Lower Lean Mass Research Articles

Prevalence of Sarcopenia and Relationships Between Muscle and Bone in Indian Men and Women.

Both ethnicity and age are important determinants of musculoskeletal health. We aimed to determine the prevalence of sarcopenia, assess the suitability of current diagnostic guidelines, and explore muscle-bone relationships in adults from India. A total of 1009 young (20-35years) and 1755 older (> 40years) men and women from existing studies were collated and pooled for the analysis. Dual-energy x-ray absorptiometry measured areal bone mineral density (aBMD) at the hip and spine, and fat and lean mass; hand dynamometer measured hand grip strength (HGS). Indian-specific cut-points for appendicular lean mass (ALM), ALM index (ALMI) and HGS were calculated from young Indian (-2SD mean) populations. Sarcopenia was defined using cut-points from The Foundations for the National Institutes of Health (FNIH), revised European Working Group on Sarcopenia in Older People (EWGSOP2), Asian Working Group for Sarcopenia (AWGS), and Indian-specific cut-points. Low lean mass cut-points were then compared for their predictive ability in identifying low HGS. The relationship between muscle variables (ALM, ALMI, HGS) and aBMD was explored, and sex differences were tested. Indian-specific cut-points (men-HGS:22.93kg, ALM:15.41kg, ALMI:6.03kg/m2; women-HGS:10.76kg, ALM:9.95kg, ALMI:4.64kg/m2) were lower than existing definitions. The Indian-specific definition had the lowest, while EWGSOP2 ALMI had the highest predictive ability in detecting low HGS (men:AUC = 0.686, women:AUC = 0.641). There were sex differences in associations between aBMD and all muscle variables, with greater positive associations in women than in men. The use of appropriate cut-points for diagnosing low lean mass and physical function is necessary in ethnic populations for accurate sarcopenia assessment. Muscle-bone relationships are more tightly coupled during ageing in Indian women than men.

Circulating Carboxylated Osteocalcin Correlates With Skeletal Muscle Mass and Risk of Fall in Postmenopausal Osteoporotic Women.

BackgroundBone and skeletal muscle represent a single functional unit. We cross-sectionally investigated body composition, risk of fall and circulating osteocalcin (OC) isoforms in osteoporotic postmenopausal women to test the hypothesis of an involvement of OC in the bone-muscle crosstalk.Materials and MethodsTwenty-nine non-diabetic, non-obese, postmenopausal osteoporotic women (age 72.4 ± 6.8 years; BMI 23.0 ± 3.3 kg/m2) underwent to: 1) fasting blood sampling for biochemical and hormone assays, including carboxylated (cOC) and uncarboxylated (uOC) osteocalcin; 2) whole-body dual energy X-ray absorptiometry (DXA) to assess total and regional body composition; 3) magnetic resonance imaging to determine cross-sectional muscle area (CSA) and intermuscular adipose tissue (IMAT) of thigh muscles; 4) risk of fall assessment through the OAK system.ResultsAppendicular skeletal muscle index (ASMMI) was low in 45% of patients. Forty percent got a low OAK score, consistent with moderate-severe risk of fall, which was predicted by low legs lean mass and increased total fat mass. Circulating cOC levels showed significantly correlated with βCTx-I, lean mass parameters including IMAT, and OAK score. Fractured and unfractured women did not differ for any of the analyzed parameters, though cOC and uOC positively correlated with legs lean mass, OAK score and bone markers only in fractured women.ConclusionsData supported the relationship between OC and skeletal muscle mass and function in postmenopausal osteoporotic women. Serum cOC, but not uOC, emerges as mediator in the bone-muscle crosstalk. Circulating cOC and uOC levels may be differentially regulated in fractured and unfractured osteoporotic women, suggesting underlying differences in bone metabolism.

Evaluation of Methods That Estimate Glomerular Filtration Rate in Patients With Prader-Willi Syndrome

