Estimation Of Muscle Mass Research Articles

Função muscular de membros inferiores e massa muscular em jogadores de futebol

Introduo: No futebol a fora muscular exerce um papel fundamental nas aes tcnicos/tticas realizadas durante uma partida. Objetivo: Investigar a relao entre a funo muscular de membros inferiores e a massa muscular total em jogadores. Mtodos: Dezesseis jogadores realizaram avaliao isocintica concntrica na extenso e flexo de joelhos por membro dominante. Foram realizadas avaliaes antropomtricas e estimativas da massa muscular. Resultados: Foi observado que a massa muscular total apresentou uma relao positiva com o pico de torque (r=0,67, p=0,005; r=0,62, p=0,011), potncia (r=0,59, p=0,017; r=0,60, p=0,015) e funo global (r= 0,59; p= 0,017; r= 0,60; p= 0,013) na extenso do joelho em ambos os membros e no trabalho total (r=0,63, p=0,009) apenas no membro dominante. Nenhuma relao significante foi encontrada na ao de flexo do joelho. Concluso: A relao entre a massa muscular total e as variveis da funo muscular podem ser utilizados como indicadores da capacidade de produo de fora e assimetrias dos membros inferiores em jogadores.

Heritability of muscle mass in Korean parent–offspring pairs in the Fifth Korean National Health and Nutrition Examination Survey (KNHANES V)

ObjectivesDecreased muscle mass is known to be associated with several serious medical conditions. We analyzed the Fifth Korean National Health and Nutrition Examination Survey (KNHANES V, 2010–2011) to estimate the heritability of muscle mass in Korean parent-offspring pairs. Study DesignCross-sectional. Main outcome measuresA total of 1233 parents (average age 57.67 ± 8.50 years) and 917 offspring (average age 29.10 ± 7.57 years) from 743 families were included in the analysis. Muscle mass was estimated based on three different indices: appendicular skeletal muscle mass (ASM) measured with a dual-energy X-ray absorptiometry (DXA), weight-adjusted ASM (SMI), and height-adjusted ASM (RASM). The heritability was estimated by employing the maximum-likelihood variance components implemented in Sequential Oligogenic Linkage Analysis Routines (SOLAR). The best-fitting model was determined out of four polygenic models. Pearson’s partial correlation coefficient was also calculated using the muscle mass indices to further study the association between father or mother and son or daughter pairs. ResultsThe heritability estimates of the muscle mass indices ranged from 55% to 80% (all p < 0.01). The correlation coefficient of father and offspring ranged from 0.11 to 0.40, while that of mother and offspring ranged from 0.23 to 0.43 (all p < 0.01). ConclusionsThe heritability estimates of muscle mass in Koreans are large and significant, suggesting that parental muscle mass is an important predictor of the offspring’s muscle mass. The result implies that there may be a genetic factor partly determining muscle mass.

Association between appendicular skeletal muscle mass and depressive symptoms: Review of the cardiovascular and metabolic diseases etiology research center cohort

BackgroundThe effects of skeletal muscle mass on depressive symptoms remain poorly understood, especially in the middle-aged population. We examined the relationship between skeletal muscle mass and depressive symptoms according to sex and menopausal status in the middle-aged Korean population. MethodsHerein, 1,151 men and 2,176 women aged 30–64 years completed questionnaires and underwent health examinations in the Cardiovascular and Metabolic Disease Etiology Research Center study. Appendicular skeletal muscle mass (ASM) was measured via bioelectrical impedance analysis and adjusted for height squared (ASM/Ht2). Both continuous values and tertile groups of ASM/Ht2 were used for analysis. Depressive symptoms were assessed using the Beck Depressive Inventory-II (BDI), and the prevalence of depressive symptoms was determined as a BDI score ≥ 20. ResultsMultiple logistic regression analysis using a fully adjusted model showed that depressive symptoms were more frequently observed among men in the lower ASM/Ht2 tertile and middle ASM/Ht2 tertile than among those in the higher ASM/Ht2 tertile. Each 1-kg/m2 decrease in ASM/Ht2 was significantly associated with the presence of depressive symptoms in men. Such significant association was not observed among premenopausal and postmenopausal women. LimitationsThe cross-sectional nature of the study design, measurement of skeletal muscle mass and depressive symptoms only once, estimation of skeletal muscle mass using bioelectrical impedance analysis, assessing depressive symptoms by self-reported questionnaire, and potential unknown confounding variables constitute the limitations of our study. ConclusionsThe independent association between low skeletal muscle mass and depressive symptoms was observed in men but not in women.

