Lower Extremity Muscle Mass Research Articles

Relationship between floating toes condition and lower limb muscle weight in 8-year-old children: the Yamanashi adjunct study of the Japan Environment and Children's Study (JECS-Y).

[Purpose] Floating toe is a condition in which the toes make insufficient contact with the ground. Weak muscle strength is reportedly one cause of floating toe. However, little evidence exists regarding the relationship between foot muscle strength and floating toe. Here we examined the relationship between foot muscle strength and floating toe by investigating the children' lower extremity muscle mass and floating toe conditions. [Participants and Methods] This cohort study enrolled 118 8-year-old children (62 females, 56 males) with recorded footprints and muscle mass evaluations using dual-energy X-ray absorptiometry. We calculated the floating toe score using the footprint. We measured the muscle weights and the muscle weights divided by the lengths of the lower limbs separately on the left and right sides using dual-energy X-ray absorptiometry. [Results] No significant correlations were observed between the floating toe score and muscle weights or muscle weights divided by lower-limb lengths for either gender or side. [Conclusion] In this study, no significant correlation was found between floating toe degree and lower limb muscle mass, suggesting that lower limb muscle strength is not the primary cause of floating toe, at least in children.

Effects of an 8-week lunge exercise on an unstable support surface on lower-extremity muscle function and balance in middle-aged women.

This study aimed to develop a more effective exercise program for lower extremity muscle function by evaluating the effects of an 8-week lunge exercise performed on an unstable support surface on lower extremity muscle function, body composition, and body balance in middle-aged women. Twenty participants were divided into two groups (control group: exercise on a stable support surface, n=10; experimental group: exercise on an unsta ble support surface, n=10). Each participant performed the exercise program for 8 weeks (three sessions a week, 50 min/session). The results revealed that body fat percentage decreased significantly in the experimental group (p<0.01). Additionally, lower-extremity muscle mass and function increased significantly in both groups (p<0.05), but with no significant difference between the groups. Moreover, the results of the static and dynamic balance tests indicated that balance improved in both groups, with significantly greater improvements in the experimental group than in the control group (p<0.05). Lunge exercise on stable and unstable support surfaces improves muscle function and static balance in middle-aged women. In particular, lunge exercise on an unstable support surface was more effective at reducing body fat than lunge exercise on a stable support surface and was also found to improve dynamic balance. Therefore, a program consisting of lunge exercises on an unstable support surface may be suitable for body improvements in middle-aged women.

Efficacy of Exercise on Muscle Function and Physical Performance in Older Adults with Sarcopenia: An Updated Systematic Review and Meta-Analysis.

This study aimed to analyze the efficacy of exercise interventions on muscle strength, muscle mass, and physical performance in older adults with sarcopenia. Randomized controlled studies assessing exercise effects on sarcopenia were searched in Web of Science, PubMed, Cochrane Library, ProQuest, EBSCOhost, Scopus, EMBASE, and VIP and CNKI up to 31 March 2022. Data were expressed as weighted/standardized mean difference (MD/SMD) with 95% confidence intervals (CI). I2 index was employed for heterogeneity. The initial search identified 5379 studies, and 23 studies involving 1252 participants met the inclusion criteria for further analysis. Results revealed that exercise interventions can significantly improve grip strength (MD = 2.38, 95%CI = 1.33–3.43), knee extension strength (SMD = 0.50, 95%CI = 0.36–0.64), muscle mass of lower extremities (MD = 0.28, 95%CI = 0.01–0.56), walking speed (SMD = 0.88, 95%CI = 0.49–1.27), and functional mobility (MD = −1.77, 95%CI = −2.11–−1.42) among older adults with sarcopenia. No significant exercise effects were found on fat-free muscle mass, appendicular muscle mass, skeletal muscle mass, and muscle mass of the upper extremities. The results of subgroup analysis indicated that both resistance training and multicomponent exercise could significantly increase the muscle strength, while aerobic exercise did not. The findings suggest that exercise intervention can effectively improve muscle function and physical performance in older adults with sarcopenia, but has limited effects on the muscle mass of the upper extremities. In addition, it is highly recommended to apply group-based and supervised resistance training and multicomponent exercise in the prevention and treatment of sarcopenia among the older population.

