Lower extremity muscle mass predicts functional performance in mobility-limited elders

Quantifying Leg Muscle Disuse Atrophy During Bed Rest Using DXA, CT, and MRI

This study evaluated whether dual-energy X-ray absorptiometry (DXA), computed tomography (CT), and magnetic resonance imaging (MRI) provide comparable outcomes in quantifying disuse-induced skeletal muscle atrophy. Although the calculation of muscle volume using MRI analysis may be considered the gold standard, the method remains labor intense and, as such, less practical and more costly. In this context, we also evaluated the efficacy of a commercially available automated MRI analysis method to measure changes in leg muscle volume after two weeks of bed rest. Twelve healthy, male adults (age: 24 ± 3 years, BMI: 23.7 ± 3.1 kg/m2) were subjected to 2 weeks of strict bed rest. Leg muscle assessments were performed before and after bed rest using DXA, single slice (thigh) CT, and MRI. MRI data analyses were performed using both a manual and automated (AMRA) method. Leg lean mass, as assessed with DXA, declined by 5% following bed rest (from 10.2 ± 1.6 to 9.7 ± 1.6 kg; p < 0.001). The thigh muscle cross-sectional area, as assessed with CT, declined by 6% following bed rest (from 155 ± 26 to 146 ± 24 cm2; p < 0.001). Muscle volume, as assessed using MRI, declined by 5% following bed rest, both when assessed manually (from 7.1 ± 1.1 to 6.7 ± 1.0 L; p < 0.001) and automatically (from 7.2 ± 1.1 to 6.8 ± 1.0 L; p < 0.001). A very strong correlation (r = 0.96; p < 0.001) with a low bias (-0.11 ± 0.29 L) was observed between manual and automated muscle volume analysis. DXA, CT, and MRI all show a ∼5% decline in leg muscle quantity following two weeks of bed rest in healthy adults. When using MRI, disuse muscle atrophy can be accurately quantified using an automated approach, rendering time-consuming manual analysis obsolete.

Body Composition and Its Outcomes and Management in Multiple Sclerosis: Narrative Review

Background: There is emerging interest in obesity and its prevalence, outcomes, and management in people with multiple sclerosis (MS). Body mass index (BMI) is the traditional marker of obesity in MS, whereas body composition, inclusive of specific body tissue compartments (e.g., fat, bone, and muscle), is often overlooked despite its relevance. Objective: This narrative review (a) underscored the use and utility of dual-energy X-ray absorptiometry (DEXA) as an accurate and reliable measure of body composition; (b) thematically analyzed and synthesized the current evidence regarding body composition (using DEXA); and (c) determined gaps to be addressed in future research. Methods: The structure and reporting of this narrative review followed the guiding criteria outlined in the Scale for the Assessment of Narrative Review Articles (SANRA). The relevant literature for this narrative review was identified via a PubMed search utilizing combined search terms such as 'body composition' and 'multiple sclerosis'. The identified research was then organized by the authors into major themes and sub-themes. The articles described within the narrative review were based on saturation of the identified themes and sub-themes. Results: Three major themes were identified, namely (1) comparison of body composition between people with MS and non-MS controls (2 meta-analyses); (2) examination of the relationships between body composition and a range of outcomes (14 cross-sectional studies); and (3) interventions that report and/or target body composition in MS (11 clinical trials). Conclusions: This narrative review mapped the existing evidence regarding body composition in MS, and posits body composition as a novel, informative, and targeted concept for this population. The narrative review underscores the importance of randomized controlled trials that focus on body composition as a significant and modifiable outcome. Such research could improve the understanding of obesity and poor body composition in MS and identify useful clinical recommendations for diagnosis and management.

Dual-energy x-ray absorptiometry derived body composition trajectories across adulthood: Reference values and associations with body roundness index and body mass index

BACKGROUND

Population-specific reference values are needed to accurately contextualise age-related changes in body composition. This study aimed to a) establish age- and sex-specific reference values and cut-points for a range of dual-energy x-ray absorptiometry (DXA) derived metrics of lean mass (LM), fat mass (FM) and bone mineral density (BMD), across adulthood in a large adult cohort; and b) determine the association between DXA-derived body composition, body roundness index (BRI), and body mass index (BMI).

METHODS

Cross-sectional data were collected from 10,033 men and women aged from 18 to 92 years. Whole-body DXA scans were performed, and a range of metrics were calculated for LM (total LM, arm LM, leg LM, appendicular lean mass: ALM, skeletal muscle index: SMI), FM (total FM: kg and %, FMI, android to gynoid: A/G ratio) and bone (BMD). Cut-points equivalent to Z-scores of 1.0-2.5 SDs from the mean of a young reference population were established for each body composition metric.

RESULTS

Detailed age- and sex-specific percentile curves were generated using the LMS method. Metrics of LM, central adiposity and BMD were higher in men, compared to women, whereas metrics of general FM accumulation were higher in women, compared to men. In both sexes, all LM metrics remained broadly stable during early and middle adulthood, after which progressively lower quantities were shown, whereas progressively higher FM metrics were shown from early adulthood through to late adulthood. In men, BMD was broadly stable across adulthood, whereas in women, markedly lower BMD was observed from the fifth decade of life. Significantly higher quantities of LM were shown across BMI categories, but not across BRI categories. The BRI was better correlated with FM%, FMI, and A/G ratio, compared to the BMI.

CONCLUSION

The reference values presented herein may support the interpretation of body composition in public health settings and the identification of people who may benefit from intervention to improve musculoskeletal and metabolic health. The BRI better reflects DXA-derived body composition and may provide screening utility beyond that of the BMI.

Comparison study of bioelectrical impedance analyzers for measuring lower limb muscle mass in middle-aged and elderly adults

OBJECTIVE

Lower limb muscle mass (LLMM) accounts for more than 50% of the total body skeletal muscle mass. Assessing leg muscle mass in middle-aged and elderly individuals is crucial for the prevention and diagnosis of sarcopenia. Current bioelectrical impedance analysis (BIA) devices are capable of measuring LLMM, but validation studies are limited. This study compares the accuracy of BIA devices with different frequencies for measuring LLMM in middle-aged and elderly populations.

METHODS

LLMM measurements were obtained using the following devices: foot-to-foot dual-frequency (StarBIA201, 5, 50 KHz), multi-segment single-frequency (Tanita BC418, 50 KHz), dual-frequency (InBody270, 20, 100 KHz), triple-frequency (Tanita MC780MA, 5, 50, 250 KHz), and six-frequency (InBody770, 1, 5, 50, 250, 500, 1,000 KHz). Dual-energy X-ray absorptiometry (DXA) served as the reference standard. Comparisons were conducted using the following metrics: (1) mean difference (bias), (2) limits of agreement (LOA), (3) Pearson correlation coefficients, and (4) ordinary least product (OLP) regression analysis.

RESULTS

A total of 153 community-dwelling individuals aged over 55 years (102 females, 51 males) were recruited. The average age of participants was 67.5 ± 8.9 years, with a BMI of 23.9 ± 3.9 kg/m2 and a body fat percentage of 35.8 ± 6.5%. The correlation coefficients of StarBIA201, BC418, InBody270, MC780, and InBody770 with DXA were 0.902, 0.903, 0.917, 0.925, and 0.928, respectively. Their mean differences were -0.141, -2.731, -0.587, -1.613, and -0.625 kg, with LOAs of 4.3, 5.7, 4.0, 5.1, and 3.8 kg, respectively. StarBIA201 and InBody270 showed no fixed or proportional biases.

CONCLUSION

This study demonstrates that the four-electrode foot-to-foot BIA method shows significant practicality and potential in assessing LLMM. Compared to multi-frequency BIA and DXA, this method is simpler to operate and more convenient, making it particularly suitable for preliminary screening and assessment of sarcopenia in clinical and community settings.

Differences in muscle composition and functionality: Exploring CT anatomical points and SARC-F components

PURPOSE

Our study aimed to 1) investigate the differences of muscle parameters in relation to each SARC-F component/question; and 2) explore the relationship between SARC-F score with these muscle parameters using various landmarks derived from computed tomography (CT) scans of patients with cancer.

METHODS

This study is a cross-sectional analysis of a cohort comprised of consecutive patients with cancer, displaying CT scans. SARC-F questionnaire was utilized as a proxy for muscle functionality, with a score ≥4 indicating a poor status. Muscle assessment via CT measurements was performed using single cross-sectional images at the level of the third lumbar vertebrae (L3) in the abdominal region, the thigh region, and the total gluteal region at the level of the second sacral vertebrae. Skeletal muscle (SM) cross-sectional area, SM index (normalized to height2), and SM radiodensity (SMD) were evaluated for all anatomical landmarks.

