Measurement of maximal isometric torque and muscle quality of the knee extensors and flexors in healthy 50- to 70-year-old women

Diagnostic accuracy of isometric knee extension strength as a sarcopenia criteria in older women

BACKGROUND

Muscle strength is one of the most reliable measures used for the identification of sarcopenia. The European Working Group on Sarcopenia in Older People update (EWGSOP2) proposed the use of grip strength and chair stand tests, while clarifying that isometric torque methods can be used when performing the grip strength test is impossible. This study aims to evaluate the diagnostic accuracy of isometric knee extension strength in screening for sarcopenia.

METHODS

This cross-sectional study included community-dwelling women aged 70 years and over. IKE and sarcopenia criteria (EWGSOP2) were assessed. Skeletal muscle mass was assessed by bioelectrical impedance analysis; muscle mass strength by handgrip; and physical performance by the 5 times sit-to-stand test, the Short Physical Performance Battery, and gait speed. The diagnostic accuracy for each sarcopenia criterion was calculated using sensitivity, specificity, positive and negative predictive value, and the area under the curve (AUC). Cutoff points for sarcopenia from IKE were defined with the ROC curve.

RESULTS

The sample comprised 94 women with a mean age of 75.9 years (standard deviation 5.6, range 70-92), of whom 25.5% (n = 24) met criteria for sarcopenia-mainly severe sarcopenia (73.8%, n = 17). Correlations were observed between IKE and each individually analyzed sarcopenia criterion except skeletal muscle mass, with AUC values exceeding 0.70 in all cases. The IKE cutoff showing the highest accuracy for the diagnosis of sarcopenia was 12.5 kg or less (AUC 0.76, 95% confidence interval [CI] 0.64-0.88; sensitivity: 65.2%, 95% CI 45.7-84.7; specificity 77.4%, 95% CI 60.3-94.5; positive predictive value 62.5%, 95 CI% 42.7-82.3; negative predictive value 88.8%, 95% CI 75.9-100).

CONCLUSIONS

IKE could be a suitable tool for measuring muscular strength in sarcopenia when other strength parameters cannot be assessed or in people with walking difficulties.

Age- and sex-dependence of muscle quality: Influence of intramuscular non-contractile tissues

PURPOSE

Muscle quality is explained by the ratio between muscle size and strength. Conventionally, muscle size is evaluated without considering the composition of contractile and non-contractile tissues in muscle, hence the influence of non-contractile tissues on muscle quality is not fully understood, especially within aging muscle. This study investigated the differences in intramuscular non-contractile tissues between different age and sex groups, and investigated their influence on muscle quality.

METHODS

Eighty-two older and 64 young females and males participated. Muscle cross-sectional area (quadriceps and hamstrings), separating contractile and non-contractile areas, was calculated from the magnetic resonance image of the right mid-thigh. Maximal voluntary isometric knee extension and flexion torque was measured. Torque/muscle area and torque/contractile area were calculated for each age and sex group.

RESULTS

Non-contractile/muscle area was higher in older than in young individuals in both muscle groups (p < 0.05), and it was greater in the hamstrings than in the quadriceps. For the hamstrings, torque/muscle area was lower in older than in young individuals in both sexes (p < 0.05). However, torque/contractile area did not show the differences between age groups, only between sexes (males>females) (p < 0.05).

CONCLUSIONS

The results indicate that 1) the presence of non-contractile tissues varies by age and muscle groups, 2) the extensive presence of non-contractile tissues can contribute to the underestimation of its muscle quality, and 3) the sex differences in muscle quality are influenced by factors other than muscle composition.

Criterion-related validity and reliability of the standing long jump test in adults: The Adult-Fit project

The purpose of this study was to analyze the criterion-related validity and the reliability of the standing long jump test (SLJ) for evaluating the lower-body explosive muscular strength in adults. A total of 410 adults participated in this study. Sociodemographic, anthropometric measurements, laboratory lower-body muscular strength tests, and the field-based SLJ were performed. In validity analysis, stepwise regression analysis showed that maximal horizontal power, sex, percentage of body fat, maximal horizontal force, and lean mass were significantly associated with the SLJ distance (R2 = 0.78; p < 0.001). Reliability analysis showed significant differences between test-retest in the SLJ test, with an overestimation of the second measurement compared to the first [12.14 ± 14.46 cm, intraclass correlation coefficient (ICC) = 0.94 (0.75-0.97), p < 0.001; Cohen's d = 0.31]. The coefficient of variation (CV) was 7.06% and the minimal detectable change (MDC90) was 29 cm. After a learning period, higher reliability values were found [0.45 ± 1.04 cm, ICC = 1.00 (0.99-1.00); p = 0.001; CV = 0.53 %; MDC90 = 1 cm]. The SLJ test may be a valid tool to assess lower-body explosive muscular strength in the adult population. A learning period may be necessary to provide reliability on the SLJ test.

Sarcopenia and aortic valve disease

Valvular heart disease, including calcific or degenerative aortic stenosis (AS), is increasingly prevalent among the older adult population. Over the last few decades, treatment of severe AS has been revolutionised following the development of transcatheter aortic valve replacement (TAVR). Despite improvements in outcomes, older adults with competing comorbidities and geriatric syndromes have suboptimal quality of life outcomes, highlighting the cumulative vulnerability that persists despite valve replacement. Sarcopenia, characterised by loss of muscle strength, mass and function, affects 21%-70% of older adults with AS. Sarcopenia is an independent predictor of short-term and long-term outcomes after TAVR and should be incorporated as a prognostic marker in preprocedural planning. Early diagnosis and treatment of sarcopenia may reduce morbidity and mortality and improve quality of life following TAVR. The adverse effects of sarcopenia can be mitigated through resistance training and optimisation of nutritional status. This is most efficacious when administered before sarcopenia has progressed to advanced stages. Management should be individualised based on the patient's wishes/preferences, care goals and physical capability. Exercise during the preoperative waiting period may be safe and effective in most patients with severe AS. However, future studies are needed to establish the benefits of prehabilitation in improving quality of life outcomes after TAVR procedures.

Walking net V ˙ O2 rises with advancing age in older women: where to go from here?

