Engagement in Muscle-Strengthening Activities Lowers Sarcopenia Risk in Older Adults Already Adhering to the Aerobic Physical Activity Guidelines

Population-specific equations of age-related maximum handgrip force: a comprehensive review

Background

The measurement of handgrip force responses is important in many aspects, for example: to complement neurological assessments, to investigate the contribution of muscle mass in predicting functional outcomes, in setting realistic treatment goals, evaluating rehabilitation strategies. Normative data about handgrip force can assist the therapist in interpreting a patient's results compared with healthy individuals of the same age and gender and can serve as key decision criteria. In this context, establishing normative values of handgrip strength is crucial. Hence, the aim of the this study is to develop a tool that could be used both in rehabilitation and in the prevention of work-related musculoskeletal disorders. This tool takes the form of population-specific predictive equations, which express maximum handgrip force as a function of age.

Methodology

In order to collect data from studies measuring maximum handgrip force, three databases were searched. The search yielded 5,058 articles. Upon the removal of duplicates, the screening of abstracts and the full-text review of potentially relevant articles, 143 publications which focussed on experimental studies on various age groups were considered as fulfilling the eligibility criteria. A comprehensive literature review produced 1,276 mean values of maximum handgrip force.

Results

A meta-analysis resulted in gender- and world region-specific (general population, USA, Europe and Asia) equations expressing maximum force as a function of age. The equations showed quantitative differences and trends in maximum handgrip force among age, gender and national groups. They also showed that values of maximum handgrip force are about 40% higher for males than for females and that age-induced decrease in force differs between males and females, with a proved 35% difference between the ages of 35 and 75. The difference was lowest for the 60-64 year olds and highest for the 18-25 year-olds. The equations also showed that differences due to region are smaller than those due to age or gender.

Conclusions

The equations that were developed for this study can be beneficial in setting population-specific thresholds for rehabilitation programmes and workstation exposure. They can also contribute to the modification of commonly used methods for assessing musculoskeletal load and work-related risk of developing musculoskeletal disorders by scaling their limit values.

Use of electrical bioimpedance in the assessment of sarcopenia in the older aldults: A scoping review

OBJECTIVE

to map and synthesize the main evidence on the use of bioelectrical impedance (BIA) and its variables in the assessment of sarcopenia in community-dwelling older adults.

METHODS

This is a scoping review carried out by searching for articles available in four databases: PUBMED, LILACS, Web of Science and CINAHL, with the following search strategy: Body Composition AND Sarcopenia AND ″electric impedance'' OR ″bioelectrical impedance analysis'' AND Aged.

RESULTS

A total of 27,660 older adults made up the sum of the samples of the included studies. Most studies included participants of both sexes (75.6%), used the variable skeletal and/or appendicular skeletal muscle mass (ASMM) (75.6%), followed by body fat (8.1%), and phase angle (8.1%) in the assessment of the body composition of subjects with sarcopenia.

CONCLUSION

The data from this research show that ASMM and phase angle are the main variables related to sarcopenia screening in community-dwelling older adults. Whereas total extracellular water/body water is still considered a confounding variable in the screening of sarcopenia in the elderly, but it can be considered useful regarding the health conditions of the elderly in the community.

Sarcopenia and sarcopenic obesity among older adults in the nordic countries: a scoping review

BACKGROUND

Sarcopenia and sarcopenic obesity (SO) are age-related syndromes that may compromise physical and mental health among older adults. The Nordic countries differ from other regions on prevalence of disease, life-style behavior, and life expectancy, which may impact prevalence of sarcopenia and SO. Therefore, the aim of this study is to review the available evidence and gaps within this field in the Nordic countries.

METHODS

PubMed, Embase, and Web of science (WOS) were searched up to February 2023. In addition, grey literature and reference lists of included studies were searched. Two independent researcher assessed papers and extracted data.