Background: Prader-Willi syndrome (PWS) is a rare, complex, multisystem disorder caused by the loss of multiple paternally expressed genes on chromosome 15q11-13 and is present in 1/15,000-30,000 individuals. Characteristics of PWS include low muscle mass and hypotonia, accumulation of excess body fat, short stature, hyperphagia, behavioral problems, cognitive disabilities, developmental delays, and hypogonadism. In these patients, serum creatinine (SCr)-based methods to calculate estimated glomerular filtration rate (eGFR) can lead to inaccurate results. eGFR is reported to be negatively correlated to muscle mass and PWS-associated low lean body mass may contribute to low SCr levels. Therefore, eGFR calculations may not accurately reflect PWS patient’s renal function. A more accurate, non-invasive, inexpensive means to monitor renal function for this patient population is desirable. Objective: To assess methods of estimating renal function in pediatric PWS patients and summarize the relationship between eGFR and patient-specific factors. Methods: The pre-treatment data of patients ≥4 years old with genetically confirmed PWS participating in an investigational study of DCCR (diazoxide choline) were evaluated. Lean body mass was measured using dual X-ray absorptiometry. Lean body mass and age were correlated to eGFR/creatinine clearance (CrCl) values calculated using four different equations: Bedside Schwartz (BS), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Modification of Diet in Renal Disease (MDRD), and Cockcroft-Gault (C-G). Results: Of the 124 patients enrolled in the study, 99 were <18 years old and 103 were taking growth hormone (GH). Mean SCr was below normal range at 0.52 mg/dL, with only two subjects (1.6%) having SCr in the normal range (0.84 to 1.21 mg/dL). eGFR calculated using BS was 120±22 mL/min/1.73m2; CKD-EPI 154±23 mL/min/1.73m2; MDRD 211±77 mL/min/1.73m2; and CrCl by C-G 191±80 mL/min. Among the three eGFR equations, CKD-EPI presented with the most reasonable eGFR values <200 mL/min/1.73m2. When stratified by different age groups, SCr increased with age while eGFR decreased (and surprisingly CrCl by C-G increased). When correlating the eGFR values to various parameters, lean mass and age showed significant negative correlations with eGFR for BS, CKD-EPI, and MDRD. In contrast, for C-G there were significant positive correlations between CrCl and both lean mass and age. Conclusion: In PWS, the combination of low SCr and excess accumulation of body fat results in eGFR values that likely overestimate actual renal function in PWS patients. The inconsistent trends in correlation values between eGFR or CrCl by C-G and both lean mass and age indicate current SCr-based methods to estimate renal function in PWS may be inadequate. The use of CKD-EPI or other non-SCr-based methods to monitor renal function should be considered in PWS.

Coronavirus Disease 2019 (COVID-19) and Nutritional Status: The Missing Link?

ABSTRACTCoronavirus disease 2019 (COVID-19) is an emerging disease that has reached pandemic status by rapidly spreading worldwide. Elderly individuals and patients with comorbidities such as obesity, diabetes, and hypertension show a higher risk of hospitalization, severe disease, and mortality by acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. These patients frequently show exacerbated secretion of proinflammatory cytokines associated with an overreaction of the immune system, the so-called cytokine storm. Host nutritional status plays a pivotal role in the outcome of a variety of different infectious diseases. It is known that the immune system is highly affected by malnutrition, leading to decreased immune responses with consequent augmented risk of infection and disease severity. Body composition, especially low lean mass and high adiposity, has consistently been linked to worsened prognosis in many different diseases. In this review, evidence concerning the impact of nutritional status on viral infection outcomes is discussed.

The Association of Mitochondrial Copy Number With Sarcopenia in Adult Survivors of Childhood Cancer.

Adult childhood cancer survivors are at risk for frailty, including low muscle mass and weakness (sarcopenia). Using peripheral blood mitochondrial DNA copy number (mtDNAcn) as a proxy for functional mitochondria, this study describes cross-sectional associations between mtDNAcn and sarcopenia among survivors. Among 1762 adult childhood cancer survivors (51.6% male; median age = 29.4 years, interquartile range [IQR] = 23.3-36.8), with a median of 20.6 years from diagnosis (IQR = 15.2-28.2), mtDNAcn estimates were derived from whole-genome sequencing. A subset was validated by quantitative polymerase chain reaction and evaluated cross-sectionally using multivariable logistic regression for their association with sarcopenia, defined by race-, age-, and sex-specific low lean muscle mass or weak grip strength. All statistical tests were 2-sided. The prevalence of sarcopenia was 27.0%, higher among female than male survivors (31.5% vs 22.9%; P < .001) and associated with age at diagnosis; 51.7% of survivors with sarcopenia were diagnosed ages 4-13 years (P = .01). Sarcopenia was most prevalent (39.0%) among central nervous system tumor survivors. Cranial radiation (odds ratio [OR] = 1.84, 95% confidence interval [CI] = 1.32 to 2.59) and alkylating agents (OR = 1.34, 95% CI = 1.04 to 1.72) increased, whereas glucocorticoids decreased odds (OR = 0.72, 95% CI = 0.56 to 0.93) of sarcopenia. mtDNAcn decreased with age (β = -0.81, P = .002) and was higher among female survivors (β = 9.23, P = .01) and among survivors with a C allele at mt.204 (β = -17.9, P = .02). In adjusted models, every standard deviation decrease in mtDNAcn increased the odds of sarcopenia 20% (OR = 1.20, 95% CI = 1.07 to 1.34). A growing body of evidence supports peripheral blood mtDNAcn as a biomarker for adverse health outcomes; however, this study is the first to report an association between mtDNAcn and sarcopenia among childhood cancer survivors.