RESULTS

A total of 128 patients were included in this analysis (53.1% females, 61.7% older adults). Patients with SARC-F scores ≥4 demonstrated significantly lower values of SMD across all landmarks assessed. Those reporting difficulties related to strength (P = 0.039), requiring assistance in walking (P = 0.033), and climbing stairs (P = 0.012) exhibited significantly lower SMD values at the L3 landmark. At gluteus and thigh levels, only patients experiencing difficulty climbing stairs (P = 0.012) showed significantly lower values of SMD. Only SMD at gluteus level was independently associated with SARC-F score (βadjusted -0.09, 95% CI -0.16 to -0.02).

CONCLUSIONS

Our findings suggest that individuals with poor muscle composition may experience a higher risk of sarcopenia/poor muscle functionality.

Site-specific skeletal muscle mass and functional prognosis in geriatric stroke patients

BACKGROUND

Evidence is scarce regarding prognostic value of site-specific muscle mass in geriatric stroke survivors. We aim to assess the association between four measures of muscle mass, namely the skeletal muscle mass index of the limbs (SMI), upper limb SMI (USMI), lower limb SMI (LSMI), and trunk muscle mass index (TMI), and the functional prognosis in stroke patients.

METHODS

This study conducted a retrospective cohort analysis involving post-acute stroke inpatients. Muscle mass data were obtained through bioelectrical impedance analysis and computed by dividing each muscle mass by the square of the height. The study outcomes included the Functional Independence Measure (FIM) motor at discharge and FIM-motor gain. Multiple regression analysis was conducted to assess the association between SMI, USMI, LSMI, and TMI with outcomes, while adjusting for confounding factors.

RESULTS

A total of 701 patients (mean age 72.8 years, 374 males) were analyzed. As a result, LSMI (β = 0.089, P = 0.003) and SMI (β = 0.083, P = 0.008) were significantly associated in the FIM-motor at discharge, with LSMI showing a stronger association. USMI (β = 0.019, P = 0.521) and TMI (β = 0.035, P = 0.231) showed no significant association. LSMI (β = 0.124, P = 0.003) and SMI (β = 0.116, P = 0.008) were significantly associated with FIM-motor gain; however, USMI (β = 0.027, P = 0.521) and TMI (β = 0.049, P = 0.231) showed no significant association with FIM-motor gain.

CONCLUSIONS

Differential associations were observed between site-specific muscle mass and functional prognosis in post-stroke patients. Among these, lower limb muscle mass was most strongly associated with activities of daily living (ADL) recovery.

Influence of endogenous and exogenous hormones on the cardiovascular response to lower extremity exercise and group III/IV activation in young females

Oral contraceptive (OC) use can increase resting blood pressure (BP) in females as well as contribute to greater activation of group III/IV afferents during upper body exercise. It is unknown, however, whether an exaggerated BP response occurs during lower limb exercise in OC users. We sought to elucidate the group III/IV afferent activity-mediated BP and heart rate responses while performing lower extremity tasks during early and late follicular phases in young, healthy females. Females not taking OCs (NOC: n = 8; age: 25 ± 4 yr) and those taking OCs (OC: n = 10; age: 23 ± 2 yr) completed a continuous knee extension/flexion passive stretch (mechanoreflex) and cycling exercise with subsystolic cuff occlusion (exercise pressor reflex), which was followed by a 2-min postexercise circulatory occlusion (PECO) (metaboreflex). Data collection occurred on two occasions: once during the early follicular phase (days 1-4) and once during the late follicular phase (days 10-14) of their menstrual cycle (NOC) or during the placebo and active pill phases (OC). Resting mean arterial BP and heart rate were not different between phases in NOC and OC participants (P > 0.05). Hemodynamic responses to metaboreflex, mechanoreflex, and collective exercise pressor reflex activation were not different between phases in both groups (P > 0.05). In conclusion, although OCs are known to increase BP at rest, our findings indicate that neither endogenous nor exogenous (OC) sex hormones modulate BP during large, lower limb muscle exercise with or without group III/IV afferent activation in young, healthy females.NEW & NOTEWORTHY Sex differences in the cardiovascular response to exercise have been demonstrated and may be dependent on sex hormone levels. Furthermore, oral contraceptives (OCs) have been shown to exaggerate the blood pressure response to upper extremity exercise. The results of this study indicate that neither endogenous nor exogenous (OC) sex hormones modulate BP during lower extremity dynamic exercise or with group III/IV afferent activation in young, healthy females.

Application of Artificial Intelligence to Automate the Reconstruction of Muscle Cross-Sectional Area Obtained by Ultrasound

PURPOSE

Manual reconstruction (MR) of the vastus lateralis (VL) muscle cross-sectional area (CSA) from sequential ultrasound (US) images is accessible, is reproducible, and has concurrent validity with magnetic resonance imaging. However, this technique requires numerous controls and procedures during image acquisition and reconstruction, making it laborious and time-consuming. The aim of this study was to determine the concurrent validity of VL CSA assessments between MR and computer vision-based automated reconstruction (AR) of CSA from sequential images of the VL obtained by US.

METHODS

The images from each sequence were manually rotated to align the fascia between images and thus visualize the VL CSA. For the AR, an artificial neural network model was utilized to segment areas of interest in the image, such as skin, fascia, deep aponeurosis, and femur. This segmentation was crucial to impose necessary constraints for the main assembly phase. At this stage, an image registration application, combined with differential evolution, was employed to achieve appropriate adjustments between the images. Next, the VL CSA obtained from the MR ( n = 488) and AR ( n = 488) techniques was used to determine their concurrent validity.

RESULTS

Our findings demonstrated a low coefficient of variation (CV) (1.51%) for AR compared with MR. The Bland-Altman plot showed low bias and close limits of agreement (+1.18 cm 2 , -1.19 cm 2 ), containing more than 95% of the data points.

CONCLUSIONS

The AR technique is valid compared with MR when measuring VL CSA in a heterogeneous sample.

Association of baseline muscle mass with functional outcomes in intensive care unit survivors: A single-center retrospective cohort study in Korea

In critical care settings, ultrasound (US) of the quadriceps muscle and Bioelectrical Impedance Analysis (BIA) are noninvasive and widely available tools to evaluate muscle mass. We studied whether baseline muscle mass affects physical function in intensive care unit (ICU) survivors after discharge. This retrospective review of a prospective cohort enrolled 30 patients admitted to the medical ICU between April 2016 and June 2018. On ICU admission, quadriceps muscle thickness and skeletal muscle mass were measured using US and BIA, respectively. Muscle strength and physical function were measured using handgrip dynamometry, the 6-min walk test, and the Barthel index questionnaire survey during every clinic visit at 1, 3, 6, and 12 months after hospital discharge. Skeletal muscle mass at ICU admission was statistically correlated with the 6-min walk distance (6MWD) and Barthel index score. The segmental lean mass of the right arm was also positively correlated with handgrip muscle strength at 6 months after discharge. Likewise, the correlation between quadriceps muscle thickness at ICU admission and 6MWD at 6 months after discharge was positive and statistically significant. Multivariate regression analysis showed that skeletal muscle mass was associated with a reduced 6MWD, but the length of ICU stay was not. The segmental lean mass of the right arm also showed a significant association with handgrip strength after discharge. Low muscle mass on ICU admission is associated with reduced muscle strength, causing impaired physical function after hospital discharge in ICU survivors.

Effects of Resistance Exercise and Essential Amino Acid Intake on Muscle Quality, Myokine, and Inflammation Factors in Young Adult Males

BACKGROUND

Recently, many studies have been devoted to discovering nutrients for exercise-like effects. Resistance exercise and the intake of essential amino acids (EAAs) are known to be factors that can affect muscle mass and strength improvement. The purpose of this study was to investigate changes in muscle quality, myokines, and inflammation in response to resistance exercise and EAA supplementation.

METHODS

Thirty-four males volunteered to participate in this study. They were assigned to four groups: (1) placebo (CO), (2) resistance exercise (RE), (3) EAA supplementation, and (4) RE + EAA supplementation. Body composition, muscle quality, myokines, and inflammation were measured at baseline and four weeks after treatment.

RESULTS

Lean body fat had decreased in both RE and RE + EAA groups. Lean body mass had increased in only the RE + EAA group. In all groups except for CO, irisin, myostatin A, and TNF-α levels had decreased. The grip strength of the right hand and trunk flexion peak torque increased in the RE group. The grip strength of the left hand, trunk flexion peak torque, and knee flexion peak torque of the left leg were increased in RE + EAA.

CONCLUSIONS

RE, EAA, and RE + EAA could effectively improve the muscle quality, myokine, and inflammation factors of young adult males. This finding highlights the importance of resistance exercise and amino acid intake.

Comparing the Impacts of Testosterone and Exercise on Lean Body Mass, Strength and Aerobic Fitness in Aging Men

BACKGROUND

Based on the largely untested premise that it is a restorative hormone that may reverse the detrimental impacts of aging, prescription of testosterone (T) has increased in recent decades despite no new clinical indications. It is apparent that middle-aged and older men with low-normal serum T levels are considering T supplementation as an anti-aging strategy. At the same time, there is evidence that physical activity (PA) is at historical lows in the Western world. In this review, we compare the impacts of T treatment aimed at achieving physiological T concentrations in middle-aged and older men, alongside the impacts of ecologically relevant forms of exercise training. The independent, and possible combined, effects of T and exercise therapy on physiological outcomes such as aerobic fitness, body composition and muscular strength are addressed.