PURPOSE

Walking net V ˙ O2 tends to increase with advancing age; however, factors contributing to this relationship have not been widely described. The implications of such findings could inform targeted strategies to promote independent mobility in older adults. Herein, we evaluated the relationship between net V ˙ O2 and age at two submaximal workloads while exploring potential moderators of this relationship.

METHODS

Secondary analyses were performed on 35 older (65 ± 3 years) women who completed a battery of physical assessments including fixed-speed, non-graded and graded (+ 2.5%) treadmill walking with indirect calorimetry to determine net V ˙ O2. Maximal oxygen uptake ( V ˙ O2max), knee extensor maximal isometric voluntary contraction (MVC), peak rate of torque development (RTD), and plantar flexor range-of-motion (PFROM) were also measured.

RESULTS

Bivariate correlations showed non-graded (r = 0.403, p = 0.017) and graded (r = 0.413, p = 0.014) net V ˙ O2 were positively related to age. Notably, these relationships strengthened after adjusting for V ˙ O2max. Regression modeling showed age, RTD:MVC ratio (composite of muscle performance), and PFROM together explained 49% and 34% of the variance in non-graded and graded net V ˙ O2, respectively. Further analyses suggested knee extensor MVC moderates the relationship between non-graded net V ˙ O2 and age, accounting for 9% of the variance [ΔR2 = 0.090, F (1,31) = 4.13, p = 0.05].

CONCLUSION

These data support the premise that, in older women, walking net V ˙ O2 rises with advancing age, and additionally, the RTD:MVC ratio and PFROM are independent correlates of non-graded net V ˙ O2. Exercise interventions with a high degree of training specificity including explosive, velocity-based elements may promote independent mobility in older women.

Sarcopenia and frailty in inflammatory bowel disease: Emerging concepts and evidence

Sarcopenia is a condition marked by progressive loss of skeletal muscle mass and function while frailty is a multidimensional concept characterized by diminished physiological reserve and increased vulnerability to stressors. Both of these were previously considered as related to aging and shown to impact the quality of life and carry prognostic significance. Emerging data show that both sarcopenia and frailty carry similar relevance in chronic illness. Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract and malnourishment, both of which contribute to the development of sarcopenia by increasing protein breakdown and reducing protein synthesis. The coexistence of frailty further compounds the clinical complexity of IBD patients. Published evidence suggests a bidirectional association with IBD contributing to muscle wasting, while the resultant sarcopenia and frailty could further exacerbate the disease course. Sarcopenia and frailty are independently associated with adverse outcomes, including hospitalizations, increased surgical interventions, and surgical complications. As therapeutic strategies for IBD evolve, understanding the nuanced relationship between inflammatory bowel disease, sarcopenia, and frailty is crucial for devising holistic management. Comprehensive care should encompass not only disease-modifying therapies but also interventions targeting frailty and sarcopenia, as they have been shown to have a significant impact not only on the disease course but also on the quality of life. Future research could focus on further elucidating underlying mechanisms, simple screening strategies, and developing targeted interventions to improve the overall quality of life for individuals grappling with the complex interplay of IBD, sarcopenia, and frailty.

The reliability and suitability of strength assessments in frail and pre-frail older adults: recommendations for strength testing in older populations

BACKGROUND

Lifelong strength is fundamental to physical function, health, and quality of life. Reliable appropriate strength assessment measures for older adults play an important role in effective evaluation of baseline ability and exercise prescription to counter disease and disuse. This study aimed to investigate the within-session reliability of maximal isometric knee extension and flexion, hip abduction and adduction, and handgrip strength measures in frail and pre-frail older adults.

METHOD

The study was conducted at a residential care home in Birmingham, UK. All care home residents aged ≥ 65 years; pre-frail or frail according to the Fried Frailty phenotype criteria; able to speak and read English; not currently involved in any other clinical trial; without severe sensory impairments; and with a predicted life expectancy greater than the trial length were eligible. Maximal isometric lower limb testing was performed using specialised resistance training equipment and a portable measurement device, and grip strength was assessed using a portable dynamometer. All eligible participants attended a single testing session and performed three trials per measure. Peak force measures were obtained for analysis. Within-session reliability for each measure was calculated from repeated-measures analysis of variance, intraclass correlation coefficients (ICC), and coefficients of variation (CV) with 95% confidence intervals.

RESULTS

Eleven frail and eleven pre-frail older adults participated in the study. Within-session absolute and relative measures were found to be reliable with the highest overall repeatability indicated between trial 2 and trial 3 for knee extension, hip abduction, and handgrip (CV ≤ 4.65%, ICC ≥ 0.96) with variation evident across all measures, except knee extension, from trial 1 to 2.

CONCLUSIONS

Overall, maximal isometric strength in frail and pre-frail older adults with no previous testing experience can be measured with good to high reliability within their first testing session. An initial two familiarisation trials followed by two measurement trials is recommended to achieve the highest level of overall repeatability.

TRIAL REGISTRATION

The trial was registered with ClinicalTrials.gov: NCT03141879 on 05/05/2017.

Muscle quality index and cardiovascular disease among US population-findings from NHANES 2011-2014

BACKGROUND AND OBJECTIVE

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the United States. However, current evidence on the association between muscle quality and CVD is limited. This study investigates the potential association between the muscle quality index (MQI) and the prevalence of CVD and CVD-related mortality.

METHODS

Participants were selected from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Data on mortality and causes of death were obtained from the National Death Index (NDI) records through December 31, 2019. Statistical analysis used in this study, including weighted multivariable linear and logistic regression, cox regression and Kaplan-Meier (K-M) analysis, to estimate the association between MQI and all-cause mortality as well as CVD mortality. In addition, subgroup analysis was used to estimate the association between MQI and CVD subtypes, such as heart attack, coronary heart disease, angina, congestive heart failure, and stroke.

RESULTS

A total of 5,053 participants were included in the final analysis. Weighted multivariable linear regression models revealed that a lower MQI.total level was independently associated with an increased risk of CVD development in model 3, with t value =-3.48, 95%CI: (-0.24, -0.06), P = 0.002. During 5,053 person-years of 6.92 years of follow-up, there were 29 deaths from CVD. Still, the association between MQI.total and CVD mortality, as well as all-cause mortality did not reach statistical significance in the fully adjusted model (HR = 0.58, 95% CI: 0.21-1.62, P = 0.30; HR = 0.91, 95% CI:0.65,1.28, P = 0.59, respectively). Subgroup analysis confirmed that MQI.total was negatively associated with congestive heart failure (OR = 0.35, 95% CI = 0.18,0.68, P = 0.01).

