Evolution of muscle mass and strength in patients admitted for a diabetic foot ulcer

Introduction: After stroke, paralysis reduces muscle strength on the affected side. The lost muscle strength can be partially restored through stroke rehabilitation. However, even if muscle strength is restored, it is not clear whether muscle mass and quality improve. In recent years, it has become possible to measure muscle mass noninvasively using bioelectrical impedance analysis. Additionally, it is known that the phase angle measured by bioelectrical impedance analysis reflects muscle quality. We measured changes in muscle strength, mass, and quality using a hand dynamometer and bioelectrical impedance analysis in patients undergoing rehabilitation after stroke and examined their relationships with activities of daily living (ADLs) improvement. Hypothesis: Post-stroke rehabilitation improves muscle strength, mass, and quality, as well as ADLs. Methods: This retrospective study was performed at two stroke rehabilitation units from January 2017 to March 2019. Muscle mass and quality were assessed using bioelectrical impedance analysis. ADLs were assessed using the functional independence measure (FIM). We measured the grip strength of the non-affected and affected sides as muscle strength. Each measurement was performed at admission and 4 weeks later. We assessed changes in motor FIM items and examined relationships among data. Results and Conclusions: This study included 179 patients (mean age, 75.5±13.0 years; male/female, 89/90; mean duration after stroke, 27.6±8.7 days). Patients received stroke rehabilitation (159.8±21.6 min/day) 7 days a week individually. Muscle strength and quality significantly increased after 4 weeks on both the non-affected and affected sides. Muscle mass decreased, but there was no significant difference. The results were similar when analyzed by sex. Changes in muscle strength and quality were significantly correlated with ADLs improvement (r=0.56 and 0.43, respectively), but muscle mass was not correlated with ADLs improvement. Thus, post-stroke rehabilitation improves muscle strength and quality, as well as ADLs. Muscle mass is not appropriate to measure the effects of stroke rehabilitation, and it is desirable to instead use muscle strength and quality to assess stroke rehabilitation.

BACKGROUND: Corticosteroid use is associated with loss of muscle mass and strength, which is associated with an unfavorable prognosis of the underlying disease, as well as an increased risk of cardiovascular disease. Patients with multiple sclerosis (MS) have a higher baseline susceptibility to cardiovascular disease and a higher risk of adverse effects due to corticosteroid use. In clinical practice, different degrees of severity of side effects of corticosteroids are reported. This may be related to the presence of a genetic predisposition, the identification of which should allow a personalized approach to therapy. AIM: To evaluate the association of polymorphic variants of the glucocorticoid receptor gene NR3C1, the FTO gene, and the melatonin receptor genes MTNR1A, MTNR1B with the development of changes in muscle mass and strength in the context of corticosteroid use in patients with MS. MATERIALS AND METHODS: The study included 80 patients (mean age 36.3±10.0 years) with MS receiving pulse corticosteroid therapy: 4 (3; 4) g methylprednisolone. Patients were enrolled over the course of one year. To assess the primary endpoint (reduction in muscle mass and strength), muscle strength and mass were monitored before and after therapy using wrist dynamometry, the time-up-and-go test, and bioimpedancemetry. Polymorphic variants of the glucocorticoid receptor gene NR3C1, the FTO gene, and the melatonin receptor genes MTNR1A and MTNR1B were identified by real-time polymerase chain reaction. Intergenic interactions were evaluated using the multifactor dimensionality reduction (MDR) method. R (v. 3.2, R Foundation for Statistical Computing, Austria) was used for statistical analysis. RESULTS: In women with loss of muscle mass after corticosteroid therapy, there was an increased incidence of depression (p=0.01) for polymorphic variant BclI (rs41423247) of the NR3C1 gene (p=0.005). Reduced dominant arm strength in women was associated with a variant of the BclI gene (rs41423247) (p=0.02), genotypes including BclI (rs41423247) and N363S (rs56149945) (p=0.03). Men with decreased strength in the non-dominant arm were more likely to be smokers (p=0.03). Combinations of genotypes of the NR3C1, FTO, MTNR1B genes were identified with increased and decreased risk of muscle mass loss in women after corticosteroid therapy. Analysis of intergenic interactions showed a strong synergism between the polymorphic variant rs993960 of the FTO gene and rs10830963 of the MTNR1B gene. CONCLUSION: The presence of polymorphic variants BclI (rs41423247), N363S (rs56149945) of the glucocorticoid receptor gene NR3C1 is associated with loss of muscle strength and mass in women receiving corticosteroid therapy for MS. Combinations of genotypes of the NR3C1, FTO, MTNR1B genes have been identified with an increased risk of muscle mass loss in women after corticosteroid therapy. Modifiable factors associated with loss of muscle mass and strength and cardiovascular risk (depression, smoking) were identified. The data obtained can be used to personalize corticosteroid therapy and prevent cardiovascular and metabolic disorders.