The Dietary Inflammatory Index Is Associated with Low Muscle Mass and Low Muscle Function in Older Australians.

Age-associated chronic, low grade systemic inflammation has been recognised as an important contributing factor in the development of sarcopenia; importantly, diet may regulate this process. This cross-sectional study examined the association of diet-related inflammation with components of sarcopenia. Participants (n = 809) aged 60–95 years from the Geelong Osteoporosis Study were studied. Body composition was measured by dual energy X-ray absorptiometry. In this study, low appendicular lean mass (ALM/height2, kg/m2) was defined as T-score < −1 and low muscle function as Timed-Up-and-Go >10 s over 3 m (TUG > 10). Dietary inflammatory index (DII®) scores, based on specific foods and nutrients, were computed using dietary data collected from a food frequency questionnaire. Associations between DII scores and low muscle mass and low muscle function, alone and combined, were determined using linear and logistic regression. After adjusting for covariates, higher DII score was associated with lower ALM/height2 (β −0.05, standard error (SE) 0.02, p = 0.028), and higher natural log-transformed (ln) (TUG) (β 0.02, standard error 0.01, p = 0.035) and higher likelihood for these components combined (odds ratio 1.33, 95% confidence interval 1.05 to 1.69, p = 0.015). A pro-inflammatory diet, as indicated by higher DII score, is associated with lower muscle mass, poorer muscle function and increased likelihood for the combination of low muscle mass and low muscle function. Further studies investigating whether anti-inflammatory dietary interventions could reduce the risk of sarcopenia are needed.

Low lean mass and cognitive performance: data from the National Health and Nutrition Examination Surveys

Low lean mass and cognitive impairment are both age-related diseases. In addition, these conditions share many risk factors. However, the association between them has been controversial in recent years. To investigate the association between low lean mass and cognitive performance in U.S. adults using NHANES data from 1999 to 2002. A total of 2550 participants were identified in the National Health and Nutrition Examination Survey Database (1999-2002). The independent variable was low lean mass, and the dependent variable was cognitive performance. Men and women were classified as having low lean mass if appendicular lean mass (ALM) adjusted for BMI (ALMBMI) was < 0.789 and < 0.512, respectively. Cognitive performance was assessed using the Digit Symbol Substitution Test (DSST). Higher scores on the DSST indicated better cognitive performance. The covariates included sex, age, race, poverty income ratio, comorbidity index, educational level, physical activity and smoking status. For the primary outcome, our multivariate linear regression analysis indicated that participants without low lean mass were associated with better cognitive performance (β = 1.50; 95% CI [0.12-2.89]). Subgroup analysis results indicated that the association was similar in sex, age, race, poverty income ratio, comorbidity index, educational level, physical activity and smoking status. Participants without low lean mass were associated with better cognitive performance. We might be able to improve cognitive performance by treating low lean mass, thus providing an opportunity for intervention at a younger age.

Structural and Functional Changes of Hands and Legs in Early Rheumatoid Arthritis.