CONCLUSION

This study highlights the potential of MQI as a measure of muscle quality, its negative correlation with congestive heart failure (CHF). However, MQI was not very useful for predicting the health outcomes such as CVD and mortality. Therefore, more attention should be paid to the early recognition of muscle weakness progression in CHF. Further studies are needed to explore more effective indicator to evaluate the association between muscle quality and health outcomes.

Performance Evaluation of Machine Learning Algorithms for Sarcopenia Diagnosis in Older Adults

BACKGROUND

Sarcopenia is a progressive and generalized skeletal muscle disorder. Early diagnosis is necessary to reduce the adverse effects and consequences of sarcopenia, which can help prevent and manage it in a timely manner. The aim of this study was to identify the important risk factors for sarcopenia diagnosis and compare the performance of machine learning (ML) algorithms in the early detection of potential sarcopenia.

METHODS

A cross-sectional design was employed for this study, involving 160 participants aged 65 years and over who resided in a community. ML algorithms were applied by selecting 11 features-sex, age, BMI, presence of hypertension, presence of diabetes mellitus, SARC-F score, MNA score, calf circumference (CC), gait speed, handgrip strength (HS), and mid-upper arm circumference (MUAC)-from a pool of 107 clinical variables. The results of the three best-performing algorithms were presented.

RESULTS

The highest accuracy values were achieved by the ALL (male + female) model using LightGBM (0.931), random forest (RF; 0.927), and XGBoost (0.922) algorithms. In the female model, the support vector machine (SVM; 0.939), RF (0.923), and k-nearest neighbors (KNN; 0.917) algorithms performed the best. Regarding variable importance in the ALL model, the last HS, sex, BMI, and MUAC variables had the highest values. In the female model, these variables were HS, age, MUAC, and BMI, respectively.

CONCLUSIONS

Machine learning algorithms have the ability to extract valuable insights from data structures, enabling accurate predictions for the early detection of sarcopenia. These predictions can assist clinicians in the context of predictive, preventive, and personalized medicine (PPPM).

Effectiveness of Home-Based Exercise and Nutrition Programs for Senior Adults on Muscle Outcomes: A Scoping Review

This scoping review investigates the volume of evidence for home-based exercise and nutrition programs and their effect on muscle quality among senior adults to inform implementation and future research. It aims to answer the research question: What are the evidence, challenges, and needs for research regarding a home-based exercise and nutrition intervention program to improve muscle outcomes in senior adults? This scoping review was conducted following the PRISMA extension for Scoping Review. The following databases were searched: PubMed, Scopus, MEDLINE, CINAHL, EMBASE, and the Cochrane Library. Applied filters were used to help condense the research articles. A total of 13 studies met the inclusion criteria for this scoping review. Most exercise interventions were either resistance or multi-component exercise programs. The nature of the nutrition intervention varied between different supplements, foods, education, or counseling. Muscle outcomes included muscle mass in nine studies, muscle function in all the studies, muscle strength in ten studies, and biochemical analyses in two studies. Two studies found improvements in muscle mass; two studies revealed improvements in all their muscle function tests; and three studies revealed improvements in muscle strength. Muscle biopsy in a study revealed enhanced muscle fibers, but both studies did not reveal any biomarker improvements. The scoping review findings revealed mixed results on the effectiveness of a home-based exercise and nutrition program. However, the current evidence does have many gaps to address before recommending this form of intervention for senior adults as an effective way to prevent and manage sarcopenia. Since this review identified multiple knowledge gaps, strengths, and limitations in this growing field, it can be a starting point to help build future study designs and interventions in this population.

High-intensity interval aerobic and resistance training to counteract low relative lean soft tissue mass in middle age: A randomized controlled trial

BACKGROUND

Age-related loss of skeletal muscle mass and function begins in early middle age, yet research to date has focused on older individuals, limiting our understanding of interventions earlier in the lifespan. To date, no high-intensity interval training studies have been conducted in middle-aged adults with low relative lean soft tissue mass.

METHODS

Eighty-two middle-aged adults (40-50 years of age) with low appendicular lean soft tissue mass index confirmed with dual energy x-ray absorptiometry (DXA) were randomly allocated (1:1) to group-based, 20-week, three times a week, high-intensity aerobic and resistance training (HIART) program or 60-min education session (Control). The primary outcome was change in total lean soft tissue mass measured by DXA. Secondary outcomes included cardiorespiratory fitness, physical function (handgrip strength, gait speed, 30-seconds sit-to-stand, quadriceps strength and muscle quality). Measures were obtained at baseline (0 weeks), mid-intervention (10 weeks) and post-intervention (20 weeks).

RESULTS

Mean age in HIART was 44.8 (SD 3.2) and 45.4 (SD 2.9) in Control group. The majority of the participants were female with 88 % in HIART and 83 % in Control group. Mean BMI in HIART was 25.8 kg/m² (SD 3.5) and 26.4 kg/m² (SD 4.1) Control group. Intention to treat analysis showed that post-intervention, HIART increased significantly more total lean soft tissue mass (0.8 kg, 95%CI 0.15, 1.46), appendicular lean soft tissue mass index (0.2 kg/m², 95%CI 0.09, 0.33), peak oxygen uptake (5.18 mL/min/kg, 2.97 to 7.39 95%CI), grip strength (2.2 kg, 95%CI 0.09, 4.32), and 30-s sit-to-stand (1.3 times, 95%CI 0.43, 2.12) with significantly greater reductions in body fat percentage (-1.1 %, 95%CI -2.03, -0.10) and maximum gait speed (-0.2 m/s, 95 % CI -0.34, -0.03) compared Control.

CONCLUSION

The HIART program is an effective exercise intervention to increase total lean soft tissue mass in middle-aged adults with low relative lean soft tissue mass compared to a waitlist control group.