Whether poststroke rehabilitation improves muscle mass and quality along with the recovery of muscle strength is not clear. In this study, we examined the changes in muscle strength, muscle mass, and muscle quality in patients undergoing poststroke rehabilitation and assessed the relationship of these variables with improvement in activities of daily living (ADL). This prospective study was conducted at stroke rehabilitation unit in Japan. Muscle mass and quality were assessed using bioelectrical impedance analysis (BIA). ADLs were assessed using the functional independence measure (FIM). Grip strength of the nonaffected and affected sides was measured using hand dynamometer. All measurements were performed at admission to the stroke rehabilitation unit and at 4 weeks thereafter. We assessed changes in motor FIM items and examined the relationships among the measured variables. This study included 179 patients. Patients received stroke rehabilitation 7 days a week individually. Muscle strength and quality significantly increased after 4 weeks on both the sides. Muscle mass decreased after 4 weeks; however, there was no significant difference between the two time points. Changes in muscle strength and quality showed a significant correlation with improvement in ADLs [r = 0.66 (male), 0.45 (female) and 0.55 (male), 0.31 (female), respectively]; however, muscle mass showed no correlation with improvement in ADLs. Poststroke rehabilitation improves muscle strength and quality, as well as ADLs. Muscle mass is not an appropriate measure to assess the effects of stroke rehabilitation; it is desirable to instead use muscle strength and quality to assess stroke rehabilitation.

Mertz, KH, Reitelseder, S, Rasmussen, MA, Bülow, J, Højfeldt, G, Jensen, M, Hjulmand, M, Lindberg, J, Kramer, MU, Bechshøft, R, and Holm, L. Changes in muscle mass and strength during follow-up after one-year resistance training interventions in older adults. J Strength Cond Res 37(10): 2064-2070, 2023-The aim of this study was to investigate if home-based resistance training compared with center-based resistance training was associated with better preservation of muscle mass and strength in older individuals, 6 months after the interventions ended. One hundred four healthy older individuals (>65 years) who had completed 1 year of either home-based light-intensity training with daily whey protein supplementation (LITW), center-based heavy resistance training with whey protein supplementation (HRTW), or daily whey protein supplementation alone (WHEY) returned for follow-up measurement 6 months after the interventions. Measures of muscle mass, strength, and power were assessed at the end of intervention as well as at follow-up. Furthermore, we compared changes in these parameters between subjects who continued resistance training (≥1 weekly training session) during follow-up (CONT) with those who stopped (STOP). Resistance training continuation during follow-up did not differ between HRTW and LITW (41 vs. 41%, P = 1.0) but was higher for both groups compared with WHEY (18%, P = 0.04-0.05). However, no between-group differences were observed between LITW/HRTW/WHEY in changes in muscle mass, strength, or power during follow-up. STOP was associated with a poorer preservation of quadriceps cross-sectional area compared with CONT (-1.7 cm 2 [-0.4 to -3.0], P = 0.01, effect size: 0.79). No effect of training continuation was observed on changes in muscle strength and power. In conclusion, maintenance of muscle mass and strength is not superior after home-based resistance training compared with center-based training. However, training continuation seems crucial for the maintenance of muscle mass, irrespective of the training intervention.

