Sarcopenia: current concepts

Comparison of body composition, nutritional status, functional status, and quality of life between osteoporotic and osteopenic postmenopausal women

BACKGROUND AND OBJECTIVE

Osteoporosis is a condition that affects body composition, physical activity, and psychological state. We aimed to examine the differences between osteoporotic and osteopenic postmenopausal women with respect to body composition, nutrition, functional status, and quality of life.

MATERIALS AND METHODS

A total of 102 osteopenic (Group 1) and 100 osteoporotic (Group 2) patients were enrolled in the study. Bone mineral density (BMD), fat tissue mass (FTM), lean tissue mass (LTM), and bone mineral content (BMC) were evaluated using dual-energy X-ray absorbtiometry. Nutritional status of the patients was assessed with the Mini Nutritional Assessment (MNA), functional status with the Nottingham Extended Activities of Daily Living (NEADL) scale, and quality of life with the assessment of health-related quality of life in osteoporosis (ECOS-16).

RESULTS

Group 2 had significantly lower FTM, LTM, and MNA scores than Group 1 (P<0.05). NEADL and ECOS-16 scores did not differ between the groups (P>0.05). A significant correlation was found between MNA and FTM, LTM, BMC, and BMD (P<0.05). Whereas the assessment of functional status showed a significant positive correlation with BMD and a significant negative correlation with age (P<0.05), no significant correlation was found between functional status and body composition (P>0.05).

CONCLUSIONS

We found lower FTM and LTM values and a poorer nutritional status in osteoporotic patients than in osteopenic ones. Nutritional status was correlated with body composition and BMD, and functional status was correlated with age and BMD.

Mechanisms Regulating Neuromuscular Junction Development and Function and Causes of Muscle Wasting

The neuromuscular junction is the chemical synapse between motor neurons and skeletal muscle fibers. It is designed to reliably convert the action potential from the presynaptic motor neuron into the contraction of the postsynaptic muscle fiber. Diseases that affect the neuromuscular junction may cause failure of this conversion and result in loss of ambulation and respiration. The loss of motor input also causes muscle wasting as muscle mass is constantly adapted to contractile needs by the balancing of protein synthesis and protein degradation. Finally, neuromuscular activity and muscle mass have a major impact on metabolic properties of the organisms. This review discusses the mechanisms involved in the development and maintenance of the neuromuscular junction, the consequences of and the mechanisms involved in its dysfunction, and its role in maintaining muscle mass during aging. As life expectancy is increasing, loss of muscle mass during aging, called sarcopenia, has emerged as a field of high medical need. Interestingly, aging is also accompanied by structural changes at the neuromuscular junction, suggesting that the mechanisms involved in neuromuscular junction maintenance might be disturbed during aging. In addition, there is now evidence that behavioral paradigms and signaling pathways that are involved in longevity also affect neuromuscular junction stability and sarcopenia.

Sarcopenia in women with rheumatoid arthritis

OBJECTIVE

To assess sarcopenia status in women with rheumatoid arthritis (RA).

MATERIAL AND METHODS

Thirty female patients with RA and 30 female controls without RA were enrolled in this study. Sarcopenia status in patients with RA was evaluated by assessing body composition using dual X-ray absorptiometry (DXA). C-reactive protein (CRP) levels and erythrocyte sedimentation rate (ESR) were measured, and body mass index (BMI) and Disease Activity Score (DAS28) were calculated. Because sarcopenia differs between men and women, the study groups comprised only females.

RESULTS

It was found that skeletal muscle index (SMI) was lower in patients with RA (5.83±0.807) than in controls (7.30±1.640). Sarcopenia (in females with an SMI of ≤5.75 kg/m2) was more common in the RA group and the difference was statistically significant (p=0.004). Sarcopenia was more common in patients with RA who were normal or overweight than in those who were obese according to their BMI. There was no relationship between sarcopenia and DAS28 in the RA group (p=0.530), whereas CRP levels were significantly higher in patients with sarcopenia (p=0.230). No relationship was found between drug use and sarcopenia in the RA group.

CONCLUSION

It was found that SMI was decreased and sarcopenia risk was elevated in patients with RA and the risk was higher in non-obese patients.

Factors associated with sarcopenia in subjects aged 80 years and over

OBJECTIVE: To analyze whether sarcopenia is associated with sociodemographic factors and chronic noncommunicable diseases in adults aged 80 years and older. METHODS: The sample consisted of 120 adults aged 80 to 95 years (83.4±2.9 years) from the city of Presidente Prudente (São Paulo, Brazil), of which 76 were females (83.4±3.0 years) and 44 were males (83.4±2.6 years). The study sociodemographic and epidemiological factors were: age stratum, gender, marital status, education level, chronic noncommunicable diseases, ethnicity, and nutritional status. Body composition was determined by Dual-Energy X-Ray Absorptiometry and sarcopenia was identified by the appendicular lean mass ratio (upper limb lean mass + lower limb lean mass [kg]/height [m]2). The Chi-square test analyzed whether sarcopenia was associated with sociodemographic and epidemiological factors and binary logistic regression expressed the magnitude of the associations. The data were treated by the software Statistical Package for the Social Sciences (17.0) at a significance level of 5%. RESULTS: The factors associated with sarcopenia were gender, age, nutritional status, and osteopenia/osteoporosis. CONCLUSION: The factors gender, age, nutritional status, and osteopenia/osteoporosis are independently associated with sarcopenia in adults aged 80 years and older.

Sarcopenia: a predictor of mortality and the need for early diagnosis and intervention

The term sarcopenia refers to the loss of muscle mass that occurs with aging. Sarcopenia is defined by the European Working Group on Sarcopenia in Older People (EWGSOP) as low muscle mass and low muscle function (strength and performance). Its prevalence varies depending on the definition used for it, but estimates propose a loss of approximately 8 % per decade until the age of 70 years; afterwards, the loss increases and ranges from 13 to 24 % per decade. Irrespective of how sarcopenia is defined, both low muscle mass and poor muscle strength are highly prevalent and important risk factors for disability and increased mortality in individuals as they age. In this review, we address age-related muscle loss and the risk factors of mortality, emphasizing the need for early diagnosis and intervention.

The effect of age on muscle characteristics of the abductor hallucis in people with hallux valgus: a cross-sectional observational study

Background

The abductor hallucis muscle plays an important role in maintaining alignment of the first metatarsophalangeal joint. The aims of this study were (1) to determine differences in abductor hallucis muscle characteristics in people with hallux valgus between three age groups (20–44 years, 45–64 years, and 65+ years); and (2) to determine the association between age and abductor hallucis size and quality.

Methods

Characteristics of the abductor hallucis muscle were measured in 96 feet with hallux valgus using musculoskeletal ultrasound. Muscle characteristics included width, thickness, cross-sectional area and echo-intensity. A one-way ANCOVA was conducted to compare the mean muscle characteristic values between the three age groups while adjusting for hallux valgus severity as a covariate. A Bonferroni post-hoc was used to adjust for multiple testing (p < 0.0167). Spearman’s rho correlation coefficient was used to determine the association between age and the abductor hallucis muscle parameters.

Results

There was a significant difference in dorso-plantar thickness (p = 0.003) and cross-sectional area (p = 0.008) between the three age groups. The Bonferroni post hoc analysis revealed a significant difference in mean thickness and mean cross-sectional area between the 20–44 age group (p = 0.003) and the 65+ age group (p = 0.006). No significant differences were noted between the three age groups for medio-lateral width (p > 0.05) or echo-intensity (p > 0.05). Increasing age was significantly associated with a reduction in dorso-plantar thickness (r = −0.27, p = 0.008) and cross-sectional area (r = −0.24, p = 0.019) but with small effect sizes. There was no significant correlation between age and medio-lateral width (r = −0.51, p = 0.142) or echo intensity (r =0.138, p =0.179).