[Physical activity in sarcopenia: rehabilitation approaches in prevention and treatment of age-related muscle disorders]

Sarcopenia is a widespread condition in the elderly people, that occurs as a result of impaired muscle structure and function and is significantly associated with reduced quality and time of life. This review represents current approaches to the diagnosis of sarcopenia with reference to recent European and Asian consensus. They include rules for the evaluation of the main muscle strength and function tests (hand dynamometry, sit-to-stand test, 6-minute walk test, physical performance battery tests, etc.), physical and instrumental methods of muscle mass analysis (densitometry, bioimpedance analysis, magnetic resonance imaging). Furthermore, the pathogenetic relationship between the lack of physical activity and muscle dysfunction in elderly people is broached, including in particular the role of myostatin, interleukin-6, somatotropin and insulin resistance. The article represents possibilities of impact of aerobic, strength and neuromuscular physical exercises on prevention and correction of sarcopenic changes in different age groups based on the analysis of current clinical studies.

Association between dietary inflammatory index score and muscle mass and strength in older adults: a study from National Health and Nutrition Examination Survey (NHANES) 1999-2002

PURPOSE

Chronic low-grade systemic inflammation affects muscle protein metabolism. The dietary inflammatory index (DII®) is a tool designed to assess the inflammatory potential of the diet. The available data on the association between DII and sarcopenia are limited. We aimed to investigate the association of the DII with components of sarcopenia in individuals over 50 years of age.

METHODS

This cross-sectional study used the National Health and Nutrition Examination Survey (NHANES) 1999-2002 dataset. Body composition was measured, and isokinetic strength of the knee extensors (peak force) was evaluated. Low muscle mass and strength were defined using sex-specific thresholds. Energy-adjusted DII (E-DII™) scores were calculated using 24-h dietary recall data. Regression models were fit to evaluate the association between E-DII scores and low muscle mass and low muscle strength, alone and combined.

RESULTS

Mean age of study participants was 62.1 ± 9.5 years, and 138 participants (7.4%) belonged to the combination group of low muscle mass and low muscle strength. In multivariable-adjusted regression models, higher E-DII score was associated with lower appendicular skeletal muscle index (ASMI) (β =  - 0.03, P  < 0.001, P trend <0.001), and lower peak force (β =  -2.15, P  = 0.04, P trend = 0.01) and higher likelihood for these components combined (OR = 1.12, 95% CI 1.01-1.25, P = 0.03).

CONCLUSION

Higher E-DII score is associated with lower muscle mass and muscle strength, and increased likelihood for the combination of low muscle mass and low muscle strength in older adults. This has important implications for healthy aging.

Prevalence of sarcopenia among Saudis and its association with lifestyle behaviors: Protocol for cross-sectional study

Background

Sarcopenia is an age-related muscular disease manifesting as a loss of muscle function and mass–leads to detrimental consequences at both individual and community levels. Modifiable lifestyle factors (such as physical behaviors and nutritional habits) may be involved in sarcopenia etiology. European Working Group on Sarcopenia in Older Population (EWGOSP2) established a cut-off point for sarcopenia diagnosis based on the European population and they recommend the use of a regional normative population. However, no sufficient data on sarcopenia prevalence is presently available in Saudi Arabia. Therefore, this project aims to define appropriate reference values from healthy Saudi young adults (Phase I) and to investigate the prevalence of sarcopenia in Saudi Arabia (Phase II) and examine selected modifiable lifestyle correlates of sarcopenia (Phase I, II).

Methods

The project will involve two phases. Phase I will include 1532 healthy Saudi young adults aged between 20–40 years. While, Phase II will include 1532 Saudi older adults aged ≥50 years. The study will measure vital signs, anthropometrics, muscle mass using bioelectrical impedance analysis and dual-energy X-ray absorptiometry, muscle strength using handgrip strength and maximal isometric strength, physical function using short physical performance battery, and 6-minute walk test to measure aerobic endurance. To explore the associations between lifestyle behaviors with sarcopenia indices, physical activity, sedentary behaviour and sleep will be evaluated subjectively using Global Physical Activity Questionnaire and Pittsburgh Sleep Quality Index and objectively via ActivPAL accelerometers. A three-day dietary food record will also be used to evaluate dietary intake. Additionally, EuroQOL five-dimension questionnaire will be utilized to assess health-related quality of life.

Discussion

The study will have significant implications in recognizing the prevalence of sarcopenia in Saudi population, which will guide our future interventional studies aimed at early prevention and treatment of this disease.

Frailty Status Improvement after 5-Month Multicomponent Program PROMUFRA in Community-Dwelling Older People: A Randomized Controlled Trial

A study was made of the effect of the PROMUFRA multicomponent frailty program upon physical frailty, kinanthropometry, pain and muscle function parameters in frail and pre-frail community-dwelling older people. Eighty-one participants were randomly allocated to the intervention group (IG) or control group (CG). The IG performed PROMUFRA for 20 weeks, using six strength exercises with three series of 8–12 repetitions until muscular failure, and seven myofascial exercises, with one set of 10 repetitions. The CG continued their routine. The frailty criteria number (FCN), kinanthropometric parameters and muscle function were measured at baseline and after the program. Between-group differences were found in the interaction for FCN, muscle mass, fat mass, skeletal muscle mass index, knee flexion range of motion (ROM), hip flexion with knee straight ROM, maximum isometric knee extension, maximum isotonic knee extension, maximum leg press and hand grip strength., and also on post-intervention frailty status. The IG showed a statistical trend towards decreased pain. In conclusion, the PROMUFRA program is a potential training approach that can bring benefits in physical frailty status, body composition, ROM and muscle function among frail or pre-frail community-dwelling older people.

Age-related differences of vastus lateralis muscle morphology, contractile properties, upper body grip strength and lower extremity functional capability in healthy adults aged 18 to 70 years

Background

There is a lack of of cross-sectional research that has investigated muscle morphology, function, and functional capability in all age-bands of healthy adults. The primary aim of this study was to evaluate age-related differences in indices of vastus lateralis (VL) muscle morphology, function and functional capability in a sample of healthy males and females aged 18-70yrs. Secondary aims were to evaluate relationships between age and VL muscle morphology and function and functional capability.

Methods

B mode Ultrasonography and Tensiomyography were used to measure VL muscle thickness, pennation angle, fascicle length, and contractile properties in 274 healthy adults aged 18-70yrs. Measurements of grip strength and functional capability (1-min chair rise test) were also taken. Data analysis included descriptive statistics, correlations, one-way ANOVAs, and multiple regressions.