Correlation between hand grip strength and regional muscle mass in older Asian adults: an observational study

BackgroundPrevious research has demonstrated a correlation between hand grip strength (HGS) and muscle strength. This study aims to determine the relationship between HGS and muscle mass in older Asian adults.MethodsWe retrospectively reviewed the dual-energy X-ray absorptiometry (DXA) records of 907 older adults (239 (26.4%) men and 668 (73.6%) women) at one medical institution in Taipei, Taiwan, from January 2019, to December 2020. Average age was 74.80 ± 9.43 and 72.93 ± 9.09 for the males and females respectively. The inclusion criteria were: 1) aged 60 and older, 2) underwent a full-body DXA scan, and 3) performed hand grip measurements. Patients with duplicate results, incomplete records, stroke history, and other neurological diseases were excluded. Regional skeletal muscle mass was measured using DXA. HGS was measured using a Jamar handheld dynamometer.ResultsTotal lean muscle mass (kg) averaged 43.63 ± 5.81 and 33.16 ± 4.32 for the males and females respectively. Average HGS (kg) was 28.81 ± 9.87 and 19.19 ± 6.17 for the males and females respectively. In both sexes, HGS and regional muscle mass consistently declined after 60 years of age. The rates of decline per decade in upper and lower extremity muscle mass and HGS were 7.06, 4.95, and 12.30%, respectively, for the males, and 3.36, 4.44, and 12.48%, respectively, for the females. In men, HGS significantly correlated with upper (r = 0.576, p < 0.001) and lower extremity muscle mass (r = 0.532, p < 0.001). In women, the correlations between HGS and upper extremity muscle mass (r = 0.262, p < 0.001) and lower extremity muscle mass (r = 0.364, p < 0.001) were less strong, though also statistically significant.ConclusionMuscle mass and HGS decline with advancing age in both sexes, though the correlation is stronger in men. HGS measurements are an accurate proxy for muscle mass in older Asian adults, particularly in males.

Fish Protein Ingestion Induces Neural, but Not Muscular Adaptations, Following Resistance Training in Young Adults.

Purpose: Nutritional supplementation in conjunction with exercise is of interest for the prevention or improvement of declines in motor performances in older adults. An understanding of the effects on both young and older adults contributes to its effective application. We investigated the effect of fish protein ingestion with resistance training on neural and muscular adaptations in young adults using interventions and assessments that have already been tested in older adults.Methods: Eighteen young adults underwent 8 weeks of isometric knee extension training. During the intervention, nine participants ingested 5 g of fish protein (n = 9, Alaska pollack protein, APP), and the other nine participants ingested casein as a control (n = 9, CAS) in addition to daily meals. Before, during, and after the intervention, the isometric knee extension force, lower extremity muscle mass, and motor unit firing pattern of knee extensor muscles were measured.Results: Maximum voluntary contraction (MVC) was significantly increased in both APP and CAS groups from 0 weeks to 4, 6, and 8 weeks of intervention (p < 0.001), but there were no significant differences between the groups (p = 0.546–0.931). Muscle mass was not significantly changed during the intervention in either group (p = 0.250–0.698). Significant changes in motor unit firing rates (p = 0.02 and 0.029 for motor units recruited at 20–40% of MVC and at 40–60%) were observed following the intervention in the APP but not CAS (p = 0.120–0.751) group.Conclusions: These results suggest that dietary fish protein ingestion changes motor unit adaptations following resistance training in young adults.

Knee effusion evaluated by ultrasonography warns knee osteoarthritis patients to develop their muscle atrophy: a three-year cohort study

This study aimed to elucidate the relationship between the quantitative value of suprapatellar effusion and the longitudinal changes in lower-extremity muscle mass (MM) in a cohort with knee osteoarthritis (KOA). Fifty-three subjects (106 legs) with bilateral radiographic KOA at baseline (BL) were enrolled. MM was calculated by bioimpedance analysis three times at BL, and at the one-year (1Y) and three-year (3Y) follow-ups. The longitudinal change in the lower-extremity MM was calculated by subtracting MMBL from MM1Y, and MM1Y from MM3Y. Subjects with ≥1.0 z-score loss were defined as having severe MM loss (SMML). Effusion was evaluated as the sagittal area of suprapatellar pouch (mm2) by ultrasonography. The ROC curve was drawn to determine the cut-off of effusion area. General estimating equations (GEEs) were conducted with the prevalence of SMML as the dependent variable and with the cut-off of effusion area as the independent variable. Sixteen legs (15.1%) demonstrated SMMLBL-1Y and another sixteen legs demonstrated SMML1Y-3Y. GEEs revealed that individuals with ≥90 mm2 effusion had significantly higher odds of SMMLBL-1Y prevalence (Odds ratio: 21.561; P-value: 0.003). Individuals with leachate knee effusion at BL had a significant risk of losing MM through the first year of the initial knee effusion assessment.