RESULTS

Thirty-three studies out of 6,363 searched studies were included in this scoping review. Overall prevalence of sarcopenia varied from 0.9 to 58.5%. A wide prevalence range was still present for community-dwelling older adults when definition criteria and setting were considered. The prevalence of SO ranged from 4 to 11%, according to the only study on this field. Based on the included studies, potential risk factors for sarcopenia include malnutrition, low physical activity, specific diseases (e.g., diabetes), inflammation, polypharmacy, and aging, whereas increased levels of physical activity and improved dietary intake may reduce the risk of sarcopenia. The few available interventions for sarcopenia were mainly focused on resistance training with/without nutritional supplements (e.g., protein, vitamin D).

CONCLUSION

The findings of our study revealed inadequate research on SO but an increasing trend in the number of studies on sarcopenia. However, most of the included studies had descriptive cross-sectional design, small sample size, and applied different diagnostic criteria. Therefore, larger well-designed cohort studies that adhere to uniform recent guidelines are required to capture a full picture of these two age-related medical conditions in Nordic countries, and plan for prevention/treatment accordingly.

Adherence to the physical activity guideline beyond the recommended minimum weekly amount: impacts on indicators of physical function in older adults

Introduction

The extent to which additional health benefits of accumulating twice the minimum amount of time in moderate-to-vigorous physical activity (MVPA) affects indicators of physical function in older adults is unclear. Therefore, the aim of the present study was to assess indicators of physical function in older adults who accumulate at least 150 but less than 300 min/week of MVPA compared to those accumulating at least 300 min/week.

Methods

Indicators of physical function, including handgrip strength, 5 times sit-to-stand test (5-STS), squat jump and 6-min walk test (6MWT) were assessed in a sample of 193 older men (n = 71, 67 ± 2 years), and women (n = 122, 67 ± 2 years), who all accumulated at least 150 weekly minutes of MVPA. Time in MVPA was assessed by accelerometry during 1 week and engagement in muscle strengthening activities (MSA) was assessed by self-report. Protein intake was assessed by a food-frequency-questionnaire. Participants were classified as physically active (≥150 but <300 min of MVPA per week) or as highly physically active (≥300 min of MVPA per week).

Results

Factorial analysis of variance revealed that older adults accumulating at least 300 min of MVPA per week had a significantly (p < 0.05) better 6MWT performance and overall physical function compared to the less active group. These findings remained significant after further adjustment for MSA, sex, waist circumference and protein intake. In contrast, no significant differences in indicators of muscle strength were observed between the two groups.

Discussion

Adherence to twice the recommended minimum amount of weekly MVPA time is related to a better physical function, evidenced by a better walking performance compared to adherence to the minimum weekly amount of MVPA. This finding emphasizes the benefits of accumulating daily MVPA beyond the minimum recommended amount to optimize the ability to perform activities of daily living, thus reducing the burden of physical disability and related health-care costs.

Increasing Muscle Mass in Elders through Diet and Exercise: A Literature Review of Recent RCTs

This study aimed to review the current evidence on the independent and combined effects of diet and exercise and their impact on skeletal muscle mass in the elderly population. Skeletal muscle makes up approximately 40% of total body weight and is essential for performing daily activities. The combination of exercise and diet is known to be a potent anabolic stimulus through stimulation of muscle protein synthesis from amino acids. Aging is strongly associated with a generalized deterioration of physiological function, including a progressive reduction in skeletal muscle mass and strength, which in turn leads to a gradual functional impairment and an increased rate of disability resulting in falls, frailty, or even death. The term sarcopenia, which is an age-related syndrome, is primarily used to describe the gradual and generalized loss of skeletal muscle mass (mainly in type II muscle fibers) and function. Multimodal training is emerging as a popular training method that combines a wide range of physical dimensions. On the other hand, nutrition and especially protein intake provide amino acids, which are essential for muscle protein synthesis. According to ESPEN, protein intake in older people should be at least 1 g/kgbw/day. Essential amino acids, such as leucine, arginine, cysteine, and glutamine, are of particular importance for the regulation of muscle protein synthesis. For instance, a leucine intake of 3 g administered alongside each main meal has been suggested to prevent muscle loss in the elderly. In addition, studies have shown that vitamin D and other micronutrients can have a protective role and may modulate muscle growth; nevertheless, further research is needed to validate these claims. Resistance-based exercise combined with a higher intake of dietary protein, amino acids, and/or vitamin D are currently recognized as the most effective interventions to promote skeletal muscle growth. However, the results are quite controversial and contradictory, which could be explained by the high heterogeneity among studies. It is therefore necessary to further assess the impact of each individual exercise and nutritional approach, particularly protein and amino acids, on human muscle turnover so that more efficient strategies can be implemented for the augmentation of muscle mass in the elderly.