Conclusion

Increasing age is associated with a greater reduction in size of the abductor hallucis muscle in people with hallux valgus. People over the age of 65 years old with hallux valgus display a significant reduction in abductor hallucis muscle size compared to those aged less than 45 years old. This is consistent with age-related changes to skeletal muscle.

Body composition and survival in dialysis patients: results from an international cohort study

BACKGROUND AND OBJECTIVES

High body mass index appears protective in hemodialysis patients, but uncertainty prevails regarding which components of body composition, fat or lean body mass, are primarily associated with survival.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data between April 2006 and December 2012 were extracted from the Fresenius Medical Care Europe subset of the international MONitoring Dialysis Outcomes initiative. Fresenius Medical Care Europe archives a unique repository of predialysis body composition measurements determined by multifrequency bioimpedance (BCM Body Composition Monitor). The BCM Body Composition Monitor reports lean tissue indices (LTIs) and fat tissue indices (FTIs), which are the respective tissue masses normalized to height squared, relative to an age- and sex-matched healthy population. The relationship between LTI and FTI and all-cause mortality was studied by Kaplan-Meier analysis, multivariate Cox regression, and smoothing spline ANOVA logistic regression.

RESULTS

In 37,345 hemodialysis patients, median (25th-75th percentile) LTI and FTI were 12.2 (10.3-14.5) and 9.8 (6.6-12.4) kg/m(2), respectively. Median (25th-75th percentile) follow-up time was 266 (132-379) days; 3458 (9.2%) patients died during follow-up. Mortality was lowest with both LTI and FTI in the 10th-90th percentile (reference group) and significantly higher at the lower LTI and FTI extreme (hazard ratio [HR], 3.37; 95% confidence interval [95% CI], 2.94 to 3.87; P<0.001). Survival was best with LTI between 15 and 20 kg/m(2) and FTI between 4 and 15 kg/m(2) (probability of death during follow-up: <5%). When taking the relation between both compartments into account, the interaction was significant (P=0.01). Higher FTI appeared protective in patients with low LTI (HR, 3.37; 95% CI, 2.94 to 3.87; P<0.001 at low LTI-low FTI, decreasing to HR, 1.79; 95% CI, 1.47 to 2.17; P<0.001 at low LTI-high FTI).

CONCLUSIONS

This large international study indicates best survival in patients with both LTI and FTI in the 10th-90th percentiles of a healthy population. In analyses of body composition, both lean tissue and fat tissue compartments and also their relationship should be considered.

Prevalence and definition of sarcopenia in community dwelling older people. Data from the Berlin aging study II (BASE-II)

BACKGROUND

Sarcopenia describes the age-associated loss of muscle mass, strength and function. The aim of this study was to compare the prevalence of sarcopenia in a cohort of community dwelling elderly people living in Berlin, Germany, according to the criteria proposed by current consensus statements and to study the respective impact on self-reported physical performance.

MATERIAL AND METHODS

This study included 1405 participants from the Berlin aging study II (BASE-II). The appendicular skeletal muscle mass index (SMI) was assessed with dual energy X-ray absorptiometry (DXA), muscle strength was measured by hand grip strength and the timed up and go" test (TUG) was performed as a functional parameter to reflect mobility.

RESULTS

The prevalence of sarcopenia was 24.3 % in terms of reduced SMI only and considerably lower for sarcopenia with reduced grip strength (4.1 %) and sarcopenia with limited mobility (2.4 %). Only 0.6 % of the participants fulfilled all three criteria. Of the subjects with a normal SMI, 8.6 % had reduced grip strength and 5.1 % had limited mobility, whereas 1.3 % subjects fulfilled both criteria. Participants with reduced strength or function reported severe difficulties in performing physical tasks significantly more often than participants with normal or reduced SMI alone (p <0.029-p <0.0001).

CONCLUSION

In BASE-II low skeletal muscle mass was much more frequent than reduced grip strength or poor function. Reduced strength and function were found to be associated with a greater impact on physical performance than reduced muscle mass. Low SMI does not seem to be a prerequisite for low strength or limitations in mobility.

Neuron specific reduction in CuZnSOD is not sufficient to initiate a full sarcopenia phenotype

Our previous studies showed that adult (8 month) mice lacking CuZn-superoxide dismutase (CuZnSOD, Sod1KO mice) have neuromuscular changes resulting in dramatic accelerated muscle atrophy and weakness that mimics age-related sarcopenia. We have further shown that loss of CuZnSOD targeted to skeletal muscle alone results in only mild weakness and no muscle atrophy. In this study, we targeted deletion of CuZnSOD specifically to neurons (nSod1KO mice) and determined the effect on muscle mass and weakness. The nSod1KO mice show a significant loss of CuZnSOD activity and protein level in brain and spinal cord but not in muscle tissue. The masses of the gastrocnemius, tibialis anterior and extensor digitorum longus (EDL) muscles were not reduced in nSod1KO compared to wild type mice, even at 20 months of age, although the quadriceps and soleus muscles showed small but statistically significant reductions in mass in the nSod1KO mice. Maximum isometric specific force was reduced by 8–10% in the gastrocnemius and EDL muscle of nSod1KO mice, while soleus was not affected. Muscle mitochondrial ROS generation and oxidative stress measured by levels of reactive oxygen/nitrogen species (RONS) regulatory enzymes, protein nitration and F₂-isoprostane levels were not increased in muscle from the nSod1KO mice. Although we did not find evidence of denervation in the nSod1KO mice, neuromuscular junction morphology was altered and the expression of genes associated with denervation acetylcholine receptor subunit alpha (AChRα), the transcription factor, Runx1 and GADD45α) was increased, supporting a role for neuronal loss of CuZnSOD initiating alterations at the neuromuscular junction. These results and our previous studies support the concept that CuZnSOD deficits in either the motor neuron or muscle alone are not sufficient to initiate a full sarcopenic phenotype and that deficits in both tissues are required to recapitulate the loss of muscle observed in Sod1KO mice.

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CuZnSOD deletion in nSod1KO mice does not induce an overt sarcopenia phenotype.

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Force is slightly reduced in the gastrocnemius of nSod1KO mice but mass is unaffected.

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Neuronal Sod1 depletion does not induce denervation despite altered NMJ morphology.

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Neuronal Sod1 depletion does not induce muscle oxidative stress or mitochondrial ROS.

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Deficits in both motor neurons and muscle are required to initiate sarcopenia.

Cancer cachexia update in head and neck cancer: Pathophysiology and treatment

The pathophysiology of cancer cachexia remains complex. A comprehensive literature search was performed up to April 2013 using PubMed, the Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, and the Google search engine. In this review, we focus on the different mediators of impaired anabolism and upregulated catabolism that alter the skeletal muscle homeostasis resulting in the wasting of cancer cachexia. We present recent evidence of targeted treatment modalities from clinical trials along with their potential mechanisms of action. We also report on the most current evidence from randomized clinical trials using multimodal treatments in patients with cancer cachexia, but also the evidence from head and neck cancer-specific trials. A more complete understanding of the pathophysiology of the syndrome may lead to more effective targeted therapies and improved outcomes for patients.

Performance of the European Working Group on Sarcopenia in Older People algorithm in screening older adults for muscle mass assessment

BACKGROUND

There is a lack of consensus on the diagnosis of sarcopenia. A screening and diagnostic algorithm was proposed by the European Working Group on Sarcopenia in Older People (EWGSOP).

OBJECTIVE

To assess the performance of the EWGSOP algorithm in determining the proportion of subjects suspected of having sarcopenia and selected to undergo subsequent muscle mass (MM) measurement.