MAIN BODY

Our findings suggest that both T treatment and exercise improve lean body mass in healthy older men. If improvement in lean body mass is the primary aim, then T treatment could be considered, and the combination of T and exercise may be more beneficial than either in isolation. In terms of muscle strength in older age, an exercise program is likely to be more beneficial than T treatment (where the dose is aimed at achieving physiological concentrations), and the addition of such T treatment does not provide further benefit beyond that of exercise alone. For aerobic fitness, T at doses aimed at achieving physiological concentrations has relatively modest impacts, particularly in comparison to exercise training, and there is limited evidence as to additive effects. Whilst higher doses of T, particularly by intramuscular injection, may have larger impacts on lean body mass and strength, this must be balanced against potential risks.

CONCLUSION

Knowing the impacts of T treatment and exercise on variables such as body composition, strength and aerobic fitness extends our understanding of the relative benefits of physiological and pharmacological interventions in aging men. Our review suggests that T has impacts on strength, body composition and aerobic fitness outcomes that are dependent upon dose, route of administration, and formulation. T treatment aimed at achieving physiological T concentrations in middle-aged and older men can improve lean body mass, whilst exercise training enhances lean body mass, aerobic fitness and strength. Men who are physically able to exercise safely should be encouraged to do so, not only in terms of building lean body mass, strength and aerobic fitness, but for the myriad health benefits that exercise training confers.

Effects of Electromyographic Biofeedback-Assisted Exercise on Functional Recovery and Quality of Life in Patients after Total Hip Arthroplasty: A Randomized Controlled Trial

The goal of the trial was to examine the effects of adding electromyographic biofeedback (EMG-BF) to the conventional program of physiotherapy after total hip arthroplasty (THA) on functional recovery and quality of life. The trial was designed as a prospective, interventional, single-blinded randomized controlled study. Ninety patients were randomized into an experimental group (EG) (n = 45; mean age 63.9 ± 8.8) and control group (CG) (n = 45; mean age 63.9 ± 9). All patients received 21 days of physiotherapy which consisted of therapeutic exercise (land-based and aquatic), electrotherapy, and education. Electromyographic biofeedback was added to a portion of the land-based exercise in EG. The Hip Disability and Osteoarthritis Outcome Score (HOOS), Numeric Rating Scale (NRS), Short Form Health Survey-36 (SF-36), use of a walking aid, 30 s chair stand test (CST) as well as the Timed Up and Go (TUG) test were used for outcome measurement. A higher proportion of the participants in both groups did not need a walking aid after the intervention (p < 0.05). All participants improved their 30 s CST and TUG results (p < 0.001), as well as their NRS and HOOS scores (p < 0.05). No significant differences between the groups were found. There were no additional benefits from adding EMG-BF to the conventional physiotherapy protocol.

Development and validation of a nomogram model for predicting low muscle mass in patients undergoing hemodialysis

BACKGROUND

Muscle mass is important in determining patients' nutritional status. However, measurement of muscle mass requires special equipment that is inconvenient for clinical use. We aimed to develop and validate a nomogram model for predicting low muscle mass in patients undergoing hemodialysis (HD).

METHODS

A total of 346 patients undergoing HD were enrolled and randomly divided into a 70% training set and a 30% validation set. The training set was used to develop the nomogram model, and the validation set was used to validate the developed model. The performance of the nomogram was assessed using the receiver operating characteristic (ROC) curve, a calibration curve, and the Hosmer-Lemeshow test. A decision curve analysis (DCA) was used to evaluate the clinical practicality of the nomogram model.

RESULTS

Age, sex, body mass index (BMI), handgrip strength (HGS), and gait speed (GS) were included in the nomogram for predicting low skeletal muscle mass index (LSMI). The diagnostic nomogram model exhibited good discrimination with an area under the ROC curve (AUC) of 0.906 (95% CI, 0.862-0.940) in the training set and 0.917 (95% CI, 0.846-0.962) in the validation set. The calibration analysis also showed excellent results. The nomogram demonstrated a high net benefit in the clinical decision curve for both sets.

CONCLUSIONS

The prediction model included age, sex, BMI, HGS, and GS, and it can successfully predict the presence of LSMI in patients undergoing HD. This nomogram provides an accurate visual tool for medical staff for prediction, early intervention, and graded management.

Associations between Power Training-Induced Changes in Body Composition and Physical Function in Older Men: A Pre-Test-Post-Test Experimental Study

BACKGROUND

It is well-established that cross-sectional measurements of poor body composition are associated with impaired physical function and that power training effectively enhances total lean mass and physical function in older adults. However, it is unclear if power training-induced changes in body composition are associated with improved physical function in older adults.

AIM

The present study investigated associations between body composition and physical function cross-sectionally and with power training-induced changes in older men.

METHODS

Forty-nine older men (68 ± 5 yrs) completed a 10-week biweekly power training intervention. Body composition was measured using dual-energy X-ray absorptiometry. Physical function was assessed as a composite Z-score combining measures from Sit-to-stand power, Timed up-and-go time, and loaded and unloaded Stair-climbing time (15 steps). Linear and quadratic regression analyses were performed to assess associations between body composition and physical function.

RESULTS

At baseline, total (R2 = 0.11, p < 0.05) and percentage body fat (R2 = 0.15, p < 0.05) showed a non-linear relationship with physical function. The apex of the quadratic regression for body composition was 21.5% body fat. Furthermore, there was a non-linear relationship between changes in body fat percentage and physical function from pre- to post-intervention (R2 = 0.15, p < 0.05).

CONCLUSION

The present study's findings indicate that participants with a body composition of ~20% body fat displayed the highest level of physical function at baseline. Furthermore, despite small pre-post changes in body fat, the results indicate that those who either preserved their body fat percentage or experienced minor alterations observed the greatest improvements in physical function.

High-velocity resistance training improves executive function in mobility-limited older adults

OBJECTIVES

To examine the effect of high-velocity resistance training (HVRT) on the executive function of middle-aged and older adults with and without mobility limitations.

METHODS

Participants (n = 41, female: 48.9%) completed a supervised 12-week HVRT intervention (2 sessions/week; at 40-60% of one-repetition maximum). The sample included 17 middle-aged adults (40-55 years); 16 older adults (>60 years) and 8 mobility-limited older adults (LIM). Executive function was assessed before and after the intervention period and was reported as z-scores. Maximal dynamic strength, peak power, quadriceps muscle thickness, maximal isometric voluntary contraction (MVIC), and functional performance were also measured pre and post intervention. Training-related adaptations in cognitive measures were calculated using a Generalized Estimating Equation model.

RESULTS

HVRT improved executive function in LIM (adjusted marginal mean differences [AMMD]: 0.21; 95%CI: 0.04, 0.38; p = 0.040) although no effect on middle-aged (AMMD: 0.04; 95%CI: -0.09; 0.17; p = 0.533) and older (AMMD: -0.11; 95%CI: -0.25; 0.02; p = 0.107) participants was observed. Improvements in maximal dynamic strength, peak power, MVIC, quadriceps muscle thickness, and functional performance were all associated with changes in executive function, and changes in the first four also seem to mediate the association between changes in functional performance and executive function.

CONCLUSIONS

HVRT-induced improvement in executive function of mobility-limited older adults were mediated by changes in lower-body muscle strength, power, and muscle thickness. Our findings reinforce the relevance of muscle-strengthening exercises to preserve cognition and mobility in older adults.

Adipocytokines and Associations With Abnormal Body Composition in Rheumatoid Arthritis

OBJECTIVE

We determined associations between adipokines and abnormal body composition in patients with rheumatoid arthritis (RA).

METHODS

Combining data from three RA cohorts, whole-body dual-energy absorptiometry measures of appendicular lean mass and fat mass indices were converted to age-, sex-, and race- and ethnicity-specific Z scores. Lean mass relative to fat mass was determined based on prior methods. Independent associations between body composition profiles and circulating levels of adiponectin, leptin, and fibroblast growth factor (FGF)-21 were assessed using linear and logistic regression models adjusting for demographic characteristics and study cohort. We also determined the improvement in the area under the curve (AUC) for prediction of low lean mass when adipokines were added to predictive models that included clinical factors such as demographic characteristics, study, and body mass index (BMI).

RESULTS

Among 419 participants, older age was associated with higher levels of all adipokines, whereas higher C-reactive protein level was associated with lower adiponectin levels and higher FGF-21 levels. Greater fat mass was strongly associated with lower adiponectin levels and higher leptin and FGF-21 levels. Higher levels of adiponectin, leptin, and FGF-21 were independently associated with low lean mass. The addition of adiponectin and leptin levels to regression models improved prediction of low lean mass when combined with demographic characteristics, study, and BMI (AUC 0.75 vs. 0.66).