Study on the relationship between vitamin D, grip strength and muscle mass in elderly diabetic patients

Objective To study the relationship between vitamin D level and muscle mass and grip strength in elderly patients with type 2 diabetes mellitus (T2DM). Methods From May 2016 to January 2018, 201 patients with type 2 diabetes mellitus aged ≥ 60 who were admitted to the Department of endocrinology of Xuanwu Hospital were selected for prospective study. According to 25-hydroxyvitamin D level(25(OH)D), the patients were divided into the vitamin D deficiency group (25(OH)D<20 μg/L, 140 cases) and the non-deficiency group (20 μg/L≤25(OH)D<70 μg/L, 61 cases). The grip strength, walking speed and muscle mass of upper and lower limbs were measured.Physical examination and laboratory examination were carried out. Results There was no significant difference between the two groups (P>0.05). The grip strength, upper limb and lower limb muscle contents in the non deficiency group were significantly higher than those in the deficiency group ((33.49±9.43) kg vs.(29.59±10.30) kg, (4.99±1.09) kg vs.(4.57±1.11) kg, (15.69±3.10) kg vs.(14.54±3.03) kg, P=0.01, 0.015, 0.017). Multivariate logistic regression analysis showed that vitamin D deficiency was independently related to grip strength and lower limb muscle mass(OR=1.286, 95% CI: 1.197-1.346, P<0.01; OR=1.231, 95%CI: 1.102-1.283, P<0.05). Conclusion Vitamin D deficiency is a risk factor for the decrease of grip strength and lower extremity muscle mass in elderly patients with type 2 diabetes. Key words: Type 2 diabetes; Vitamin D; Grip; Muscle mass

Association between asymmetry in lower extremity lean mass and functional mobility in older adults living in the community: Results from the Korean Frailty and Aging Cohort Study.

The asymmetry in lower extremity strength is known to be related to the functional mobility in older adults living in the community. However, little is known about the association between lower extremity lean mass asymmetry and functional mobility in this patient group. Hence, this study aimed to determine whether asymmetry in lower extremity muscle mass has a significant relationship with functional mobility in older adults living in the community.This cross-sectional study analyzed the pre-existing data from the Korean Frailty and Aging Cohort Study. A total of 435 older people (aged 70–84 years) were divided into the following groups according to their Limb Asymmetry Index (LAsI): low, intermediate, and high asymmetric groups. LAsI is calculated using lower extremity lean mass, and comparisons between groups were conducted. The participants were also further divided into better and worse mobility groups based on their physical performance test results (Timed Up and Go and Short Physical Performance Battery), and comparisons between groups were conducted. Comparisons between fallers and non-fallers were also conducted. In addition, this study investigated the factors that had a significant effect on gait speed and fall experience within the past year among older adults living in the community.The LAsI was significantly associated with gait speed in older adults living in the community. Older adults in the highest tertile of the LAsI had a slower gait speed than those in the lowest tertile of the LAsI. However, no significant difference was observed in the LAsI between the better mobility group and worse mobility group. Moreover, the LAsI was not a significant predictor of falls.Asymmetry in lower extremity lean mass was significantly associated with gait speed in older adults living in the community.

Modulation of Neural and Muscular Adaptation Processes During Resistance Training by Fish Protein Ingestions in Older Adults.