Background and Objectives: The aim of this study was to assess if there are structural and functional changes of hands and legs already in early rheumatoid arthritis (ERA), compared with the population-based control group. Additionally, we aimed to identify if the changes are symmetrical in hands and legs and if there are factors that are associated with these changes. The study was conducted, and, thus far, the results have been controversial. Materials and Methods: The study group consisted of 83 consecutive patients with ERA and 321 control subjects. Dual-Energy X-Ray Absorptiometry (DXA) machine was used to measure bone, lean and fat mass. Inflammation and bone markers, smoking and nutritional habits were assessed, to evaluate the effects of different factors. The 30-Second Chair Stand Test (30-CST) and the Handgrip Strength Test (HST) were used to estimate muscle strength. Results: The presence of ERA was associated with lower arm, leg lean mass and higher fat mass of arm, compared with control subjects. ERA was also associated with lower mean handgrip in HST and worse muscle strength of legs in the 30-CST. Bone mass changes were not so evident both in arms and legs. Smoking habits did not seem to have relevant effect on bone mass, muscle structural and functional changes, both on hands and legs. In ERA, lean mass of arm and leg was negatively associated with C-reactive protein (CRP). The intake of proteins in ERA was not associated with lean mass changes both in hands and legs. Conclusions: Structural and functional changes of hands and legs are different in ERA. ERA patients had higher fat mass of arm, lower lean mass of arm and leg and, accordingly, decreased muscle function. The lowering of lean mass of arm and leg in ERA was associated with the elevation of CRP.

Sarcopenia and mortality in different clinical conditions: A meta-analysis

ObjectivesSarcopenia is recognized to be a health problem which is as serious as obesity, but its relevance to mortality is unclear. We conducted a meta-analysis of cohort studies on lean mass and mortality in populations with different health conditions. MethodsIn this study, a systematic search of PubMed, Cochrane Library and Embase was performed for cohort studies published before Dec 20, 2017 which examined the relationship between lean mass and mortality. We included studies reporting lean mass measurement by dual-energy X-ray absorptiometry, bioimpedance analysis or computed tomography, as continuous (per standard deviation [SD] decrease) or binary variables (using sarcopenia cutoffs). We excluded studies which used muscle mass surrogates, anthropometric measurement of muscle, rate of change in muscle mass, and sarcopenia defined by composite criteria. The primary study outcome was all-cause mortality. Pooled hazard ratio estimates were calculated using a random effects model. ResultsA total of 9602 articles were identified from the systematic search, and 188 studies with 98 468 participants from 34 countries were included in the meta-analysis. Of the 68 studies included in the present meta-analysis, the pooled HR was 1.36 and 1.74 for every SD decrease in lean mass and in people with low lean mass (cutoffs), respectively. Significant associations were also observed in elderly and all disease subgroups, irrespective of the measurement modalities. ConclusionsLower lean mass is robustly associated with increased mortality, regardless of health conditions and lean mass measurement modalities. This meta-analysis highlighted low lean mass as a key public health issue.

The effect of different measurement modalities in the association of lean mass with mortality: A systematic review and meta-analysis

ObjectivesLean mass is commonly measured by 3 modalities, dual energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), and computerized tomography (CT). CT is considered the most accurate, while lean mass measured by DXA and BIA often consists of non-muscle compartment, and hence considered less accurate when compared with CT. It remains unclear if the association of lean mass with mortality would differ using different measurement modalities. MethodsA systematic review and meta-analysis of lean mass and mortality was conducted. The analysis was stratified by different measurement modalities and health conditions. Pooled hazard ratios were estimated using a random effects model. ResultsThis meta-analysis included 188 studies with 98 468 participants. Reduced lean mass measured by BIA, DXA, and CT, was associated with increased risk of mortality with a hazard ratio (HR) of 1.35 (95% CI, 1.21–1.49), 1.18 (95% CI, 1.06–1.30), and 1.44 (95% CI, 1.32–1.57), respectively. Similarly, low lean mass defined by BIA-, DXA-, and CT-measurement was associated with increased risk of mortality, with an HR of 1.81 (95% CI, 1.56–2.10), 1.44 (95% CI, 1.29–1.60), and 1.78 (95% CI, 1.64–1.93). ConclusionsReduced and low lean mass were robustly associated with increased mortality in studies using different measurement modalities.

Different definitions of sarcopenia and mortality in cancer: A meta-analysis

ObjectivesSarcopenia has been an emerging theme in clinical oncology. Various definitions of sarcopenia have been proposed, but their prognostic performance have yet to be evaluated and compared. The aim of this meta-analysis is to comprehensively evaluate the performance of different cutoff definitions of sarcopenia in cancer mortality prognostication. MethodsThis is a meta-analysis. Cohort studies on lean mass and mortality published before December 20, 2017 were obtained by systematic search on PubMed, Cochrane Library, and Embase. Inclusion criteria were cohort studies reporting binary lean mass categorized according to clearly defined cutoffs, and with all-cause mortality as study outcome. Studies were stratified according to the cutoff(s) used in defining low lean mass. The cutoff-specific hazard ratios (HRs) and 95% confidence intervals (CIs) of low lean mass on cancer mortality were pooled with a random-effects model and compared. ResultsAltogether 81 studies that studied binary lean mass were included. The pooled HRs on cancer mortality using the 3 most used definitions were: 1.74 (95% CI, 1.46–2.07) using the definition proposed by International Consensus of Cancer Cachexia, 1.45 (95% CI, 1.21–1.75) using that by Martin, and 1.58 (95% CI, 1.35–1.84) using that by Prado. The associations between sarcopenia and cancer mortality using other definitions were all statistically significant, despite different estimates were observed. ConclusionsThe association of low lean mass with increased mortality was consistent across different definitions; this provides further evidence on the poorer survival in cancer patients with sarcopenia. However, further studies evaluating the performance of each definition are warranted.