Results

Negative correlations were found between age and muscle thickness (r_s = -.56), pennation angle (r_s = -.50), fascicle length (r_s = -.30), maximal displacement (r_s = -.24), grip strength (r_s = -.27) and the 1-min chair rise test (r_s = -.32). Positive correlations were observed between age and the echo intensity of the muscle (r_s = .40) and total contraction time (r_s = .20). Differences in the indices of muscle health were noticeable between the 18–29 age band and the 50–59 and 60–70 age bands (p < 0.05). The interaction of age and level of physical activity predicted changes in the variables (r² = .04—.32).

Conclusion

Age-related differences in muscle health are noticeable at 50 years of age, and age-related differences are larger in females compared to males. It was suggested that the thickness of the VL changed the most with age across the adult lifespan and that physical activity likely acts to abate detrimental change.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03183-4.

A Custom-Made Electronic Dynamometer for Evaluation of Peak Ankle Torque after COVID-19

The negative effects of SARS-CoV-2 infection on the musculoskeletal system include symptoms of fatigue and sarcopenia. The aim of this study is to assess the impact of COVID-19 on foot muscle strength and evaluate the reproducibility of peak ankle torque measurements in time by using a custom-made electronic dynamometer. In this observational cohort study, we compare two groups of four participants, one exposed to COVID-19 throughout measurements and one unexposed. Peak ankle torque was measured using a portable custom-made electronic dynamometer. Ankle plantar flexor and dorsiflexor muscle strength was captured for both feet at different ankle angles prior and post COVID-19. Average peak torque demonstrated no significant statistical differences between initial and final moment for both groups (p = 0.945). An increase of 4.8%, p = 0.746 was obtained in the group with COVID-19 and a decrease of 1.3%, p = 0.953 was obtained in the group without COVID-19. Multivariate analysis demonstrated no significant differences between the two groups (p = 0.797). There was a very good test−retest reproducibility between the measurements in initial and final moments (ICC = 0.78, p < 0.001). In conclusion, peak torque variability is similar in both COVID-19 and non-COVID-19 groups and the custom-made electronic dynamometer is a reproducible method for repetitive ankle peak torque measurements.

Novel approaches to sarcopenic obesity and weight management before and after kidney transplantation

PURPOSE OF REVIEW

Although a widely recognized and complex pathophysiological condition, sarcopenic obesity remains less appreciated and may elude diagnosis and workup in both kidney transplant waitlisted candidates and kidney transplant recipients. The lack of consensus definition, and practical diagnostic tools for evaluating waitlisted candidates and transplant recipients are barriers to early detect and initiate therapeutic management for sarcopenic obesity. Although sarcopenia leads to poor clinical outcomes, posttransplant obesity yields conflicting results. Exercise and nutritional managements are common therapies for sarcopenic obese patients; however, surgery weight loss or bariatric surgery in both transplant candidates and potential living kidney donors shows promising benefits for kidney transplant access in waitlist obese candidates but may require to be selected for appropriate patients.

RECENT FINDINGS

Pathogenesis and management for sarcopenia and obesity are interconnected. The benefits of exercise to improve muscle mass and function is clear in waitlist kidney transplant candidates and transplant recipients. However, there are several barriers for those to increase exercise and improve physical activity including patient, provider, and healthcare or environmental factors. The advantages of fat mass reduction to lose weight can promote muscle mass and strength. However, epidemiological data regarding the obesity paradox in dialysis-dependent patients when overnutrition provides survival benefits for this population should be taken into account when performing weight loss especially bariatric surgery.

SUMMARY

Barriers in providing optimal care to kidney transplant waitlisted candidates and transplant recipients may partly result from underdiagnosis of sarcopenic obesity; notwithstanding that this entity has increasingly been more recognized. Mechanistic studies to better understand pathogenesis of sarcopenic obesity will help determine pathogenesis and clinical tools for diagnosis of this entity, which can facilitate further studies related to the outcomes and weight management to ultimately improve kidney transplant outcomes.

Effectiveness of the PROMUFRA program in pre-frail, community-dwelling older people: A randomized controlled trial

This study evaluated the effect of PROMUFRA program on physical frailty, kinanthropometric, muscle function and functional performance variables in pre-frail, community-dwelling older people. Participants (n = 50, 75 ± 7 years) were randomly assigned to two groups: intervention group (IG), and control group (CG). The IG performed multi-component exercise program, focused on high-intensity resistance training (HIRT) combined with self-massage for myofascial release (SMMR) for 12 weeks (2 d.wk^-1). Two measurements were performed, at baseline and post-3 months. Participants (n = 43) were analyzed and significant differences were found in group-time interaction for muscle mass (p = 0.017), fat mass (p = 0.003), skeletal muscle mass index (p = 0.011), maximum isometric knee extension (p = 0.042), maximum dynamic knee extension (p = 0.001), maximum leg press (p < 0.001), Barthel Index (p = 0.039) and EuroQol 5-dimensions-3-levels (p = 0.012). We conclude that PROMUFRA program is an effective training method to achieve healthy improvements for the pre-frail community.

Age-Group Differences in the Performance of Selected Tests of Physical Function and Association With Lower Extremity Strength

BACKGROUND AND PURPOSE

It is not known whether short functional performance tests used in aging research are appropriate for use in healthy older adults. The purpose of this study was to investigate age-group differences (sixth decade vs seventh decade) in selected functional performance tests and the association between lower extremity strength and functional performance.

METHODS

One hundred fifty-nine (18.2% [n = 29] male) healthy older adults (mean (standard deviation) age 60.4 (5.3) years), adults were recruited from the University of Limerick Campus Community. Knee extensor (KE) peak torque (PT) was assessed from a maximal voluntary isometric contraction. Subsequently, participants completed 10-m maximal and habitual gait speed tests, 5 repetition and 30-second chair rise tests, and a 900-m gait speed test.