Assessments of both neural and muscular adaptations during interventions would provide valuable information for developing countermeasures to age-related muscle dysfunctions. We investigated the effect of fish protein ingestion on training-induced neural and muscular adaptations in older adults. Twenty older adults participated 8 weeks of isometric knee extension training intervention. The participants were divided into two groups who took fish protein (n = 10, Alaska pollack protein, APP) or casein (n = 10, CAS). Maximal muscle strength during knee extension, lower extremity muscle mass (body impedance method), and motor unit firing pattern of knee extensor muscle (high-density surface electromyography) were measured before, during, and after the intervention. Muscle strength were significantly increased in both CAS (124.7 ± 5.8%) and APP (117.1 ± 4.4%) after intervention (p < .05), but no significant differences between the groups were observed (p > .05). Significant increases in lower extremity muscle mass from 0 to 8 weeks were demonstrated only for APP (102.0 ± 3.2, p < .05). Greater changes in motor unit firing pattern following intervention were represented in CAS more than in APP. These results suggest that nutritional supplementations could modulate neural and muscular adaptations following resistance training and fish protein ingestion preferentially induces muscular adaptation without the detectable neural adaptation in older adults.

Rhodiola/Cordyceps-Based Herbal Supplement Promotes Endurance Training-Improved Body Composition But Not Oxidative Stress and Metabolic Biomarkers: A Preliminary Randomized Controlled Study.

Rhodiola crenulata (R) and Cordyceps sinensis (C) are commonly used herbs that promote health in traditional Chinese medicine. These two herbs have also been shown to exhibit anti-inflammation and antioxidant functions. Regular endurance training reveals potent endurance capacity, body composition improvement, and metabolic-related biomarker benefits. However, it is not known whether the combination of Rhodiola crenulata and Cordyceps sinensis (RC) supplementation during endurance training provides additive health benefits. The purpose of this study was to investigate the effects of 8-week endurance training plus RC supplementation on body composition, oxidative stress, and metabolic biomarkers in young sedentary adults. Methods: Fourteen young sedentary adults (8M/6F) participated in this double-blind randomized controlled study. Participants were assigned to exercise training with placebo groups (PLA, n = 7, 4M/3F; age: 21.4 ± 0.4 years) and exercise training with the RC group (RC, 20 mg/kg/day; n = 7, 4M/3F; age: 21.7 ± 0.4 years). Both groups received identical exercise training for eight weeks. The body composition, circulating oxidative stress, and blood metabolic biomarkers were measured before and after the 8-week intervention. Results: Improvement in body composition profiles were significantly greater in the RC group (body weight: p = 0.044, BMI: p = 0.003, upper extremity fat mass: p = 0.032, lower extremity muscle mass: p = 0.029, trunk fat mass: p = 0.011) compared to the PLA group after training. The blood lipid profile and systemic oxidative stress makers (thiobarbituric reactive substanceand total antioxidant capacity) did not differ between groups. Although endurance training markedly improved endurance capacity and glycemic control ability (i.e., fast blood glucose, insulin, and HOMA index), there were no differences in these variables between treatments. Conclusions: In this preliminary investigation, we demonstrated that an 8-week RC supplementation (20 mg/kg/day) faintly enhanced endurance training-induced positive adaptations in body composition in young sedentary individuals, whereas the blood lipid profile and systemic oxidative stress states were not altered after such intervention.

P2657Prognostic impact of skeletal muscle mass in upper and lower extremities in patients with ST-segment elevation myocardial infarction

Abstract Introduction Sarcopenia, characterized by the loss of skeletal muscle mass and muscle strength, has been demonstrated the importance in cardiovascular diseases including ST-segment elevation myocardial infarction (STEMI). However, there is few data comparing the effects on the prognosis of skeletal muscle mass of upper and lower extremities in STEMI patients. Purpose Our purpose was to examine whether skeletal muscle mass of upper and lower extremities affect the prognosis after STEMI. Methods A total of 432 patients with STEMI were enrolled in this study. Dual-energy X-ray absorptiometry scan was performed before discharge. Each of upper and lower extremity skeletal muscle masses was indexed by height squared (kg/m2), and divided into two groups using the first quartile value for each sex. All patients were followed up for the primary composite outcome of all-cause death, nonfatal myocardial infarction, nonfatal ischemic stroke, hospitalization for congestive heart failure, and unplanned revascularization. Results During a median follow-up of 32 months, 68 patients experienced primary composite outcome. The event rate was significantly higher in patients with low-lower extremity skeletal muscle mass index (LESMI) than in those with high-LESMI (24.3% vs 12.9%, log-rank p&lt;0.001), as well as in those with low-upper extremity muscle mass index than in those with high-upper extremity muscle mass index (UESMI) (19.6% vs 14.5%, log-rank p=0.047). However, after adjustment for age, gender, renal function, diabetes mellitus, infarct size, body mass index, and body fat percentage, only low-LESMI was independently and significantly associated with the primary composite outcome (adjusted hazard ratio for LESMI 2.11, 95%-confidence interval 1.06–4.14, p=0.034, adjusted hazard ratio for UESMI 1.04, 95%-confidence interval 0.52–2.08, p=0.906,). Conclusions Decreased muscle mass of lower extremity, rather than upper extremity, might have prognostic impact in patients with STEMI.

