Association between sarcopenia and mortality in healthy older people

Effect of Exercise and Nutrition Intervention for Older Adults with Impaired Physical Function with Preserved Muscle Mass (Functional Sarcopenia): A Randomized Controlled Trial

Background

Functional sarcopenia is characterized by decreased physical performance and grip strength despite preserved muscle mass. The effectiveness of a program combining exercise and nutritional support-known interventions for individuals with low muscle mass-was evaluated for its impact on older adults with functional sarcopenia.

Methods

An unblinded, parallel-group randomized controlled trial was conducted in a public medical center in a rural Korean community. Eligible older adults with functional sarcopenia were randomized into either the intervention group, receiving a 12-week program of group exercises and nutritional support, or the control group, receiving education on lifestyle management. Outcomes measured included changes in gait speed, grip strength, physical performance, and quality of life indices.

Results

The study enrolled 42 participants, with 21 allocated to each group. Compared with the control group, the intervention group showed significant improvements in the primary outcome of gait speed (mean change (m/s) 0.24 vs 0.00, p<0.001) and secondary outcomes, such as Short Physical Performance Battery scores, grip strength, and quality of life. No significant adverse events were reported.

Conclusion

The 12-week exercise and nutritional intervention significantly enhanced physical performance, grip strength, and quality of life among community-dwelling older adults with functional sarcopenia. This suggests that strategies commonly recommended for sarcopenia, including exercise and nutritional support, are also beneficial for individuals with functional sarcopenia, indicating the potential for broader application of such interventions.

Safety and tolerability of a low glycemic load dietary intervention in adults with cystic fibrosis: a pilot study

Introduction

To achieve and maintain adequate weight, people with cystic fibrosis (CF) May often consume energy-dense, nutrient-poor foods high in added sugars and refined carbohydrates; however, little is known about the glycemic and metabolic effects of dietary composition in this patient population. The objective of this pilot study was to investigate the safety and tolerability of a low glycemic load (LGL) diet in adults with CF and abnormal glucose tolerance (AGT).

Methods

Ten adults with CF and AGT completed this prospective, open-label pilot study. Mean age was 27.0 ± 2.1 years, 64% were female, and all had pancreatic insufficiency. Each participant followed his/her typical diet for 2 weeks, then transitioned to a LGL diet via meal delivery service for 8 weeks. The primary outcome was change in weight from baseline to study completion, with safety established if no significant decline was noted. Other key safety outcomes included change in hypoglycemia measured by patient report and continuous glucose monitoring (CGM). Exploratory outcomes included changes in other CGM measures, body composition by dual energy X-ray absorptiometry (DXA), and patient reported outcomes.

Results

There were no significant changes in weight or in subjectively-reported or objectively-measured hypoglycemia. Favorable non-significant changes were noted in CGM measures of hyperglycemia and glycemic variability, DXA measures of fat mass, and gastrointestinal symptom surveys.

Discussion

A LGL dietary intervention was safe and well tolerated in adults with CF and AGT. These results lay the groundwork for future trials investigating the impact of low-glycemic dietary interventions on metabolic outcomes in the CF population.

Strong association between sarcopenic obesity and non-alcoholic fatty liver disease: An observational study with ISarcoPRM algorithm

BACKGROUND

In recent times, sarcopenia and non-alcoholic fatty liver disease (NAFLD) have garnered widespread attention in public health. Nevertheless, the relationship between sarcopenia and NAFLD remains uncertain. This study investigated the association between NAFLD and sarcopenia in the elderly population.

METHODS

In this cross-sectional study, 1099 adults aged 60 and older participated. The participants were classified based on their body composition, and the International Society of Physical and Rehabilitation Medicine's diagnostic algorithm (ISarcoPRM) was utilized to diagnose sarcopenia, while the fatty liver index was utilized to diagnose NAFLD. Binary logistic regression analysis determined the correlation between NAFLD and sarcopenia.

RESULTS

Of the 1099 participants, 213 (58.2 %) males and 480 (65.5 %) females were afflicted with NAFLD. After adjusting for other clinical factors, exercise was found to decrease the likelihood of NAFLD in females (but not in males) by approximately 70 % [relative risk (RR): 0.312, 95 % confidence interval (CI): 0.182-0.547]. In addition, sarcopenia was not discerned as a risk factor for NAFLD in either gender (both p > 0.05). However, obesity increased the likelihood of NAFLD in males by 27.5 (95 % CI: 10.4-73.1) and in females by 28.1 (95 % CI: 17.1-46.4), and sarcopenic obesity increased the likelihood of NAFLD by 49.5 (95 % CI: 11.1-219.1) in males and 35.5 (95 % CI: 18.5-68.2) in females (all p < 0.001).

CONCLUSION

Our study suggests that sarcopenia is not a risk factor for NAFLD in non-obese elderly subjects. However, a strong association was observed between obesity, especially sarcopenic obesity, and NAFLD. Regular physical activity seems protective for NAFLD in older females.

Impact of possible sarcopenia on functional prognosis in patients with acute stroke with premorbid disability

AIM

How possible sarcopenia affects functional prognosis in patients with premorbid disability remains unclear. This study aimed to compare and investigate the impact of possible sarcopenia at admission on functional outcomes at discharge in patients with acute stroke with and without premorbid disability.

METHODS

This cohort study enrolled patients who were consecutively admitted to a single center for acute stroke. Calf circumference and grip strength were measured within 7 days of admission, and possible sarcopenia was determined using the Asian Working Group for Sarcopenia 2019 criteria. The Functional Independence Measure (FIM) score at discharge during the acute phase was the primary outcome. To examine the impact of possible sarcopenia on FIM scores at discharge, patients were divided into two groups according to being with or without premorbid disability according to the modified Rankin Scale, and multiple linear regression analysis was performed in each group.

RESULTS

This study included 456 patients with acute stroke (median age, 80 years). In the premorbid-disability group (n = 166), possible sarcopenia was present in 140 patients (84%). Patients without possible sarcopenia had significantly higher FIM scores at discharge compared with those with possible sarcopenia (P < 0.001). However, multiple linear regression analysis showed that possible sarcopenia was not associated with FIM scores at discharge in the premorbid-disability group (β = -0.054, P = 0.346).

CONCLUSIONS

The results of this study demonstrated that a high rate of possible sarcopenia was observed in patients with stroke with premorbid disability; however, this did not affect functional prognosis. Geriatr Gerontol Int 2024; 24: 359-363.

Sarcopenia as the Mobility Phenotype of Aging: Clinical Implications

Sarcopenia, which is characterized by an age-related decline in muscle mass and function, poses significant challenges to geriatric care. Its definition has evolved from muscle-specific criteria to include muscle mass, muscle function, and physical performance, recognizing sarcopenia as a physical frailty. Sarcopenia is associated with adverse outcomes, including mortality, falls, fractures, cognitive decline, and admission to long-term care facilities. Neuromechanical factors, protein-energy balance, and muscle protein synthesis-breakdown mechanisms contribute to its pathophysiology. The identification of sarcopenia involves screening tests and a comprehensive assessment of muscle mass, strength, and physical function. Clinical approaches aligned with the principles of comprehensive geriatric assessment prioritize patient-centered care. This assessment aids in identifying issues related to activities of daily living, cognition, mood, nutrition, and social support, alongside other aspects. The general approach to factors underlying muscle loss and functional decline in patients with sarcopenia includes managing chronic diseases and evaluating administered medications, with interventions including exercise and nutrition, as well as evolving pharmacological options. Ongoing research targeting pathways, such as myostatin-activin and exercise mimetics, holds promise for pharmacological interventions. In summary, sarcopenia requires a multifaceted approach, acknowledging its complex etiology and tailoring interventions to individual patient needs.

Phenotype validation of the Korean working group on sarcopenia guideline

BACKGROUND

This study aimed to validate the proposed Korean Working Group on Sarcopenia (KWGS) guideline, which introduces the concept of functional sarcopenia, in older Korean adults.

METHODS

Data from the Aging Study of Pyeongchang Rural Area, a longitudinal cohort of community-dwelling older adults, were utilized to compare frailty status and institutionalization-free survival among participants according to sarcopenia status. Based on the KWGS guideline, severe sarcopenia was defined as low muscle mass and strength with slow gait speed; sarcopenia (not severe) was defined as low muscle mass with low muscle strength or slow gait speed; and functional sarcopenia was defined as low muscle strength and slow gait speed without low muscle mass.

RESULTS

Among the 1302 participants, 329 (25.3 %) had severe sarcopenia, 147 (11.3 %) had sarcopenia (not severe), and 277 (21.3 %) had functional sarcopenia. Frailty was significantly greater in participants with any phenotype of sarcopenia than in those without sarcopenia. Additionally, participants with functional sarcopenia were frailer than those with sarcopenia (not severe). Furthermore, the rates of institutionalization and mortality were higher in participants with any phenotype of sarcopenia than in those without sarcopenia. There was no statistical difference between the rates of sarcopenia (not severe) and those with functional sarcopenia. These findings remained consistent after adjusting for age and sex.

CONCLUSIONS

Each phenotype according to the KWGS guideline was associated with significantly greater frailty and increased risk of institutionalization and mortality. Functional sarcopenia was associated with greater frailty and had comparable prognosis with sarcopenia (not severe).

Association of body fat distribution with all-cause and cardiovascular mortality in US adults: a secondary analysis using NHANES

OBJECTIVE

To investigate the association of fat and lean mass in specific regions with all-cause and cardiovascular-related mortality.

DESIGN

Population based cohort study.

SETTING

US National Health and Nutrition Examination Survey (2003-2006 and 2011-2018).

PARTICIPANTS

22 652 US adults aged 20 years or older.

EXPOSURES

Fat and lean mass in specific regions obtained from the whole-body dual-energy X-ray absorptiometry.

MAIN OUTCOME MEASURES

All-cause and cardiovascular-related mortality.