RESULTS AND DISCUSSION

There was no difference in 10-m gait speed between those in the sixth and seventh decades (P > .05). Compared with the sixth decade, those in the seventh decade required an extra 39 seconds to complete 900 m, an extra 0.6 seconds to complete 5 chair rises and performed 2 fewer chair rises in a 30-second time period (P < .05). All tests had a weak association with KE strength (r = 0.226-0.360; P < .05), except for 900-m gait speed that had a moderate association (r = -0.537; P < .001). Our findings suggest that gait speed tests of 10 m or less cannot detect age-related difference in functional capacity when used in healthy older adults.

CONCLUSION

Extended physical performance tests should be used in aging research on healthy older adults.

Muscle Evaluation in Axial Spondyloarthritis-The Evidence for Sarcopenia

Sarcopenia is a syndrome defined as a progressive and generalized skeletal muscle disorder associated with an increased likelihood of adverse outcomes such as falls, fractures, physical disability, and death. The actual definition of sarcopenia is based on a reduction in the values of three parameters: strength, muscle mass quantity or quality, and physical performance (the determinant of severity). Muscle wasting is a common feature in several chronic diseases, such as spondyloarthritis (SpA), and significantly increases patient morbidity and mortality. Although there has been huge progress in this field over recent years, the absence of a clear definition and clear diagnostic criteria of sarcopenia has resulted in inconsistent information regarding muscle-involvement in SpA. Thus, the aim of this review is to collect relevant evidence on muscular changes occurring during the disease process from the published literature, according to the recommended tools for sarcopenia evaluation proposed by the European Working Group on Sarcopenia in Older People 2 (EWGSOP2). In addition, data from histological, electromyography, and biochemical muscle analyses of SpA patients are also reviewed. Overall, a reduction in muscle strength with a systemic decrease in lean mass seems to be associated with a gait speed compromise. This information is usually fragmented, with no studies considering the three parameters together. This paper represents a call-to-action for the design of new studies in the future.

Physical Exercise in the Oldest Old

Societies are progressively aging, with the oldest old (i.e., those aged >80-85 years) being the most rapidly expanding population segment. However, advanced aging comes at a price, as it is associated with an increased incidence of the so-called age-related conditions, including a greater risk for loss of functional independence. How to combat sarcopenia, frailty, and overall intrinsic capacity decline in the elderly is a major challenge for modern medicine, and exercise appears to be a potential solution. In this article, we first summarize the physiological mechanisms underlying the age-related deterioration in intrinsic capacity, particularly regarding those phenotypes related to functional decline. The main methods available for the physical assessment of the oldest old are then described, and finally the multisystem benefits that exercise (or "exercise mimetics" in those situations in which volitional exercise is not feasible) can provide to this population segment are reviewed. In summary, lifetime physical exercise can help to attenuate the loss of many of the properties affected by aging, especially when the latter is accompanied by an inactive lifestyle and benefits can also be obtained in frail individuals who start exercising at an advanced age. Multicomponent programs combining mainly aerobic and resistance training should be included in the oldest old, particularly during disuse situations such as hospitalization. However, evidence is still needed to support the effectiveness of passive physical strategies including neuromuscular electrical stimulation or vibration for the prevention of disuse-induced negative adaptations in those oldest old people who are unable to do physical exercise. © 2019 American Physiological Society. Compr Physiol 9:1281-1304, 2019.

A new approach to the classification of muscle health: preliminary investigations

OBJECTIVE

Upper leg skeletal or lean tissue mass (LTM), strength and muscle quality have emerged as time-sensitive indices of muscular health. The aim of this study was to generate a comparative data set based on these indices, in healthy young (n  =  30, 29.0  ±  3.0 y old) and older (n  =  32, 58.7  ±  2.8 years old) adults, in order to evaluate their construct validity in establishing cut-points for muscle health.

APPROACH

Whole body and upper leg LTM was obtained (iDXATM; GE Healthcare, Madison, WI) prior to the assessment of maximal voluntary isometric torque of the knee extensors and flexors (Cybex Isokinetic Dynamometer; Humac Norm, USA).

MAIN RESULTS

Peak isometric upper leg torque showed the greatest age-related difference (-29.0%), followed by muscle quality (-19.1%) and upper leg LTM (-9.8%).

SIGNIFICANCE

Cut-points based on Z and T-scores generated from the young adult mean suggest muscle quality demonstrates the greatest construct validity toward the aim of classifying the muscular health of adults. Data generated from large, representative and sex-specific samples are required to adequately classify the muscular health of adults.

Influence of between-limb asymmetry in muscle mass, strength, and power on functional capacity in healthy older adults

PURPOSE

Numerous daily tasks such as walking and rising from a chair involve bilateral lower limb movements. During such tasks, lower extremity function (LEF) may be compromised among older adults. LEF may be further impaired due to high degrees of between-limb asymmetry. The present study investigated the prevalence of between-limb asymmetry in muscle mass, strength, and power in a cohort of healthy older adults and examined the influence of between-limb asymmetry on LEF.

METHODS

Two hundred and eight healthy older adults (mean age 70.2 ± 3.9 years) were tested for LEF (400 m walking and 30-seconds chair stand). Furthermore, maximal isometric and dynamic knee extensor strength, leg extensor power, and lower limb lean tissue mass (LTM) were obtained unilaterally.

RESULTS

Mean between-limb asymmetry in maximal muscle strength and power ranged between 10% and 13%, whereas LTM asymmetry was 3 ± 2.3%. Asymmetry in dynamic knee extensor strength was larger for women compared with men (15.0 ± 11.8% vs 11.1 ± 9.5%; P = .005) Leg strength and power were positively correlated with LEF (r²  = .43-.46, P < .001). The weakest leg was not a stronger predictor of LEF than the strongest leg. Between-limb asymmetry in LTM and isometric strength was negatively associated with LEF (LTM; r²  = .12, P = .005, isometric peak torque; r²  = 0.40, P = .03.) but dynamic strength and power were not.

CONCLUSION

The present study supports the notion that in order to improve or maintain LEF, healthy older adults should participate in training interventions that increase muscle strength and power, whereas the effects of reducing between-limb asymmetry in these parameters might be of less importance.