Engaging in both resistance and endurance exercise within the same training program, termed 'concurrent exercise training,' is common practice in many athletic disciplines that require a combination of strength and endurance and is recommended by a number of organizations to improve muscular and cardiovascular health and reduce the risk of chronic metabolic disease. Dietary protein ingestion supports skeletal muscle remodeling after exercise by stimulating the synthesis of muscle proteins and can optimize resistance exercise-training mediated increases in skeletal muscle size and strength; however, the effects of protein supplementation on acute and longer-term adaptive responses to concurrent resistance and endurance exercise are unclear. The purpose of this systematic review is to evaluate the effects of dietary protein supplementation on acute changes in muscle protein synthesis and longer-term changes in muscle mass, strength, and aerobic capacity in responses to concurrent resistance and endurance exercise in healthy adults. A systematic search was conducted in five databases: Scopus, Embase, Medline, PubMed, and Web of Science. Acute and longer-term controlled trials involving concurrent exercise and protein supplementation in healthy adults (ages 18-65years) were included in this systematic review. Main outcomes of interest were changes in skeletal muscle protein synthesis rates, muscle mass, muscle strength, and whole-body aerobic capacity (i.e., maximal/peak aerobic capacity [VO2max/peak]). The quality of studies was assessed using the National Institute of Health Quality Assessment for Controlled Intervention Studies. Four acute studies including 84 trained young males and ten longer-term studies including 167 trained and 391 untrained participants fulfilled the eligibility criteria. All included acute studies demonstrated that protein ingestion enhanced myofibrillar protein synthesis rates, but not mitochondrial protein synthesis rates during post-exercise recovery after an acute bout of concurrent exercise. Of the included longer-term training studies, five out of nine reported that protein supplementation enhanced concurrent training-mediated increases in muscle mass, while five out of nine studies reported that protein supplementation enhanced concurrent training-mediated increases in muscle strength and/or power. In terms of aerobic adaptations, all six included studies reported no effect of protein supplementation on concurrent training-mediated increases in VO2max/peak. Protein ingestion after an acute bout of concurrent exercise further increases myofibrillar, but not mitochondrial, protein synthesis rates during post-exercise recovery. There is some evidence that protein supplementation during longer-term training further enhances concurrent training-mediated increases in skeletal muscle mass and strength/power, but not whole-body aerobic capacity (i.e., VO2max/peak).

1209 Prior studies have been unable to demonstrate significant relationships between change in muscle mass and change in strength as a result of progressive resistance training (PRT). Methods that measure change in muscle cross-sectional area (CSA) may not be sensitive enough to detect the qualitative changes in muscle mass that may be partly responsible for change in muscle strength. However, methods that measure density such as dual energy x-ray absorptiometry (DEXA) may provide a better assessment of the relationship between change in muscle mass and change in muscle strength. Therefore, we conducted a study to determine whether change in lean mass determined by regional DEXA or change in muscle CSA determined by magnetic resonance imaging (MRI) are better related to change in muscle strength from PRT. As part of a longitudinal AIDS clinical trial, 25 HIV positive men were randomly assigned to receive weekly injections of an anabolic agent (AA, 600mg) alone or in combination with PRT at 80% of the one repetition maximum (1RM) three times weekly for 12 weeks. Muscle strength for leg press was determined by the 1RM method. Lean slice mass (LSM) of the right thigh was measured by DEXA and muscle CSA of the right thigh was measured by MRI at baseline and 12 weeks. Change in muscle CSA by MRI and change in leg press strength were significantly correlated with change in LSM by DEXA (r=0.779, p<0.05 and r=0.720, p<0.05, respectively) in the AA+PRT group, however, these relationships were not significant in the AA alone group. Additionally, change in leg press strength and change in muscle CSA by MRI were not significantly correlated in either group. This data suggests that DEXA and MRI both provide measurement techniques to determine quantitative changes in muscle mass from the combined anabolic and PRT regimen. However, regional DEXA analysis may provide a better assessment of qualitative change in muscle mass as it relates to strength gains from PRT.