RESULTS

During a median of 83 months of follow-up, 1432 deaths were identified. Associations between body composition metrics and mortality risks were evident above specific thresholds. For all-cause mortality, Android fat mass showed elevated HRs above 2.46 kg (HR: 1.17, 95% CI 1.02 to 1.34), while Android lean mass (ALM) had similar trends above 2.75 kg (HR: 1.17, 95% CI 1.03 to 1.33), and Android total mass above 5.75 kg (HR: 1.08, 95% CI 1.01 to 1.16). Conversely, lower HRs were observed below certain thresholds: Gynoid fat mass (GFM) below 3.71 kg (HR: 0.72, 95% CI 0.56 to 0.93), Gynoid lean mass below 6.44 kg (HR: 0.77, 95% CI 0.64 to 0.92), and Gynoid total mass below 11.78 kg (HR: 0.76, 95% CI 0.70 to 0.84). Notably, below 0.722 kg, the HR of visceral adipose tissue mass (VATM) was 1.25 (95% CI 1.04 to 1.48) for all-cause mortality, and above 3.18 kg, the HR of total abdominal fat mass was 2.41 (95% CI 1.15 to 5.05). Cardiovascular-related mortality exhibited associations as well, particularly for Android fat mass (AFM) above 1.78 kg (HR: 1.22, 95% CI 1.01 to 1.47) and below 7.16 kg (HR: 0.50, 95% CI 0.36 to 0.69). HRs varied for Gynoid total mass below and above 10.98 kg (HRs: 0.70, 95% CI 0.54 to 0.93, and 1.12, 95% CI 1.02 to 1.23). Android per cent fat, subcutaneous fat mass (SFM), AFM/GFM, and VATM/SFM were not statistically associated with all-cause mortality. Android per cent fat, Gynoid per cent fat, AFM/GFM, and VATM/SFM were not statistically associated with cardiovascular-related mortality. Conicity index showed that the ALM/GLM had the highest performance for all-cause and cardiovascular-related mortality with AUCs of 0.785, and 0.746, respectively.

CONCLUSIONS

The relationship between fat or lean mass and all-cause mortality varies by region. Fat mass was positively correlated with cardiovascular mortality, regardless of the region in which they located. ALM/GLM might be a better predictor of all-cause and cardiovascular-related mortality than other body components or body mass index.

Fourier-Transform Infrared Spectroscopy as a Screening Tool for Osteosarcopenia in Community-Dwelling Older Women

Osteosarcopenia is a complex geriatric syndrome characterized by the presence of both sarcopenia and osteopenia/osteoporosis. This condition increases rates of disability, falls, fractures, mortality, and mobility impairments in older adults. The purpose of this study was to analyze the Fourier-transform infrared (FTIR) spectroscopy diagnostic power for osteosarcopenia in community-dwelling older women (n = 64; 32 osteosarcopenic and 32 non-osteosarcopenia). FTIR is a fast and reproducible technique highly sensitive to biological tissues, and a mathematical model was created using multivariate classification techniques that denoted the graphic spectra of the molecular groups. Genetic algorithm and support vector machine regression (GA-SVM) was the most feasible model, achieving 80.0% of accuracy. GA-SVM identified 15 wave numbers responsible for class differentiation, in which several amino acids (responsible for the proper activation of the mammalian target of rapamycin) and hydroxyapatite (an inorganic bone component) were observed. Imaging tests and low availability of instruments that allow the observation of osteosarcopenia involve high health costs for patients and restrictive indications. Therefore, FTIR can be used to diagnose osteosarcopenia due to its efficiency and low cost and to enable early detection in geriatric services, contributing to advances in science and technology that are potential "conventional" methods in the future.

Leisure-time physical activity and sarcopenia among older adults from low- and middle-income countries

BACKGROUND

There are no data on the association between leisure-time physical activity (LTPA) and sarcopenia in older adults from low- and middle-income countries (LMICs). This study aimed to investigate the association between LTPA and sarcopenia in individuals aged ≥65 years living in six LMICs.

METHODS

Cross-sectional data from the Study on Global AGEing and Adult Health (China, Ghana, India, Mexico, Russia and South Africa) were analysed. Sarcopenia referred to the presence of both low skeletal muscle mass and weak handgrip strength. LTPA was assessed using the Global Physical Activity Questionnaire and was analysed as a dichotomized variable [high LTPA (>150 min/week of moderate-to-vigorous LTPA) or low LTPA (≤150 min/week)]. Multivariable logistic regression analysis was conducted to assess associations.

RESULTS

There were 14 585 individuals included in this study [mean (SD) age 72.6 (11.5) years; 55.0% women]. The prevalence of high LTPA and sarcopenia was 8.9% and 12.0%, respectively. After adjusting for potential confounders, low LTPA was significantly associated with higher odds for sarcopenia [prevalence odds ratio (POR) = 1.85, 95% confidence interval (CI) = 1.29-2.65] compared with high LTPA. Significant associations were found in women (POR = 3.22, 95% CI = 1.82-5.68) but not in men (POR = 1.52, 95% CI = 0.99-2.35).

CONCLUSIONS

A positive and significant association between low LTPA and sarcopenia was found among older adults from LMICs. The promotion of LTPA among older adults in LMICs may aid in the prevention of sarcopenia, especially among females, pending future longitudinal research.

Beneficial effects of walking-based home program for improving cardio-respiratory performance and physical activity in sarcopenic older people: a randomized controlled trial

BACKGROUND

Sarcopenia is an age-related loss of muscle mass, decline in physical performance, and/or loss of muscle strength. Improving physical activity (PA) is associated with a reduced risk of sarcopenia. Additionally, the World Health Organization 2020 guidelines recommend 150 minutes/week of moderate-intensity or 75 minutes/week of vigorous PA plus resistance exercise twice a week. An increase in walking steps/day also enhances PA.

AIM

The study explored the benefits of a pedometer-based walking program plus a resistance exercise program in older adults with sarcopenia.

DESIGN

A randomized control trial.

SETTING

In community dwelling.

POPULATION

Older individuals with sarcopenia.

METHODS

Screening for sarcopenia was defined according to the Asian Working Group of Sarcopenia criteria in 2019, which is composed of the skeletal muscle mass index (SMI), muscle strength, and physical performance. Bioimpedance analysis, handgrip strength, and gait speed were measured for the SMI, muscle strength, and physical performance, respectively. to explore the effectiveness of a pedometer-based walking program plus TheraBand resistance exercise over 12 weeks. The intervention group was required to wear a pedometer and walk 7 500 steps/day for 5 days/week and perform the TheraBand resistance exercise twice a week, while the control group continued their routine daily activities. Respiratory muscle strength, functional capacity (i.e., 6-minute walk test), and PA were assessed before and after the 12-week program. To evaluate the benefits of the home-based walking program plus resistance exercise, two-way mixed ANOVAs were performed.

RESULTS

Sixty older individuals with sarcopenia aged ≥60 years were enrolled; however, a total of 57 older adults (28 in the invention group and 29 in the control group) completed the study. Inspiratory muscle strength, functional capacity, and PA increased between and within groups after the 12-week program (all P<0.05). Furthermore, muscle strength and physical performance improved in the intervention group after the 12-week program but not in the control group.

CONCLUSIONS

A pedometer-based intervention program with TheraBand resistance exercise could improve cardio-respiratory performance and PA among older Thai individuals with sarcopenia. Further study needs to consider type of exercise and dietary supplements.

CLINICAL REHABILITATION IMPACT

Increasing the number of steps walked per day may reduce the risk of developing sarcopenia in older people.

Fish oil administration combined with resistance exercise training improves strength, resting metabolic rate, and inflammation in older adults

BACKGROUND

While fish oil (FO) has attracted great attention due to their health-enhancing properties, its potential to enhance benefits from resistance exercise training (RET) has not been fully elucidated yet.

AIMS

The aim of this study was to investigate effects of FO administration during 12 weeks of programmed RET on muscular strength, resting metabolic rate (RMR), and systemic inflammation in healthy older adults.

METHODS

Twenty-eight healthy older adults were randomly assigned to three experimental groups: sedentary control (CON), resistance exercise training (RET), or RET combined with FO (RET-FO). A one-repetition (1RM) of maximum muscle strength, RMR, substrate oxidation, and blood inflammatory biomarkers were assessed before and after the intervention. Statistical significance was set at p ≤ 0.05.

RESULTS

1RM muscle strength was significantly increased in RET and RET-FO while substantially decreased in CON. RMR greatly increased in RET and RET-FO with no change in CON. RET-FO exhibited significantly increased fatty acid oxidation, but no change was found in CON and RET. Systemic interleukin 6 (IL-6) and C-reactive protein (CRP) were significantly decreased from baseline in RET-FO while no change was observed in CON and RET.

CONCLUSION

Our data indicate chronic RET reversed aging-induced loss of muscle strength and improved RMR, while FO administration combined with RET appears to enhance fat metabolism and mildly reduce some indicators of systemic inflammation.

Influence of sarcopenia as defined by EWGSOP2 on complications after pancreaticoduodenectomy and on the prognosis of pancreatic head cancer: A prospective cohort study

OBJECTIVES

It has been reported that sarcopenia is associated with higher postoperative complication rates in various surgeries and with a poorer prognosis in various carcinomas. However, many of these reports did not strictly follow the definition of sarcopenia. Therefore, we prospectively evaluated the influence of sarcopenia, as defined by the European Working Group on Sarcopenia in Older People 2 (EWGSOP2), on complications after pancreaticoduodenectomy (PD) and on the prognosis of pancreatic head carcinoma.

METHODS

We prospectively investigated 180 patients who underwent PD at Chiba University Hospital from January 2016 to March 2020. The skeletal muscle mass, grip strength, and gait speed of the patients were measured preoperatively. Sarcopenia was defined in accordance with the EWGSOP2 definition. We evaluated the frequency and severity of postoperative complications in infectious, non-infectious, and overall complications. We analyzed the prognosis of 83 patients with pancreatic head carcinoma who underwent PD.

RESULTS

There were no differences in the severity and frequency of infectious, non-infectious, and overall complications between patients with and without sarcopenia. In patients with pancreatic head carcinoma, the recurrence-free and overall survival rates were significantly lower in patients with sarcopenia than in those without sarcopenia (P = 0.017 and P = 0.011, respectively). In multivariate analysis, sarcopenia was an independent risk factor for poor recurrence-free survival and overall survival (HR, 4.48; 95% CI, 1.68-11.98; P = 0.003 and HR, 3.25; 95% CI, 1.19-8.86; P = 0.021, respectively).

CONCLUSIONS

Sarcopenia, as defined by EWGSOP2, did not affect complications after PD. Sarcopenia is an important prognostic factor for surgically resected pancreatic head carcinoma.