CORP: Measurement of upper and lower limb muscle strength and voluntary activation

Muscle strength, the maximal force-generating capacity of a muscle or group of muscles, is regularly assessed in physiological experiments and clinical trials. An understanding of the expected variation in strength and the factors that contribute to this variation is important when designing experiments, describing methodologies, interpreting results, and attempting to replicate methods of others and reproduce their findings. In this review (Cores of Reproducibility in Physiology), we report on the intra- and inter-rater reliability of tests of upper and lower limb muscle strength and voluntary activation in humans. Isometric, isokinetic, and isoinertial strength exhibit good intra-rater reliability in most samples (correlation coefficients ≥0.90). However, some tests of isoinertial strength exhibit systematic bias that is not resolved by familiarization. With the exception of grip strength, few attempts have been made to examine inter-rater reliability of tests of muscle strength. The acute factors most likely to affect muscle strength and serve as a source of its variation from trial-to-trial or day-to-day include attentional focus, breathing technique, remote muscle contractions, rest periods, temperature (core, muscle), time of day, visual feedback, body and limb posture, body stabilization, acute caffeine consumption, dehydration, pain, fatigue from preceding exercise, and static stretching >60 s. Voluntary activation, the nervous system’s ability to drive a muscle to create its maximal force, exhibits good intra-rater reliability when examined with twitch interpolation (correlation coefficients >0.80). However, inter-rater reliability has not been formally examined. The methodological factors most likely to influence voluntary activation are myograph compliance and sensitivity; stimulation location, intensity, and inadvertent stimulation of antagonists; joint angle (muscle length); and the resting twitch.

Sarcopenia: revised European consensus on definition and diagnosis

Background

in 2010, the European Working Group on Sarcopenia in Older People (EWGSOP) published a sarcopenia definition that aimed to foster advances in identifying and caring for people with sarcopenia. In early 2018, the Working Group met again (EWGSOP2) to update the original definition in order to reflect scientific and clinical evidence that has built over the last decade. This paper presents our updated findings.

Objectives

to increase consistency of research design, clinical diagnoses and ultimately, care for people with sarcopenia.

Recommendations

sarcopenia is a muscle disease (muscle failure) rooted in adverse muscle changes that accrue across a lifetime; sarcopenia is common among adults of older age but can also occur earlier in life. In this updated consensus paper on sarcopenia, EWGSOP2: (1) focuses on low muscle strength as a key characteristic of sarcopenia, uses detection of low muscle quantity and quality to confirm the sarcopenia diagnosis, and identifies poor physical performance as indicative of severe sarcopenia; (2) updates the clinical algorithm that can be used for sarcopenia case-finding, diagnosis and confirmation, and severity determination and (3) provides clear cut-off points for measurements of variables that identify and characterise sarcopenia.

Conclusions

EWGSOP2's updated recommendations aim to increase awareness of sarcopenia and its risk. With these new recommendations, EWGSOP2 calls for healthcare professionals who treat patients at risk for sarcopenia to take actions that will promote early detection and treatment. We also encourage more research in the field of sarcopenia in order to prevent or delay adverse health outcomes that incur a heavy burden for patients and healthcare systems.

Physical inactivity and protein energy wasting play independent roles in muscle weakness in maintenance haemodialysis patients

Background

Muscle weakness is associated with increased mortality risk in chronic haemodialysis (CHD) patients. Protein energy wasting (PEW) and low physical activity could impair muscle quality and contribute to muscle weakness beyond muscle wasting in these patients. Aim of this study was to assess clinical and biological parameters involved in the reduction of muscle strength of CHD patients.

Methods

One hundred and twenty-three CHD patients (80 males, 43 females; 68,8 [57.9–78.8] y.o.) were included in this study. Maximal voluntary force (MVF) of quadriceps was assessed using a belt-stabilized hand-held dynamometer. Muscle quality was evaluated by muscle specific torque, defined as the strength per unit of muscle mass. Muscle mass was estimated using lean tissue index (LTI), skeletal muscle mass (SMM) assessed by bioelectrical impedance analysis and creatinine index (CI). Voorrips questionnaire was used to estimate physical activity. Criteria for the diagnosis of PEW were serum albumin, body mass index < 23 kg/m², creatinine index < 18.82 mg/kg/d and low dietary protein intake estimated by nPCR < 0.80g/kg/d.

Results

MVF was 76.1 [58.2–111.7] N.m. and was associated with CI (β = 5.3 [2.2–8.4], p = 0.001), LTI (β = 2.8 [0.6–5.1], p = 0.013), Voorrips score (β = 17.4 [2.9–31.9], p = 0.02) and serum albumin (β = 1.9 [0.5–3.2], p = 0.006). Only serum albumin (β = 0.09 [0.03–0.15], p = 0.003), Voorrips score (β = 0.8 [0.2–1.5], p = 0.005) and CI (β = 0.2 [0.1–0.3], p<0.001) remained associated with muscle specific torque. Thirty patients have dynapenia defined as impaired MVF with maintained SMM and were younger with high hs-CRP (p = 0.001), PEW criteria (p<0.001) and low Voorrips score (p = 0.001), and reduced dialysis vintage (p<0.046).

Conclusions

Beyond atrophy, physical inactivity and PEW conspire to impair muscle strength and specific torque in CHD patients and could be related to muscle quality.

Trial registration

ClinicalTrials.gov NCT02806089

The Relationship Between Concentric Hip Abductor Strength and Performance of the Y-Balance Test (YBT)

Side-lying hip abduction is an action used during manual muscle testing and is also prescribed as a rehabilitation exercise to improve dynamic single-leg stability. Little is known about the functional cross-over of this activity. The aims of this study were to investigate the relationship between concentric hip abductor strength and performance of the Y-Balance test (YBT). Forty-five recreational gym users (27 male, age 26.2 [8.4] years; 18 female, age 27.4 [7.5] years) had dynamic single-leg stability and concentric hip abductor peak torque assessed in the nondominant limb using a YBT and isokinetic dynamometry, respectively. All components of the YBT had a moderate association with concentric hip abductor torque which were greater in the posteromedial (r = .574, p > .001) and posterolateral (r = .657, p > .001) directions compared to the anterior direction (r = .402, p = .006). Greater concentric hip abductor strength is associated with greater scores on components of the YBT, particularly the posterior reaches.