[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.

Synergistic Effect of Increased Total Protein Intake and Strength Training on Muscle Strength: A Dose-Response Meta-analysis of Randomized Controlled Trials

Background

Protein supplementation augments muscle strength gain during resistance training. Although some studies focus on the dose-response relationship of total protein intake to muscle mass or strength, the detailed dose-response relationship between total protein intake and muscle strength increase is yet to be clarified, especially in the absence of resistance training.

Objective

We aimed to assess the detailed dose-response relationship between protein supplementation and muscle strength, with and without resistance training.

Design

Systematic review with meta-analysis.

Data Sources

PubMed and Ichushi-Web (last accessed on March 23, 2022).

Eligibility Criteria

Randomized controlled trials investigating the effects of protein intake on muscle strength.

Synthesis Methods

A random-effects model and a spline model.

Results

A total of 82 articles were obtained for meta-analyses, and data from 69 articles were used to create spline curves. Muscle strength increase was significantly augmented only with resistance training (MD 2.01%, 95% CI 1.09–2.93) and was not augmented if resistance training was absent (MD 0.13%, 95% CI − 1.53 to 1.79). In the dose-response analysis using a spline model, muscle strength increase with resistance training showed a dose-dependent positive association with total protein intake, which is 0.72% (95% CI 0.40–1.04%) increase in muscle strength per 0.1 g/kg body weight [BW]/d increase in total protein intake up to 1.5 g/kg BW/d, but no further gains were observed thereafter.

Conclusion

Concurrent use of resistance training is essential for protein supplementation to improve muscle strength. This study indicates that 1.5 g/kg BW/d may be the most appropriate amount of total protein intake for maintaining and augmenting muscle strength along with resistance training.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-022-00508-w.

Associations of physical activity with sarcopenia and sarcopenic obesity in middle-aged and older adults: the Louisiana osteoporosis study

BACKGROUND

This study examined the associations between physical activity, obesity, and sarcopenia in middle-aged and older adults.

METHODS

We analyzed the data of 8, 919 study participants aged between 45 to 97 (mean age = 57.2 ± 8.8) from a Southern state in the United States. Self-reported physical activity was classified to regular exercise ≥ 3 times/week, < 3 times/week, and no regular exercise. Associations between physical activity, obesity and sarcopenia were explored with generalized linear models and ordinal logistic regressions stratified by age (middle-aged and older adults) and gender adjusting for covariates.

RESULTS

In middle-aged and older adults, all examined obesity related traits (e.g., body mass index, waist circumference) were inversely associated with physical activity levels (p < 0.01) in both genders. Exercising ≥ 3 times/week was negatively associated with lean mass indicators (e.g., appendicular lean mass) in middle-aged and older females (p < 0.01), while the negative associations become positive after adjusting for weight. Positive associations between physical activity and grip strength were only found in middle-aged males (p < 0.05). Ordinal logistic regression revealed that those exercising ≥ 3 times/week were less likely to have obesity, sarcopenia, and sarcopenia obesity in all groups (p < 0.01), except for sarcopenia in older males and females (p > 0.05). Positive associations of exercising < 3 times/week with sarcopenia and sarcopenia obesity were only found in middled adults.