Relationship between pressure ulcer risk and sarcopenia in patients with hip fractures

OBJECTIVE

Pressure ulcer (PU) is a frequent complication of hip fractures. PUs can develop at any time after a hip fracture but most appear within 2-4 days after surgery. The purpose of this study was to investigate the association between hip fractures due to sarcopenia and the risk of PUs in patients with hip fracture.

METHOD

Between March 2017 and March 2019, patients aged ≥65 years of age with hip fractures were included in this retrospective cohort study. PU risk assessment according to the Braden Scale was performed within the first few hours after arrival at hospital. Skeletal muscle mass index (SMI) and hand grip strength were evaluated for a diagnosis of sarcopenia.

RESULTS

Of the 289 patients admitted to the study institution, 180 patients were finally enrolled in the study (129 females; 51 males). In male patients, as SMI increased, so too did the Braden Scale score, which was statistically significant (p=0.02). However, there was no statistically significant difference between SMIs and Braden Scale scores in female patients (p=0.304). In male patients, there was no statistically significant difference between hand grip strength and Braden Scale score (p=0.251). However, in female patients, as hand grip strength increased, so too did the Braden Scale score; this was also statistically significant (p=0.041).

CONCLUSION

In this study, decreased muscle mass and muscle weakness in patients with hip fractures were associated with increased PU risk as measured by Braden Scale scores in both males and females.

Effects of age and gender on body composition indices as predictors of mortality in middle-aged and old people

To determine whether body composition indices interact with age and gender as a predictor of all-cause mortality, 1200 participants at least 40 years of age were recruited in 2009 and 2010. A multi-frequency bioelectrical impedance analysis device was used to measure each participant's body composition indices, including the fat mass index (FMI), fat free mass index (FFMI), skeletal muscle mass index (SMMI), and visceral fat area index (VFAI). A baseline questionnaire was used to collect demographic information about lifestyle habits, socioeconomic status, and medical conditions. All claimed records of death from 2009 to 2018 in the National Health Insurance Research Databank were identified. The all-cause mortality rate was 8.67% after a mean follow-up period of 5.86 ± 2.39 person-years. The Cox proportional hazard model analysis showed significantly negative associations between FFMI or SMMI with all-cause mortality in the total group and those aged ≥ 65 y/o. The FFMI and SMMI were negative predictors of mortality in both genders. The FMI and VFAI were positive predictors of mortality exclusively in females. In conclusion, the SMMI is a better predictor of mortality than the BMI, FMI, and FFMI, especially in older adults. A higher fat mass or visceral fat distribution may predict higher mortality in females.

Association between total protein intake and low muscle mass in Korean adults

Background

Adults with low muscle mass have a poor prognosis. Studies that examined the association between total protein intake and low muscle mass among adults are limited. Thus, we investigated the association between total protein intake and low muscle mass among Korean adults aged ≥19 years.

Methods

We included 15,995 adults (6528 male and 9467 female) aged ≥19 years from the Korea National Health and Nutrition Examination Surveys (2008–2011). We divided the participants into groups according to protein intake quartile: Q1, Q2, Q3 and Q4 groups. The odds ratios (ORs) and 95% confidence intervals (CIs) of low muscle mass according to protein intake were analysed via multivariable logistic regression analysis. Stratified analyses according to sex, age and comorbidities were also performed.

Results

Of the participants, 3.8% had weight-adjusted low muscle mass. The prevalence rates of low muscle mass were 1.5, 3.0, 3.9 and 7.2% in the Q4, Q3, Q2 and Q1 groups, respectively (p < 0.001). Compared with the Q4 group, the Q1 group had the highest ORs for low muscle mass, followed by the Q2 and Q3 groups (Model 5; OR, 95% CI: 2.03, 1.36–3.02 for Q3; 2.44, 1.64–3.61 for Q2; and 4.32, 2.89–6.45 for Q4) after adjusting for confounding variables (p for trend < 0.001). The associations between protein intake and low muscle mass were stronger in younger individuals, men, individuals without hypertension, those with diabetes mellitus and those without dyslipidemia.

Conclusions

The prevalence of low muscle mass in Korean adults significantly increased with lower protein intake. Nutrition education for proper protein intake is also important for adults.

Trial registration

Retrospectively registered.

The Relationship between Body Composition, Dietary Intake, Physical Activity, and Pulmonary Status in Adolescents and Adults with Cystic Fibrosis

Measures of body fat and lean mass may better predict important clinical outcomes in patients with cystic fibrosis (CF) than body mass index (BMI). Little is known about how diet quality and exercise may impact body composition in these patients. Dual X-ray absorptiometry (DXA) body composition, 24-h dietary recall, and physical activity were assessed in a cross-sectional analysis of 38 adolescents and adults with CF and 19 age-, race-, and gender-matched healthy volunteers. Compared with the healthy volunteers, participants with CF had a lower appendicular lean mass index (ALMI), despite no observed difference in BMI, and their diets consisted of higher glycemic index foods with a greater proportion of calories from fat and a lower proportion of calories from protein. In participants with CF, pulmonary function positively correlated with measures of lean mass, particularly ALMI, and negatively correlated with multiple measures of body fat after controlling for age, gender, and BMI. Higher physical activity levels were associated with greater ALMI and lower body fat. In conclusion, body composition measures, particularly ALMI, may better predict key clinical outcomes in individuals with CF than BMI. Future longitudinal studies analyzing the effect of dietary intake and exercise on body composition and CF-specific clinical outcomes are needed.

Low muscle mass in older adults and mortality: A systematic review and meta-analysis

Sarcopenia comprises a loss of muscle function and muscle mass. So far, the association between the later and mortality in older adults is inconsistent. A meta-analysis was performed to assess whether muscle mass measured by appendicular skeletal muscle mass index (ASMI) is associated with higher mortality in older adults. Articles of interest were searched for in two databases (PudMed® and Embase®). Cohort and case-control studies reporting ASMI and mortality and enrolling community-dwelling adults aged 65 years or more were included. Nine articles were eligible and included for analysis (n = 10,028). All but one study were considered of high quality by Newcastle-Ottawa Scale assessment. We calculated the standardized mean difference (SMD) for ASMI between dead and living individuals during follow-up across studies. A reduced pooled ASMI in individuals who died as compared to those who survived (ASMI SMD = -0.18, CI95% -0.23 to -0.12, REM) was found. A meta-regression was performed including ASMI SMD, grip strength SMD, body mass index (BMI), sex, study quality, method used to assess ASMI, site of study and age. BMI and ethnicity were found to significantly impact the difference in ASMI between dead and living individuals. These results reinforce the prognostic importance of assessing muscle mass in older adults.

Effects of Photobiomodulation/Laser Therapy Combined With Resistance Training on Quadriceps Hypertrophy and Strength, and Postural Balance in Older Women: A Randomized, Triple-Blinded, Placebo-Controlled Study

BACKGROUND AND PURPOSE

Physical and therapeutic strategies to maintain and rehabilitate skeletal muscle mass, strength, and postural balance are clinically relevant to improve the health, well-being, and quality of life of older adults. The purpose of this study was to investigate the effects of photobiomodulation (PBM)/laser therapy combined with a resistance training (RT) program on quadriceps hypertrophy and strength, and postural balance in older women.

METHODS

In a randomized, triple-blinded, placebo-controlled design, twenty-two older women (age 66.6 ± 5.2 years) were engaged in a supervised 10-wk RT program (2 times per week) involving unilateral leg extension exercise, in which each leg of the same participant was randomly assigned to receive active (λ = 808 nm, optical output = 100 mW, total energy = 42 J) or placebo laser PBM immediately before the RT sessions. Maximal dynamic strength by unilateral knee extension 1-repetition maximum (1RM), muscle hypertrophy by vastus lateralis muscle thickness, and postural balance by one-legged stance test on a force platform were assessed before and after the training program.

RESULTS

Significance statistical analysis revealed a similar improvement (time P = .003) from pre- to posttraining for muscle hypertrophy and strength, and postural balance between active and placebo laser conditions. However, clinical interpretation for muscle hypertrophy showed a moderate effect (effect size [ES] = 0.58) for the active laser and a small effect (ES = 0.38) for the placebo laser. Clinical difference was not noticed between conditions for other analyzed variables.

CONCLUSIONS

These findings indicate that RT alone can be clinically important for counteracting the deleterious effects of aging on muscle size, strength, and balance, and that applying laser PBM therapy before the RT sessions may further improve gains in muscle hypertrophy.

Besides Sarcopenia, Pre-Sarcopenia Also Predicts All-Cause Mortality in Older Chileans

PURPOSE

Many studies have demonstrated that Sarcopenia causes a serious impact on health, including death in older adults. The objective of this study was to determine the association of sarcopenia and pre-sarcopenia with all-cause mortality in older Chileans.

SUBJECTS AND METHODS

Follow-up of 2311 community-dwelling people ≥ 60y from the Alexandros cohort. Anthropometric measurements, handgrip strength, mobility, and physical performance tests were performed. Sarcopenia, pre-sarcopenia, and severe sarcopenia were defined using the 2010 European Working Group on Sarcopenia in Older People (EWGSOP1) algorithm. Muscle mass was estimated using a prediction model with cut-off points validated for the Chilean population. Physical performance was determined by 3 m walking speed or five chair-stands or time up go test (TUG). Mortality data were obtained from death certificates of the National Civil Registry. Life tables for survival data, Kaplan Meier estimations, and Cox regression were calculated.

RESULTS

The prevalence of sarcopenia was 20.2% (95% CI:18.6% to 21.9%) and similar in both sexes; pre-sarcopenia was identified in 20.4% (95% CI:18.8% to 22.1%) of the sample. Kaplan Meier survival estimates demonstrated lower survival rates for the people with sarcopenia and pre-sarcopenia (Log rank test for equality of survivor functions: p<0.0001). A dose-response was observed in the survival rates according to the stages of sarcopenia, showing the lowest survival rates for the people with severe sarcopenia, followed by older adults with sarcopenia, pre-sarcopenia, and without sarcopenia (Log rank test for equality of survivor functions: p<0.0001). After adjusting for age, sex, nutritional status, and number of chronic diseases, hazard ratios for death showed higher risk for subjects with sarcopenia (HR=1.47, 95% CI:1.17-1.83) and pre-sarcopenia (HR=1.35, 95% CI:1.03-1.78) in comparison with people without sarcopenia.