CONCLUSION

Adipokines are associated with both excess adiposity and low lean mass in patients with RA. Improvements in the prediction of body composition abnormalities suggest that laboratory screening could help identify patients with altered body composition who may be at greater risk of adverse outcomes.

Effects of muscle mass and muscle quality estimated by phase angle on functional outcomes in older patients undergoing rehabilitation: A prospective cohort study

BACKGROUND

Both skeletal muscle mass and muscle quality are important predictors of poor prognosis in older patients. However, the effects of muscle mass and muscle quality estimated by the phase angle (PhA) on functional outcomes in older patients undergoing rehabilitation have yet to be reported. This study aimed to investigate whether appendicular skeletal muscle index (SMI) and muscle quality estimated by PhA were independently associated with activities of daily living (ADL) and physical function in older patients undergoing rehabilitation.

METHODS

This prospective cohort study included older patients in a subacute rehabilitation hospital (n = 443). Baseline SMI and PhA were measured using bioelectrical impedance analysis, and low SMI or low PhA were determined using each cutoff value. The primary outcomes were ADL abilities measured using the functional independence measure for motor function (FIM-M) score and physical function measured using the short physical performance battery (SPPB) score at hospital discharge. Association between low SMI and low PhA and FIM-M or SPPB scores at discharge were determined using multiple regression analysis adjusted for confounding factors.

RESULTS

There were significant differences between the normal- and low-PhA groups in the FIM-M and SPPB scores at discharge (P < 0.001). In multiple regression analysis, low PhA was independently associated with FIM-M (β = -0.109, P = 0.013) and SPPB scores (β = 0.535, P < 0.001) at discharge; however, low SMI was not independently associated with these functional outcomes.

CONCLUSION

Decreased muscle quality estimated by the PhA was independently associated with poor ADL abilities and poor physical function in older patients undergoing rehabilitation.

Serum α-Carotene, but Not Other Antioxidants, Is Positively Associated with Muscle Strength in Older Adults: NHANES 2001-2002

Aging is associated with an increased reactive oxygen species that can decrease muscle strength. Thus, antioxidant substances could be positively associated with muscle strength in older adults. To investigate the association between serum antioxidants and muscle strength in older adults. A cross-sectional study evaluating 1172 individuals (627 men and 545 women), aged 50 to 85 years from NHANES 2001-2002, was performed. Carotenoids (α-carotene, trans-β-carotene, cis-β-carotene, β-cryptoxanthin, lutein/zeaxanthin combination, trans-lycopene), vitamin E, and retinol were analyzed via the high-performance liquid chromatography method. Muscle strength was evaluated by the isokinetic knee extension test. Linear regression was performed to evaluate the association between tertiles of serum antioxidant levels and strength, adjusted for confounders (energy and protein intake, body mass index, sex, age, C-reactive protein, uric acid, race/ethnicity, marital status, annual household income, educational level, physical activity, smoking, hypertension, arthritis, and diabetes). Alpha-carotene levels (p-trend = 0.027) were positively associated with muscle strength. However, serum vitamin E, trans-β-carotene, cis-β-carotene, β-cryptoxanthin, carotenoids, and retinol levels were not associated with strength. Serum α-carotene, but not other antioxidants, was positively associated with muscle strength in older adults.

Body Composition and Nutrients Dietary Intake Changes during COVID-19 Lockdown in Spanish Healthy Postmenopausal Women

(1) Background: During the COVID-19 lockdown, high rates of physical inactivity and dietary imbalances were reported in both adults and adolescents. Physical separation and isolation not only have a significant impact on the performance of physical activity but also affect people’s lives, particularly their dietary habits. In the present study, we aimed to examine whether or not bioelectrical impedance-derived body composition parameters and dietary habits were affected during the pandemic-associated lockdown in postmenopausal Spanish women. (2) Methods: Sixty-six women participated in the study (58.7 ± 5.4 years) before (between July−October 2019) and after (August−October 2020) the lockdown, which occurred as a consequence of the COVID-19 pandemic in Spain. Body composition parameters were measured by bioelectrical impedance analysis while dietary intake of proteins, fat, carbohydrates, and energy was measured by a food frequency questionnaire. (3) Results Regarding body composition, no differences were observed in fat mass in % (mean increase 0.05 (2.74); p = 0.567), fat mass in kg (mean increase −0.07 (4.137); p = 0.356) or lean mass in kg (mean increase 0.20 (1.424); p = 0.636). Similarly, no statistically significant differences were observed between the two study periods for any of the nutrients studied, nor for energy intake (p > 0.05 in all cases). (4) Conclusions: After comprehensively assessing body composition and dietary intake of protein, fat, carbohydrates, and energy before and after COVID-19 lockdown in healthy adult women in Spain no changes in the parameters studied were observed during the period analyzed in the women examined.

Isolated Soy Protein Supplementation Combined With Resistance Training Improves Muscle Strength, Mass, and Physical Performance of Aging Female Mice

Background/Purpose: In recent years, the aging population has gradually increased, and the aging process is accompanied by health-associated problems, such as loss of muscle mass and weakness. Therefore, it is important to explore alternative strategies for improving the health status and physical fitness of the aged population. In this study, we investigated the effect of soy protein supplementation combined with resistance training on changes in the muscle mass, muscle strength, and functional activity performance of aging mice. Methods: Female Institute of Cancer Research (ICR) mice were divided into four groups (n = 8 per group): sedentary control (SC), isolated soy protein (ISP) supplementation, resistance training (RT), and a combination of ISP and RT (ISP + RT). The mice in designated groups received oral ISP supplementation (0.123 g/kg/day), RT (5 days/week for a period of 4 weeks), or a combination of both ISP plus RT for 4 weeks. Afterward, we assessed muscle strength, endurance, and anaerobic endurance performance and analyzed blood biochemical and pathological tissue sections to investigate whether there were adverse effects or not in mice. Results: ISP supplementation effectively improved the muscle mass, muscle endurance, and endurance performance of aging female mice. The RT group not only showed similar results with ISP but also increased muscle strength and glycogen content. Nevertheless, the combination of ISP supplementation and RT had greater beneficial effects on muscle strength, physical performance, and glycogen levels (p < 0.05). In addition, the combination of ISP supplementation and RT had significantly increased type II muscle percentage and cross-sectional area (p < 0.05). Conclusion: Although ISP or RT alone improved muscle mass and performance, the combination of ISP with RT showed greater beneficial effects in aging mice. Our findings suggest that regular exercise along with protein supplementation could be an effective strategy to improve overall health and physical fitness among the elderly.

Test-Retest Reliability of Isokinetic Strength Measurements in Lower Limbs in Elderly

Strength is essential for carrying out the usual activities of daily life. As there is a loss of strength in elderly, many treatments are based on delaying the loss of strength or maintaining it. Isokinetic dynamometry is the gold standard for assessing strength. It is essential that studies are conducted to allow us to identify the reliability of isokinetic strength assessments in older people. This study aimed to test the absolute and relative intra-session reliability of peak torque and work of a concentric knee extension-flexion performed at 60°/s in elderly. Fifty-two elderly subjects performed three repetitions of bilateral concentric knee extension-flexion at 60°/s using an isokinetic dynamometer. The relative and absolute reliability were calculated between the second and third repetition. The intra-class correlation coefficient values were between 0.94 and 0.98 for peak torque and work in all measures, which is considered “excellent”, except for left leg flexors in women, with values between 0.85 and 0.88, which is considered “good”. The standard error of measurement (SEM) percentage oscillated from 3.9% to 10.5%, with a smallest real difference (SRD) percentage of 10.9% to 29.2% for peak torque. The relative reliability of peak torque and work were excellent for all measures except flexors in women, evidencing the utility of isokinetic dynamometry for monitoring lower limb maximal muscle strength and work of concentric knee extension-flexion at 60°/s/s in the elderly. In addition, an SRD > 19.9% in peak torque and an SRD > 23.1% in work is considered a true change.

Prevalence of sarcopenia in community dwelling outpatient postmenopausal Hungarian women

Background

Ageing is an inherent feature of life and as per the United Nations, in the year 2020, 985 million women were ≥ 50 years of age worldwide, and the figure is expected to rise to 1.65 billion by 2050. Preservation of health and well-being in the elderly are challenging, and on the same note generalized changes in the musculoskeletal system contribute to this scenario. Musculoskeletal changes with ageing are referred to as sarcopenia. Reduced muscle mass and physical performance are hallmarks of sarcopenia, exclaimed with difficulty in independent activity and poor quality of life. Knowing that there is a hiatus in our knowledge as regards to the prevalence of sarcopenia in Hungary, the aim of this study was to determine the prevalence of sarcopenia in a community dwelling outpatient postmenopausal Hungarian cohort using the EWGSOP2 consensus recommendation.