Adults with GH deficiency (GHD) suffer from muscle weakness, which can be caused by the frequently reported decrease in muscle mass. However, measurements of both muscle strength and mass of muscle tested are scarce in adults with GHD. The aim of the present study was, therefore, to investigate intrinsic muscle strength (strength expressed per muscle volume unit) in adults with GHD at baseline and after 52 weeks of recombinant human GH (rhGH) therapy given in low, more physiological doses. A second objective was to investigate the influence of GH on muscle bioenergetics in the resting muscle. Isometric and isokinetic quadriceps strengths were measured in 28 males with GHD and in healthy controls matched for age and height. Quadriceps mass, determined by magnetic resonance imaging, and muscle bioenergetics, determined by phosphorus nuclear magnetic resonance spectroscopy, were measured in 20 of 28 patients with GHD and in controls matched for age and height. All patients were treated with doses of rhGH ranging from 0.6-1.8 IU/day, given for 52 weeks. Measurements of muscle mass, strength, and bioenergetics were repeated after 52 weeks of treatment with rhGH. The mean GH dose at 52 weeks of rhGH treatment was 1.3 +/- 0.8 IU/day. The mean serum insulin-like growth factor I level at baseline was 9.4 +/- 0.7 nmol/L and significantly increased to 26.4 +/- 1.2 nmol/L after 52 weeks of rhGH treatment. Adults with GHD had significantly reduced quadriceps muscle mass (P = 0.034) and reduced isometric muscle strength (P = 0.002) and tended to have low isokinetic muscle strength (P = 0.06), which all improved after rhGH therapy. Intrinsic muscle strength was not significantly different in adults with GHD compared with that in healthy controls and did not change during rhGH therapy. No bioenergetic abnormalities at baseline or after rhGH therapy were found in males with GHD. In conclusion, quadriceps muscle mass is decreased in adults with GHD and increased with rhGH therapy. These changes in muscle mass account for the changes in muscle strength found in these patients, as no changes in intrinsic muscle strength were found.

Hip fracture in elderly persons has a serious impact on long-term physical function. This study determines the change in muscle strength and muscle mass after a hip fracture, and the associations between these changes and mobility recovery. Ninety community-dwelling women aged 65 years and older who had recently experienced a fracture of the proximal femur were included in the study. At 2 to 10 days after hospital admission, the women's grip strength, ankle dorsiflexion strength, and regional muscle mass (by dual-energy x-ray absorptiometry) were measured, and the prefracture level of independence for five mobility function items was assessed. All measurements were repeated at 12 months. At follow-up, only 17.8% of the women had returned to their prefracture level of mobility function for all five items. Mobility function recovery was not related to change in skeletal muscle mass of the nonfractured leg or the arms. However, women who lost grip strength (mean loss of -28.7%, SD = 16.9%), or who lost ankle strength of the nonfractured leg (mean loss of -21.5%, SD = 14.7%), had a worse mobility recovery compared with those who gained strength (p = .04 and p = .09, respectively). In addition, chronic disease (p = .03), days hospitalized (p = .04), and self-reported hip pain (p = .07) were independent predictors of decline in mobility function. The results suggest that loss of muscle strength, but not loss of muscle mass, is an independent predictor of poorer mobility recovery 12 months after a hip fracture. When confirmed by other studies, these findings may have implications for rehabilitation strategies after a hip fracture.

Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Amsterdam UMC. Background Maintenance of muscle strength and muscle mass is important for long-term health. Periods of physical inactivity and poor dietary intake (e.g. waiting for a medical procedure) can provoke loss of muscle strength and muscle mass. Purpose We aim to determine the course of muscle strength and muscle mass in patients with severe aortic stenosis from before until six months after an elective transcatheter aortic valve implantation (TAVI). Moreover, we aim to explore baseline characteristics associated with change. Methods All patients undergoing an elective TAVI in our high-volume tertiary center were asked to participate. Included patients received three home visits (pre-procedural and 30 days and 6 months post-procedural). During these home visits, handgrip strength was measured with a handheld dynamometer. Muscle mass was determined as skeletal muscle index with a bioelectrical impedance (BIA) measurement. Multivariate mixed linear models were used to determine changes over time. A linear model adjusted for age and sex was performed to explore baseline characteristics associated with changes in muscle strength or muscle mass. Results In total 112 patients were included, mean age of the participants was 81 ± 5 years and 58% were male. The preprocedural measurement took place on a median of 48 [IQR: 19 – 79] days before the TAVI. Preprocedural handgrip strength was on average 36 kg for male and 24 kg for female patients and decreased after the TAVI (-0.12 [95% CI: -0.21, -0.02] kg/month, p=0.02). Living alone and lower hemoglobin level were predictive for a higher decrease in strength (β -2.20 [95% CI: -3.98, -0.42], p=0.02 and β 0.14 [95% CI: 0.02, 0.27] per mmol/l, p=0.03, respectively). Appendicular skeletal muscle index was 7.2 kg/m2 for males and 6.1 kg/m2 for females and did not change after TAVI (0.00 [95%CI: -0.01, 0.01] kg/m2/month, p=0.95). No baseline characteristics were associated with a change in muscle mass. Conclusion Muscle strength significantly declines and muscle mass remains the same from before until six months after the TAVI procedure. Patients living alone or patients with low hemoglobin levels are at increased risk to lose muscle strength. Future studies should focus on the prevention of strength loss, for instance with interventions focusing on nutrition and exercise around the TAVI procedure.

Background and objectiveThe benefits of weight reduction for musculoskeletal disorders are well understood. Steep declines in muscle mass following considerable weight reduction can decrease muscle strength and, consequently, physical performance. However, only a limited number of studies have examined the changes in muscle mass and strength in the context of interventional weight reduction programs. Thus, we investigated the influence of muscle mass decrease caused by diet-induced weight reduction on muscle strength in obese men.MethodsA total of 24 men with obesity (body mass index [BMI]: 29.2 ± 2.6 kg/m2; age: 52.4 ± 10.0 years) attended a 12-week weight reduction program that implemented dietary restrictions. Each participant underwent assessments of body weight (by a digital scale), body composition (by whole-body dual-energy X-ray absorptiometry [DEXA]), and upper and lower extremity muscle strength (by a hand-held dynamometer and a Biodex System 3 dynamometer, respectively) before and after the program.ResultsThe program led to significant reductions of 10.5% of weight and 6.1% of lower extremity muscle mass. Similarly, lower extremity muscle strength (measured using a Biodex System 3 dynamometer) was significantly decreased (isometric 60° peak torque decreased by 10% and isokinetic 60°/s peak torque decreased by 9.4%); however, the level of body weight-normalized lower extremity muscle strength did not significantly change (increased by +1.2% and +1.4%). The decrease in muscle strength was related to but did not entirely depend on decrease in muscle mass. Although handgrip strength did not significantly differ (−2.2%), the weight-normalized level of this parameter significantly improved (+9.1%). In addition, decrease in the percentage of whole-body fat mass and increase in the percentage of muscle mass index were observed.ConclusionWe recommend performing exercise after diet-induced weight reduction to regain muscle mass and strength and improve body weight-normalized lower extremity muscle strength.

BackgroundMalnutrition, low muscle strength and muscle mass are highly prevalent in older hospitalized patients and associated with adverse outcomes. Malnutrition may be a risk factor for developing low muscle mass. We aimed to investigate the association between the risk of malnutrition and 1) muscle strength and muscle mass at admission and 2) the change of muscle strength and muscle mass during hospitalization in older patients.MethodsThe EMPOWER study included 378 patients aged seventy years or older who were acutely or electively admitted to four different wards of an academic teaching hospital in Amsterdam. Patients were grouped into low risk of malnutrition and high risk of malnutrition based on the Short Nutritional Assessment Questionnaire (SNAQ) score and were assessed for hand grip strength and muscle mass using hand held dynamometry respectively bioelectrical impedance analysis (BIA) within 48 h after admission and at day seven, or earlier at the day of discharge. Muscle mass was expressed as skeletal muscle mass, appendicular lean mass, fat free mass and the skeletal muscle index.ResultsThe mean age of the patients was 79.7 years (SD 6.39), 48.9% were female. At admission, being at high risk of malnutrition was significantly associated with lower muscle mass (Odds Ratio, 95% CI, 0.90, 0.85–0.96), but not with muscle strength. Muscle strength and muscle mass did not change significantly during hospitalization in both groups.ConclusionIn older hospitalized patients, a high risk of malnutrition is associated with lower muscle mass at admission, but not with muscle strength nor with change of either muscle strength or muscle mass during hospitalization.