CONCLUSION

The results confirm a dose-response increase in the risk of all-cause death in older adults with sarcopenia and pre-sarcopenia compared to non-sarcopenic individuals.

Relation of body fat mass and fat-free mass to total mortality: results from 7 prospective cohort studies

BACKGROUND

Fat mass and fat-free mass may play independent roles in mortality risk but available studies on body composition have yielded inconsistent results.

OBJECTIVE

The aim was to determine the relations of body fat mass and fat-free mass to risk of mortality.

METHODS

In pooled data from 7 prospective cohorts encompassing 16,155 individuals aged 20 to 93 y (median, 44 y), we used Cox regression and restricted cubic splines to estimate HRs and 95% CIs for the relation of body composition, measured by bioelectrical impedance analysis, to total mortality. We adjusted for age, study, sex, ethnicity, history of diabetes mellitus, education, smoking, physical activity, and alcohol consumption.

RESULTS

During a median follow-up period of 14 y (range, 3-21 y), 1347 deaths were identified. After mutual adjustment for fat mass and fat-free mass, fat mass showed a J-shaped association with mortality (overall P value < 0.001; P for nonlinearity = 0.003). Using a fat mass index of 7.3 kg/m2 as the reference, a high fat mass index of 13.0 kg/m2 was associated with an HR of 1.56 (95% CI: 1.30, 1.87). In contrast, fat-free mass showed an inverse association with mortality (overall P value < 0.001; P for nonlinearity = 0.001). Compared with a low fat-free mass index of 16.1 kg/m2, a high fat-free mass of 21.9 kg/m2 was associated with an HR of 0.70 (95% CI: 0.56, 0.87).

CONCLUSIONS

Fat mass and fat-free mass show opposing associations with mortality. Excess fat mass is related to increased mortality risk, whereas fat-free mass protects against risk of mortality. These findings suggest that body composition provides important prognostic information on an individual's mortality risk not provided by traditional proxies of adiposity such as BMI.

Utility of Ultrasound as a Valid and Accurate Diagnostic Tool for Sarcopenia: Sex-Specific Cutoff Values in Chronic Kidney Disease

OBJECTIVES

Patients with chronic kidney disease (CKD) have aberrant changes in body composition, including low skeletal muscle mass, a feature of "sarcopenia." The measurement of the (quadriceps) rectus femoris (RF) cross-sectional area (CSA) is widely used as a marker of muscle size. Cutoff values are needed to help discriminate the condition of an individual's muscle (eg, presence of sarcopenia) quickly and accurately. This could help distinguish those at greater risk and aid in targeted treatment programs.

METHODS

Transverse images of the RF were obtained by B-mode 2-dimensional ultrasound imaging. Sarcopenic levels of muscle mass were defined by established criteria (1, appendicular skeletal muscle mass [ASM]; 2, ASM/height² ; and 3, ASM/body mass index) based on the ASM and total muscle mass measured by a bioelectrical impedance analysis. The discriminative power of RF-CSA was assessed by receiver operating characteristic curves, and optimal cutoffs were determined by the maximum Youden index (J).

RESULTS

One hundred thirteen patients with CKD (mean age [SD], 62.0 [14.1] years; 48% male; estimated glomerular filtration rate, 38.0 [21.5] mL/min/1.73m² ) were included. The RF-CSA was a moderate predictor of ASM (R² = 0.426; P < .001) and total muscle mass (R² = 0.438; P < .001). With a maximum J of 0.47, in male patients, an RF-CSA cutoff of less than 8.9 cm² was deemed an appropriate cutoff for detecting sarcopenic muscle mass. In female patients, an RF-CSA cutoff of less than 5.7 cm² was calculated on the basis of ASM/height² (J = 0.71).

CONCLUSIONS

Ultrasound may provide a low-cost and simple means to diagnose sarcopenia in patients with CKD. This would allow for early management and timely intervention to help mitigate the effects in this group.

Liver fibrosis-induced muscle atrophy is mediated by elevated levels of circulating TNFα

Liver cirrhosis is a critical health problem associated with several complications, including skeletal muscle atrophy, which adversely affects the clinical outcome of patients independent of their liver functions. However, the precise mechanism underlying liver cirrhosis-induced muscle atrophy has not been elucidated. Here we show that serum factor induced by liver fibrosis leads to skeletal muscle atrophy. Using bile duct ligation (BDL) model of liver injury, we induced liver fibrosis in mice and observed subsequent muscle atrophy and weakness. We developed culture system of human primary myotubes that enables an evaluation of the effects of soluble factors on muscle atrophy and found that serum from BDL mice contains atrophy-inducing factors. This atrophy-inducing effect of BDL mouse serum was mitigated upon inhibition of TNFα signalling but not inhibition of myostatin/activin signalling. The BDL mice exhibited significantly up-regulated serum levels of TNFα when compared with the control mice. Furthermore, the mRNA expression levels of Tnf were markedly up-regulated in the fibrotic liver but not in the skeletal muscles of BDL mice. The gene expression analysis of isolated nuclei revealed that Tnf is exclusively expressed in the non-fibrogenic diploid cell population of the fibrotic liver. These findings reveal the mechanism through which circulating TNFα produced in the damaged liver mediates skeletal muscle atrophy. Additionally, this study demonstrated the importance of inter-organ communication that underlies the pathogenesis of liver cirrhosis.

Factors associated with measures of sarcopenia in pre and postmenopausal women

BACKGROUND

Menopause associated low serum estradiol marks varieties of derangements in muscle mass and functions leading to sarcopenia. This cross-sectional study was carried out to examine the factors associated with measures of sarcopenia; skeletal muscle mass (SMM), muscle strength and physical performance (PP) in a group of premenopausal (PrMW) and postmenopausal women (PMW) selected from Sri Lanka.

METHODS

Randomly selected 184 PrMW and 166 PMW from Galle district, Sri Lanka were studied. SMM was measured with duel energy X ray absorptiometry and relative appendicular SMM index (RSMI; kg/m2) was calculated. Other measurements made include handgrip strength (HGS; kg) and gait speed (GS; m/s), anthropometric indices, consumption of macro and micronutrients, and pattern of physical activities (PA). A serum sample was analyzed for fasting insulin, serum estradiol and vitamin D. Variables which significantly correlated with RSMI, HGS and GS of PrMW and PMW were separately entered into multiple linear regression models to extract the associated factors.

RESULTS

Mean (SD) age of PrMW and PMW were 42.4 (6.0) and 55.8 (3.8) years respectively. In the regression analysis, RSMI in PrMW showed significant associations with body mass index (BMI), HGS, total-body-fat-mass (TBFM) and weight (adjusted R2 = 0.85) and in PMW with BMI, weight, TBFM, hip-circumference and fasting insulin (adjusted R2 = 0.80). BMI showed the strongest association with RSMI in both PrMW (r = 0.87, R2 = 0.76) and in PMW (r = 0.87, R2 = 0.76). HGS in PrMW showed significant associations with appendicular SMM (ASMM), total-body-bone-mineral-content, vigorous PA score, age and weight (adjusted R2 = 0.33) and in PMW with ASMM and height (adjusted R2 = 0.23). ASMM showed the strongest association with HGS in both PrMW (r = 0.44, R2 = 0.20) and PMW (r = 0.44, R2 = 0.20). GS in PrMW showed significant associations with height, BMI and energy consumption (adjusted R2 = 0.13) while in PMW, with carbohydrate consumption and total-body-bone-mineral-density (adjusted R2 = 0.09). While in PrMW, height showed the strongest association with GS (r = 0.28, R2 = 0.08) in PMW, it was carbohydrate consumption (r = 0.24, R2 = 0.06).

CONCLUSIONS

Factors that are associated with different measures of sarcopenia are not uniform and vary widely from anthropometry to nutrient intake indicating that these measures are somewhat independent and are governed by different factors.

Sarcopenia and Its Relationships with Depression, Cognition, and Physical Activity in Thai Community-Dwelling Older Adults

Background

Age-related sarcopenia is associated with physical decline, including poor functional capacity, lack of physical activity, problems with activities of daily living, and disability. However, little is known about the association between mental health problems and cognitive function in older adults with sarcopenia. Therefore, this study explored community-dwelling older adults' sarcopenia prevalence and related associations with depression, cognitive performance, and physical activity.

Methods

This cross-sectional study included 330 community-dwelling older adults (66.85 ± 5.54 years, 76.06% female). Based on the Asian Working Group for Sarcopenia guidelines, gait speed, muscle mass, and handgrip were assessed. All participants responded to a set of questionnaires (e.g., Global Physical Activity Questionnaire, cognitive assessment, and depression scale). Logistic regression analysis and multivariate logistic regression were used to determine independent predictors for sarcopenia.

Results

Overall, 16.1% of the participants were identified as having sarcopenia. Further, advanced age (i.e., mean age ≥ 70 years; odds ratio: 4.67), high depression scores (odds ratio: 2.09), mild cognitive impairment (odds ratio: 0.22), and low physical activity levels (odds ratio: 1.96) were significant associated risk factors for sarcopenia after adjusting for age, sex, and educational level.

Conclusions

Sarcopenia can lead to adverse health outcomes (i.e., depressive symptoms, cognitive decline, and low physical activity) in older adults.

TNF Receptor-Associated Factor 6 Mediates TNFα-Induced Skeletal Muscle Atrophy in Mice During Aging

During aging, muscle mass decreases, leading to sarcopenia, associated with low-level chronic inflammation (inflammaging), which induces sarcopenia by promoting proteolysis of muscle fibers and inhibiting their regeneration. Patients with a variety of pathologic conditions associated with sarcopenia, including rheumatoid arthritis (RA), have systemically elevated TNFα serum levels, and transgenic mice with TNFα overexpression (TNF-Tg mice, a model of RA) develop sarcopenia between adolescence and adulthood before they age. However, if and how TNFα contributes to the pathogenesis of sarcopenia during the normal aging process and in RA remains largely unknown. We report that TNFα levels are increased in skeletal muscles of aged WT mice, associated with muscle atrophy and decreased numbers of satellite cells and Type IIA myofibers, a phenotype that we also observed in adult TNF-Tg mice. Aged WT mice also have increased numbers of myeloid lineage cells in their skeletal muscles, including macrophages and granulocytes. These cells have increased TNFα expression, which impairs myogenic cell differentiation. Expression levels of TNF receptor-associated factor 6 (TRAF6), an E3 ubiquitin ligase, which mediates signaling by some TNF receptor (TNFR) family members, are elevated in skeletal muscles of both aged WT mice and adult TNF-Tg mice. TRAF6 binds to TNFR2 in C2C12 myoblasts and mediates TNFα-induced muscle atrophy through NF-κB-induced transcription of the muscle-specific E3 ligases, Atrogen1 and Murf1, which promote myosin heavy-chain degradation. Haplo-deficiency of TRAF6 prevents muscle atrophy and the decrease in numbers of satellite cells, Type IIA myofibers, and myogenic regeneration in TRAF6^+/- ;TNF-Tg mice. Our findings suggest that pharmacologic inhibition of TRAF6 signaling in skeletal muscles during aging could treat/prevent age- and RA-related sarcopenia by preventing TNFα-induced proteolysis and inhibition of muscle fiber regeneration. © 2020 American Society for Bone and Mineral Research.