Dilution of oral D3 -Creatine to measure creatine pool size and estimate skeletal muscle mass: development of a correction algorithm.

BackgroundMuscle mass can be measured directly in vivo by isotope dilution, using Creatine‐(methyl‐d3) monohydrate (D3‐Cr) by mouth followed by measurement of the steady‐state enrichment of D3‐creatinine (D3‐Crn) in urine. Isotope dilution methods require knowledge of the amount of tracer delivered to the pool of interest. In a subset of human subjects, a small amount of orally administered D3‐Cr ‘spills’ into urine after absorption and prior to transport into skeletal muscle cells. The objectives were to develop a method to correct for spillage to compare the estimate of muscle mass by D3‐Cr dilution to other assessments of fat‐free mass.MethodsSubjects (19 males, 23–81 years old; 20 females, 20–77 years old) ingested a single dose of 60 mg D3‐Cr and urine was collected prior to and daily for 4 days following the dose. Fasting morning urine samples was assessed for D3‐Cr, total Cr, D3‐Crn, and total Crn concentrations, as well as isotopic enrichments of D3‐Crn, by LC/MS. The 24‐h urine collections over 3 days after the dose of D3‐Cr were also performed to determine D3‐Cr spillage. Total body water, fat mass, and fat‐free mass were assessed by bioelectrical impedance spectroscopy (BIS).ResultsSpillage of D3‐Cr in the urine was greater in women than men. D3‐Crn enrichment and the ratio of Cr/Crn were used in an algorithm to calculate Cr pool size and muscle mass. Specifically, an algorithm was developed for the estimation of spillage based on the relationship between the fasting Cr/Crn ratio and the cumulative proportion of the D3‐Cr dose excreted over 3 days based on 24‐h urine collections. Muscle mass corrected using the algorithm based on fasting urine levels correlated (r = 0.9967, P < 0.0001) with that corrected by measuring D3‐Cr dose excreted. Muscle mass measured by D3‐Crn enrichment also correlated (r = 0.8579, P < 0.0001, algorithm corrected) with that measured by 24‐h Crn excretion. Muscle mass measured by D3‐Cr dilution method correlated with intracellular water by BIS, whether using spillage corrected by the algorithm (r = 0.9041, P < 0.0001) or measured by 3 day D3‐Cr losses (r = 0.91, P < 0.0001) and similarly correlated with fat‐free mass by BIA (r = 0.8857 and 0.8929, P < 0.0001, respectively).ConclusionsThe D3‐Cr dilution method is further validated here as a non‐invasive, easy‐to‐use test for measuring muscle mass. The technical issue of D3‐Cr spillage can be corrected for with a simple algorithm based on fasting spot urine samples. Muscle mass by Cr dilution potentially has broad applications in clinical and research settings.

Prevalence of sarcopenia and diagnostic ability assessment of widely available methods of muscle mass and performance estimation in cirrhotic patients

Prevalence of sarcopenia and diagnostic ability assessment of widely available methods of muscle mass and performance estimation in cirrhotic patients

Value of sarcopenia assessed by computed tomography for the prediction of postoperative morbidity following oncological colorectal resection: A comparison with the malnutrition screening tool

