weight-adjusted definition but nearly zero for men and women by height-adjusted definition. The prevalence of sarcopenia increased with age for men but for women only when applied with weight-adjusted definition.

CONCLUSIONS

The prevalence of sarcopenia and sarcopenic obesity differs by gender and definition criteria. The height-adjusted definition may tend to underestimate the prevalence of sarcopenia and sarcopenic obesity, especially in women.

Nutrition and sarcopenia: a review of the evidence and implications for preventive strategies

Prevention of age-related losses in muscle mass and strength is key to protecting physical capability in older age and enabling independent living. To develop preventive strategies, a better understanding is needed of the lifestyle factors that influence sarcopenia and the mechanisms involved. Existing evidence indicates the potential importance of diets of adequate quality, to ensure sufficient intakes of protein, vitamin D, and antioxidant nutrients. Although much of this evidence is observational, the prevalence of low nutrient intakes and poor status among older adults make this a current concern. However, as muscle mass and strength in later life are a reflection of both the rate of muscle loss and the peak attained in early life, efforts to prevent sarcopenia also need to consider diet across the lifecourse and the potential effectiveness of early interventions. Optimising diet and nutrition throughout life may be key to preventing sarcopenia and promoting physical capability in older age.

Inducible nitric oxide synthase (iNOS) in muscle wasting syndrome, sarcopenia, and cachexia

Muscle atrophy—also known as muscle wasting—is a debilitating syndrome that slowly develops with age (sarcopenia) or rapidly appears at the late stages of deadly diseases such as cancer, AIDS, and sepsis (cachexia). Despite the prevalence and the drastic detrimental effects of these two syndromes, there are currently no widely used, effective treatment options for those suffering from muscle wasting. In an attempt to identify potential therapeutic targets, the molecular mechanisms of sarcopenia and cachexia have begun to be elucidated. Growing evidence suggests that inflammatory cytokines may play an important role in the pathology of both syndromes. As one of the key cytokines involved in both sarcopenic and cachectic muscle wasting, tumor necrosis factor α (TNFα) and its downstream effectors provide an enticing target for pharmacological intervention. However, to date, no drugs targeting the TNFα signaling pathway have been successful as a remedial option for the treatment of muscle wasting. Thus, there is a need to identify new effectors in this important pathway that might prove to be more efficacious targets. Inducible nitric oxide synthase (iNOS) has recently been shown to be an important mediator of TNFα-induced cachectic muscle loss, and studies suggest that it may also play a role in sarcopenia. In addition, investigations into the mechanism of iNOS-mediated muscle loss have begun to reveal potential therapeutic strategies. In this review, we will highlight the potential for targeting the iNOS/NO pathway in the treatment of muscle loss and discuss its functional relevance in sarcopenia and cachexia.

Update in geriatric medicine

INTRODUCTION

With an aging population, internists will provide care to a growing number of older adults, a population at risk of developing multiple chronic medical conditions and geriatric syndromes. For this update in geriatric medicine, we highlight recent key articles focused on preventive strategies and lifestyle changes that reduce the burden of disease and functional decline in older adults.

METHODS

We identified English-language articles published between March 1, 2010 and March 31, 2011 by review of the contents of major geriatrics/general medicine journals and journal watch services including: New England Journal of Medicine, Annals of Internal Medicine, Journal of the American Medical Association, Lancet, Archives of Internal Medicine, British Medical Journal, Journal of the American Geriatrics Society, and the Journals of Gerontology. We also reviewed updates to the Cochrane database of systematic reviews and articles highlighted by the ACP Journal Club and Journal Watch. Inclusion criteria included (1) randomized controlled trials, (2) conditions exclusive or common to older adults, and (3) commonly seen in generalist practices. After abstract review, each author selected five articles, and these were reviewed again by all authors. Through multiple discussions, consensus was reached on the final articles selected for inclusion based on their quality and potential to improve the health of older patients cared for by generalists.

Development of a screening tool for risk of locomotive syndrome in the elderly: the 25-question Geriatric Locomotive Function Scale

OBJECTIVE

To evaluate the reliability and validity of a new questionnaire, the 25-question Geriatric Locomotive Function Scale (GLFS-25), for early detection of locomotive syndrome.

METHODS

This new screening tool was designed to detect Japanese individuals under high-risk conditions who may soon require care services because of problems of the locomotive organs. Content validity, construct validity, criterion validity, internal-consistency reliability, and reproducibility (test-retest reliability) were examined using psychometric analysis, and a cutoff score to detect locomotive syndrome was determined. To investigate construct validity of the GLFS-25 and determine the cutoff score, the Akaike Information Criteria (AIC) were used.