Measurement of muscle health in aging

Muscle health is a critical component in the struggle against physical frailty and the efforts to maintain metabolic health until the limit of chronological age. Consensus opinion is to evaluate muscle health in terms of muscle mass, strength and functional capability. There has been considerable variability in the components of muscle health which have been investigated in addition to variability in the tools of assessment and protocol for measurement. This is in stark contrast to the validated measurement of bone health across the adult life span. The purpose of this review was to identify indices of muscle mass, strength and functional capability most responsive to change with ageing and where possible to provide an estimate of the rate of change. We suggest lean tissue mass (LTM) or skeletal muscle (SM) is best evaluated from the thigh region due to its greater responsiveness to ageing compared to the whole body. The anterior compartment of the thigh region undergoes a preferential age-related decline in SM and force generating capacity. Therefore, we suggest that knee extensor torque is measured to represent the force generating capacity of the thigh and subsequently, to express muscle quality (strength per unit tissue). Finally, we suggest measures of functional capability which allow participants perform to a greater maximum are most appropriate to track age-related difference in functional capacity across the adult lifespan. This is due to their ability encompass a broad spectrum of abilities. This review suggests indices of muscular health for which reference ranges can be generated across the lifespan.

Muscle strength can better differentiate between gradations of functional performance than muscle quality in healthy 50-70y women

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Muscle strength is a better predictor of functional performance than muscle quality.

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Extended gait speed is a functionally relevant measure in healthy 50–70 y women.

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Healthy adults need functional assessments that allow performance toward maximum.

Objective

It is not known which laboratory indices of muscle mass, strength or quality can distinguish functional performance in healthy middle aged women. The aim of this study was to (a) examine the association between upper leg lean tissue mass, knee extensor strength, muscle quality (strength per unit lean tissue mass) and functional performance and (b) to determine the utility of tertiles of muscle strength and muscle quality to distinguish gradations of functional capacity in healthy 50–70 y women.

Methods

Using a cross-sectional study design, one hundred and twenty-eight healthy 50–70 y women (mean age: 60.4, SD = 5.1 y) underwent body composition assessment (dual X-ray absorptiometry) and performed maximal voluntary isometric contractions of the knee extensors (Con-Trex Dynamometer). Functional performance was assessed using a 5 repetition and 30 s chair rise test and 900 m gait speed test.

Results

Ordered by muscle strength or muscle quality, those in the highest tertile (T1) demonstrated greater functional performance than those in lowest tertile (T3). There was no association between upper leg lean tissue mass and functional performance (r = ≤0.06). Muscle strength explained a greater proportion of the variance in all functional performance measures relative to muscle quality (R² = 0.13–0.36 vs. R² = 0.11–0.16).

Conclusion

Upper leg lean tissue mass is not associated with physical performance in healthy 50–70 y women. These results suggest strength relative to the body mass being accelerated distinguishes gradations in functional performance better than muscle quality healthy 50–70 y women.

The Need for Standardized Assessment of Muscle Quality in Skeletal Muscle Function Deficit and Other Aging-Related Muscle Dysfunctions: A Symposium Report

A growing body of scientific literature suggests that not only changes in skeletal muscle mass, but also other factors underpinning muscle quality, play a role in the decline in skeletal muscle function and impaired mobility associated with aging. A symposium on muscle quality and the need for standardized assessment was held on April 28, 2016 at the International Conference on Frailty and Sarcopenia Research in Philadelphia, Pennsylvania. The purpose of this symposium was to provide a venue for basic science and clinical researchers and expert clinicians to discuss muscle quality in the context of skeletal muscle function deficit and other aging-related muscle dysfunctions. The present article provides an expanded introduction concerning the emerging definitions of muscle quality and a potential framework for scientific inquiry within the field. Changes in muscle tissue composition, based on excessive levels of inter- and intra-muscular adipose tissue and intramyocellular lipids, have been found to adversely impact metabolism and peak force generation. However, methods to easily and rapidly assess muscle tissue composition in multiple clinical settings and with minimal patient burden are needed. Diagnostic ultrasound and other assessment methods continue to be developed for characterizing muscle pathology, and enhanced sonography using sensors to provide user feedback and improve reliability is currently the subject of ongoing investigation and development. In addition, measures of relative muscle force such as specific force or grip strength adjusted for body size have been proposed as methods to assess changes in muscle quality. Furthermore, performance-based assessments of muscle power via timed tests of function and body size estimates, are associated with lower extremity muscle strength may be responsive to age-related changes in muscle quality. Future aims include reaching consensus on the definition and standardized assessments of muscle quality, and providing recommendations to address critical clinical and technology research gaps within the field.

Twelve weeks' progressive resistance training combined with protein supplementation beyond habitual intakes increases upper leg lean tissue mass, muscle strength and extended gait speed in healthy older women

The age-related decline in functional capability is preceded by a reduction in muscle quality. The purpose of this study was to assess the combined effects of progressive resistance training (PRT) and protein supplementation beyond habitual intakes on upper leg lean tissue mass (LTM), muscle quality and functional capability in healthy 50–70 years women. In a single-blinded, randomized, controlled design, 57 healthy older women (age 61.1 ± 5.1 years, 1.61 ± 0.65 m, 65.3 ± 15.3 kg) consumed 0.33 g/kg body mass of a milk-based protein matrix (PRO) for 12 weeks. Of the 57 women, 29 also engaged in a PRT intervention (PRO + PRT). In comparison to the PRO group (n = 28), those in the PRO + PRT group had an increase in upper leg LTM [0.04 (95% CI −0.07 to 0.01) kg vs. 0.13 (95% CI 0.08–0.18) kg, P = 0.027], as measured by Dual-energy X-ray absorptiometry; an increase in knee extensor (KE) torque [−1.6 (95% CI −7.3 to 4.4 N m) vs. 10.2 (95% CI 4.3–15.8 N m), P = 0.007], as measured from a maximal voluntary isometric contraction (Con-Trex MJ; CMV AG); and an increase in extended gait speed [-0.01 (95% CI −0.52–0.04) m s⁻¹ vs. 0.10 (95% CI 0.05–0.22) m s⁻¹, P = 0.001] as measured from a maximal 900 m effort. There was no difference between groups in the time taken to complete 5 chair rises or the number of chair rises performed in 30 s (P > 0.05). PRT in healthy older women ingesting a dietary protein supplement is an effective strategy to improve upper leg LTM, KE torque and extended gait speed in healthy older women.