DESIGN

A cross-sectional study.

SETTING

The cohorts, Frailty in Brazilian Older People Study-Rio de Janeiro (FIBRA-RJ), Brazil; Coyoacan Cohort (CC), Mexico City, Mexico; and Toledo Study for Healthy Aging (TSHA), Toledo, Spain.

SUBJECTS

Three thousand two hundred and sixty community-dwelling individuals, 65 years and older.

METHODS

Initially, the EWGSOP algorithm was applied using its originally proposed cut-off values for gait speed and handgrip strength; in the second step, values tailored for the specific cohorts were used.

RESULTS

Using the originally suggested EWGSOP cut-off points, 83.4% of the total cohort (94.4% in TSHA, 75.5% in FIBRA-RJ, 67.8% in CC) would have been considered as suspected of sarcopenia. Adapted cut-off values lowered the proportion of abnormal results to 34.2% (quintile-based approach) and 23.71% (z-score approach).

CONCLUSIONS

The algorithm proposed by the EWGSOP is of limited clinical utility in screening older adults for sarcopenia due to the high proportion of subjects selected to further undergo MM assessment. Tailoring cut-off values to specific characteristics of the population being studied reduces the number of people selected for MM assessment, probably improving the performance of the algorithm. Further research including the objective measure of MM is needed to determine the accuracy of these specific cut-off points.

Muscle-derived extracellular signal-regulated kinases 1 and 2 are required for the maintenance of adult myofibers and their neuromuscular junctions

The Ras-extracellular signal-regulated kinase 1 and 2 (ERK1/2) pathway appears to be important for the development, maintenance, aging, and pathology of mammalian skeletal muscle. Yet no gene targeting of Erk1/2 in muscle fibers in vivo has been reported to date. We combined a germ line Erk1 mutation with Cre-loxP Erk2 inactivation in skeletal muscle to produce, for the first time, mice lacking ERK1/2 selectively in skeletal myofibers. Animals lacking muscle ERK1/2 displayed stunted postnatal growth, muscle weakness, and a shorter life span. Their muscles examined in this study, sternomastoid and tibialis anterior, displayed fragmented neuromuscular synapses and a mixture of modest fiber atrophy and loss but failed to show major changes in fiber type composition or absence of cell surface dystrophin. Whereas the lack of only ERK1 had no effects on the phenotypes studied, the lack of myofiber ERK2 explained synaptic fragmentation in the sternomastoid but not the tibialis anterior and a decrease in the expression of the acetylcholine receptor (AChR) epsilon subunit gene mRNA in both muscles. A reduction in AChR protein was documented in line with the above mRNA results. Evidence of partial denervation was found in the sternomastoid but not the tibialis anterior. Thus, myofiber ERK1/2 are differentially required for the maintenance of myofibers and neuromuscular synapses in adult mice.

Plantaris muscle weakness in old mice: relative contributions of changes in specific force, muscle mass, myofiber cross-sectional area, and number

The age-related decline in muscle function contributes to the movement limitations in daily life in old age. The age-related loss in muscle force is attributable to loss of myofibers, myofiber atrophy, and a reduction in specific force. The contribution of each of these determinants to muscle weakness in old age is, however, largely unknown. The objective of this study is to determine whether a loss in myofiber number, myofiber atrophy, and a reduction in specific muscle force contribute to the age-related loss of muscle force in 25-month-old mouse. Maximal isometric force of in situ m. plantaris of C57BL/6J male adult (9 months) and old (25 months) mice was determined and related to myofiber number, myofiber size, intramuscular connective tissue content, and proportion of denervated myofibers. Isometric maximal plantaris muscle force was 13 % lower in old than adult mice (0.97 ± 0.05 N vs. 0.84 ± 0.03 N; P < 0.05). M. plantaris mass of old mice was not significantly smaller than that of adult mice. There was also no significant myofiber atrophy or myofiber loss. Specific muscle force of old mice was 25 % lower than that of adult mice (0.55 ± 0.05 vs. 0.41 ± 0.03 N·mm(-2), P < 0.01). In addition, with age, the proportion of type IIB myofibers decreased (43.6 vs. 38.4 %, respectively), while the connective tissue content increased (11.6 vs. 16.4 %, respectively). The age-related reduction in maximal isometric plantaris muscle force in 25-month-old male C57BL/6J mice is mainly attributable to a reduction in specific force, which is for 5 % explicable by an age-related increase in connective tissue, rather than myofiber atrophy and myofiber loss.

Interleukin-6 predicts short-term global functional decline in the oldest old: results from the BELFRAIL study

The chronic inflammatory state at old age may contribute to the pathophysiology of or reflect chronic conditions resulting in loss of physical and mental functioning. Therefore, our objective was to examine the predictive value of a large battery of serum inflammatory markers as risk indicators for global functional decline and its specific physical and mental determinants in the oldest old. Global functional decline and specific aspects of physical and mental functional decline were assessed during an average of 1.66 years (±0.21) in a sample of 303 persons aged 80 years or older of the BELFRAIL study. Serum levels of 14 inflammatory proteins, including cytokines, growth factors, and acute phase proteins, were measured at baseline. Almost 20 % of the participants had a significant global functional decline over time. Interleukin (IL)-6 serum levels were uniquely positively associated with global functional decline, even after correcting for multiple confounders (odds ratio 1.51). Odds ratios for the individual aspects (physical dependency, physical performance, cognition, and depression) of functioning were lower, and composite scores of physical or mental decline were not significant. The proportion of global functional decline exhibited a dose-response curve with increasing levels of IL-6. Thus, IL-6 is an independent risk indicator for accelerated global functional decline in the oldest old. Our results suggest that simple serum levels of IL-6 may be very useful in short-term identification or evaluation of global functional status in the oldest old.

Cardiorespiratory fitness and body composition in postmenopausal women

The object of the study was to analyze the relationship between aerobic fitness and body composition in postmenopausal women. We hypothesized that postmenopausal women that had higher adiposity had lower cardiorespiratory capacity, regardless of the characteristics of menopause. The sample included 208 women (57.57 ± 6.62 years), whose body composition and the basal metabolic rate were evaluated by octopolar bioimpedance (InBody 720) and the oxygen uptake by the modified Bruce protocol. Most of the sample showed obesity and a high visceral fat area. The visceral fat area and the basal metabolic rate explained 30% of the variation of oxygen uptake, regardless of age, time, nature or hormone therapy. The values of the latter variables were reduced in the presence of high central adiposity (−6.16 ml/kg/min) and the basal metabolic rate of less than 1238 kcal/day (−0.18 ml/kg/min). The women with oxygen uptake above 30.94 ml/kg/min showed lower values of total and central adiposity when compared with other groups. With an increase of aerobic fitness, there was a growing tendency of the average values of the soft lean mass index, with differences between the groups low-high and moderate-high. These results suggest worsening of the cardiorespiratory condition with an increase of central adiposity and a decrease of the BMR, regardless of age and menopause characteristics.

The association of major patterns of physical activity, sedentary behavior and sleep with health-related quality of life: a cohort study

OBJECTIVE

To examine the prospective association of patterns of physical activity, sedentary behavior and sleep with health-related quality of life (HRQL) in the general population of Spain.

METHODS

A cohort study with 4271 individuals aged ≥ 18 years was recruited in 2008-2010 and followed-up prospectively through 2012. Activity patterns were derived from factor analysis. HRQL was assessed with the SF-12 questionnaire, and suboptimal HRQL was defined as a score below the sex-specific sample median.