Is Evaluation of Lower Extremity Muscle Mass Important Before Thoracic Surgery?

Is Evaluation of Lower Extremity Muscle Mass Important Before Thoracic Surgery?

Whole-body vibration in children with disabilities demonstrates therapeutic potentials for pediatric cancer populations: a systematic review

Low levels of physical activity often observed in pediatric oncology might be attributed to various functional deficits, especially those of the lower limbs as these affect gait, mobility, and, consequently, physical activity. In the past few years, whole-body vibration (WBV) has emerged as a new therapy modality for improving physical functioning. Although WBV is increasingly applied in children with disabilities, its impact on lower limb function in pediatric cancer patients and survivors has not yet been investigated. To establish whether there is evidence that WBV may be beneficial for pediatric cancer patients and survivors, this review summarizes current data on WBV studies among children with disabilities and extracts relevant information for the pediatric cancer population. Two independent reviewers performed a systematic literature search following the PRISMA guidelines. Nine studies were included in the analysis. Results demonstrate that WBV is a safe, highly compliant, and effective approach in cohorts of children with disabilities. The largest effects of WBV were observed in lower extremity muscle mass and strength, balance control, gait, and walking ability. Furthermore, we were able to develop first recommendations for WBV protocols. WBV seems to be feasible and effective for improving parameters that may be relevant to the pediatric cancer population. Efforts are needed to conduct first WBV interventions in children with cancer proving the effects. The developed recommendations for WBV protocols might help to implement these intervention studies.

Bioelectrical Impedance Analysis Results for Estimating Body Composition Are Associated with Glucose Metabolism Following Laparoscopic Sleeve Gastrectomy in Obese Japanese Patients.

We investigated the association between body composition and changes in glucose metabolism following laparoscopic sleeve gastrectomy (LSG) in obese Japanese patients. Thirty-two Class III obese patients were assessed before LSG and 3, 6, and 12 months postoperatively. Variables including fat mass (FM), % body fat (%FM), total and skeletal muscle mass (MM), the ratio of lower extremity MM to body weight (BW) (L/W), and the ratio of upper extremity MM to BW (U/W) were measured while using bioelectrical impedance analysis (BIA). LSG significantly decreased BW, FM, and %FM in all time periods observed after surgery with concomitant improvements in metabolic markers. MM was decreased at three months but maintained from 3–12 months post-surgery. Importantly, %MM, U/W, and the L/W ratio increased after LSG. Furthermore, change in FM was positively correlated with change in BW 12 months after LSG, whereas changes in %MM were negatively correlated with fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c). Finally, multivariable stepwise regression analyses showed that changes in % total MM was an independent determinant of FPG and change in % skeletal MM was a significant independent determinant of HbA1c in Class III obese Japanese patients after LSG.

Relationship between decreased lower extremity muscle mass and knee pain severity in both the general population and patients with knee osteoarthritis: Findings from the KNHANES V 1-2.