The effect of a controlled 8-week metabolic ward based lysine supplementation on muscle function, insulin sensitivity and leucine kinetics in young men

IntroductionSarcopenia is generally used to describe the age-related loss of muscle mass and strength believed to play a major role in the pathogenesis of physical frailty and functional impairment that...

aging process is associated with changes in muscle mass and strength with decline of muscle strength after the 30(th) life year. The aim of this study was to investigate these changes in muscle mass and strength. for this analysis 26 participants were subdivided in two groups. Group 1 comprises participants aged <40 years (n=14), group 2 those >40 years (n=12). We assessed anthropometrics, range of motions, leg circumferences and isometric strength values of the knee joints. besides comparable anthropometrics, circumferences and strength were higher in group 1 than in group 2. Circumference of upper leg (20 cm above knee articular space) showed for right leg a trend to a significant (median: 54.45 cm (1(st) quartile: 49.35/3(rd) quartile: 57.78) vs 49.80 cm (49.50/50.75), p=0.0526) and for left leg a significant 54.30 cm (49.28/58.13) vs 49.50 cm (48.00/52.53), p=0.0356) larger circumference in group 1. Isometric strength was in 60° knee flexion significantly higher in group 1 than in group 2 for right (729.88N (561.47/862.13) vs 456.92N (304.67/560.12), p=0.00448) and left leg (702.49N (581.36/983.87) vs 528.49N (332.95/648.58), p=0.0234). aging process leads to distinct muscle mass and strength loss. Muscle strength declines from people aged <40 years to those >40 years between 16.6% and 40.9%.

ObjectivesAcute hospitalization may lead to a decrease in muscle measures, but limited studies are reporting on the changes after discharge. The aim of this study was to determine longitudinal changes in muscle mass, muscle strength, and physical performance in acutely hospitalized older adults from admission up to 3 months post-discharge. DesignA prospective observational cohort study was conducted. Setting and ParticipantsThis study included 401 participants aged ≥70 years who were acutely hospitalized in 6 hospitals. All variables were assessed at hospital admission, discharge, and 1 and 3 months post-discharge. MethodsMuscle mass in kilograms was assessed by multifrequency Bio-electrical Impedance Analysis (MF-BIA) (Bodystat; Quadscan 4000) and muscle strength by handgrip strength (JAMAR). Chair stand and gait speed test were assessed as part of the Short Physical Performance Battery (SPPB). Norm values were based on the consensus statement of the European Working Group on Sarcopenia in Older People. ResultsA total of 343 acute hospitalized older adults were included in the analyses with a mean (SD) age of 79.3 (6.6) years, 49.3% were women. From admission up to 3 months post-discharge, muscle mass (−0.1 kg/m2; P = .03) decreased significantly and muscle strength (−0.5 kg; P = .08) decreased nonsignificantly. The chair stand (+0.7 points; P < .001) and gait speed test (+0.9 points; P < .001) improved significantly up to 3 months post-discharge. At 3 months post-discharge, 80%, 18%, and 43% of the older adults scored below the cutoff points for muscle mass, muscle strength, and physical performance, respectively. Conclusions and ImplicationsPhysical performance improved during and after acute hospitalization, although muscle mass decreased, and muscle strength did not change. At 3 months post-discharge, muscle mass, muscle strength, and physical performance did not reach normative levels on a population level. Further research is needed to examine the role of exercise interventions for improving muscle measures and physical performance after hospitalization.