Methods

In this cross-sectional study, women arriving for routine bone densitometry examination at the Regional Osteoporosis Center, Department of Obstetrics and Gynecology, Faculty of Medicine, University of Debrecen were invited to participate in the study. A total of a 100 community-dwelling women were recruited who confirmed to the inclusion criteria of self-reported postmenopausal status, ≥ 50 years of age and gave written informed consent. The study procedures included the self-administered SARC-F questionnaire, followed by assessment of muscle strength, muscle quantity and physical preformance. Muscle strength was determined with the hand grip strength (HGS), appendicular skeletal muscle mass was assessed using dual energy X-ray absorptiometry and physical performance was determined by the gait speed (GS) test.

Results

As per the EWGSOP2 definition, the percentage of study participants with probable sarcopenia (low muscle strength), sarcopenia (low muscle strength and low muscle quantity) and severe sarcopenia (low muscle strength, muscle quantity and low physical performance) was 36, 31 and 8%, respectively. Multiple linear regression analysis revealed that height, weight, HGS and GS were all independent predictors of appendicular skeletal muscle mass.

Conclusion

The 31% prevalence of sarcopenia in the studied post-menopausal women highlights the need for adequate assessment of the condition in the elderly. Our findings most probably bear public health implications and may accelerate formulation of policies promoting healthy ageing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05167-2.

Effect of Resistance Training Combined with Beta-Hydroxy-Beta-Methylbutyric Acid Supplements in Elderly Patients with Sarcopenia after Hip Replacement

Objectives

To evaluate the efficacy of resistance training (RT) combined with beta‐hydroxy‐beta‐methylbutyric acid (HMB) in the treatment of elderly patients with sarcopenia after hip replacement.

Methods

From January 1, 2018 to December 31, 2018, 200 elderly patients (68 men, mean age 76.3 years and 137 women, mean age 79.1 years) who experienced femoral neck fracture with sarcopenia after hip arthroplasty were assigned to four groups: RT + HMB group, RT group, HMB group, and negative control group. Baseline data, body composition, grip strength, Barthel index (BI), Harris hip score (HHS), and visual analog scale score (VAS) were compared among the four groups before and 3 months after surgery.

Results

A total of 177 participants completed the trial, including 43 in the HMB + RT group, 44 in the HMB group, 45 in the RT group, and 45 in the negative control group. At the 3‐month follow‐up, the body composition and grip strength of the HMB + RT group and RT group were significantly improved compared with those before operation. The HMB group had no significant change, while the measures in the negative control group significantly decreased. Postoperative BI and HSS did not reach pre‐injury levels in any of the four groups, but postoperative VAS score was significantly improved. However, there was no significant difference in BI, HSS, or VAS among the four groups.

Conclusion

RT, with or without HMB supplementation, can effectively improve body composition and grip strength in elderly patients with sarcopenia after hip replacement at short‐term follow‐up. Simultaneously, use of exclusive HMB supplementation alone may also help to prevent decreases in muscle mass and grip strength in these patients.

The effects of exercise training on hypertensive older adults: an umbrella meta-analysis

Exercise training has been shown to blunt many of the physiological declines and common diseases of the aging process. One such beneficial effect is the reduction of blood pressure (BP) in hypertensive older adults. However, there is no consensus about which benefits of aerobic (AT) or resistance training (RT) may be lost by the use of combined training (CT) or even what benefits could be acquired only by performing CT, considering the extensive health needs of older adults with hypertension. Thus, we performed an umbrella meta-analysis. The benefits conferred by CT are extensive and encompass cardiorespiratory fitness, muscular fitness, and blood lipid profile improvements. CT may be recommended to improve the extensive health needs of hypertensive older adults that go beyond blood pressure reduction.

The effect of resistance training programs on lean body mass in postmenopausal and elderly women: a meta-analysis of observational studies

Aging and menopause are associated with morphological and functional changes which may lead to loss of muscle mass and therefore quality of life. Resistance training (RT) is an effective training mode to increase muscle mass. We reviewed the existing literature to identify studies implementing RT protocols and evaluating muscle hypertrophy exclusively in healthy, postmenopausal and elderly women. Participants’ age range was comprised between 50 and 80 years. The primary outcome observed was muscle hypertrophy. Fat mass was also evaluated, if available. PubMed and Web of Science were the screened database, and original articles written in English and published from 2000 up to 2020 were included. 26 articles were considered eligible and included. Quality assessment revealed a “moderate quality” of the included studies, however the majority of studies was able to reach level 4 of evidence and on overall grade of recommendation C. In total, data from 745 female participants subjected to different forms of resistance training were considered. Heterogeneity across studies was present regarding study design, intervention length (mean 16 weeks), training frequency (3 d/w), no. of exercises (n = 7.4) and participants’ age (65.8 ± 4.9 years). Small-to-moderate significant increases (k = 43; SMD = 0.44; 95% CI 0.28; 0.60; p < 0.0001) of lean body mass were observed in post-menopausal and elderly women, regardless of age, intervention period, weekly training frequency and no. of exercises. No effects were noted for fat mass (k = 17; SMD = 0.27; 95% CI − 0.02; 0.55; p = 0.07). Studies need to concentrate on providing information regarding training parameters to more effectively counteract the effects of aging and menopause on skeletal muscle mass.

Lean mass as a risk factor for intensive care unit admission: an observational study

PURPOSE

Intensive care unit (ICU) survivors have reduced physical function likely due to skeletal muscle wasting and weakness acquired during critical illness. However, the contribution of pre-morbid muscle mass has not been elucidated. We aimed to examine the association between pre-ICU muscle mass and ICU admission risk. Secondary outcomes include the relationship between muscle mass and ICU outcomes.

METHODS

ICU admissions between June 1, 1998, and February 1, 2019, were identified among participants of Geelong Osteoporosis Study (GOS), a population-based cohort study. Cox proportional hazard regression models estimated hazard ratios (HR) for ICU admission across T-score strata and continuous values of DXA-derived lean mass measures of skeletal mass index (SMI, lean mass/body mass %) and appendicular lean mass corrected for height (ALM/h2, kg/m2). Multivariable regression was used to determine the relationship between lean mass and ICU outcomes.

RESULTS

One hundred and eighty-six of 3126 participants enrolled in GOS were admitted to the ICU during the follow-up period. In adjusted models, lean mass was not predictive of ICU admission (SMI: HR 0.99 95%CI 0.97-1.01, p = 0.32; ALM/h2: HR 1.11 95%CI 0.94-1.31, p = 0.23), while greater appendicular lean mass was related to reduced 28-day mortality (ALM/h2 adjOR: 0.25, 95%CI 0.10-0.63, p = 0.003, SMI adjOR: 0.91, 95%CI 0.82-1.02, p = 0.09).

CONCLUSION

Lean mass was not associated with ICU admission in this population-based cohort study; however, greater appendicular lean mass was associated with reduced mortality. This suggests pre-ICU muscle status may not predict development of critical illness but is associated with better survival after critical illness occurs.

Sarcopenic Obesity in Rheumatoid Arthritis: Prevalence and Impact on Physical Functioning

OBJECTIVE

We determined the prevalence of sarcopenic obesity in patients with rheumatoid arthritis (RA) using multiple methods and assessed associations with physical functioning.

METHODS

This study evaluated data from three RA cohorts. Whole-body dual-energy absorptiometry (DXA) measures of appendicular lean mass index (ALMI, kg/m2) and fat mass index (FMI) were converted to age, sex, and race-specific Z-Scores and categorized using a recently validated method and compared it to a widely-used existing method. The prevalence of body composition abnormalities in RA was compared with two reference populations. In the RA cohorts, associations between body composition and change in the Health Assessment Questionnaire (HAQ) and the Short Physical Performance Battery (SPPB) in follow-up were assessed using linear and logistic regression, adjusting for age, sex, race, and study.

RESULTS

The prevalence of low lean mass and sarcopenic obesity were higher in patients with RA (14.2; 12.6%, respectively) compared with the reference population cohorts (7-10%; 4-4.5%, respectively, all p< 0.05). There was only moderate agreement among methods of sarcopenic obesity categorization (Kappa 0.45). The recently validated method categorized fewer subjects as obese, and many of these were categorized as low lean mass only. Low lean mass, obesity, and sarcopenic obesity were each associated with higher HAQ and lower SPPB at baseline and numerically greater worsening.

CONCLUSION

RA patients had higher rates of low lean mass and sarcopenic obesity than the general population. The recently validated methods characterized body composition changes differently from traditional methods and were more strongly associated with physical function.

Quantitative peripheral computed tomography to measure muscle area and assess lean soft tissue mass in children

BACKGROUND

Skeletal muscle is one of the main components of lean soft tissue mass (LSTM). Low levels in children affect locomotion, posture, and increase the risk of metabolic syndrome.