Advanced Skeletal Muscle Mass Reduction (Sarcopenia) Secondary to Neuromuscular Disease

We describe a young male patient chronically on a ventilator secondary to decreased mobility from amyotrophic lateral sclerosis (ALS). He had both a tracheostomy for breathing and percutaneous endoscopic gastrostomy (PEG) for feeding. Using 24-hour urinary creatinine excretion data, we calculated an estimate of skeletal muscle (SM) mass. SM mass was indexed to height and weight to obtain the SM index. The SM index is used as a determinant to define sarcopenia. From the data, we found that this patient had the smallest SM index ever recorded at 2.2 kg/m², consistent with extremely advanced sarcopenia. As a comparison, "severe" sarcopenia in a male is defined as a SM index ≤ 8.5 kg/m². This method can be used in ICU patients to evaluate for sarcopenia which is a predictive marker for mortality.

Effects of Sarcopenia on Prognosis After Resection of Gallbladder Cancer

BACKGROUND

This study aimed to determine the prognostic significance of radiographic sarcopenia (RS) in patients with gallbladder cancer (GBC).

METHODS

From March 2001 to December 2013, 158 GBC patients who underwent curative intent surgery were included. The presence of RS was determined by skeletal muscle mass index using abdominal computed tomography.

RESULTS

The 1-, 3-, and 5-year overall survival (OS) rates were 63.6%, 41.9%, and 36.4%, respectively, for patients with RS (n = 88), and 84.3%, 62.6%, and 54.3%, respectively, for those without RS (n = 70) (P = 0.006). Multivariate analysis showed that RS (hazard rate [HR] 1.704, P = 0.024) was a significant prognostic factor for patient survival, as well as disease stage (IV: HR 7.181, P < 0.001), radicality (HR 2.830, P = 0.001), adjuvant therapy (HR 0.537, P = 0.017), and intraoperative blood loss ≥ 1 L (HR 1.851, P = 0.023).

CONCLUSIONS

This study showed a significant association between RS and OS in GBC patients. Because RS is the only significant prognostic factor that can be evaluated preoperatively, its assessment would be helpful to provide early preventive therapy allowing the maintenance of muscle mass and patient-tailored treatment based on their physiologic reserves (e.g., skeletal muscle mass).

Characteristics of sarcopenia by European consensuses and a phenotype score

BACKGROUND

We aimed to assess the clinical characteristics of sarcopenia by the original and revised European Working Group on Sarcopenia in Older People (EWGSOP 1 and 2), and to propose a new sarcopenia phenotype score (SPS) to improve relevance of clinical outcomes.

METHODS

Analyses were performed in 1408 older adults of the Aging Study of PyeongChang Rural Area, a community-based cohort in Korea. For sarcopenia definitions, we used EWGSOP 1, EWGSOP 2, and SPS, a new index counting number of abnormal domains among components of grip strength, gait speed, or muscle mass. Frailty status by the frailty index and the Cardiovascular Health Study frailty score was compared with sarcopenia measures. Prediction ability for composite outcome combining death and institutionalization due to functional decline was assessed among sarcopenia measures.

RESULTS

Generally, sarcopenia spectrum by both EWGSOP 1 and 2 was associated with worse functional status in parameters of geriatric assessments. However, population who were considered as sarcopenic by EWGSOP 1, but not by EWGSOP 2, showed increased risk of composite outcome and worse frailty status, compared with people who were classified as not sarcopenic by both EWGSOP 1 and 2. With SPS, dose-response relationship was observed with both frailty status and outcome prediction. Prediction for composite outcome was better in SPS than in EWGSOP 2 classification.

CONCLUSIONS

A new SPS might be used to classify sarcopenic burden in older adults to resolve possible inconsistencies in phenotype correlation and outcome prediction of EWGSOP 2 criteria.

Network analysis of human muscle adaptation to aging and contraction

Resistance exercise (RE) remains a primary approach for minimising aging muscle decline. Understanding muscle adaptation to individual contractile components of RE (eccentric, concentric) might optimise RE-based intervention strategies. Herein, we employed a network-driven pipeline to identify putative molecular drivers of muscle aging and contraction mode responses. RNA-sequencing data was generated from young (21±1 y) and older (70±1 y) human skeletal muscle before and following acute unilateral concentric and contralateral eccentric contractions. Application of weighted gene co-expression network analysis identified 33 distinct gene clusters ('modules') with an expression profile regulated by aging, contraction and/or linked to muscle strength. These included two contraction 'responsive' modules (related to 'cell adhesion' and 'transcription factor' processes) that also correlated with the magnitude of post-exercise muscle strength decline. Module searches for 'hub' genes and enriched transcription factor binding sites established a refined set of candidate module-regulatory molecules (536 hub genes and 60 transcription factors) as possible contributors to muscle aging and/or contraction responses. Thus, network-driven analysis can identify new molecular candidates of functional relevance to muscle aging and contraction mode adaptations.

The Predictive Value of Sarcopenia and Its Individual Criteria for Cardiovascular and All-Cause Mortality in Suburb-dwelling Older Chinese

OBJECTIVES

The aim of the present study is to investigate the associations between the Asian Working Group for Sarcopenia (AWGS) sarcopenic definition, and its individual criteria, and risk of cardiovascular disease (CVD) and all-cause mortality in the Chinese elderly.

METHODS

Longitudinal analysis of 1,264 participants aged 60 years or older at baseline (2013-2014) living in suburban areas, China. Sarcopenia was defined according to the recommended algorithm of AWGS. Muscle mass was measured by a direct segmental multifrequency bioelectrical impedance analysis. Muscle strength was assessed by handgrip strength, and physical performance measured via usual walking speed.

RESULTS

Cox proportional hazard models were used to assess the risk of CVD and all-cause mortality. After 40 months of follow-up, forty-eight deaths (4.2%) died in this cohort. The mortality rate with sarcopenia was 4.7% in men and 3.8% in women. After adjusting for potential confounders, the risk of all-cause death was 4.15 times higher in subjects with sarcopenia. Furthermore, low muscle mass (HR: 2.62, 95% CI 1.34-5.13) and low grip strength (HR: 5.79; 95% CI 2.28-14.71), but not walking speed, were found to be significantly associated with all-cause mortality. Risk of CVD mortality was significantly greater in sarcopenia. Low grip strength and low walking speed were associated with 11 times (HR: 11.03, 95% CI 1.58-77.02) and 13 times (HR: 13.02; 95% CI 1.18-143.78) higher risk of CVD mortality.

CONCLUSIONS

Sarcopenia and components of sarcopenia were associated with greater CVD and all-cause mortality. Pertinent prevention or rehabilitation programs projects should look to promote healthy aging in different types of sarcopenia group.

Mice with myocyte deletion of vitamin D receptor have sarcopenia and impaired muscle function

BACKGROUND

It has long been recognized that vitamin D deficiency is associated with muscle weakness and falls. Vitamin D receptor (VDR) is present at very low levels in normal muscle. Whether vitamin D plays a direct role in muscle function is unknown and is a subject of hot debate. Myocyte-specific deletion of VDR would provide a strategy to answer this question.

METHODS

Myocyte-specific vitamin D receptor (mVDR) null mice were generated by crossing human skeletal actin-Cre mice with floxed VDR mice. The effects of gene deletion on the muscle phenotype were studied in terms of body tissue composition, muscle tissue histology, and gene expression by real-time PCR.

RESULTS

Unlike whole-body VDR knockout mice, mVDR mice showed a normal body size. The mVDR showed a distinct muscle phenotype featuring reduced proportional lean mass (70% vs. 78% of lean mass), reduced voluntary wheel-running distance (22% decrease, P = 0.009), reduced average running speed, and reduced grip strength (7-16% reduction depending on age at testing). With their decreased voluntary exercise, and decreased lean mass, mVDR have increased proportional fat mass at 20% compared with 13%. Surprisingly, their muscle fibres showed slightly increased diameter, as well as the presence of angular fibres and central nuclei suggesting ongoing remodelling. There were, however, no clear changes in fibre type and there was no increase in muscle fibrosis. VDR is a transcriptional regulator, and changes in the expression of candidate genes was examined in RNA extracted from skeletal muscle. Alterations were seen in myogenic gene expression, and there was decreased expression of cell cycle genes cyclin D1, D2, and D3 and cyclin-dependent kinases Cdk-2 and Cdk-4. Expression of calcium handling genes sarcoplasmic/endoplasmic reticulum calcium ATPases (SERCA) Serca2b and Serca3 was decreased and Calbindin mRNA was lower in mVDR muscle.

CONCLUSIONS

This study demonstrates that vitamin D signalling is needed for myocyte function. Despite the low level of VDR protein normally found muscle, deleting myocyte VDR had important effects on muscle size and strength. Maintenance of normal vitamin D signalling is a useful strategy to prevent loss of muscle function and size.

[How does vitamin D influence body composition, sarcopenia and lifespan in older persons? A retrospective study of nine years]

Introduction

Background: hypovitaminosis D has a prevalence of 50,4% in older persons. This population has grown globally in an impressive way during the last 20 years. In addition, the deficiency of vitamin D (< 30 ng/ml) could raise the risk of mortality in this population. Objectives: to know whether vitamin D levels less than 30 ng/ml have an impact on mortality for overall causes, cardiovascular causes, cancer or injuries (falls) in a follow-up period of nine years in elderly subjects. Methods: a retrospective longitudinal study with nine years period of observation; 418 elderly subjects were followed, and they were recruited in 2004 to participate in a study about vitamin D supplementation and muscle strength. Results: vitamin D levels below 30 ng/dl increase by almost three times the probability of dying (OR = 2.77, IC = 1.81-3.85), while the same level of vitamin D is associated with a double risk of dying from cardiovascular causes (OR = 1.78, CI = 1.21-2.09) in the unadjusted model. For cancer mortality and falls, no significant results were obtained. Vitamin D would not act as a protective factor against mortality. Conclusions: vitamin D levels less than 30 ng/ml could be a risk factor for general mortality.