RESULTS

Study 1 analyzed 711 Japanese elderly people ≥65 years old. No floor or ceiling effects were included in the GLFS-25. Internal consistency was confirmed by a Cronbach's α reliability coefficient of 0.961. As for the association between the GLFS-25 and European Quality of Life Scale-5 Dimensions (EQ-5D), Spearman's correlation coefficient was 0.85 (P < 0.001), showing excellent concurrent validity of the GLFS-25. Categorical principal component analysis showed that the construct structure consisted of one item cluster or the GLFS-25 was unifactorial. The AIC showed that one cluster of seven items was located in the center, with significant associations with the other five clusters. In study 2, 205 individuals were analyzed, and the test-retest interclass correlation was satisfactory (range 0.712-0.924). The cutoff score for identifying locomotive syndrome was set at 16. Validity and reliability of this new measurement were psychometrically confirmed as sufficient.

CONCLUSIONS

The GLFS-25 offers a valid and reliable questionnaire scale for detecting locomotive syndrome in elderly Japanese individuals.

Frailty in the older surgical patient: a review

The rate of surgical procedures in the older population is rising. Despite surgical, anaesthetic and medical advances, older surgical patients continue to suffer from adverse postoperative outcomes. Comorbidities and reduction in physiological reserve are consistently identified as major predictors of poor postoperative outcome in this population. Frailty can be defined as a lack of physiological reserve seen across multiple organ systems and is an independent predictor of mortality, morbidity and institutionalisation after surgery. Despite this identification of frailty as a significant predictor of adverse postoperative outcome, there is not yet a consensus on the definition of frailty or how best to assess and diagnose it. This review describes our current definitions of frailty and discusses the available methods of assessing frailty, the impact on the older surgical population and the emerging potential for modification of this important syndrome.

Respiratory impairment and the aging lung: a novel paradigm for assessing pulmonary function

BACKGROUND

Older persons have an increased risk of developing respiratory impairment because the aging lung is likely to have experienced exposures to environmental toxins as well as reductions in physiological capacity.

METHODS

Systematic review of risk factors and measures of pulmonary function that are most often considered when defining respiratory impairment in aging populations.

RESULTS

Across the adult life span, there are frequent exposures to environmental toxins, including tobacco smoke, respiratory infections, air pollution, and occupational dusts. Concurrently, there are reductions in physiological capacity that may adversely affect ventilatory control, respiratory muscle strength, respiratory mechanics, and gas exchange. Recent work has provided a strong rationale for defining respiratory impairment as an age-adjusted reduction in spirometric measures of pulmonary function that are independently associated with adverse health outcomes. Specifically, establishing respiratory impairment based on spirometric Z-scores has been shown to be strongly associated with respiratory symptoms, frailty, and mortality. Alternatively, respiratory impairment may be defined by the peak expiratory flow, as measured by a peak flow meter. The peak expiratory flow, when expressed as a Z-score, has been shown to be strongly associated with disability and mortality. However, because it has a reduced diagnostic accuracy, peak expiratory flow should only define respiratory impairment when spirometry is not readily available or an older person cannot adequately perform spirometry.

CONCLUSIONS

Aging is associated with an increased risk of developing respiratory impairment, which is best defined by spirometric Z-scores. Alternatively, in selected cases, respiratory impairment may be defined by peak expiratory flow, also expressed as a Z-score.

Skeletal muscle apoptotic signaling predicts thigh muscle volume and gait speed in community-dwelling older persons: an exploratory study

Background

Preclinical studies strongly suggest that accelerated apoptosis in skeletal myocytes may be involved in the pathogenesis of sarcopenia. However, evidence in humans is sparse. In the present study, we investigated whether apoptotic signaling in the skeletal muscle was associated with indices of muscle mass and function in older persons.

Methodology/Principal Findings

Community-dwelling older adults were categorized into high-functioning (HF) or low-functioning (LF) groups according to their short physical performance battery (SPPB) summary score. Participants underwent an isokinetic knee extensor strength test and 3-dimensional magnetic resonance imaging of the thigh. Vastus lateralis muscle samples were obtained by percutaneous needle biopsy and assayed for the expression of a set of apoptotic signaling proteins. Age, sex, number of comorbid conditions and medications as well as knee extensor strength were not different between groups. HF participants displayed greater thigh muscle volume compared with LF persons. Multivariate partial least squares (PLS) regressions showed significant correlations between caspase-dependent apoptotic signaling proteins and the muscular percentage of thigh volume (R² = 0.78; Q² = 0.61) as well as gait speed (R² = 0.81; Q² = 0.56). Significant variables in the PLS model of percent muscle volume were active caspase-8, cleaved caspase-3, cytosolic cytochrome c and mitochondrial Bak. The regression model of gait speed was mainly described by cleaved caspase-3 and mitochondrial Bax and Bak. PLS predictive apoptotic variables did not differ between functional groups. No correlation was determined between apoptotic signaling proteins and muscle strength or quality (strength per unit volume).

Conclusions/Significance

Data from this exploratory study show for the first time that apoptotic signaling is correlated with indices of muscle mass and function in a cohort of community-dwelling older persons. Future larger-scale studies are needed to corroborate these preliminary findings and determine if down-regulation of apoptotic signaling in skeletal myocytes will provide improvements in the muscle mass and functional status of older persons.