CONCLUSION

The associations of exercise frequency with obesity and sarcopenia vary considerably across gender and age groups. Exercise programs need to be individualized to optimize health benefits. Future research exploring physical activity strategies to balance weight reduction and lean mass maintaining is warranted in middle-aged and especially older adults.

Effects of Reallocating Time Spent in Different Physical Activity Intensities on Sarcopenia Risk in Older Adults: An Isotemporal Substitution Analysis

Simple Summary

The role of daily time spent sedentary and in different intensities of physical activity (PA) for maintenance of muscle health is currently unclear. Therefore, we investigated the impact of reallocating time spent in different PA intensities on a sarcopenia risk score (SRS) in older adults, while considering PA type (muscle strengthening activities, MSA) and protein intake. In the present study, we show for the first time that reallocating sedentary time with at least light-intensity PA was significantly related to a lower SRS, which remained evident after adjustment by PA type (MSA) and protein intake. Similarly, reallocating time in light- to moderate-to-vigorous-intensity PA was related to a significantly lower SRS. Our results emphasize the importance of displacing sedentary behaviours for more active pursuits, where PA of even light intensities may alleviate age-related deteriorations of muscle health in older adults.

Abstract

The role of daily time spent sedentary and in different intensities of physical activity (PA) for the maintenance of muscle health currently remains unclear. Therefore, we investigated the impact of reallocating time spent in different PA intensities on sarcopenia risk in older adults, while considering PA type (muscle strengthening activities, MSA) and protein intake. In a sample of 235 community-dwelling older adults (65–70 years), a sarcopenia risk score (SRS) was created based on muscle mass assessed by bioimpedance, together with handgrip strength and performance on the five times sit-to-stand (5-STS) test assessed by standardized procedures. Time spent in light-intensity PA (LPA), moderate-to-vigorous PA (MVPA), and being sedentary was assessed by accelerometry, and PA type (MSA) by self-report. Linear regression models based on isotemporal substitution were employed. Reallocating sedentary time to at least LPA was significantly (p < 0.05) related to a lower SRS, which remained evident after adjustment by PA type (MSA) and protein intake. Similarly, reallocating time in LPA by MVPA was related to a significantly (p < 0.05) lower SRS. Our results emphasize the importance of displacing sedentary behaviours for more active pursuits, where PA of even light intensities may alleviate age-related deteriorations of muscle health in older adults.

Minimal-Dose Resistance Training for Improving Muscle Mass, Strength, and Function: A Narrative Review of Current Evidence and Practical Considerations

Resistance training (RT) is the only non-pharmacological intervention known to consistently improve, and therefore offset age-related declines in, skeletal muscle mass, strength, and power. RT is also associated with various health benefits that are underappreciated compared with the perceived benefits of aerobic-based exercise. For example, RT participation is associated with reduced all-cause and cancer-related mortality and reduced incidence of cardiovascular disease, hypertension, and symptoms of both anxiety and depression. Despite these benefits, participation in RT remains low, likely due to numerous factors including time constraints, a high-perceived difficulty, and limited access to facilities and equipment. Identification of RT strategies that limit barriers to participation may increase engagement in RT and subsequently improve population health outcomes. Across the lifespan, declines in strength and power occur up to eight times faster than the loss of muscle mass, and are more strongly associated with functional impairments and risks of morbidity and mortality. Strategies to maximise healthspan should therefore arguably focus more on improving or maintaining muscle strength and power than on increasing muscle mass per se. Accumulating evidence suggests that minimal doses of RT, characterised by lower session volumes than in traditional RT guidelines, together with either (1) higher training intensities/loads performed at lower frequencies (i.e. low-volume, high-load RT) or (2) lower training intensities/loads performed at higher frequencies and with minimal-to-no equipment (i.e. resistance 'exercise snacking'), can improve strength and functional ability in younger and older adults. Such minimal-dose approaches to RT have the potential to minimise various barriers to participation, and may have positive implications for the feasibility and scalability of RT. In addition, brief but frequent minimal-dose RT approaches (i.e. resistance 'exercise snacking') may provide additional benefits for interrupting sedentary behaviour patterns associated with increased cardiometabolic risk. Compared to traditional approaches, minimal-dose RT may also limit negative affective responses, such as increased discomfort and lowered enjoyment, both of which are associated with higher training volumes and may negatively influence exercise adherence. A number of practical factors, including the selection of exercises that target major muscle groups and challenge both balance and the stabilising musculature, may influence the effectiveness of minimal-dose RT on outcomes such as improved independence and quality-of-life in older adults. This narrative review aims to summarise the evidence for minimal-dose RT as a strategy for preserving muscle strength and functional ability across the lifespan, and to discuss practical models and considerations for the application of minimal-dose RT approaches.