Computed tomography (CT) can be used for accurate estimation of whole-body muscle mass and muscle density and for detection of sarcopenia. The goal of this study was to evaluate the additional value of CT measured sarcopenia and muscle attenuation alongside the Malnutrition Universal Screening Tool (MUST) for the prediction of post-operative morbidity after oncological colorectal resection, whilst correcting for known risk factors. A prospective cohort study of 80 patients undergoing elective colorectal surgery in the Netherlands. Patients were screened for nutritional risk upon admission using the MUST. Additionally, preoperative CT scans were used to determine skeletal muscle mass for the detection of sarcopenia and muscle attenuation. Univariate and multivariable analyses were performed to evaluate associations between the MUST, muscle attenuation and sarcopenia on the one hand and post-operative complications measured by the Clavien-Dindo score on the other hand. American Society of Anesthesiology-classification (ASA) ≥3, age ≥70, MUST ≥2 and lower than median muscle attenuation were significantly associated with a higher risk for postoperative complications (Clavien-Dindo score ≥2) (p≤0.05), whereas sarcopenia was not (p=0.59). Multivariate analyses showed that only MUST ≥2 remained significantly associated with postoperative complications when corrected for age (p=0.03, OR 5.8, 95%CI 1.1-29.6), but not when corrected for age ≥70 and ASA ≥3. Muscle attenuation and sarcopenia were not significantly associated with postoperative complications. Our results suggest that using CT measured sarcopenia may have only little additional value over the MUST for the prediction of increased short-term post-operative morbidity after oncological colorectal surgery. It also underlines the importance of currently implemented easy-to-use nutritional screening tools (MUST) and raises the question of the evaluation of muscle quality versus quantity in body composition imaging. However, further research is needed to investigate the role of sarcopenia for predicting outcome after colorectal surgery, and investigate the role of muscle attenuation measurements for the prediction of muscle function. CATEGORY OF SUBMISSION: observational study.

Upper arm anthropometrics versus DXA scan in survivors of acute respiratory distress syndrome.

Survivors of acute respiratory distress syndrome (ARDS) experience severe muscle wasting. Upper arm anthropometrics can provide a quick, non-invasive estimate of muscle status, but its accuracy is unknown. This study examines the accuracy of upper arm percent muscle area (UAMA) with reference measures of lean mass from dual energy X-ray absorptiometry (DXA). Data are from 120 ARDS survivors participating in a multi-center national study. Receiver Operating Characteristic (ROC) Curves, by patient sex, demonstrated that UAMA did no better than chance in discriminating low appendicular skeletal muscle mass identified using DXA findings (c-statistics, 6m: 0.50-0.59, 12m: 0.54-0.57). Modest correlations of UAMA with DXA measures (whole-body: r=0.46-0.49, arm-specific: r=0.50-0.51, p<0.001) and Bland-Altman plots indicate poor precision. UAMA is not an appropriate screening measure for estimating muscle mass when compared to a DXA reference standard. Alternate screening measures should be evaluated in ARDS survivors.

The sarcopenia index: A novel measure of muscle mass in lung transplant candidates.

Frailty, including low muscle mass, is an emerging risk factor for poor outcomes after lung transplant. The sarcopenia index (SI)-(serum creatinine value/cystatin C value)×100-is a novel blood test to approximate muscle mass. We sought to validate SI among lung transplant patients. We retrospectively identified adult lung transplant recipients from 2000 through 2012 at our institution who underwent computed tomography within 1year before transplant and had preserved blood samples. Creatinine and cystatin C values were measured using the samples and used to calculate SI. Muscle mass was estimated by computed tomographic measurement of skeletal muscle cross-sectional surface area (SA) at the L1 to L3 vertebral levels. Correlation between SI and SA was evaluated. Of 28 patients meeting eligibility criteria, most were white (96%) and men (54%). Median (interquartile range) body mass index, SI, and SA were 25.9 (22-30) kg/m2 , 106 (91-119), and 157 (113-195) cm2, respectively. The Pearson correlation coefficient between SI and SA was significant at L2 (0.43; P=.02) and L3 (0.41; P=.03). Sarcopenia index is a potentially objective measure for estimating muscle mass that is noninvasive and less expensive. Sarcopenia index could be considered in lung transplant candidate selection following prospective validation in larger cohorts.

Estimation of lean body mass by creatinine kinetics increases the prevalence of muscle wasting in peritoneal dialysis patients compared to bioimpedance.

Dialysis patients are at increased risk for muscle wasting, and time efficient screening tests are required for to allow for early detection. Creatinine kinetics have been advocated to estimate lean body mass (LBM) in peritoneal dialysis (PD) patients, and can be readily calculated in clinical practice from peritoneal dialysate effluent and urine collections. Bioimpedance is increasingly available, and we compared methods in 434 PD patients (55% men, 33.3% diabetics), mean age 55.2 ± 16.2 years. LBM was lower by creatinine kinetics (47.8 ± 16.6 kg men, 37.8 ± 11.2 kg women) vs. bioimpedance (53.2 ± 11.5 kg men, 39.2 ± 7.2 kg women), p < 0.01. The prevalence of muscle wasting was much greater using creatinine kinetics (72.4% men, 52.4% women) vs. bioimpedance (55.2% men, 37.3%), p < 0.05. Estimates of LBM were much lower using creatinine kinetics compared to bioimpedance. Studies reporting the prevalence of muscle loss in PD patients will differ depending upon the method used to estimate muscle mass.