RESULTS

Three main activity patterns were identified. A higher adherence to the pattern named "vigorous activity-seated at the computer" was inversely associated with a suboptimal score in the physical-composite summary (PCS) of the SF-12 (multivariate adjusted odds ratio [aOR] for the highest vs. the lowest quartile 0.71; 95% confidence interval [IC] 0.55-0.90; p-trend=0.003). The "light activity-seated for reading" pattern was inversely associated with a suboptimal score in the mental-composite summary (aOR=0.73; 95% CI=0.61-0.89; p-trend=0.002). However, a higher adherence to the "seated for watching TV-daytime sleeping" pattern was directly associated with suboptimal PCS (aOR=1.35; 95% CI=1.10-1.66; p-trend=0.008).

CONCLUSION

Patterns including any physical activity were associated with better physical or mental HRQL. However, a pattern defined by sedentary behavior with diurnal sleep showed worse HRQL and should be a priority target of preventive interventions.

Echo intensity is negatively associated with functional capacity in older women

Muscle quality is an important component of the functional profile of the elderly, and previous studies have shown that both muscle quantity and quality independently contribute to muscle strength of the elderly. This study aimed to verify the association between quadriceps femoris muscle quality, analyzed by specific tension and echo intensity (EI), and rate of torque development (RTD) of the knee extensor muscles with the functional performance in elderly active women. Forty-five healthy, active elderly women (70.28 ± 6.2) volunteered to participate in this study. Quadriceps femoris muscle thickness and EI were determined by ultrasonography. Knee extension isometric peak torque and RTD were obtained from maximal isometric voluntary contraction curves. The 30-s sit-to-stand-up (30SS) test and usual gait speed (UGS) test were applied to evaluate functional performance. Rectus femoris EI presented a significant negative correlation with 30SS (r = -0.505, P < 0.01), UGS (r s = -0.347, P < 0.05), and isometric peak torque (r = -0.314, P < 0.05). The quadriceps femoris EI correlated negatively with 30SS (r = -0.493, P < 0.01) and isometric peak torque (r = -0.409, P < 0.01). The EI of the quadriceps femoris and all quadriceps muscle portions significantly correlated with RTD. RTD significantly correlated with physical performance in both functional tests (30SS = r = 0.340, P < 0.05; UGS = r s = 0.371, P < 0.05). We concluded that muscle EI may be an important predictor of functional performance and knee extensor power capacity in elderly, active women.

The intriguing regulators of muscle mass in sarcopenia and muscular dystrophy

Recent advances in our understanding of the biology of muscle have led to new interest in the pharmacological treatment of muscle wasting. Loss of muscle mass and increased intramuscular fibrosis occur in both sarcopenia and muscular dystrophy. Several regulators (mammalian target of rapamycin, serum response factor, atrogin-1, myostatin, etc.) seem to modulate protein synthesis and degradation or transcription of muscle-specific genes during both sarcopenia and muscular dystrophy. This review provides an overview of the adaptive changes in several regulators of muscle mass in both sarcopenia and muscular dystrophy.

Aging alters contractile properties and fiber morphology in pigeon skeletal muscle

In this study, we tested the hypothesis that skeletal muscle from pigeons would display age-related alterations in isometric force and contractile parameters as well as a shift of the single muscle fiber cross-sectional area (CSA) distribution toward smaller fiber sizes. Maximal force output, twitch contraction durations and the force-frequency relationship were determined in tensor propatagialis pars biceps muscle from young 3-year-old pigeons, middle-aged 18-year-old pigeons, and aged 30-year-old pigeons. The fiber CSA distribution was determined by planimetry from muscle sections stained with hematoxylin and eosin. Maximal force output of twitch and tetanic contractions was greatest in muscles from young pigeons, while the time to peak force of twitch contractions was longest in muscles from aged pigeons. There were no changes in the force-frequency relationship between the age groups. Interestingly, the fiber CSA distribution in aged muscles revealed a greater number of larger sized muscle fibers, which was verified visually in histological images. Middle-aged and aged muscles also displayed a greater amount of slow myosin containing muscle fibers. These data demonstrate that muscles from middle-aged and aged pigeons are susceptible to alterations in contractile properties that are consistent with aging, including lower force production and longer contraction durations. These functional changes were supported by the appearance of slow myosin containing muscle fibers in muscles from middle-aged and aged pigeons. Therefore, the pigeon may represent an appropriate animal model for the study of aging-related alterations in skeletal muscle function and structure.

Cardiovascular program to improve physical fitness in those over 60 years old - pilot study

Background

In Spain, more than 50% of 60-year-olds are obese. Obesity is a disease with serious cardiovascular risks. The mortality rate for cardiovascular disease in Spain is 31.1%.

Objectives

To improve aerobic fitness, strength, flexibility and balance, and body composition (BC) in persons over 60 years old.

Materials and methods

A clinical intervention study of 24 participants was carried out over a period of 3 months. Aerobic fitness was assessed using the Rockport 1-Mile Walk Test. Upper-body strength was evaluated with an ad hoc test. Flexibility and balance were evaluated using the Sit and Reach Test and the Stork Balance Stand Test, respectively. Anthropometric measurements were taken by bioelectrical impedance.

Results

After 3 months of training, aerobic fitness was improved, as demonstrated by improved test times (pretest 13.04 minutes, posttest 12.13 minutes; P<0.05). Body composition was also improved, but the results were not statistically significant (fat mass pretest 31.58%±5.65%, posttest 30.65%±6.31%; skeletal muscle mass pretest 43.99±9.53 kg, posttest 46.63±10.90 kg).

Conclusion

Our data show that in subjects over 60 years old, aerobic fitness was improved due to program intervention. However, these results should be treated with caution, because of the limited sample size and the brief time period of this pilot study. A more rigorous study would include a sample of at least 100 participants.

A population-based approach to define body-composition phenotypes

BACKGROUND

Abnormal body compositions such as high adiposity (HA), low muscle mass (LM), or a combination of the 2 [high adiposity with low muscle mass (HA-LM)] are relevant phenotypes, but data on their prevalence and impact on health are still limited. This is largely because of a lack of a consensus definition for these conditions. Of particular interest is the HA-LM phenotype, also termed "sarcopenic obesity," which may confer greater health risk.

OBJECTIVE

We propose a new approach for operationalizing abnormal body-composition phenotypes in a representative adult population.

DESIGN

Whole-body dual-energy X-ray absorptiometry data obtained from the 1999-2004 NHANES were analyzed for 13,236 subjects aged ≥18 y (maximum weight and height of 136 kg and 1.96 m, respectively). Sex- and body mass index (BMI)-specific decile groups of appendicular skeletal muscle index (ASMI; kg/m²) and fat mass index (FMI; kg/m²) were developed. Cutoffs for HA and LM were incorporated into a diagnostic framework to characterize 4 specific body-composition phenotypes-low adiposity with high muscle mass, high adiposity with high muscle mass, low adiposity with low muscle mass, and HA-LM-and a subclassification of the phenotypes into classes I, II, and III.

RESULTS

Abnormal phenotypes were prevalent across the age spectrum and BMI categories. The association between ASMI or FMI and age was modified by sex and BMI. The prevalence of HA-LM in the whole sample was 10.3% in women and 15.2% in men. The prevalence of all subclasses of HA-LM in obese women and men was 14.7% and 22.9%, respectively. HA-LM class III was more prevalent in obese men (2.3%) than in obese women (0.3%).

CONCLUSIONS

We developed sex- and BMI-specific reference curves to harmonize the classification of body-composition phenotypes. The application of this classification will be particularly useful in the identification of cases of sarcopenic obesity. The association of these phenotypes with metabolic deregulation and increased disease risk awaits verification.

Sleep-wake disturbances in sedentary community-dwelling elderly adults with functional limitations

OBJECTIVES

To evaluate sleep-wake disturbances in sedentary community-dwelling elderly adults with functional limitations.

DESIGN

Cross-sectional.