Associations between Circulating Inflammatory Biomarkers and Indicators of Muscle Health in Older Men and Women

Systemic inflammation is believed to contribute to declining muscle health during aging. The present study aims to examine associations between indicators of muscle health and pro- and anti-inflammatory biomarkers in older men and women, while also considering the impacts of physical activity and protein intake. An assessment of skeletal muscle index (SMI) by bioelectrical impedance analysis, handgrip strength, and 5-sit-to-stand time, using standardized procedures, was conducted in a population of older men (n = 90) and women (n = 148) aged 65–70 years. The inflammatory biomarkers C-reactive protein (CRP), fibrinogen, interleukin (IL)-6, IL-10, IL-18, tumor necrosis factor (TNF)-α, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1α were assessed in blood samples. Data were analyzed and stratified according to biological sex using multiple linear regression models. In older women, SMI was inversely associated with the pro-inflammatory markers CRP (β = −0.372; p < 0.05), fibrinogen (β = −0.376; p < 0.05), and IL-6 (β = −0.369; p < 0.05). Importantly, these associations were independent of abdominal adiposity (waist circumference), protein intake, physical activity level, as well as any adherence to muscle strengthening guidelines (≥2 sessions/week). In contrast, no corresponding associations were observed in men. In conclusion, our findings indicate the detrimental influence of a pro-inflammatory environment on muscle health regardless of important lifestyle-related factors in older women. However, the lack of such associations in older men highlights the importance of considering biological sex when examining the complex interaction between the systemic inflammatory environment and muscle health.

Healthy Eating Is Associated with Sarcopenia Risk in Physically Active Older Adults

Healthy Diet and physical activity may play important roles in the maintenance of muscle health during aging. The aim of the present study was to explore the impact of adherence to healthy dietary patterns on sarcopenia risk in a sample of physically active older men and women, while considering adherence to guidelines on muscle strengthening activities (MSA) and protein intake. Based on a sample of 191 physically active men and women (65-70 years), dietary intake was assessed using a 90-items food-frequency-questionnaire (FFQ) and Healthy Diet Score (HDS) was calculated. Physical activity was assessed by accelerometry and self-report. A sarcopenia risk score (SRS) was derived based on three indicators of muscle health: muscle mass was assessed using bioelectrical impedance and handgrip strength and 5 times sit-to-stand (5-STS) were determined by standardized procedures. Analysis of covariance (ANCOVA) was used to examine differences in SRS and its components across sex-specific tertiles of HDS, with adjustments for covariates including total energy intake, protein intake and MSA. A significant main effect (p < 0.05) of HDS on SRS was observed, where those belonging to the highest HDS tertile had lower SRS compared to those in the lowest tertile. A corresponding significant effect was observed for 5-STS performance, with better performance in those with the highest HDS adherence compared to those with the lowest. The present study supports guidelines emphasizing diet quality beyond amounts of macro- and micronutrients in the prevention of age-related deterioration of muscle health. Importantly, the benefits from healthy dietary patterns are evident in older adults who already adhere to guidelines for health-enhancing physical activity.