Dual Energy X-ray Absorptiometry and Bioimpedance Analysis are Clinically Useful for Measuring Muscle Mass in Kidney Transplant Recipients With Sarcopenia

PurposeComputed tomography (CT) is considered the gold standard method for the diagnosis and characterization of sarcopenia. The aim of the present study was to determine the correlation between the volume of psoas muscle measured using CT and the measurement of muscle mass with dual energy X-ray absorptiometry (DXA) and bioimpedance analysis (BIA) in kidney transplant recipients. MethodsFifty-eight recipients (42 males and 16 females) were enrolled. Diagnostic criteria for sarcopenia were according to those of the Asia Working Group for Sarcopenia. The volume of psoas muscle was extracted using image recognition software from three-dimensional CT images. ResultsThe volume of psoas muscle was 227.2 ± 61.3 mL in Group 1 (sarcopenia), 283.9 ± 75.3 mL in Group 2 (presarcopenia), and 363.7 ± 138.0 mL in Group 3 (without sarcopenia). Muscle mass measured using DXA was 15.80 ± 3.19 kg in Group 1, 16.36 ± 2.49 kg in Group 2, and 21.21 ± 4.14 kg in Group 3. Additionally, muscle mass assessed using BIA was 17.22 ± 4.11 kg in Group 1, 17.86 ± 3.30 kg in Group 2, and 21.48 ± 5.39 kg in Group 3. There were significant differences in the mean volume of psoas muscle between the 3 groups. There was a significant positive correlation between the volume of psoas muscle and the muscle mass assessed using DXA (r = 0.797; P < .001) and BIA (r = 0.761; P < .001). Furthermore, there was a significant positive correlation between DXA and BIA (r = 0.900; P < .001). ConclusionsIt was suggested that estimating muscle mass using DXA and BIA is a preferred method for diagnosis of sarcopenia in kidney transplant recipients.

Association of Thigh Muscle Mass with Insulin Resistance and Incident Type 2 Diabetes Mellitus in Japanese Americans.

BackgroundSkeletal muscle plays a major role in glucose metabolism. We investigated the association between thigh muscle mass, insulin resistance, and incident type 2 diabetes mellitus (T2DM) risk. In addition, we examined the role of body mass index (BMI) as a potential effect modifier in this association.MethodsThis prospective study included 399 Japanese Americans without diabetes (mean age 51.6 years) who at baseline had an estimation of thigh muscle mass by computed tomography and at baseline and after 10 years of follow-up a 75-g oral glucose tolerance test and determination of homeostasis model assessment of insulin resistance (HOMA-IR). We fit regression models to examine the association between thigh muscle area and incidence of T2DM and change in HOMA-IR, both measured over 10 years.ResultsThigh muscle area was inversely associated with future HOMA-IR after adjustment for age, sex, BMI, HOMA-IR, fasting plasma glucose, total abdominal fat area, and thigh subcutaneous fat area at baseline (P=0.033). The 10-year cumulative incidence of T2DM was 22.1%. A statistically significant interaction between thigh muscle area and BMI was observed, i.e., greater thigh muscle area was associated with lower risk of incident T2DM for subjects at lower levels of BMI, but this association diminished at higher BMI levels.ConclusionThigh muscle mass area was inversely associated with future insulin resistance. Greater thigh muscle area predicts a lower risk of incident T2DM for leaner Japanese Americans.

The use of ultrasound for the estimation of muscle mass: one site fits most?

The use of ultrasound for the estimation of muscle mass: one site fits most?

Estimation of skeletal muscle mass, serum creatinine and creatine kinase at the onset of amyotrophic lateral sclerosis

Background: Amyotrophic Lateral Sclerosis (ALS) is a rapid progressive devastating neurodegenerative disease, however, clinical manifestation at the timing of disease onset is unclear.