SETTING

Lifestyle Interventions and Independence in Elder (LIFE) Study.

PARTICIPANTS

Community-dwelling persons (mean age 78.9) who spent fewer than 20 min/wk in the previous month engaged in regular physical activity and fewer than 125 min/wk of moderate physical activity, and had a Short Physical Performance Battery (SPPB) score of <10 (N = 1,635).

MEASUREMENTS

Mobility was evaluated according to 400-m walk time (slow gait speed defined as <0.8 m/s) and SPPB score (≤ 7 defined moderate to severe mobility impairment). Physical inactivity was defined according to sedentary time, as a percentage of accelerometry wear time with activity of <100 counts/min; participants in the top quartile of sedentary time were classified as having a high sedentary time. Sleep-wake disturbances were evaluated using the Insomnia Severity Index (ISI) (range 0-28; ≥ 8 defined insomnia), Epworth Sleepiness Scale (ESS) (range 0-24; ≥ 10 defined daytime drowsiness), Pittsburgh Sleep Quality Index (PSQI) (range 0-21; >5 defined poor sleep quality), and Berlin Questionnaire (high risk of sleep apnea).

RESULTS

Prevalence rates were 43.5% for slow gait speed and 44.7% for moderate to severe mobility impairment, with 77.0% of accelerometry wear time spent as sedentary time. Prevalence rates were 33.0% for insomnia, 18.1% for daytime drowsiness, 47.8% for poor sleep quality, and 32.9% for high risk of sleep apnea. Participants with insomnia had a mean ISI score of 12.1, those with daytime drowsiness had a mean ESS score of 12.5, and those with poor sleep quality had a mean PSQI score of 9.2. In adjusted models, measures of mobility and physical inactivity were generally not associated with sleep-wake disturbances, using continuous or categorical variables.

CONCLUSION

In a large sample of sedentary community-dwelling elderly adults with functional limitations, sleep-wake disturbances were prevalent but only mildly severe and were generally not associated with mobility impairment or physical inactivity.

Mechanisms of skeletal muscle ageing; avenues for therapeutic intervention

Age-related loss of muscle mass and function, termed sarcopenia, is a catastrophic process, which impacts severely on quality of life of older people. The mechanisms underlying sarcopenia are unclear and the development of optimal therapeutic interventions remains elusive. Impaired regenerative capacity, attenuated ability to respond to stress, elevated reactive oxygen species production and low-grade systemic inflammation are all key contributors to sarcopenia. Pharmacological intervention using compounds such as 17AAG, SS-31 and Bimagrumab or naturally occurring polyphenols to target specific pathways show potential benefit to combat sarcopenia although further research is required, particularly to identify the mechanisms by which muscle fibres are completely lost with increasing age.

Testosterone is essential for skeletal muscle growth in aged mice in a heterochronic parabiosis model

As humans age, they lose both muscle mass and strength (sarcopenia). Testosterone, a circulating hormone, progressively declines in aging and is associated with loss of muscle mass and strength. The surgical joining of a young and old mouse (heterochronic parabiosis) activates Notch signaling and restores muscle regenerative potential in aged mice. We hypothesize that testosterone is at least one of the factors required for the improvement seen in muscles in old mice in heterochronic parabiosis with young mice. To test this hypothesis, we established the following heterochronic parabioses between young (Y; 5 months old) and old (O; 22-23 months old) C57BL6 male mice: (1) Y:O; (2) castrated Y:O (ØY:O); (3) castrated + testosterone-treated Y:O (ØY + T:O). A group of normal young mice received empty implants, and old mice were used as controls. Parabiotic pairings were maintained for 4 weeks prior to analysis. Serum testosterone levels were three-fold higher in young than in old mice. The ØY + T:O pairing demonstrated significantly elevated levels of serum testosterone and an improvement in gastrocnemius muscle weight, muscle ultrastructure, muscle fiber cross-sectional area, and Notch-1 expression in old mice. These changes were not present in aged mice in the ØY:O pairing. These data indicate that testosterone has a critical role in mediating the improved muscle mass and ultrastructure seen in an experimental model of heterochronic parabiosis.

Current understanding of sarcopenia: possible candidates modulating muscle mass

The world's elderly population is expanding rapidly, and we are now faced with the significant challenge of maintaining or improving physical activity, independence, and quality of life in the elderly. Sarcopenia, the age-related loss of skeletal muscle mass, is characterized by a deterioration of muscle quantity and quality leading to a gradual slowing of movement, a decline in strength and power, increased risk of fall-related injury, and often, frailty. Since sarcopenia is largely attributed to various molecular mediators affecting fiber size, mitochondrial homeostasis, and apoptosis, the mechanisms responsible for these deleterious changes present numerous therapeutic targets for drug discovery. Muscle loss has been linked with several proteolytic systems, including the ubuiquitin-proteasome, lysosome-autophagy, and tumor necrosis factor (TNF)-α/nuclear factor-kappaB (NF-κB) systems. Although many factors are considered to regulate age-dependent muscle loss, this gentle atrophy is not affected by factors known to enhance rapid atrophy (denervation, hindlimb suspension, etc.). In addition, defects in Akt-mammalian target of rapamycin (mTOR) and serum response factor (SRF)-dependent signaling have been found in sarcopenic muscle. Intriguingly, more recent studies indicated an apparent functional defect in autophagy- and myostatin-dependent signaling in sarcopenic muscle. In this review, we summarize the current understanding of the adaptation of many regulators in sarcopenia.

Sarcopenia according to the european working group on sarcopenia in older people (EWGSOP) versus Dynapenia as a risk factor for disability in the elderly

BACKGROUND

Sarcopenia, defined as low muscle mass (LMM), and dynapenia have been associated with adverse outcomes in elderly.

OBJECTIVE

Contrast the association of sarcopenia versus dynapenia with incidence of disability.

DESIGN

A four-year prospective study (2006-2010).

SETTING

São Paulo, Brazil.

PARTICIPANTS

478 individuals aged 60 and older from the Saúde, Bem-Estar e Envelhecimento (SABE) study who were non-disabled at baseline.

MEASUREMENTS

Sarcopenia, measured according to the European Working Group on Sarcopenia in Older People (EWGSOP), includes: LMM assessed by skeletal muscle mass index ≤8.90kg/m2 (men) and ≤6.37kg/m2 (women); low muscle strength (LMS) assessed by handgrip strength <30kg (men) and <20kg (women); and low physical performance (LPP) assessed by gait speed ≤0.8m/s. Diagnosis of sarcopenia required LMM plus LMS or LPP. Dynapenia was defined as handgrip strength <30kg (men) and <20kg (women). Covariates included socio-demographic and behavioral variables, medical conditions, hospitalization, depressive symptoms, cognition, perception of vision, hearing and body mass index.

OUTCOMES

Disability in mobility or instrumental activities of daily living (IADL) or disability in activities of daily living (ADL) and IADL.

RESULTS

The incidence density of mobility or IADL disability was 43.4/1000 person/year and 22.6/1000 person/year for IADL and ADL disability. There was no significant difference in incidence density according sarcopenia or dynapenia status. After controlling for all covariates, sarcopenia was associated with mobility or IADL disability (relative risk ratio = 2.23, 95%Confidence Interval: 1.03-4.85). Dynapenia was not associated with disability.

CONCLUSIONS

Sarcopenia according to the EWGSOP definition can be used in clinical practice as a screening tool for early functional decline (mobility or IADL disability).