Chronic Fish Oil Consumption with Resistance Training Improves Grip Strength, Physical Function, and Blood Pressure in Community-Dwelling Older Adults

Fish oil (FO) has received great attention for its health-enhancing properties. However, its potential synergistic effects with resistance training (RT) are not well established. The purpose of this study was to investigate the effects of FO supplementation during 12-weeks of RT on handgrip strength, physical function, and blood pressure (BP) in community-dwelling older adults. Twenty-eight healthy older adults (10 males, 18 females; 66.5 ± 5.0 years) were randomly assigned to three groups: Control (CON), resistance training (RT), resistance training with FO (RTFO). Handgrip strength, physical function [five times sit-to-stand (5T-STS), timed up and go (TUG), 6-m walk (6MW), 30-s sit-to-stand (30S-STS)], and BP were measured pre- and post-intervention. ANOVA was used with significance set at P ≤ 0.05. Handgrip strength significantly increased in RT (+5.3%) and RTFO (+9.4%) but decreased in CON (−3.9%). All physical function outcomes increased in RT and RTFO. CON exhibited significantly decreased TUG and 30S-STS with no change in 5T-STS and 6MW. BP substantially decreased only in RTFO, systolic blood pressure (−7.8 mmHg), diastolic blood pressure (−4.5 mmHg), mean arterial pressure (−5.6 mmHg), while no change was found in CON and RT. Chronic RT enhanced strength and physical function, while FO consumption combined with RT improved BP in community-dwelling older adults.

Association of Appendicular Lean Mass, and Subcutaneous and Visceral Adipose Tissue With Mortality in Older Brazilians: The São Paulo Ageing & Health Study

Body composition changes as a result of ageing may impact the survival of older adults. However, its influence on mortality risk is uncertain. Currently, the best method for body composition analysis in clinical practice is DXA. Nonetheless, the few studies on body composition by DXA and mortality risk in the elderly have some limitations. We investigated the association between body composition by DXA and mortality in a cohort of elderly subjects. Eight hundred thirty-nine community-dwelling subjects (516 women, 323 men) ≥ 65 years of age were assessed by a questionnaire, clinical data, laboratory exams, and body composition by DXA at baseline. Total fat and its components (eg, visceral adipose tissue [VAT]) were estimated. Appendicular lean mass (ALM) adjusted for fat and ALM divided by height² was used to ascertain the presence of low muscle mass (LMM). Mortality was recorded during follow-up. Multivariate logistic regression was used to compute ORs for all-cause and cardiovascular mortality. Over a mean follow-up of 4.06 ± 1.07 years, there were 132 (15.7%) deaths. In men, after adjustment for relevant variables, the presence of LMM (OR, 11.36, 95% CI, 2.21 to 58.37, P = 0.004) and VAT (OR, 1.99, 95% CI, 1.38 to 2.87, P < 0.001, for each 100-g increase) significantly increased all-cause mortality risk, whereas total fat, measured by the fat mass index, was associated with decreased mortality risk (OR, 0.48, 95% CI, 0.33 to 0.71, P < 0.001). Similar results were observed for cardiovascular mortality. In women, only LMM was a predictor of all-cause (OR, 62.88, 95% CI, 22.59 to 175.0, P < 0.001) and cardiovascular death (OR, 74.54, 95% CI, 9.72 to 571.46, P < 0.001). LMM ascertained by ALM adjusted for fat and fat mass by itself are associated with all-cause and cardiovascular mortality risk in the elderly. Visceral and subcutaneous fat have opposite roles on mortality risk in elderly men. Thus, DXA is a promising tool to estimate risk of mortality in the elderly. © 2019 American Society for Bone and Mineral Research.

Bioimpedance analysis and physical functioning as mortality indicators among older sarcopenic people

OBJECTIVES

To assess the prognostic significance of various characteristics and measurements of sarcopenia and physical functioning on all-cause mortality among home-dwelling older people with or at-risk of sarcopenia.

DESIGN

Cross-sectional and longitudinal analyses.

SETTING

Porvoo sarcopenia trial in open care.

PARTICIPANTS

Community-dwelling people aged 75 and older (N = 428, of which 182 were re-examined at one year) with four years of follow-up.

MEASUREMENTS

Body mass index (BMI), physical functioning (physical component of the RAND-36) and physical performance tests (Short Physical Performance Battery (SPPB)), hand grip strength, walking speed, Charlson Comorbity Index, bioimpedance-based surrogates for muscle mass: Single Frequency Skeletal Muscle Index (SF-SMI), and Calf Intracellular Resistance Skeletal Muscle Index (CRi-SMI). Date of death was retrieved from central registers. Survival analyses were performed using Life-Table analyses and Cox models.

RESULTS

Most test variables (except BMI) were associated with four-year mortality in a dose-dependent fashion. After controlling for age, gender and co-morbidity, physical performance and functioning (both SPPB and RAND-36), muscle strength (hand grip strength) and CRi-SMI appeared to be independent mortality risk indicators (p < 0.001) whereas SF-SMI was not. When CRi-SMI values were grouped by gender-specific cut-off points, the probability of surviving for four years decreased by 66% among the older people with low CRi-SMI (HR = 0.34, 95%CI 0.15-0.78, p = 0.011). When low CRi-SMI was further controlled for SPPB, the prognostic significance remained significant (HR = 0.55, 95%CI 0.33-0.92, p = 0.021). After controlling for age, gender, comorbidity, and CRi-SMI, the physical component of the RAND-36 (p = 0.007), SPPB (p < 0,001) and hand grip strength (p = 0.009) remained significant mortality predictors. Twelve-month changes were similarly associated with all-cause mortality during the follow-up period.

CONCLUSION

CRi-SMI, muscle strength, physical performance and physical functioning are each strong independent predictors of all-cause mortality among home-dwelling older people. Compared to these indicators, BMI seemed to be clearly inferior. Of two bioimpedance-based muscle indices, CRi SMI was better predictor of mortality than SF-SMI. In this regard, muscle mass, muscle strength and physical performance are all suitable targets for the prevention of sarcopenia-related over-mortality.

Relative sarcopenia and mortality and the modifying effects of chronic kidney disease and adiposity

BACKGROUND

Conventional definitions of sarcopenia based on lean mass may fail to capture low lean mass relative to higher fat mass, that is, relative sarcopenia. The objective of this study is to determine the associations of sarcopenia and relative sarcopenia with mortality independent of co-morbidities, and whether chronic kidney disease (CKD) and adiposity alter these associations.

METHODS

Dual energy X-ray absorptiometry-derived appendicular lean mass index (ALMI, kg/m2 ) and fat mass index (FMI, kg/m2 ) were assessed in 14 850 National Health and Nutrition Examination Survey participants from 1999 to 2006 and were linked to death certificate data in the National Death Index with follow-up through 2011. Sarcopenia was defined using sex-specific and race/ethnicity-specific standard deviation scores compared with young adults (T-scores) as an ALMI T-score < -2 and relative sarcopenia as fat-adjusted ALMI (ALMIFMI ) T-score < -2. Glomerular filtration rate (GFR) was estimated using creatinine-based (eGFRCr ) and cystatin C-based (eGFRCys ) regression equations.

RESULTS

Three (3.0) per cent of National Health and Nutrition Examination Survey participants met criteria for sarcopenia and 8.7% met criteria for relative sarcopenia. Sarcopenia and relative sarcopenia were independently associated with mortality (HR sarcopenia 2.20, 95% CI 1.69 to 2.86; HR relative sarcopenia 1.60, 95% CI 1.31 to 1.96). The corresponding population attributable risks were 5.2% (95% CI 3.4% to 6.4%) and 8.4% (95% CI 4.8% to 11.2%), respectively. Relative sarcopenia remained significantly associated with mortality (HR 1.32, 95% CI 1.08 to 1.61) when limited to the subset who did not meet the criteria for sarcopenia. The risk of mortality associated with relative sarcopenia was attenuated among persons with higher FMI (P for interaction <0.01) and was not affected by CKD status for either sarcopenia or relative sarcopenia.

CONCLUSIONS

Sarcopenia and relative sarcopenia are significantly associated with mortality regardless of CKD status. Relative sarcopenia is nearly three-fold more prevalent amplifying its associated mortality risk at the population level. The association between relative sarcopenia and mortality is attenuated in persons with higher FMI.

Effects of linear versus nonperiodized resistance training on isometric force and skeletal muscle mass adaptations in sarcopenic older adults

The aim of this study was to compare the effects of linear periodization (LP) versus nonperiodized (NP) resistance training on upper-body isometric force and skeletal muscle mass (SMM) in sarcopenic older adults. Twenty sarcopenic older adults were randomly assigned into the LP and NP groups and performed 16 weeks of resistance training. The SMM was measured by octopolar bioelectrical impedance. The isometric force for handgrip and trunk were assessed by dynamometer. Evaluations were performed at baseline, after 4, 8, 12, and 16 weeks of resistance training. For total weight lifted, there was a main effect for time (F=126.986, P<0.001), statistically significant difference between condition (F=13.867, P=0.001) and interaction (F=8.778, P<0.001), whereby total weight lifted was greater for NP after 4 months of training. Isometric force for handgrip and trunk increased across time (P<0.001) but no significant differences between groups or interaction were observed (P>0.05). The SMM increased across time (P<0.05), however no significant difference between groups or interaction were observed (P>0.05). There were strong and significant correlations between handgrip maximum force and SMM (LP: rho=0.79, P=0.004 vs. NP: rho=−0.43, P=0.244) and handgrip mean force and SMM (LP: rho=0.68, P=0.021 vs. NP: rho=−0.37, P=0.332) only for the LP group. In conclusion, LP and NP resistance training induced similar benefits on upper-body isometric force and SMM in sarcopenic older adults. However, LP presented lower total weight lifted, suggesting that it is possible to obtain similar gains in isometric force and SMM with less total work.