ObjectiveTo identify the prevalence of and risk factors for knee pain and radiographic knee osteoarthritis (RKOA) and to investigate the relationship between decreased lower extremity muscle mass (DLEM) and knee pain severity.MethodsUsing data from the Korea National Health and Nutrition Examination Survey, 3,278 participants who were ≥50 years old and who underwent dual x-ray absorptiometry, plain knee radiographs and completed a knee pain questionnaire were enrolled. Lower extremity muscle mass (LEM) was defined as the sum of the fat-free soft tissue mass of the legs, and lower extremity muscle mass index (LMI) was calculated as LEM/body weight (%). DLEM was defined as an LMI more than two standard deviations below the mean of a gender-matched young reference group. Categorical variables were presented as numbers (weighted %).ResultsThe prevalence of knee pain and RKOA were 22% (n = 721) and 34.7% (n = 1,234), respectively. Multivariate logistic regression analysis showed being female (OR 2.15, 95% CI 1.67–2.79), older (OR 1.03, 95% CI 1.01–1.04), less educated (OR 1.72, 95% CI 1.09–2.71), stiffness (OR 16.15, 95% CI 12.04–21.66), bed rest (OR 2.49, 95% CI 1.81–3.43), RKOA (OR 2.20, 95% CI 1.78–2.74) and DLEM (OR 1.54, 95% CI 1.09–2.17) were associated with knee pain. Participants with simultaneous RKOA and DLEM complained of more severe pain (pain score 7.18 ± 2.48) than those with knee pain without RKOA or DLEM (5.02 ± 2.44), those with only RKOA (6.29 ± 2.50), or those with only DLEM (6.78 ± 2.18) (P<0.001). These results remained after multivariate analyses of variance (MANOVAs).ConclusionThe prevalence of knee pain and RKOA were 22% and 34.7%, respectively, in the general Korean population. DLEM was an independent risk factor for knee pain and it was associated with increased pain severity, regardless of RKOA.

Reliability of a device for the knee and ankle isometric and isokinetic strength testing in older adults.

Lower extremity muscle mass, strength, power, and physical performance are critical determinants of independent functioning in later life. Isokinetic dynamometers are becoming very common in assessing different features of muscle strength, in both research and clinical practice; however, reliability studies are still needed to support the extended use of those devices. The purpose of this study is to assess the test-retest reliability of knee and ankle isokinetic and isometric strength testing protocols in a sample of older healthy subjects, using a new and untested isokinetic multi-joint evaluation system. Sixteen male and fourteen female older adults (mean age 65.2 ± 4.6 years) were assessed in two testing sessions. Each participant performed a randomized testing procedure that includes different isometric and isokinetic tests for knee and ankle joints. All participants concluded the trial safety and no subject reported any discomfort throughout the overall assessment. Coefficients of correlation between measures were calculated showing moderate to strong effects among all test-retest assessments and paired-sample t test showed only one significant difference (p<0.05) in the maximal isokinetic bilateral knee flexion torque. The multi-joint evaluation system for the assessment of knee and ankle isokinetic and isometric strength provided reliable test-retest measures in healthy older adults. Ib.

Lower thigh muscle mass is associated with all-cause and cardiovascular mortality in elderly hemodialysis patients.

Higher body mass index appears protective in hemodialysis patients, although it remains to be determined which component of muscle or fat mass is primarily associated with this survival advantage. Eighty-one hemodialysis patients in our institution were prospectively followed from July 2011 to August 2015. Muscle and fat mass were evaluated by measuring the cross-sectional areas of the thigh and abdomen using computed tomography. The relationship between muscle and fat mass, and all-cause and cardiovascular mortality was studied using the Kaplan-Meier analyses and multivariate Cox proportional hazard models. During more than 4 years of follow-up, 26 patients (32%) died. In the Kaplan-Meier curve analyses, lower thigh muscle mass was significantly associated with all-cause and cardiovascular mortality (log-rank test, P<0.01 and P<0.001, respectively), but there was no such association with thigh fat, abdominal muscle and fat mass levels. In multivariate Cox proportional hazard models, each 0.1 cm2/kg increase in the thigh muscle area adjusted by dry weight was associated with an estimated 22% lower risk of all-cause mortality (95% confidence interval (95% CI), 0.64-0.95, P<0.05) and a 30% lower risk of cardiovascular mortality (95% CI, 0.54-0.90, P<0.01). Lower thigh muscle mass is significantly associated with all-cause and cardiovascular mortality in hemodialysis patients. Our findings indicate the importance of focusing on the muscle mass of lower extremities to predict the clinical outcomes of hemodialysis patients.

The association between the body composition and lifestyle affecting pulmonary function in Japanese workers.