[Gender-specific differences in age-associated endocrinology]

The endocrine system is intimately involved in modulating lifespan and quality of life. Facing an ever increasing proportion of aged people in the western society, there is great interest in understanding the complex interrelations between increasing age and hormonal regulation. Age-associated endocrinological changes comprise the decline of basal hormonal levels, pulsatile hormone distribution, and activity of hormonal axis, which result in changes in body composition. Men and women experience different age-associated alterations of the hormonal system. Aging per se is a risk factor for diseases like diabetes mellitus type 2, thyroid disorders, osteoporosis, frailty, and sarcopenia. Gender-specific differences with respect to symptoms, interactions, diagnosis, and therapy must be taken into consideration. Current data do not allow a general recommendation for hormonal substitution, neither for women nor for men. New research approaches following a multifactorial pathway are required to elucidate the complexity of age-associated endocrinological changes and to develop gender-specific therapies for endocrinological diseases.

Respiratory impairment and dyspnea and their associations with physical inactivity and mobility in sedentary community-dwelling older persons

OBJECTIVES

To evaluate the prevalence of respiratory impairment and dyspnea and their associations with objectively measured physical inactivity and performance-based mobility in sedentary older persons.

DESIGN

Cross-sectional.

SETTING

Lifestyle Interventions and Independence for Elders Study.

PARTICIPANTS

Community-dwelling older persons (n = 1,635, mean age 78.9) who reported being sedentary (<20 min/wk of regular physical activity and <125 min/wk of moderate physical activity in past month).

MEASUREMENTS

Respiratory impairment was defined as low ventilatory capacity (forced expiratory volume in 1 second less than lower limit of normal (LLN)) and respiratory muscle weakness (maximal inspiratory pressure <LLN). Dyspnea was defined as moderate to severe ratings on the modified Borg index, immediately after a 400-m walk test (400-MWT). Physical inactivity was defined according to high sedentary time as the highest quartile of participants with accelerometry-measured activity of <100 counts/min. Performance-based mobility was evaluated using the Short Physical Performance Battery (≤ 7 defined as moderate to severe mobility impairment) and 400-MWT gait speed (<0.8 m/s defined as slow).

RESULTS

Prevalence rates were 17.7% for low ventilatory capacity, 14.7% for respiratory muscle weakness, 31.6% for dyspnea, 44.7% for moderate to severe mobility impairment and 43.6% for slow gait speed. Significant associations were found between low ventilatory capacity and slow gait speed (adjusted odds ratio (aOR) = 1.41, 95% confidence interval (CI) = 1.03-1.92), between respiratory muscle weakness and moderate to severe mobility impairment (aOR = 1.42, 95% CI = 1.03-1.95), and between dyspnea and high sedentary time (aOR = 1.98, 95% CI = 1.28-3.06) and slow gait speed (aOR = 1.70, 95% CI = 1.22-2.38).

CONCLUSION

Respiratory impairment and dyspnea are prevalent in sedentary older persons and are associated with objectively measured physical inactivity and poor performance-based mobility. Because they are modifiable, respiratory impairment and dyspnea should be considered in the evaluation of sedentary older persons.

Aging related changes in determinants of muscle force generating capacity: a comparison of muscle aging in men and male rodents

Human aging is associated with a progressive decline in skeletal muscle mass and force generating capacity, however the exact mechanisms underlying these changes are not fully understood. Rodents models have often been used to enhance our understanding of mechanisms of age-related changes in human skeletal muscle. However, to what extent age-related alterations in determinants of muscle force generating capacity observed in rodents resemble those in humans has not been considered thoroughly. This review compares the effect of aging on muscle force generating determinants (muscle mass, fiber size, fiber number, fiber type distribution and muscle specific tension), in men and male rodents at similar relative age. It appears that muscle aging in male F344*BN rat resembles that in men most; 32-35-month-old rats exhibit similar signs of muscle weakness to those of 70-80-yr-old men, and the decline in 36-38-month-old rats is similar to that in men aged over 80 yrs. For male C57BL/6 mice, age-related decline in muscle force generating capacity seems to occur only at higher relative age than in men. We conclude that the effects on determinants of muscle force differ between species as well as within species, but qualitatively show the same pattern as that observed in men.

24-weeks Pilates-aerobic and educative training to improve body fat mass in elderly Serbian women

Background

The purpose of this study was to examine the differences in anthropometric measurements using an aerobic and Pilates exercise program which lasted 24 weeks.

Method

This was a clinical intervention study of 303 women over the age of 60 living in Novi Sad, Serbia. Changes in body mass index and skinfold thickness were estimated through height, weight, and anthropometric measurements. The program comprised Pilates exercises for upper- and lower-body strength, agility, and aerobic capacity.

Results

Fat mass (FM) improved significantly (pre-test, 32.89%, 8.65; post-test, 28.25%, 6.58; P<0.01). Bone diameters and muscle perimeters showed no significant changes pre- and post-test (P>0.05), but there was a higher correlation between FM (%) and waist–hip ratio (rho, 0.80; P<0.01).

Conclusion

A mixed program of aerobics and Pilates, controls and improves baseline muscle mass and decreases FM values, without causing deterioration during practice and follow-up exercises.

A cross-sectional study of loss of muscle mass corresponding to sarcopenia in healthy Chinese men and women: reference values, prevalence, and association with bone mass

A cross-sectional survey was conducted in Shanghai, eastern China, to evaluate the prevalence of loss of muscle mass corresponding to sarcopenia in Chinese men and women and compare the results with the prevalence in other populations. We also analyzed the differences between men and women, and assessed the effect of lean mass and fat mass of different regions on bone mass. A total of 1766 men and 1778 women aged 18-96 years participated in this study. Bone mineral density of spine and femur, and lean mass and fat mass of several body regions were measured by dual-energy X-ray absorptiometry. Class 1 and class 2 sarcopenia were defined as the appendicular lean mass (ALM) index (ALM/height(2)) 1 and 2 standard deviations below the sex-specific means for young adults. Mean values for ALM index were 7.93 for men and 6.04 kg/m(2) for women, aged 18-40 years. The reference values for classes 1 and 2 sarcopenia were 7.01 and 6.08 kg/m(2) in men and 5.42 and 4.79 kg/m(2) in women. The prevalence of sarcopenia was 4.8% in women and 13.2% in men aged 70 years and older, which is lower than that in Caucasian populations, but the same as that in Japanese and Koreans in Asia. Men demonstrated greater declines in muscle mass with aging than women, partly due to the protective effect of fat mass on lean mass in women. Leg lean mass was the strongest factor on femur bone mass; however, trunk lean mass was the strongest factor on spine bone mass. Maintaining a healthy weight is important for the elderly in order to avoid osteoporosis and sarcopenia.

Longitudinal impact of aging on muscle quality in middle-aged men

The present follow-up study aims at assessing the longitudinal changes in muscle quality after an interval of 9.45 years in middle-aged men. In addition, the relative contribution of muscle mass, muscle strength, and muscle power at middle age to these changes was investigated. The results showed a small, though unexpected, increase in total body and leg muscle mass (respectively 0.22 ± 0.04 and 0.29 ± 0.06 % yearly, p < 0.0001), whereas basic strength (-0.71 to -0.87 % yearly, p < 0.0001) and velocity-dependent strength and power (-1.19 to -1.86 % yearly, p < 0.0001) declined. Consequently, muscle quality, defined as the ratio of basic strength or velocity-dependent strength and power to muscle mass decreased (-1.46 to -2.43 % yearly, p < 0.0001) from baseline to follow-up. We found that baseline basic strength is a strong determinant of the decline in muscle quality basic strength with advancing age, whereas only a small part of the age-associated decline in muscle quality based on velocity-dependent strength and power could be explained. To conclude, our results indicate that muscle becomes less efficient at middle age and that baseline muscle strength is a strong predictor of this change. These findings imply that unmeasured neural factors, influencing both contraction speed and the capacity of muscle to produce strength, are possibly other involved determinants. Therefore, timely interventions including strength training and higher-velocity strength training at middle age are recommended.