Body composition and mortality in the general population: A review of epidemiologic studies

IMPACT STATEMENT

Current understanding of the association of body composition on mortality in the general population is limited. This review evaluated the available epidemiologic studies on body composition and mortality that leveraged diverse approaches to estimate body composition. Although studies showed inconsistent results, there was evidence suggesting that high fat mass and low lean body mass may be independently associated with mortality in the general population. This review may help partially explain the "obesity paradox" phenomenon and facilitate further studies to advance the understanding of the association of body composition on health in the general and patient populations.

Sarcopenia Definitions and Their Associations With Mortality in Older Australian Women

OBJECTIVES

To investigate the relationship of 4 sarcopenia definitions with long-term all-cause mortality risk in older Australian women.

DESIGN

Data from the Perth Longitudinal Study in Aging Women from 2003 to 2013 was examined in this prospective cohort study. The 4 sarcopenia definitions were the United States Foundation for the National Institutes of Health (FNIH), the European Working Group on Sarcopenia in Older People (EWGSOP), and adapted FNIH (AUS-POP_F) and EWGSOP (AUS-POP_E) definitions using Australian population-specific cut-points [<2 standard deviation (SD)] below the mean of young healthy Australian women. All-cause mortality was captured via linked data systems.

SETTING AND PARTICIPANTS

In total, 903 community-dwelling older Australian women (baseline mean age 79.9 ± 2.6 years) with concurrent measures of muscle strength (grip strength), physical function (timed-up-and-go; TUG) and appendicular lean mass (ALM) were included.

MEASURES

Cox-proportional hazards modeling was used to examine the relationship between sarcopenia definitions and mortality over 5 and 9.5 years.

RESULTS

Baseline prevalence of sarcopenia by the 4 definitions differed substantially [FNIH (9.4%), EWGSOP (24.1%), AUS-POP_F (12.0%), AUS-POP_E (10.7%)]. EWGSOP and AUS-POP_E had increased age-adjusted hazard ratios (aHRs) for mortality over 5 years [aHR 1.88 95% confidence interval (CI) (1.24‒2.85), P < .01; aHR 2.52 95% CI (1.55‒4.09), P < .01, respectively] and 9.5 years (aHR 1.39 95% CI (1.06‒1.81), P = .02; aHR 1.94 95% CI (1.40‒2.69), P < .01, respectively). No such associations were observed for FNIH or AUS-POP_F. Sarcopenia components including weaker grip strength (per SD, 4.9 kg; 17%) and slower TUG (per SD, 3.1 seconds; 40%) but not ALM adjusted-variants (ALM/body mass index or ALM/height²) were associated with greater relative hazards for mortality over 9.5 years.

CONCLUSIONS/RELEVANCE

Unlike FNIH, the EWGSOP sarcopenia definition incorporating weak muscle strength and/or poor physical function was related to prognosis, as was the regionally adapted version of EWGSOP. Although sarcopenia definitions were not developed based on prognosis, this is an important consideration for globally standardizing the sarcopenia framework.

Association between activity energy expenditure and peak oxygen consumption with sarcopenia

Background

Sedentariness may be an important risk factor for sarcopenia. The aim of this work was to assess the association between muscle mass and strength and markers of usual physical activity such as activity energy expenditure and peak oxygen uptake.

Methods

Young and old participants were assessed measuring body composition by DEXA (double beam X ray absorptiometry), handgrip strength, peak oxygen consumption and workload during an exercise calorimetry in a braked cycle ergometer and a 72 h activity energy expenditure using Actiheart actigraphs. A heart rate/energy expenditure curve derived from the exercise calorimetry was used to calibrate each actigraph. Sarcopenia was defined as having an appendicular fat free mass index below 7.5 kg/m² and 5.6 kg/m² in men and women respectively, or a handgrip strength z score below 1, using local normal data or having both parameters below the cutoff points.

Results

We analyzed data from 192 assessments performed in participants aged 22 to 88 years (106 women). Sarcopenic participants (as determined by muscle mass, strength or both) had a significantly lower peak oxygen uptake and work load and a significantly lower activity energy expenditure. When analyzing lean mass and strength as continuous variables, peak oxygen consumption was a significant predictor of fat free mass in men. Among women, the association was observed only when percentage of muscle mass was expressed as a z score.

Conclusions

Activity energy expenditure and peak oxygen consumption are associated with a lower muscle mass and the presence of sarcopenia and should be considered as risk factors for this condition.

Comparison of sarcopenia and cachexia in men with chronic heart failure: results from the Studies Investigating Co-morbidities Aggravating Heart Failure (SICA-HF)

AIMS

Changes in heart failure (HF) patients' body composition may be associated with reduced exercise capacity. The aim of the present study was to determine the overlap in wasting syndromes in HF (cachexia and sarcopenia) and to compare their functional impact.

METHODS AND RESULTS

We prospectively enrolled 207 ambulatory male patients with clinically stable chronic HF. All patients underwent a standardized protocol examining functional capacity, body composition, and quality of life (QoL). Cachexia was present in 39 (18.8%) of 207 patients, 14 of whom also fulfilled the characteristics of sarcopenia (sarcopenia + cachexia group, 6.7%), whereas 25 did not (cachectic HF group, 12.1%). Sarcopenia without cachexia was present in 30 patients (sarcopenic HF group, 14.4%). A total of 44 patients (21.3%) presented with sarcopenia; however, 138 patients showed no signs of wasting (no wasting group, 66%). Patients with sarcopenia had lower strength and exercise capacity than both the no wasting and the cachectic HF group. Handgrip strength, quadriceps strength, peak oxygen uptake (VO₂ ), distance in the 6-minute walk test (6MWT), and QoL results were lowest in the sarcopenia + cachexia group vs. the no wasting group (P < 0.05 for all). Likewise, the sarcopenic HF group showed lower handgrip strength, quadriceps strength, 6MWT, peak VO₂ , and QoL results vs. the no wasting group (P < 0.05 for all).

CONCLUSION

Losing muscle with or without weight loss appears to have a more pronounced role than weight loss alone with regard to functional capacity and QoL among male patients with chronic HF.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT01872299.

Effect of Squat Exercises on Lung Function in Elderly Women with Sarcopenia

We explored whether a mechanically-assisted squat exercise improved muscle mass, muscle function, and pulmonary function in elderly women with or without sarcopenia. In total, 76 community-dwelling elderly subjects (>60 years of age) were screened. We ultimately included 30 subjects who completed more than 80% of the six-week course of mechanically-assisted squat exercises (three days per week, 30 min per day). We measured body composition, lung function, knee extensor strength, hand grip strength, and the 3-min walk distance (3MWD) before and after the exercise program. Subjects with sarcopenia had poor hand grip strength and knee extensor strength, and a slow walking speed. Their lung function parameters, including forced vital capacity (FVC), was lower than those of the controls. After six weeks of squat exercises, the hand grip strength, knee extensor strength, and 3MWD increased significantly in both groups. Appendicular skeletal muscle mass and leg lean mass were increased in subjects without sarcopenia. The FVC (L) increased significantly only in the sarcopenia group (p = 0.019). The mechanically-assisted squat exercise program increased muscle function and lung function, including FVC, in patients with sarcopenia. Muscle mass increased in subjects without sarcopenia.

Creatinine Excretion as a Determinant of Accelerated Skeletal Muscle Loss with Critical Illness

Objective

The 24-h urinary creatinine excretion rate has been used as an approximation of the skeletal muscle (SM) mass in non-intensive care unit (ICU) settings. The study goal or aim was to determine reductions in SM mass in patients with recurrent critical illness who are admitted to a medical ICU.

Methods

Retrospective ICU patient records between 2013 and 2015 were reviewed. Inclusion of ICU patients with repeat 24-h urinary creatinine excretion levels at two different ICU admissions done routinely as part of care. The study design is a case series with patients as their own control.

Results

Three patients were found to have data on two separate ICU admissions. The reduction in creatinine excretion among ICU patients was correlated with estimated SM mass. All patients had >50% reduction in creatinine excretion and ≥47% reduction in estimated SM mass over 4 months. All patients were bed-bound after the first ICU admission and met the definition of sarcopenia by the second ICU admission; all patients died during the second ICU admission. The final SM mass in all patients was <4 kg m^-2.

Conclusion

Patients with chronic critical illness admitted to the medical ICU, who become bed bound, can experience up to 50% reduction in SM mass as gleaned from creatinine excretion within 4 months. Low SM mass may predispose patients to increased mortality. Measurement of 24-h urinary creatinine excretion may be a useful ICU biomarker to determine SM mass for diagnostic and prognostic purposes.

Vitamin D and muscle

Vitamin D is increasingly recognised to play an important role in normal muscle function. Low vitamin D status is associated with an increased risk of falls and proximal weakness. Since vitamin D deficiency is very common, and the signs are non-specific, it is important to maintain a high index of suspicion of vitamin D deficiency in patients with muscle pain and weakness, and it is simple to measure serum 25(OH) vitamin D. Therapy is cheap, safe and effective, but sometimes a larger dose may be needed, and, as shown in our case report, willingness of people to pay for an over the counter medication can be an issue. Following a striking case report that demonstrates muscle defects in severe vitamin D deficiency, we discuss clinical studies examining specific effects of vitamin D on physical performance, muscle strength and falls. Finally, we present an overview of molecular mechanisms that explain vitamin D's biological effects on muscle.

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Low vitamin D is associated with an increased risk of falls and proximal weakness.

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Therapy is cheap, safe and effective, but larger doses may be needed and willingness to pay for over the counter medications can be an issue.

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We present an overview of molecular mechanisms that explain vitamin D’s biological effects on muscle.

Physical Activity and Sarcopenia in the Geriatric Population: A Systematic Review

INTRODUCTION

Sarcopenia is an aging-related health problem in the geriatric population. Sarcopenia reduces muscle mass, muscle strength, and physical performance. Although physical activity is protective against sarcopenia for older adults, there are limited studies in this area. The purpose of this study was to integrate and analyze research on physical activity and sarcopenia in the geriatric population.

METHODS

Studies that assess sarcopenia were searched across electronic databases that included Medline, PubMed, CINAHL, and Cochrane Database of Systematic Reviews. Studies that implemented physical activity-related intervention or research were included. A critical appraisal skills program was used for quality assessment of the selected articles. Study selection and data extraction were counted by 2 independent reviewers.