Daily Supplementation With Whey, Soy, or Whey-Soy Blended Protein for 6 Months Maintained Lean Muscle Mass and Physical Performance in Older Adults With Low Lean Mass

BackgroundFew studies have investigated the effect of long-term protein supplementation alone on muscle health in older adults with low lean mass. ObjectiveTo determine the effect of whey, soy or whey-soy blended protein supplementation on lean muscle mass and physical performance in older adults with low lean mass. DesignA 4-arm randomized controlled trial. Participants/settingChinese older adults (n = 123, 65-79 years) with low lean mass (appendicular skeletal muscle index < 7.0 kg/m2 in men and < 5.4 kg/m2 in women) living in the urban area of Guangzhou participated between October 2015 and June 2016. InterventionParticipants were randomly assigned to receive approximately 16 g/d of whey, soy, or whey-soy blend protein or maintained habitual diets in control group for 6 months. Main outcome measuresLean mass, handgrip strength, and physical performance (gait speed, chair stand test, and Short Physical Performance Battery) were assessed at baseline and 6 months. Statistical analysesTwo-way analysis of variance with the main effects of treatment and time and treatment × time interaction and analysis of covariance was used to determine differences in outcomes. ResultsAppendicular skeletal muscle index, lean mass, percent lean mass in legs and appendicular areas, gait speed, and Short Physical Performance Battery score were maintained in the treatment groups and decreased in the control group, resulting in significant reduction in these variables from baseline in the control compared with treatment groups (all P < .01; percent differences between treatment and control groups ranged from 80% to 156%). The chair stand test time at month 6 decreased from baseline in the treatment groups and increased in the control group, resulting in a significant increase in the control compared with treatment groups (all P < .01; percent differences between treatment and control groups ranged from 132% to 155%). Handgrip strength remained unchanged. There were no significant differences in outcomes among treatment groups. ConclusionsSupplementation with whey, soy, or whey-soy blended protein for 6 months equally maintained lean muscle mass and physical performance in older adults with low lean mass.

Systematic review and meta-analysis of lean mass and mortality: Rationale and study description

ObjectivesMuscle mass is one of the key components in defining sarcopenia and is known to be important for locomotion and body homeostasis. Lean mass is commonly used as a surrogate of muscle mass and has been shown to be associated with increased mortality. However, the relationship of lean mass with mortality may be affected by different clinical conditions, modalities used, cut-off point to define low or normal lean mass, and even types of cancer among cancer patients. Thus, we aim to perform a comprehensive meta-analysis of lean mass with mortality by considering all these factors. MethodsSystematic search was done in PubMed, Cochrane Library and Embase for articles related to lean mass and mortality. Lean mass measured by dual X-ray absorptiometry, bioelectrical impedance analysis, and computerized tomography were included. ResultsThe number of relevant studies has increased continuously since 2002. A total of 188 studies with 98 468 people were included in the meta-analysis. The association of lean mass with mortality was most studied in cancer patients, followed by people with renal diseases, liver diseases, elderly, people with cardiovascular disease, lung diseases, and other diseases. The meta-analysis can be further conducted in subgroups based on measurement modalities, site of measurements, definition of low lean mass adopted, and types of cancer for studies conducted in cancer patients. ConclusionsThis series of meta-analysis provided insight and evidence on the relationship between lean mass and mortality in all directions, which may be useful for further study and guideline development.

Marked skeletal muscle deficits are associated with 6-minute walk distance in paediatric pulmonary hypertension.