Enhanced skeletal muscle for effective glucose homeostasis

As the single largest organ in the body, the skeletal muscle is the major site of insulin-stimulated glucose uptake in the postprandial state. Skeletal muscles provide the physiological foundation for physical activities and fitness. Reduced muscle mass and strength is commonly associated with many chronic diseases, including obesity and insulin resistance. The complications of diabetes on skeletal muscle mass and physiology, resulting from either insulin deprivation or insulin resistance, may not be life-threatening, but accelerate the lost physiological functions of glucose homeostasis. The formation of skeletal muscle commences in the embryonic developmental stages at the time of mesoderm generation, where somites are the developmental milestone in musculoskeletal formation. Dramatic skeletal muscle growth occurs during adolescence as a result of muscle fiber hypertrophy since muscle fiber formation is mostly completed before birth. The rate of growth rapidly decelerates in the late stages of adulthood as adipose tissue gradually accumulates more fat when energy intake exceeds expenditure. Physiologically, the key to effective glucose homeostasis is the hormone insulin and insulin sensitivity of target tissues. Enhanced skeletal muscle, by either intrinsic mechanism or physical activity, offers great advantages and benefits in facilitating glucose regulation. One key protein factor named myostatin is a dominant inhibitor of muscle mass. Depression of myostatin by its propeptide or mutated receptor enhances muscle mass effectively. The muscle tissue utilizes a large portion of metabolic energy for its growth and maintenance. We demonstrated that transgenic overexpression of myostatin propeptide in mice fed with a high-fat diet enhanced muscle mass and circulating adiponectin, while the wild-type mice developed obesity and insulin resistance. Enhanced muscle growth has positive effects on fat metabolism through increasing adiponectin expression and its regulations. Molecular studies of the exercise-induced glucose uptake in skeletal muscle also provide insights on auxiliary substances that mimic the plastic adaptations of muscle to exercise so that the body may amplify the effects of exercise in contending physical activity limitations or inactivity. The recent results from the peroxisome proliferator-activated receptor γ coactivator 1α provide a promising therapeutic approach for future metabolic drug development. In summary, enhanced skeletal muscle and fundamental understanding of the biological process are critical for effective glucose homeostasis in metabolic disorders.

Signaling pathways controlling skeletal muscle mass

The molecular mechanisms underlying skeletal muscle maintenance involve interplay between multiple signaling pathways. Under normal physiological conditions, a network of interconnected signals serves to control and coordinate hypertrophic and atrophic messages, culminating in a delicate balance between muscle protein synthesis and proteolysis. Loss of skeletal muscle mass, termed "atrophy", is a diagnostic feature of cachexia seen in settings of cancer, heart disease, chronic obstructive pulmonary disease, kidney disease, and burns. Cachexia increases the likelihood of death from these already serious diseases. Recent studies have further defined the pathways leading to gain and loss of skeletal muscle as well as the signaling events that induce differentiation and post-injury regeneration, which are also essential for the maintenance of skeletal muscle mass. In this review, we summarize and discuss the relevant recent literature demonstrating these previously undiscovered mediators governing anabolism and catabolism of skeletal muscle.

Do ACE inhibitors improve the response to exercise training in functionally impaired older adults? A randomized controlled trial

Background.

Loss of muscle mass and strength with ageing is a major cause for falls, disability, and morbidity in older people. Previous studies have found that angiotensin-converting enzyme inhibitors (ACEi) may improve physical function in older people. It is unclear whether ACEi provide additional benefit when added to a standard exercise training program. We examined the effects of ACEi therapy on physical function in older people undergoing exercise training.

Methods.

Community-dwelling people aged ≥65 years with functional impairment were recruited through general (family) practices. All participants received progressive exercise training. Participants were randomized to receive either 4 mg perindopril or matching placebo daily for 20 weeks. The primary outcome was between-group change in 6-minute walk distance from baseline to 20 weeks. Secondary outcomes included changes in Short Physical Performance Battery, handgrip and quadriceps strength, self-reported quality of life using the EQ-5D, and functional impairment measured using the Functional Limitations Profile.

Results.

A total of 170 participants (n = 86 perindopril, n = 84 placebo) were randomized. Mean age was 75.7 (standard deviation [SD] 6.8) years. Baseline 6-minute walk distance was 306 m (SD 99). Both groups increased their walk distance (by 29.6 m perindopril, 36.4 m placebo group) at 20 weeks, but there was no statistically significant treatment effect between groups (−8.6m [95% confidence interval: −30.1, 12.9], p = .43). No statistically significant treatment effects were observed between groups for the secondary outcomes. Adverse events leading to withdrawal were few (n = 0 perindopril, n = 4 placebo).

Interpretation.

ACE inhibitors did not enhance the effect of exercise training on physical function in functionally impaired older people.

Sarcopenia as a prognostic index of nutritional status in concurrent cirrhosis and hepatocellular carcinoma

BACKGROUND AND AIMS

Abnormal body composition such as severe skeletal muscle depletion or sarcopenia has emerged as an independent predictor of clinical outcomes in a variety of clinical conditions. This study is the first study to report the frequency and prognostic significance of sarcopenia as a marker of nutritional status in patients with hepatocellular carcinoma (HCC).

METHODS

We analyzed 116 patients with HCC who were consecutively evaluated for liver transplant. Skeletal muscle cross-sectional area was measured by CT. Sarcopenia was defined using previously established cutpoints.

RESULTS

Ninety-eight patients were males (85%), and the mean age was 58±6 years. Sarcopenia was present in 35 patients (30%). By univariate Cox analysis, male sex (HR, 3.84; P=0.02), lumbar skeletal muscle index (HR, 0.97; P=0.04), INR (HR, 8.18; P<0.001), MELD score (HR, 1.19; P<0.001), Child-Pugh (HR, 3.95; P<0.001), serum sodium (HR, 0.84; P<0.001), TNM stage (HR, 2.59; P<0.001), treatment type (HR, 0.53; P<0.001), and sarcopenia (HR, 2.27; P=0.004) were associated with increased risks of mortality. By multivariate Cox regression analysis, only MELD score (HR, 1.08; P=0.04), Child-Pugh (HR, 2.14; P=0.005), sodium (HR, 0.89; P=0.01), TNM stage (HR, 1.92; P<0.001), and sarcopenia (HR, 2.04; P=0.02) were independently associated with mortality. Median survival for sarcopenic patients was 16±6 versus 28±3 months in nonsarcopenic (P=0.003).

CONCLUSIONS

Sarcopenia is present in almost one third of patients with HCC, and constitutes a strong and independent risk factor for mortality. Our results highlight the importance of body composition assessment in clinical practice.

Relationship between Body Mass Index (BMI) and body fat percentage, estimated by bioelectrical impedance, in a group of Sri Lankan adults: a cross sectional study

Background

Body Mass Index (BMI) is used as a useful population-level measure of overweight and obesity. It is used as the same for both sexes and for all ages of adults. The relationship between BMI and body fat percentage (BF %) has been studied in various ethnic groups to estimate the capacity of BMI to predict adiposity. We aimed to study the BMI–BF% relationship, in a group of South Asian adults who have a different body composition compared to presently studied ethnic groups. We examined the influence of age, gender in this relationship and assessed its’ linearity or curvilinearity.

Methods

A cross sectional study was conducted, where adults of 18–83 years were grouped into young (18–39 years) middle aged (40–59 years) and elderly (>60 years). BF% was estimated from bioelectrical impedance analysis. Pearsons’ correlation coefficient(r) was calculated to see the relationship between BMI-BF% in the different age groups. Multiple regression analysis was performed to determine the effect of age and gender in the relationship and polynomial regression was carried out to see its’ linearity. The relationships between age-BMI, age-BF % were separately assessed.