The incidence of sarcopenia among hospitalized older patients: results from the Glisten study.

BackgroundNew evidence is emerging on the importance of lean body mass during periods of illness and recovery. The preservation of lean body mass during such periods of intense stress impacts both patient and treatment outcomes. However, data concerning the incidence of sarcopenia among older people during hospitalization are scarce. The objective of this study was to evaluate the development of sarcopenia in a sample of hospitalized older subjects.MethodsWe used data of 394 participants from the multicentre Italian Study conducted by the Gruppo Lavoro Italiano Sarcopenia—Trattamento e Nutrizione (GLISTEN) in 12 Acute Care Wards (Internal Medicine and Geriatrics) of University Hospitals across Italy. This study was designed to determine the prevalence of sarcopenia at hospital admission and the change in muscle mass and strength during hospitalization. Sarcopenia was defined as low skeletal mass index (kg/m2) along with either low handgrip strength or slow walking speed [European Working Groups on Sarcopenia in Older People (EWGSOP) criteria]. Estimation of skeletal muscle mass was performed by bioelectrical impedance analysis (BIA).ResultsThe mean age of the 394 enrolled patients (including 211 females who accounted for 53% of the sample) was 79.6 ± 6.4 years. Among those without sarcopenia at hospital admission, 14.7% of the study sample met the EWGSOP sarcopenia diagnostic criteria at discharge. The incidence of sarcopenia during hospitalization was significantly associated with the number of days spent in bed but was not correlated with the total length of hospital stay. In particular, patients who developed sarcopenia spent an average of 5.1 days in bed compared with 3.2 days for those with no sarcopenia at discharge (P = 0.02). Patients with sarcopenia showed a significantly lower body mass index compared with non‐sarcopenic peers (25.0 ± 3.8 kg/m2 vs. 27.6 ± 4.9 kg/m2, respectively; P < 0.001). Similarly, the skeletal mass index at admission was significantly lower among patients who developed sarcopenia during hospital stay.ConclusionsIncident sarcopenia during hospital stay is relatively common and is associated with nutritional status and the number of days of bed rest.

Sarcopenia in patients with hip fracture: A multicenter cross-sectional study.

BackgroundSarcopenia is prevalent in older persons and is a risk factor for falls, fractures, and mortality. The aim of this study was to determine a) the feasibility of determining sarcopenia in patients with acute hip fracture, b) the prevalence of sarcopenia and c) associations of sarcopenia with nutritional status and comorbidities.MethodsA multicenter cross-sectional study on sarcopenia in male and female patients with acute hip fracture. Participants were previously ambulatory and living in the community. Sarcopenia was assessed postoperatively with muscle mass estimated by anthropometry using triceps skinfold, arm circumference, height, weight and sex. Grip strength was measured by Jamar dynamometer and pre-fracture mobility was by self-report using the New Mobility Score.ResultsOut of 282 patients, 202 were assessed for sarcopenia of whom 74 (37%) were diagnosed as sarcopenic. Sarcopenia was associated with age, odds ratio (OR) 1.4 per 5 years, 95% confidence interval (CI) [1.1, 1.8], ASA Physical Status Classification System score, OR 2.3 per point, 95% CI [1.3, 4.3] and number of medications at discharge, OR 1.2 per medication, 95% CI [1.0, 1.3] and inversely associated with BMI, OR 0.8, 95% CI [0.7, 0.9] and serum albumin, OR 0.9, 95% CI [0.8,1.0].ConclusionsThirty-seven percent of assessed subjects were diagnosed with sarcopenia. Our data demonstrates that the prevalence of sarcopenia is associated with older age, malnutrition and comorbidities. Determining sarcopenia at the bedside was feasible in postoperative hip fracture patients by using grip strength, estimation of muscle mass by anthropometry and self-reported mobility.