Poor growth is common in children with pulmonary hypertension; however, skeletal muscle deficits have not been described and the association between muscle deficits and functional status is unknown. Patients aged 8-18 years with pulmonary hypertension (diagnostic Groups 1, 2, or 3) and World Health Organization functional class I or II underwent dual-energy absorptiometry to measure leg lean mass Z-score (a surrogate for skeletal muscle). Muscle strength was assessed using dynamometry. Physical activity questionnaires were administered. Clinical data, including 6-minute walk distance, were reviewed. Relationships between skeletal muscle, physical activity score, and 6-minute walk distance were assessed by correlations and linear regression. Sixteen patients (12.1 ± 3.2 years, 50% female, 56% Group 1, 56% functional class II) were enrolled. Leg lean mass Z-score was significantly less than reference data (-1.40 ± 1.12 versus 0.0 ± 0.9, p < 0.001) and worse in those with functional class II versus I (-2.10 ± 0.83 versus -0.50 ± 0.73, p < 0.01). Leg lean mass Z-score was positively associated with right ventricular systolic function by tricuspid annular plane systolic Z-score (r = 0.54, p = 0.03) and negatively associated with indexed pulmonary vascular resistance (r = -0.78, p < 0.001). Leg lean mass Z-score and forearm strength were positively associated with physical activity score. When physical activity score was held constant, leg lean mass Z-score independently predicted 6-minute walk distance (R2 = 0.39, p = 0.03). Youth with pulmonary hypertension demonstrate marked skeletal muscle deficits in association with exercise intolerance. Future studies should investigate whether low leg lean mass is a marker of disease severity or an independent target that can be improved.

Associations between Physical Function, Bone Density, Muscle Mass and Muscle Morphology in Older Men with Sarcopenia: A Pilot Study.

Background and Objectives: It is thought that muscle and bone interact only on a biomechanical level, however, some research is now emerging that links bone and muscle on a cellular level. The aim of this study was to explore associations between physical function, muscle mass and bone density in community-dwelling elderly men with sarcopenia. A secondary goal was to analyze if muscle morphology was associated with bone density and physical functioning. Materials and Methods: Body composition was measured by dual-energy X-ray absorptiometry (DXA). Bone density was evaluated according to WHO criteria. Sarcopenia was diagnosed according to European Working Group on Sarcopenia in Older People (EWGSOP) criteria: low muscle mass and low muscle strength or low physical performance. Microbiopsy of musculus vastus lateralis was performed with a disposable muscle microbiopsy system. The perimeter and cross-sectional area of muscle fibers were calculated using image analysis software in whole slide images; type of fibers and their distribution were evaluated as well. Results: A total of 151 men, 60 years or older were included in this study. Mean age of the subjects was 72.9 ± 8.02 years. Sarcopenia was diagnosed in 45 (29.8%) men. Multiple significant correlations were found between bone mineral density, lean mass, appendicular lean mass, arm and leg lean mass, gait speed, balance test and handgrip strength in sarcopenic men. Lean mass was associated with femoral neck BMD (bone mineral density; r = 0.418, p = 0.006) and handgrip strength (r = 0.553, p < 0.001). In the sarcopenia group, 25 muscle biopsies were examined. In 9 sarcopenic men with T-scores equal or below −2.5, the muscle fiber area had a significant correlation with the balance test (r = 0.73, p = 0.025). Conclusions: In men with sarcopenia, low lean muscle mass was associated with low femoral neck BMD and low muscle strength. In sarcopenic men with osteoporosis, low muscle fiber area was associated with low scores in a balance test.

The longitudinal associations between bone mineral density and appendicular skeletal muscle mass in Chinese community-dwelling middle aged and elderly men