AIM

(1) To evaluate the association between muscle cross-sectional area (MCSA) of the lower left leg measured by peripheral quantitative computed tomography (pQCT) and total LSTM; namely, total left leg and left lower leg LSTM assessed by dual-energy X-ray absorptiometry (DXA) in a group of children, (2) to examine if MCSA is a predictor of LSTM, (3) to determine the ability of pQCT to identify children with low LSTM.

SUBJECTS AND METHODS

Lower left leg MCSA and LSTM were measured using pQCT and DXA, respectively, in 396 children.

RESULTS

Statistically significant positive correlations were found between the lower leg MCSA - total LSTM (r² = 0.789), total leg LSTM (r² = 0.79), and lower leg LSTM (r² = 0.791) (p < .01). MCSA explained 64-68% of the variance in LSTM. Receiver operator characteristic (ROC) curves determined the capacity of the lower left leg MCSA to identify low LSTM in girls (AUC 0.95) and boys (AUC 0.87).

CONCLUSIONS

Our results showed that lower left leg MCSA, measured using pQCT, could be a tool to predict low LSTM in children.

Exercise in patients with hip osteoarthritis - effects on muscle and functional performance: A randomized trial

Background: It is believed that clinical management of osteoarthritis should address muscle weakness to improve physical function and prevent disability and frailty.Objectives: This sub-study investigated the effects of supervised progressive resistance training (RT), supervised Nordic Walking (NW), and unsupervised home-based exercise (HBE) on muscle and functional performance; and associations between these exercise-induced changes in persons with hip osteoarthritis.Methods: Forty-two patients with hip osteoarthritis were recruited from a larger RCT (NCT01387867). All the groups (RT, n = 15; NW, n = 12; HBE, n = 15) exercised 1 h 3 times/week for 4 months. Quadriceps cross-sectional area (QCSA, MRI-determined); quadriceps strength (QMVC); leg extensor power (LEP); functional performance (chair stands (30sCS); stair climbs (TSC); and 6-minute walk (6MWT)) were assessed at baseline and 4 months.Results: Per protocol analyses (one-way ANOVA and Bonferroni test) showed significant between-group differences for improvements in QCSA in the most symptomatic leg favoring RT versus NW (2.3 cm², 95% CI [0.6, 3.9]) and HBE (2.3 cm² [0.8, 3.9]); and 30sCS (1.8 repetitions [0.2-3.3]), and 6MWT (35.1 m [3.5-66.7]) favoring NW versus HBE. Associations existed between exercise-induced changes in QCSA and QMVC (r = 0.366, p = .019) for the most symptomatic leg and between changes in 6MWT and QMVC (r = 0.320, p = .04) and LEP (r = 0.381, p = .01), respectively, for the least symptomatic leg.Conclusions: Resistance training appeared effective for improving muscle mass, but less effective for improving muscle strength, power, and functional performance. Only exercise-induced changes in muscle strength and power of the least symptomatic leg, not the most symptomatic leg, were related to changes in functional performance.

Myostatin Inhibition-Induced Increase in Muscle Mass and Strength Was Amplified by Resistance Exercise Training, and Dietary Essential Amino Acids Improved Muscle Quality in Mice

It has been frequently reported that myostatin inhibition increases muscle mass, but decreases muscle quality (i.e., strength/muscle mass). Resistance exercise training (RT) and essential amino acids (EAAs) are potent anabolic stimuli that synergistically increase muscle mass through changes in muscle protein turnover. In addition, EAAs are known to stimulate mitochondrial biogenesis. We have investigated if RT amplifies the anabolic potential of myostatin inhibition while EAAs enhance muscle quality through stimulations of mitochondrial biogenesis and/or muscle protein turnover. Mice were assigned into ACV (myostatin inhibitor), ACV+EAA, ACV+RT, ACV+EAA +RT, or control (CON) over 4 weeks. RT, but not EAA, increased muscle mass above ACV. Despite differences in muscle mass gain, myofibrillar protein synthesis was stimulated similarly in all vs. CON, suggesting a role for changes in protein breakdown in muscle mass gains. There were increases in MyoD expression but decreases in Atrogin-1/MAFbx expression in ACV+EAA, ACV+RT, and ACV+EAA+RT vs. CON. EAA increased muscle quality (e.g., grip strength and maximal carrying load) without corresponding changes in markers of mitochondrial biogenesis and neuromuscular junction stability. In conclusion, RT amplifies muscle mass and strength through changes in muscle protein turnover in conjunction with changes in implicated signaling, while EAAs enhance muscle quality through unknown mechanisms.

Osteoporosis Detection by Physical Function Tests in Resident Health Exams: A Japanese Cohort Survey Randomly Sampled from a Basic Resident Registry

Osteoporosis may increase fracture risk and reduce healthy quality of life in older adults. This study aimed to identify an assessment method using physical performance tests to screen for osteoporosis in community dwelling individuals. A total of 168 women aged 50–89 years without diagnosed osteoporosis were randomly selected from the resident registry of a cooperating town for the evaluation of physical characteristics, muscle strength, and several physical performance tests. The most effective combinations of evaluation items to detect osteoporosis (i.e., T-score ≤ −2.5 at the spine or hip) were selected by multivariate analysis and cutoff values were determined by likelihood ratio matrices. Thirty-six women (21.4%) were classified as having osteoporosis. By analyzing combinations of two-step test (TST) score and body mass index (BMI), osteoporosis could be reliably suspected in individuals with TST ≤ 1.30 and BMI ≤ 23.4, TST ≤ 1.32 and BMI ≤ 22.4, TST ≤ 1.34 and BMI ≤ 21.6, or TST < 1.24 and any BMI. Setting cut-off values for TST in combination with BMI represents an easy and possibly effective screening tool for osteoporosis detection in resident health exams.

Skeletal Muscle Adaptive Responses to Different Types of Short-Term Exercise Training and Detraining in Middle-Age Men

INTRODUCTION

Whether short-term, single-mode exercise training can improve physical fitness prior to a period of reduced physical activity (e.g. post-surgery recovery) is not well characterized in clinical populations nor middle-age adults. We investigated skeletal muscle adaptive responses following endurance exercise training (ENT), high-intensity interval training (HIIT) or resistance exercise training (RET), and a subsequent period of detraining, in sedentary, middle-age men.

METHODS

Thirty-five sedentary, males (39±3 yr) were randomized to parallel groups and undertook six weeks of either ENT (n=12), HIIT (n=12) or RET (n=11) followed by 2.5 weeks of detraining. Skeletal muscle fiber characteristics, body composition, muscle thickness, muscle strength, aerobic capacity, resting energy expenditure and glucose homeostasis were assessed at baseline, and after exercise training and detraining.

RESULTS

Lean mass increased after RET and HIIT (+3.2±1.6% and +1.6±2.1%, P<0.05). Muscle strength (sum of leg press, leg extension and bench press 1RMs) increased after all training interventions (RET: +25±5%; HIIT: +10±5%; ENT: +7±7%, P<0.05). Aerobic capacity increased only after HIIT and ENT (+14±7% and +11±11%, P<0.05). Type I and II muscle fiber size increased for all groups post-training (main effect of time, P<0.05). Following a period of detraining, the gains in lean mass and maximal muscle strength were maintained in RET and HIIT groups, but maximal aerobic capacity declined below post-training levels in HIIT and ENT (P<0.05).

CONCLUSION

Six weeks of HIIT induced widespread adaptations prior to detraining in middle-age men. Exercise training-induced increases in aerobic capacity declined during 2.5 weeks of detraining but gains in lean mass and muscle strength were maintained.

Responses to Maximal Strength Training in Different Age and Gender Groups

Purpose

The present study aimed to investigate the potential impact of age, gender, baseline strength, and selected candidate polymorphisms on maximal strength training (MST) adaptations.

Methods

A total of 49 subjects (22 men and 27 women) aged 20–76 years, divided into five age groups, completed an 8 weeks MST intervention. Each MST session consisted of 4 sets with 4 repetitions at ∼85–90% of one-repetition maximum (1RM) intensity in leg-press, three times per week. 1RM was tested pre and post the intervention and blood samples were drawn to genotype candidate polymorphisms ACE I/D (rs1799752), ACTN3 R577X (rs1815739), and PPARGC1A Gly482Ser (rs8192678).

Results

All age groups increased leg-press 1RM (p < 0.01), with a mean improvement of 24.2 ± 14.0%. There were no differences in improvements between the five age groups or between male and female participants, and there were no non-responders. Baseline strength status did not correlate with 1RM improvements. PPARGC1A rs8192678 T allele carriers had a 15% higher age- and gender corrected baseline 1RM than the CC genotype (p < 0.05). C allele carriers improved 1RM (%) by 34.2% more than homozygotes for the T allele (p < 0.05).

Conclusion

To the best of our knowledge, this is the first study to report improvement in leg-press maximal strength regardless of gender, baseline strength status in all age groups. The present study is also first to demonstrate an association between the PPARGC1A rs8192678 and maximal strength and its trainability in a moderately trained cohort. MST may be beneficial for good health and performance of all healthy individuals.