RESULTS

Of the 149 references identified through the database search, 10 studies were included in this systematic review. Seven studies were randomized controlled trials, and 3 were cross-sectional or longitudinal. The results of 8 studies indicated significant improvement in muscle mass, muscle strength, and physical performance through exercise intervention, as determined by long-term observation.

CONCLUSIONS

Physical activity is an effective protective strategy for sarcopenia. Most studies of older adults exercise intervention indicated that the participants achieved positive results, but maintenance of muscle strength appeared to depend on continuous implementation of certain types of physical activities. A limitation of these 10 reviewed studies was that there was no consistency in the measurement of sarcopenia. Therefore, sarcopenia measurement needs further investigation.

Effects of Milk Proteins Supplementation in Older Adults Undergoing Resistance Training: A Meta-Analysis of Randomized Control Trials

BACKGROUND

Older adults experience age-related physiological changes that affect body weight and body composition. In general, nutrition and exercise have been identified as potent stimulators of protein synthesis in skeletal muscle. Milk proteins are excellent sources of all the essential amino acids and may represent an ideal protein source to promote muscle anabolism in older adults undergoing resistance training. However, several randomized control trials (RCTs) have yielded mixed results on the effects of milk proteins supplementation in combination with resistance training on body weight and composition.

METHODS

PubMed, Web of Science and Cochrane databases were searched for literature that evaluated the effects of milk proteins supplementation on body weight and composition among older adults (age ≥ 60 years) undergoing resistance training up to September 2016. A random-effects model was used to calculate the pooled estimates and 95% confidence intervals (CIs) of effect sizes.

RESULTS

The final analysis included 10 RCTs involving 574 participants (mean age range from 60 to 80.8 years). Overall, the combination of milk proteins supplementation and resistance training did not have significant effect on fat mass (0.30, 95% CI -0.25, 0.86 kg) or body weight (1.02, 95% CI: -0.01, 2.04 kg). However, a positive effect of milk proteins supplementation paired with resistance training on fat-free mass was observed (0.74, 95% CI 0.30, 1.17 kg). Greater fat-free mass gains were observed in studies that included more than 55 participants (0.73, 95% CI 0.30, 1.16 kg), and in studies that enrolled participants with aging-related medical conditions (1.60, 95% CI 0.92, 2.28 kg). There was no statistical evidence of publication bias among the studies.

CONCLUSION

Our findings provide evidence that supplementation of milk protein, in combination with resistance training, is effective to elicit fat-free mass gain in older adults.

Relative muscle mass and the risk of incident type 2 diabetes: A cohort study

Aims

The association between relative muscle mass (RMM) and incidence of type 2 diabetes (T2DM) is largely unknown. We examined whether RMM predicted development of T2DM in an apparently young healthy population.

Methods

This cohort study was comprised of 113,913 men and 89,854 women, free of T2DM at baseline, who underwent a health checkup examination and were followed-up annually or biennially for an average of 2.9 years. We used skeletal muscle mass index (SMI) as an indicator of RMM. SMI (%) [total skeletal muscle mass (kg)/body weight (kg)×100] was estimated using a bioelectrical impedance analyzer. The study outcome was incident T2DM, defined as fasting serum glucose ≥126 mg/dL, HbA1C ≥6.5%, or use of medication for T2DM.

Results

During 589,098.8 person-years of follow-up, 4,264 individuals developed T2DM (incidence rate, 7.2 per 1000 person-years). Median age (range) at baseline was 39.1 years (18.1–87.1). RMM was negatively associated with incidence of T2DM in a dose-response manner. The multivariate-adjusted hazard ratios (95% CIs) for incident T2DM comparing quartiles 3, 2 and 1 of RMM to the highest quartile were 1.32 (1.14–1.52), 1.63 (1.42–1.86), and 2.21 (1.94–2.51), respectively, for males and 1.18 (0.88–1.58), 1.46 (1.11–1.91), and 1.96 (01.51–2.53) for females (P for trend <0.001; 0.011). This association was stronger in younger or premenopausal subjects.

Conclusions

RMM was negatively associated with development of T2DM in a large sample of young and middle-aged Korean adults. Further research is required to determine whether preservation of muscle mass through intervention affects the risk of T2DM.

Lack of knowledge and availability of diagnostic equipment could hinder the diagnosis of sarcopenia and its management

Objectives

Sarcopenia is an emerging clinical challenge in an ageing population and is associated with serious negative health outcomes. This study aimed to assess the current state of the art regarding the knowledge about the concept of sarcopenia and practice of the diagnostic strategy and management of sarcopenia in a cohort of Dutch healthcare professionals (physicians, physiotherapists, dietitians and others) attending a lecture cycle on sarcopenia.

Material and methods

This longitudinal study included Dutch healthcare professionals (n = 223) who were asked to complete a questionnaire before, directly after and five months after (n = 80) attending a lecture cycle on the pathophysiology of sarcopenia, diagnostic strategy and management of sarcopenia, i.e. interventions and collaboration.

Results

Before attendance, 69.7% of healthcare professionals stated to know the concept of sarcopenia, 21.4% indicated to know how to diagnose sarcopenia and 82.6% had treated patients with suspected sarcopenia. 47.5% used their clinical view as diagnostic strategy. Handgrip strength was the most frequently used objective diagnostic measure (33.9%). Five months after attendance, reported use of diagnostic tests was increased, i.e. handgrip strength up to 67.4%, gait speed up to 72.1% and muscle mass up to 20.9%. Bottlenecks during implementation of the diagnostic strategy were experienced by 67.1%; lack of awareness among other healthcare professionals, acquisition of equipment and time constraints to perform the diagnostic measures were reported most often. Before attendance, 36.4% stated not to consult a physiotherapists or exercise therapists (PT/ET) or dietitian for sarcopenia interventions, 10.5% consulted a PT/ET, 32.7% a dietitian and 20.5% both a PT/ET and dietitian. Five months after attendance, these percentages were 28.3%, 21.7%, 30.0% and 20.0% respectively.

Conclusion

The concept of sarcopenia is familiar to most Dutch healthcare professionals but application in practice is hampered, mostly by lack of knowledge, availability of equipment, time constraints and lack of collaboration.

Musculoskeletal decline and mortality: prospective data from the Geelong Osteoporosis Study

BACKGROUND

We aimed to examine the relationship between musculoskeletal deterioration and all-cause mortality in a cohort of women studied prospectively over a decade.

METHODS

A cohort of 750 women aged 50-94 years was followed for a decade after femoral neck bone mineral density (BMD) and appendicular lean mass (ALM) were measured using dual energy X-ray absorptiometry, in conjunction with comorbidities, health behaviour data, and other clinical measures. The outcome was all-cause mortality identified from the Australian National Deaths Index. Using Cox proportional hazards models and age as the time variable, mortality risks were estimated according to BMD groups (ideal-BMD, osteopenia, and osteoporosis) and ALM groups (T-scores > -1.0 high, -2.0 to -1.0 medium, <-2.0 low).

RESULTS

During 6712 person years of follow-up, there were 190 deaths, the proportions increasing with diminishing BMD: 10.7% (23/215) ideal-BMD, 23.5% (89/378) osteopenia, 49.7% (78/157) osteoporosis; and with diminishing ALM: 17.0% (59/345) high, 26.2% (79/301) medium, 50.0% (52/104) low. In multivariable models adjusted for smoking, polypharmacy, and mobility, compared with those with ideal BMD, mortality risk was greater for those with osteopenia [hazard ratio (HR) 1.77, 95% confidence interval (CI) 1.11-2.81] and osteoporosis (HR 2.61, 95%CI 1.60-4.24). Similarly, compared with those with high ALM, adjusted mortality risk was greater for medium ALM (HR 1.36, 95%CI 0.97-1.91) and low ALM (HR 1.65, 95%CI 1.11-2.45). When BMD and ALM groups were tested together in the model, BMD remained a predictor of mortality (HR 1.74, 95%CI 1.09-2.78; HR 2.82, 95%CI 1.70-4.70; respectively), and low ALM had borderline significance (HR 1.52, 95%CI 1.00-2.31), which was further attenuated after adjusting for smoking, polypharmacy, and mobility.

CONCLUSIONS

Poor musculoskeletal health increased the risk for mortality independent of age. This appears to be driven mainly by a decline in bone mass. Low lean mass independently exacerbated mortality risk, and this appeared to operate through poor health exposures.

Light-load resistance exercise increases muscle protein synthesis and hypertrophy signaling in elderly men

The present study investigated whether well-tolerated light-load resistance exercise (LL-RE) affects skeletal muscle fractional synthetic rate (FSR) and anabolic intracellular signaling as a way to counteract age-related loss of muscle mass. Untrained healthy elderly (>65-yr-old) men were subjected to 13 h of supine rest. After 2.5 h of rest, unilateral LL-RE, consisting of leg extensions (10 sets, 36 repetitions) at 16% of 1 repetition maximum (RM), was conducted. Subsequently, the subjects were randomized to oral intake of 4 g of whey protein per hour (PULSE, n = 10), 28 g of whey protein at 0 h and 12 g of whey protein at 7 h postexercise (BOLUS, n = 10), or 4 g of maltodextrin per hour (placebo, n = 10). Quadriceps muscle biopsies were taken at 0, 3, 7, and 10 h postexercise from the resting and the exercised leg of each subject. Myofibrillar FSR and activity of select targets from the mechanistic target of rapamycin complex 1-signaling cascade were analyzed from the biopsies. LL-RE increased myofibrillar FSR compared with the resting leg throughout the 10-h postexercise period. Phosphorylated (T308) AKT expression increased in the exercised leg immediately after exercise. This increase persisted in the placebo group only. Levels of phosphorylated (T37/46) eukaryotic translation initiation factor 4E-binding protein 1 increased throughout the postexercise period in the exercised leg in the placebo and BOLUS groups and peaked at 7 h. In all three groups, phosphorylated (T56) eukaryotic elongation factor 2 decreased in response to LL-RE. We conclude that resistance exercise at only 16% of 1 RM increased myofibrillar FSR, irrespective of nutrient type and feeding pattern, which indicates an anabolic effect of LL-RE in elderly individuals. This finding was supported by increased signaling for translation initiation and translation elongation in response to LL-RE.