BackgroundThe present study aimed to investigate longitudinal associations between bone mineral densities (BMDs) and appendicular skeletal muscle (ASM) mass in different regions of the body using three different indicators, in Chinese community-dwelling middle-aged and elderly men.MethodsA total of 1,343 men aged ≥ 40 years from a Chinese community were assessed at baseline (2014–2016), one-year follow-up (2016–2017; n = 648), two-year follow-up (2017–2018; n = 407), and three-year follow up (2018–2019; n = 208). At all the four time-points, measurements included ASM mass and BMDs for all regions of the body using dual-energy X-ray absorptiometry. A questionnaire was completed by patients and biochemical markers were assessed. We applied three different indicators to define ASM mass or lean mass respectively, including the appendicular skeletal muscle index (ASM adjusted by height, ASMI, according to the Asian Working Group for Sarcopenia), skeletal muscle index (ASM adjusted by weight, SMI, according to the International Working Group on Sarcopenia), and the appendicular skeletal muscle/body mass index (ratio of ASM and Body mass index (BMI), ASM/BMI, according to the Foundation for the National Institutes of Health). After adjusting for potential confounders, the generalized additive mixed model (GAMM) was used to analyze the trend in ASM mass over time, and to test the association between ASM mass and regional and whole-body BMDs.ResultsThe incidence of low lean mass was 8.2% defined by ASMI, 16.3% defined by SMI, and 8.3% defined by ASM/BMI. There was a linear relationship between BMDs and ASM mass, and ASMI, ASM/BMI, and SMI gradually decreased with time. After adjusting for covariances, GAMM analysis determined longitudinal associations between BMDs and ASM mass by three indicators respectively: the skull BMD was negatively associated with ASM mass. For each unit increase in skull BMD, ASMI decreased by 0.28 kg/m2 (95% confidence interval (CI) [−0.39 to −0.16]), ASM/BMI decreased by 0.02 m2 (95% CI [−0.03 to −0.00]), and SMI decreased by 0.01% (95% CI[−0.01 to −0.00]). The remaining parameters (including whole-body mean BMD, thoracic spinal BMD, lumbar spinal BMD, hip BMD, femoral neck BMD, pelvic BMD, left arm BMD, right arm BMD, left leg BMD, right leg BMD) were positively correlated with ASM mass. The ASMI increased by 3.07 kg/m2for each unit increase in the femoral neck BMD (95% CI [2.31–3.84]). The ASM/BMI increased by 0.22 m2for each unit increase in the left arm BMD (95% CI [0.12–0.33]), and the SMI increased by 0.05% per unit increase in the left arm BMD (95% CI [0.02–0.08]).ConclusionsCompared to ASMI and ASM/BMI, SMI was more sensitive to screen for the low lean mass. Skull BMD was negatively associated with ASM mass, while BMDs throughout the rest of the body were positively correlated with ASM mass among the middle-aged and elderly Chinese men.

Serum FSH Is Associated With BMD, Bone Marrow Adiposity, and Body Composition in the AGES-Reykjavik Study of Older Adults.

Follicle-stimulating hormone (FSH) concentrations increase during the perimenopausal transition and remain high after menopause. Loss of bone mineral density (BMD) and gain of bone marrow adiposity (BMA) and body fat mass also occur during this time. In mice, blocking the action of FSH increases bone mass and decreases fat mass. To investigate the associations between endogenous FSH levels and BMD, BMA, and body composition in older adults, independent of estradiol and testosterone levels. Older adults from the AGES-Reykjavik Study, an observational cohort study. Areal BMD, total body fat, and lean mass were measured with dual-energy x-ray absorptiometry. Lumbar vertebral BMA was measured by 1H-magnetic resonance spectroscopy. Volumetric BMD and visceral and subcutaneous adipose tissue (VAT, SAT) areas were measured with quantitative computed tomography. The least squares means procedure was used to determine sex hormone-adjusted associations between quartiles of serum FSH and BMD, BMA, and body composition. In women (N = 238, mean age 81 years), those in the highest FSH quartile, compared with the lowest quartile, had lower adjusted mean spine integral BMD (-8.6%), lower spine compressive strength index (-34.8%), higher BMA (+8.4%), lower weight (-8.4%), lower VAT (-17.6%), lower lean mass (-6.1%), and lower fat mass (-11.9%) (all P < 0.05). In men, FSH level was not associated with any outcome. Older postmenopausal women with higher FSH levels have higher BMA, but lower BMD and lower fat and lean mass, independent of estradiol and testosterone levels. Longitudinal studies are needed to better understand the underlying mechanisms.

Overweight and obesity in young adults with patellofemoral pain: Impact on functional capacity and strength