Stay Home: Role of Physical Exercise Training in Elderly Individuals' Ability to Face the COVID-19 Infection

Recently, the novel coronavirus epidemic occurred in China and spread worldwide to become a global pandemic. COVID-19 is a fatal viral infection causing death, particularly in aged individuals, due to impaired immunity. To date, no intervention is available to prevent COVID-19 and its manifestations. Physical exercise training generally has health benefits, and it assists in the prevention of several chronic diseases. Therefore, this review is aimed at exploring the role of physical exercise training in the face of COVID-19 in older adults and elderly individuals. From this point of view, this review suggests that physical exercise training plays a key role in promoting immune system regulation, delaying immunity dysfunction, reducing circulatory inflammation markers, and preventing sarcopenia and thus could prevent the risk of acquiring COVID-19 infection and reduce the complications of recommended self-isolation in older adults and elderly individuals. Additionally, immunity biomarkers were optimistically demonstrated in older adults following physical exercise training, thereby reducing mortality and morbidity rates. Finally, in accordance with recommendations to stay home and perform self-isolation to prevent the spread of COVID-19, all populations are strongly recommended to practice regular home exercise training at home to promote immune system functioning.

Is impaired dopaminergic function associated with mobility capacity in older adults?

The capacity to move is essential for independence and declines with age. Slow movement speed, in particular, is strongly associated with negative health outcomes. Prior research on mobility (herein defined as movement slowness) and aging has largely focused on musculoskeletal mechanisms and processes. More recent work has provided growing evidence for a significant role of the nervous system in contributing to reduced mobility in older adults. In this article, we report four pieces of complementary evidence from behavioral, genetic, and neuroimaging experiments that, we believe, provide theoretical support for the assertion that the basal ganglia and its dopaminergic function are responsible, in part, for age-related reductions in mobility. We report four a posteriori findings from an existing dataset: (1) slower central activation of ballistic force development is associated with worse mobility among older adults; (2) older adults with the Val/Met intermediate catecholamine-O-methyl-transferase (COMT) genotype involved in dopamine degradation exhibit greater mobility than their homozygous counterparts; (3) there are moderate relationships between performance times from a series of lower and upper extremity tasks supporting the notion that movement speed in older adults is a trait-like attribute; and (4) there is a relationship of functional connectivity within the medial orbofrontal (mOFC) cortico-striatal network and measures of mobility, suggesting that a potential neural mechanism for impaired mobility with aging is the deterioration of the integrity of key regions within the mOFC cortico-striatal network. These findings align with recent basic and clinical science work suggesting that the basal ganglia and its dopaminergic function are mechanistically linked to age-related reductions in mobility capacity.

Daily lifestyle behaviors and risks of sarcopenia among older adults

BACKGROUND

Lifestyle behaviors are modifiable factors that can provide information for designing intervention strategies for sarcopenia. The present study aimed to identify the relationships between a range of daily lifestyle behaviors and sarcopenia risks among older adults.

METHODS

A nationwide telephone-based survey targeting older adults (≥65 years) was performed in Taiwan. Data based on self-reported daily lifestyle behaviors (food selection, physical activity, sitting time, and sleep duration), the presence or absence of sarcopenia (measured by SARC-F), and personal characteristics were obtained. Binary logistic regression models were applied.

RESULTS

A total of 1068 older adults participated in this survey. In the adjusted model, older adults who selected unbalanced foods (odds ratio [OR] = 1.93, 95% confidence interval [CI] = 1.12-3.34), engaged in insufficient physical activity (OR = 5.14, 95% CI = 3.04-8.70), and sat for longer periods of time (OR = 1.98, 95% CI = 1.09-3.59) were more likely to have higher risks of sarcopenia. No significant association was observed for sleep duration.

CONCLUSIONS

The results of this study highlight that, among health behaviors, an unbalanced food selection (six nutrients), not meeting physical activity recommendations (150 min/week), and a higher sitting time (≥7 h/day) were risk factors for sarcopenia among older adults. Intervention programs for sarcopenia prevention in older adults should focus on promoting balanced food selection, sufficient physical activity, and reduced sitting time.

Decreased lower-extremity muscle performance is associated with decreased hip bone mineral density and increased estimated fracture risk in community-dwelling postmenopausal women

The present study demonstrated that the lower-extremity muscle performance in Chinese community-dwelling postmenopausal women with lower bone mineral density (BMD) was positively associated with hip BMD and negatively associated with estimated fracture risk.

PURPOSE

Postmenopausal women are at high risk for osteoporotic fractures. It has been shown that decreased lower-extremity muscle performance is associated with osteoporotic fractures. However, the relationship between muscle performance and bone mineral density in postmenopausal women is inconsistent in the literature. The present study was to investigate the relationship between lower-extremity muscle performance and BMD or estimated fracture risk in community-dwelling postmenopausal women.

METHODS

Two hundred forty-seven postmenopausal women aged 50-85 years were recruited in the study. The short physical performance battery (SPPB) tool including the chair stand test (CST), gait speed test (GST), and balance test (BT) was used to determine lower-extremity functioning and the CST, GST, BT, and SPPB total scores were recorded. The BMD of lumbar spine (LSBMD), femoral neck (FNBMD), and total hip (THBMD) were measured by dual-energy X-ray absorptiometry (DXA), and the vertebral fracture was confirmed by lateral spine X-rays radiographs. In addition, patients' 10-year estimated major osteoporotic fracture risk (MOFR) and hip fracture risk (HFR) were assessed by the Fracture Risk Assessment Tool (FRAX). Linear regression analysis was used to analyze the association between muscle performance and BMD.

RESULTS

The CST, GST, and SPPB total scores were positively associated with LSBMD, THBMD, and FNBMD before adjustment for age, height, and weight. The SPPB total score was positively associated with FNBMD and THBMD, but not with LSBMD after adjustment for age, height, and weight. The BT score was positively associated with FNBMD and THBMD, but not with LSBMD before and after adjustment for age, height, and weight. Moreover, the CST, GST, BT, and SPPB scores were negatively associated with the FRAX score.

CONCLUSION

The lower-extremity muscle performance in community-dwelling postmenopausal women is positively associated with FNBMD and THBMD and negatively associated with the FRAX score.

Interactions among IGF-1, AKT2, FOXO1, and FOXO3 variations and between genes and physical activities on physical performance in community-dwelling elders

This study assessed the interactions among IGF-1, AKT2, FOXO1, and FOXO3 variations and the interactions of gene and physical activity on handgrip strength, arm muscle mass-adjusted handgrip (armGrip), gait speed (GS), timed up and go (TUG), and leg press strength (LPS). Nine single nucleotide polymorphisms (SNPs) containing three IGF-1 SNPs (rs6214, rs5742692, and rs35767), two AKT2 SNPs (rs892119 and rs35817154), two FOXO1 SNPs (rs17446593 and rs10507486), and two FOXO3 SNPs (rs9480865 and rs2153960) were genotyped in 472 unrelated elders with a mean age of 73.8 years. We observed significant interactions of IGF-1 SNP rs6214 and rs35767 with regular physical activity on TUG and GS; and AKT2 SNP rs892119 and FOXO3 SNP rs9480865 with regular physical activity on armGrip. Genotype GG of IGF-1 rs6214 and rs35767 in individuals without regular physical activity had poor performance in TUG and GS, as well as GG of AKT2 rs892119 decreased armGrip in individuals without regular physical activity. After FDR adjustment, no significant gene-gene interactions were found. A sedentary lifestyle may increase the risk of impairing physical performance and regular physical activity is a remedy for sarcopenia, even a little regular physical activity can overcome carrying some risk alleles in this pathway.

Relative contribution of muscle strength, lean mass, and lower extremity motor function in explaining between-person variance in mobility in older adults

BACKGROUND

Approximately 35% of individuals > 70 years have mobility limitations. Historically, it was posited lean mass and muscle strength were major contributors to mobility limitations, but recent findings indicate lean mass and muscle strength only moderately explain mobility limitations. One likely reason is that lean mass and muscle strength do not necessarily incorporate measures globally reflective of motor function (defined as the ability to learn, or to demonstrate, the skillful and efficient assumption, maintenance, modification, and control of voluntary postures and movement patterns). In this study we determined the relative contribution of lean mass, muscle strength, and the four square step test, as an index of lower extremity motor function, in explaining between-participant variance in mobility tasks.

METHODS

In community-dwelling older adults (N = 89; 67% women; mean 74.9 ± 6.7 years), we quantified grip and leg extension strength, total and regional lean mass, and time to complete the four square step test. Mobility was assessed via 6-min walk gait speed, stair climb power, 5x-chair rise time, and time to complete a complex functional task. Multifactorial linear regression modeling was used to determine the relative contribution (via semi-partial r2) for indices of lean mass, indices of muscle strength, and the four square step test.