[Purpose] The purpose of this study was to identify factors related to physical characteristics and lifestyle that affect pulmonary function. [Subjects and Methods] Ninety seven healthy male workers were recruited for this study, and basic information and details about lifestyle were collected. Body composition analyzer and visceral fat measuring device were conducted as measurements. Pulmonary function was measured using spirometer. A multiple stepwise linear regression analysis was performed with pulmonary function as the dependent variable. Variables with a significant association with pulmonary function on univariate analysis were imputed as independent variables. [Results] Height, fat free mass, upper extremity muscle mass, lower extremity muscle mass, and trunk muscle mass had significant positive correlations with FEV1 and FVC. Age, percentage of body fat, and visceral fat area were negatively correlated with FEV1 and FVC. Regarding the association between pulmonary function and lifestyle, a significant difference was found between the smoking index and the presence or absence of metabolic syndrome risk factors and both FEV1 and FVC. The multiple stepwise linear regression analysis with FEV1 as the dependent variable, adjusted for age and height, revealed that visceral fat area and fat free mass were significantly associated with FEV1. A similar analysis, FVC as the dependent variable identified visceral fat area. [Conclusion] FEV1 was independently associated with visceral fat area and fat free mass. FVC was independently associated with visceral fat area. These results may be valuable in preventing the decrease in respiratory function and, hence, in further preventing the onset of COPD.

The changes of lower muscle strength and physical performance in robust and pre-frail outpatient older adults

Objective: Muscle mass loss, muscle strength decline and poor physical performance, slow gait speed and decreased mobility are characteristics of sarcopenia and the frailty syndrome. Frailty is a dynamic state and it may transit with aging. The purpose of this study was to examine the changes and associations among lower extremity muscle mass and muscle strength observed longitudinally for 3 years in robust and pre-frail outpatient older adults. Methods: This was a 3-year longitudinal cohort study of outpatient older adults recruited from geriatric clinics. Frailty status was characterized according to Fried's Frailty Phenotype. Predicted muscle mass (PMM) of lower extremity was measured by bioelectrical impendence analysis (Tanita BC-418 Pro Segmental Body Composition Analyzer). Cybex Norm dynamometer was used to measure knee extensors and flexors isokinetic muscle strength at 0, 60, and 180 degrees/second. Physical performance was assessed by the 5-times sit-to-stand test (5tSTS), timed up and go test (TUGT) and 5-meter walk test (5MmWT). Data were collected annually and then analyzed by analysis of variance (ANOVA) and Pearson correlation. Results: Overall, 95 subjects (49 males, 46 females) completed all three follow-up examinations. The mean age was 77.48 (±5.79) years. There were 26.3% of subjects in the robust and 73.7% in the pre-frail status. The PMM was significantly decreased in robust older adults (p=0.04), the isokinetic muscle strength of knee extensors at 180 degrees/second decreased significantly both in robust (p=0.005) and pre-frail (p=0.002) group. Regarding physical performance, TUGT was significantly worse in follow up from baseline in both groups (robust p=.05; pre-frail p＜0.001). The change of TUGT from baseline to follow up correlated significantly with the change of isokinetic muscle strength of knee extensors at 0 degrees/second (r=.23, p=0.024). Conclusion: Knee extensor muscle strength was critical for detecting the ageing related changes of muscle strength in robust and pre-frail outpatient older adults. Furthermore, it was significantly related to the ability to stand up, walk, and turn.

Changes in lower extremity muscle mass and muscle strength after weight loss in obese men: A prospective study

Obesity is not only associated with internal diseases but also with surgical problems. Surgical diseases related to obesity frequently occur in the load bearing joints of the lower limbs. To decrease the occurrence of surgical diseases related to obesity, weight loss has been recommended. It is important for obese men to maintain muscle mass and muscle strength after weight loss because low muscle mass and muscle strength are also related to the occurrence of surgical diseases. To date, the importance of muscle mass and muscle strength after weight loss in obese men has been underappreciated. The purpose of this study was to investigate changes in lower extremity muscle mass and muscle strength resulting from a weight loss programme consisting of caloric restriction and exercise. All participants concurrently attended a 12-week diet class 1day/week and a 12-week exercise class 3days/week. Body weight and body composition by dual-energy X-ray absorptiometry and knee extensor strength by dynamometry were assessed. The weight loss programme led to a 14.1% weight loss accompanied by significant loss of leg muscle mass, static maximal muscle strength, dynamic maximal muscle strength and dynamic muscle endurance but not with significant loss of dynamic muscle power. Decline of muscle strength was related to a decrease in muscle mass, but not completely dependent on a decrease in muscle mass. Body weight-normalised muscle strength increased significantly. We recommend utilising resistance exercise to restore muscle mass and muscle strength in the legs after substantial weight loss.