PurposeThis study aimed to (a) investigate the proportion of overweight/obesity in a cohort of young adults with patellofemoral pain (PFP) and (b) explore the association of body mass index (BMI), body fat, and lean mass with functional capacity and hip and knee strength in people with PFP. MethodsWe included a mixed-sex sample of young adults (18−35 years old) with PFP (n = 100). Measurements for BMI, percentage of body fat, and lean mass (assessed by bioelectrical impedance) were obtained. Functional capacity was assessed by the Anterior Knee Pain Scale, plank test, and single-leg hop test. Strength of the knee extensors, knee flexors, and hip abductors was evaluated isometrically using an isokinetic dynamometer. The proportion of overweight/obesity was calculated based on BMI. The association between BMI, body fat, and lean mass and functional capacity and strength was investigated using partial correlations, followed by hierarchical regression analysis, adjusted for covariates (sex, bilateral pain, and current pain level). ResultsA total of 38% of our cohort had their BMI categorized as overweight/obese. Higher BMI was associated with poor functional capacity (ΔR2 = 0.06−0.12, p ≤ 0.001) and with knee flexion strength only (ΔR2 = 0.04, p = 0.030). Higher body fat was associated with poor functional capacity (ΔR2 = 0.05−0.15, p ≤ 0.015) and reduced strength (ΔR2 = 0.15−0.23, p < 0.001). Lower lean mass was associated with poor functional capacity (ΔR2 = 0.04−0.13, p ≤ 0.032) and reduced strength (ΔR2 = 0.29− 0.31, p < 0.001). ConclusionBMI, body fat, and lean mass should be considered in the assessment and management of young people with PFP because it may be detrimental to function and strength.

Obesity Associated with Low Lean Mass and Low Bone Density Has Higher Impact on General Health in Middle-Aged and Older Adults

It is believed that the phenomenon of simultaneous changes in body composition could have a higher negative impact on general health. Thus, we aimed to investigate the prevalence of concomitant body composition disturbances and evaluate the association with dietary intake, sedentary behaviour, muscle strength, and performance. This is a cross-sectional study with 218 community-dwelling adults, aged 63 (59–69) years, both sexes (52% female) recruited from the Health Survey of the City of São Paulo. Assessments include appendicular lean mass (LM), fat mass and bone mineral density (BMD) by DXA, grip strength, time spent sitting, and dietary intake. Subjects were clustered into 8 groups: (1) normal, (2) osteopenia (OP), (3) low LM, (4) obesity, (5) OP + low LM, (6) obesity + OP, (7) obesity + low LM, and (8) obesity + OP + low LM. Statistical analyses include ANCOVA, the chi-square test, and linear regression models. 52 (23%) individuals presented obesity associated with another body composition change, with 14 (6%) having the combination of the 3 conditions (obesity + OP + low LM). All groups with obesity showed lower protein intake ( p ≤ 0.001 ); however, those with obesity or obesity + low LM spent more time in a sitting position ( p = 0.002 ), and the group with obesity + OP + low LM had the lowest grip strength. The combination of obesity with low LM and OP presented the aggravating factor of being associated with lower grip strength. In a context of demographic and nutrition transition, the findings represent a demand for longitudinal investigations.

Use of standardized body composition measurements and malnutrition screening tools to detect malnutrition risk and predict clinical outcomes in children with chronic conditions

Better tools are needed to diagnose and identify children at risk of clinical malnutrition. We aimed to compare body composition (BC) and malnutrition screening tools (MSTs) for detecting malnutrition on admission; and examine their ability to predict adverse clinical outcomes [increased length of stay (LOS) and complications] in complex pediatric patients. This was a prospective study in children 5-18 y old admitted to a tertiary pediatric hospital (n=152). MSTs [Pediatric Yorkhill Malnutrition Score (PYMS), Screening Tool for the Assessment of Malnutrition in Pediatrics (STAMP), and Screening Tool for Risk of Impaired Nutritional Status and Growth (STRONGkids)] were completed on admission. Weight, height, and BC [fat mass (FM) and lean mass (LM) by DXA] were measured (n=118). Anthropometry/BC and MSTs were compared with each other and with clinical outcomes. Subjects were significantly shorter with low LM compared to reference data. Depending on the diagnostic criteria used, 3%-17% were classified as malnourished. Agreement between BC/anthropometric parameters and MSTs was poor. STAMP and STRONGkids identified children with low weight, LM, and height. PYMS, and to a lesser degree STRONGkids, identified children with increased LOS, as did LM compared with weight or height. Patients with complications had lower mean±SD LM SD scores (-1.38±1.03 compared with -0.74±1.40, P<0.05). In multivariable models, PYMS high risk and low LM were independent predictors of increased LOS (OR: 3.76; 95% CI: 1.36, 10.35 and OR: 3.69; 95% CI: 1.24, 10.98, respectively). BMI did not predict increased LOS or complications. LM appears better than weight and height for predicting adverse clinical outcomes in this population. BMI was a poor diagnostic parameter. MSTs performed differently in associations to BC/anthropometry and clinical outcomes. PYMS and LM provided complementary information regarding LOS. Studies on specific patient populations may further clarify the use of these tools and measurements.