Results

Out of 1114 participants, 49.1% were males. The study sample represented a wide range of BMI values (14.8-41.1 kg/m²,Mean 23.8 ± 4.2 kg/m²). A significant positive correlation was observed between BMI-BF%, in males (r =0.75, p < 0.01; SEE = 4.17) and in females (r = 0.82, p < 0.01; SEE = 3.54) of all ages. Effect of age and gender in the BMI-BF% relationship was significant (p < 0.001); with more effect from gender. Regression line found to be curvilinear in nature at higher BMI values where females (p < 0.000) having a better fit of the curve compared to males (p < 0.05). In both genders, with increase of age, BMI seemed to increase in curvilinear fashion, whereas BF% increased in a linear fashion.

Conclusions

BMI strongly correlate with BF % estimated by bioelectrical impedance, in this sub population of South Asian adults. This relationship was curvilinear in nature and was significantly influenced by age and gender. Our findings support the importance of taking age and gender in to consideration when using BMI to predict body fat percentage/obesity, in a population.

The Cooperative Lifestyle Intervention Program-II (CLIP-II): design and methods

A complication of cardiovascular disease (CVD) and the metabolic syndrome (MetS) among older adults is loss of mobility. The American Heart Association has identified weight management as a core component of secondary prevention programs for CVD and is an important risk factor for physical disability. The American Society for Nutrition and the Obesity Society have highlighted the need for long-term randomized clinical trials to evaluate the independent and additive effects of diet-induced weight loss (WL) and physical activity in older persons on outcomes such as mobility, muscle function, and obesity related diseases. Here we describe the rationale, design, and methods of a translational study, the Cooperative Lifestyle Intervention Program-II (CLIP-II). CLIP-II will randomize 252 obese, older adults with CVD or MetS to a weight loss only treatment (WL), aerobic exercise training (AT)+WL, or resistance exercise training (RT)+WL for 18 months. The dual primary outcomes are mobility and knee extensor strength. The interventions will be delivered by YMCA community partners with our staff as trainers and advisers. This study will provide the first large scale trial to evaluate the effects of diet-induced WL on mobility in obese, older adults with CVD or MetS as compared to WL combined with two different modes of physical activity (AT and RT). Because uncertainty exists about the best approach for promoting WL in older adults due to concerns with the loss of lean mass, the design also permits a contrast between AT+WL and RT+WL on muscle strength.

Gonadotropins Are Related to Lean Mass in Healthy Postmenopausal Women

BACKGROUND

It has been suggested that the changes in hormone levels that occur with menopause and aging are related to loss of muscle mass. However, the role of gonadotropins in this process is unknown.

OBJECTIVES

To analyze the relationship between follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and lean mass in a cohort of healthy women.

METHODS

This is a cross-sectional study including 91 postmenopausal women (48-65 years old). Serum FSH, LH, and estradiol (E2) were measured. Lean mass was estimated by bioelectrical impedance analysis and expressed as appendicular skeletal muscle mass (AMM) index.

RESULTS

AMM index was negatively correlated with FSH levels (r = -0.33, p = 0.001) and LH (r = -0.293, p = 0.005), while there was no association with E2. When muscle mass expressed as AMM index was stratified into tertiles, there were significant differences between the lowest and the highest tertile for both FSH (82.4 ± 30, vs. 67.9 ± 25.8 mIU/mL, p = 0.04) and LH (40.9 ± 15.2 vs. 36.1 ± 12.3 mIU/mL, p = 0.03). In logistic regression analysis adjusted for age and E2 levels, high concentrations of FSH (OR = 1.03, 95% CI = 1.01-1.05, p = 0.008) and LH (OR = 1.06, 95% CI = 1.01-1.1, p = 0.01) were risk factors for having lower lean mass expressed as AMM index.

CONCLUSIONS

Menopausal women with high levels of gonadotropins have lower levels of lean mass than those with lower gonadotropins levels.

Development and validation of anthropometric equations to estimate appendicular muscle mass in elderly women

OBJECTIVE

This study aimed to examine the cross validity of two anthropometric equations commonly used and propose simple anthropometric equations to estimate appendicular muscle mass (AMM) in elderly women.

METHODS

Among 234 physically active and functionally independent elderly women, 101 (60 to 89 years) were selected through simple drawing to compose the study sample. The paired t test and the Pearson correlation coefficient were used to perform cross-validation and concordance was verified by intraclass correction coefficient (ICC) and by the Bland and Altman technique. To propose predictive models, multiple linear regression analysis, anthropometric measures of body mass (BM), height, girth, skinfolds, body mass index (BMI) were used, and muscle perimeters were included in the analysis as independent variables. Dual-Energy X-ray Absorptiometry (AMMDXA) was used as criterion measurement. The sample power calculations were carried out by Post Hoc Compute Achieved Power. Sample power values from 0.88 to 0.91 were observed.

RESULTS

When compared, the two equations tested differed significantly from the AMMDXA (p <0.001 and p = 0.001). Ten population / specific anthropometric equations were developed to estimate AMM, among them, three equations achieved all validation criteria used: AMM (E2) = 4.150 +0.251 [bodymass (BM)] - 0.411 [bodymass index (BMI)] + 0.011 [Right forearm perimeter (PANTd) 2]; AMM (E3) = 4.087 + 0.255 (BM) - 0.371 (BMI) + 0.011 (PANTd) 2 - 0.035 [thigh skinfold (DCCO)]; MMA (E6) = 2.855 + 0.298 (BM) + 0.019 (Age) - 0,082 [hip circumference (PQUAD)] + 0.400 (PANTd) - 0.332 (BMI). The equations estimated the criterion method (p = 0.056 p = 0.158), and explained from 0.69% to 0.74% of variations observed in AMMDXA with low standard errors of the estimate (1.36 to 1.55 kg) and high concordance (ICC between 0,90 and 0.91 and concordance limits from -2,93 to 2,33 kg).

CONCLUSION

The equations tested were not valid for use in physically active and functionally independent elderly women. The simple anthropometric equations developed in this study showed good practical applicability and high validity to estimate AMM in elderly women.

Six-year longitudinal changes in body composition of middle-aged and elderly Japanese: age and sex differences in appendicular skeletal muscle mass

AIM

Little is known about longitudinal changes of body composition measured by dual-energy X-ray absorptiometry (DXA) in middle-aged and elderly individuals. We evaluated longitudinal changes of body composition, and age and sex differences in appendicular skeletal muscle mass.

METHODS

Participants were 1454 community-dwelling Japanese men and women aged 40-79 years. Body composition at baseline and 6-year follow up was measured by DXA.

RESULTS

Fat increased significantly in men of all ages, and in women aged in their 40s and 50s. Among men, arm lean tissue mass (LTM) changed by 0.9%, -0.5%, -1.4% and -3.7%, respectively, for the 40s to the 70s, and decreased significantly in the 60s and 70s. Leg LTM in men changed by -0.4%, -1.3%, -1.7% and -3.9%, respectively, and decreased significantly from the 50s to the 70s. Compared with the preceding age groups, significant differences were observed between the 60s and 70s in arm and leg LTM change in men. Among women, arm LTM changed by 0.7%, 0.2%, 1.6% and -1.5%, respectively, which was significant in the 60s and 70s. Leg LTM decreased significantly in all age groups of women by -2.0%, -2.8%, -2.4% and -3.9%, respectively. With respect to sex differences, leg LTM loss rates were significantly higher in women than men at the 40s and 50s.

CONCLUSIONS

Longitudinal data suggest that arm and leg LTM decreased markedly in men in their 70s, and leg LTM had already decreased in women in their 40s.