RESULTS

When aggregated by sex, the four square step test explained 17-34% of the variance for all mobility tasks (p <  0.01). Muscle strength explained ~ 12% and ~ 7% of the variance in 6-min walk gait speed and 5x-chair rise time, respectively (p <  0.02). Lean mass explained 32% and ~ 4% of the variance in stair climb power and complex functional task time, respectively (p <  0.02). When disaggregated by sex, lean mass was a stronger predictor of mobility in men.

CONCLUSION

The four square step test is uniquely associated with multiple measures of mobility in older adults, suggesting lower extremity motor function is an important factor for mobility performance.

TRIAL REGISTRATION

NCT02505529 -2015/07/22.

Effects of Elastic Resistance Exercise on Postoperative Outcomes Linked to the ICF Core Sets for Osteoarthritis after Total Knee Replacement in Overweight and Obese Older Women with Sarcopenia Risk: A Randomized Controlled Trial

(1) Background: Knee osteoarthritis (KOA) and aging are associated with high sarcopenia risk; sarcopenia may further affect outcomes after total knee replacement (TKR). Elastic resistance exercise training (RET) limits muscle attenuation in older adults. We aimed to identify the effects of post-TKR elastic RET on lean mass (LM) and functional outcomes in overweight and obese older women with KOA by using the brief International Classification of Functioning, Disability and Health Core Set for osteoarthritis (Brief-ICF-OA). (2) Methods: Eligible women aged ≥60 years who had received unilateral primary TKR were randomly divided into an experimental group (EG), which received postoperative RET twice weekly for 12 weeks, and a control group (CG), which received standard care. The primary and secondary outcome measures were LM and physical capacity, respectively, and were linked to the Brief-ICF-OA. The assessment time points were 2 weeks prior to surgery (T₀) and postoperative at 1 month (T₁; before RET) and 4 months (T₂; upon completion of RET) of follow-up. An independent t test with an intention-to-treat analysis was conducted to determine the between-group differences in changes of outcome measures at T₁ and T₂ from T₀. (3) Results: Forty patients (age: 70.9 ± 7.3 years) were randomly assigned to the EG (n = 20) or CG (n = 20). At T₂, the EG exhibited significantly greater improvements in leg LM (mean difference (MD) = 0.86 kg, p = 0.004) and gait speed (MD = 0.26 m/s, p = 0.005) compared with the CG. Furthermore, the EG generally obtained significantly higher odds ratios than the CG for treatment success for most Brief-ICF-OA categories (all p < 0.001). Conclusions: Early intervention of elastic RET after TKR yielded positive postoperative outcomes based on the Brief-ICF-OA. The findings of this study may facilitate clinical decision-making regarding the optimal post-TKR rehabilitation strategy for older women with KOA.

Resistance Training Volume Enhances Muscle Hypertrophy, but Not Strength in Postmenopausal Women: A Randomized Controlled Trial

Nascimento de Oliveira Júnior, G, de Freitas Rodrigues de Sousa, J, Augusto da Silva Carneiro, M, Martins, FM, Santagnello, SB, Campos Souza, MV, and Orsatti, FL. Resistance training volume enhances muscle hypertrophy, but not strength in postmenopausal women: a randomized controlled trial. J Strength Cond Res XX(X): 000-000, 2020-Among several possible resistance training (RT) variables to be manipulated, the training volume has been considered as a critical variable to maximize RT-induced hypertrophy. Many of the studies that compared one set of RT with 3 sets have failed to show a difference in muscle hypertrophy in older adults. However, it is not clear whether further increases in RT volume (i.e., 6 sets) would result in even greater RT-related hypertrophy than 3 sets in older adults. This study aimed to investigate whether higher-volume RT (HV-RT) maximizes gains in lean body mass and muscle strength (MS) when compared with lower-volume RT (LV-RT) in postmenopausal women (PW). Fifty-eight PW were randomized into 1 of the 3 groups: control group (CT, no exercise), HV-RT (6 sets per exercise), and LV-RT (3 sets per exercise). Volunteers took part in a supervised training program (leg press 45°, leg extension, leg curl and standing calf raises) and were assessed for leg lean mass (LLM; dual X-ray absorptiometry) and lower limb MS (leg press and leg extension; 1 repetition maximum [1RM]) before and after 12 weeks of RT. Both HV-RT and LV-RT groups increased (p < 0.05) LLM and MS when compared with the CT group. Higher increases in LLM gains were observed for the HV-RT group when compared with the LV-RT group (6.1 and 2.3%, p < 0.001). Both HV-RT and LV-RT groups similarly increased 1RM in the leg press and leg extension. Thus, there seems to be a dose-response relationship between RT volume and muscle hypertrophy, but not for MS gains in PW.

The impact of functional exercise on the reversal of acromegaly induced frailty: a case report

BACKGROUND

Acromegaly is an endocrine disease caused by the excess secretion of growth hormone and is responsible for the development of multiple comorbidities that can reduce physiologic reserve. The hypersecretion of growth hormone (GH) affects virtually every organ in the body and can predispose an individual to frailty; a state of vulnerability resulting from cumulative decline across multiple systems. Frailty results in a loss of physiologic reserve and vulnerability to adverse outcomes such as morbidity and mortality. Case Description: The patient was a 73-year-old male with acromegaly who declined into a cycle of frailty following coronary artery bypass graft (CABG) and aortic valve replacement surgery. Prolonged hospitalization and lack of adequate physical stress led to the depletion of reserve in the cardiopulmonary, cognitive, musculoskeletal, and neuromuscular systems, leaving a previously independent adult fully dependent for mobility. Outcomes: The patient participated in a twelve-week multicomponent physical therapy program in a skilled nursing facility. The exercise program was designed and administered to impact multiple systems and provide the necessary overload for adaptation. The patient demonstrated significant improvement in the Berg Balance Scale (BBS), Tinetti (POMA), Functional Outcome Scale (FOS), and returned to independent community ambulation.. Discussion: The case illustrates the effectiveness of a multicomponent functional-based exercise program to improve markers of frailty and reverse functional decline in a frail older adult with acromegaly.

Low one-repetition-maximum knee extension is significantly associated with poor grip strength, female sex, and various aging-related syndromes

OBJECTIVE

Muscle strength in older adults is usually measured according to grip strength, which demonstrates upper muscle strength only. In this study, we used one-repetition-maximum (1-RM) knee extension as a measure of lower limb strength and assessed its relationship with grip strength and various geriatric syndromes.

METHODS

One hundred outpatients over the age of 65 years were recruited from a geriatric medicine center in India. The 1-RM knee extension was measured along with grip strength. Various geriatric conditions were measured, such as: nutrition (using the Mini Nutritional Assessment), cognition (Hindi Mental State Questionnaire), depression (5-item Geriatric Depression Scale), frailty (Fried and Rockwood models), and osteoporosis (dual-energy X-ray absorptiometry scan). Sarcopenia was diagnosed using the Asian Working Group for Sarcopenia criteria.

RESULTS

The mean age of participants was 72.5 years with 69% of them male. Median values of 1-RM knee extension and grip strength were 2.29 (0.5-10.0) and 17.5 (0-78), respectively. The 1-RM knee extension had moderate correlation with grip strength (r = 0.491, P < 0.001). Among demographic details, only female sex (P < 0.001) was significantly associated with lower 1-RM values. Further, after adjusting for age and sex, lower value of log10 1-RM knee extension was found to be significantly associated with malnutrition (P = 0.001), dementia (P = 0.016), depression (P = 0.047), frailty (Rockwood: P = 0.049; Fried: P = 0.011), and sarcopenia (P < 0.001).

CONCLUSION

The 1-RM knee extension has only moderate correlation with grip strength. A lower 1-RM knee extension value is significantly associated with female sex and various geriatric conditions, such as malnutrition, dementia, depression, frailty, and sarcopenia.

Key Components of Human Myofibre Denervation and Neuromuscular Junction Stability are Modulated by Age and Exercise

The decline in muscle mass and function with age is partly caused by a loss of muscle fibres through denervation. The purpose of this study was to investigate the potential of exercise to influence molecular targets involved in neuromuscular junction (NMJ) stability in healthy elderly individuals. Participants from two studies (one group of 12 young and 12 elderly females and another group of 25 elderly males) performed a unilateral bout of resistance exercise. Muscle biopsies were collected at 4.5 h and up to 7 days post exercise for tissue analysis and cell culture. Molecular targets related to denervation and NMJ stability were analysed by immunohistochemistry and real-time reverse transcription polymerase chain reaction. In addition to a greater presence of denervated fibres, the muscle samples and cultured myotubes from the elderly individuals displayed altered gene expression levels of acetylcholine receptor (AChR) subunits. A single bout of exercise induced general changes in AChR subunit gene expression within the biopsy sampling timeframe, suggesting a sustained plasticity of the NMJ in elderly individuals. These data support the role of exercise in maintaining NMJ stability, even in elderly inactive individuals. Furthermore, the cell culture findings suggest that the transcriptional capacity of satellite cells for AChR subunit genes is negatively affected by ageing.