Creatine (methyl-d3) dilution in urine for estimation of total body skeletal muscle mass: accuracy and variability vs. MRI and DXA

A noninvasive method to estimate muscle mass based on creatine ( methyl-d3) (D3-creatine) dilution using fasting morning urine was evaluated for accuracy and variability over a 3- to 4-mo period. Healthy older (67- to 80-yr-old) subjects ( n = 14) with muscle wasting secondary to aging and four patients with chronic disease (58-76 yr old) fasted overnight and then received an oral 30-mg dose of D3-creatine at 8 AM ( day 1). Urine was collected during 4 h of continued fasting and then at consecutive 4- to 8-h intervals through day 5. Assessment was repeated 3-4 mo later in 13 healthy subjects and 1 patient with congestive heart failure. Deuterated and unlabeled creatine and creatinine were measured using liquid chromatography-tandem mass spectrometry. Total body creatine pool size and muscle mass were calculated from D3-creatinine enrichment in urine. Muscle mass was also measured by whole body MRI and 24-h urine creatinine, and lean body mass (LBM) was measured by dual-energy X-ray absorptiometry (DXA). D3-creatinine urinary enrichment from day 5 provided muscle mass estimates that correlated with MRI for all subjects ( r = 0.88, P < 0.0001), with less bias [difference from MRI = -3.00 ± 2.75 (SD) kg] than total LBM assessment by DXA, which overestimated muscle mass vs. MRI (+22.5 ± 3.7 kg). However, intraindividual variability was high with the D3-creatine dilution method, with intrasubject SD for estimated muscle mass of 2.5 kg vs. MRI (0.5 kg) and DXA (0.8 kg). This study supports further clinical validation of the D3-creatine method for estimating muscle mass. NEW & NOTEWORTHY Measurement of creatine ( methyl-d3) (D3-creatine) and D3-creatinine excretion in fasted morning urine samples may be a simple, less costly alternative to MRI or dual-energy X-ray absorptiometry (DXA) to calculate total body muscle mass. The D3-creatine enrichment method provides estimates of muscle mass that correlate well with MRI, and with less bias than DXA. However, intraindividual variability is high with the D3-creatine method. Studies to refine the spot urine sample method for estimation of muscle mass may be warranted.

Developing and Validating an Age-Independent Equation Using Multi-Frequency Bioelectrical Impedance Analysis for Estimation of Appendicular Skeletal Muscle Mass and Establishing a Cutoff for Sarcopenia.

Background: Appendicular skeletal muscle (or lean) mass (ALM) estimated using dual-energy X-ray absorptiometry (DXA) is considered to be a preferred method for sarcopenia studies. However, DXA is expensive, has limited portability, and requires radiation exposure. Bioelectrical impedance analysis (BIA) is inexpensive, easy to use, and portable; thus BIA might be useful in sarcopenia investigations. However, a large variety of models have been commercially supplied by different companies, and for most consumer products, the equations estimating ALM are not disclosed. It is therefore difficult to use these equations for research purposes. In particular, the BIA equation is often age-dependent, which leads to fundamental difficulty in examining age-related ALM loss. The aims of the current study were as follows: (1) to develop and validate an equation to estimate ALM using multi-frequency BIA (MF-BIA) based on theoretical models, and (2) to establish sarcopenia cutoff values using the equation for the Japanese population. Methods: We measured height (Ht), weight, and ALM obtained using DXA and a standing-posture 8-electrode MF-BIA (5, 50, 250 kHz) in 756 Japanese individuals aged 18 to 86-years-old (222 men and 301 women as developing equation group and 97 men and 136 women as a cross validation group). The traditional impedance index (Ht2/Z50) and impedance ratio of high and low frequency (Z250/Z5) of hand to foot values were calculated. Multiple regression analyses were conducted with ALM as dependent variable in men and women separately. Results: We created the following equations: ALM = (0.6947 × (Ht2/Z50)) + (−55.24 × (Z250/Z5)) + (−10,940 × (1/Z50)) + 51.33 for men, and ALM = (0.6144 × (Ht2/Z50)) + (−36.61 × (Z250/Z5)) + (−9332 × (1/Z50)) + 37.91 for women. Additionally, we conducted measurements in 1624 men and 1368 women aged 18 to 40 years to establish sarcopenia cutoff values in the Japanese population. The mean values minus 2 standard deviations of the skeletal muscle mass index (ALM/Ht2) in these participants were 6.8 and 5.7 kg/m2 in men and women, respectively. Conclusion: The current study established and validated a theoretical and age-independent equation using MF-BIA to estimate ALM and provided reasonable sarcopenia cutoff values.

Modified Creatinine Index and the Risk of Bone Fracture in Patients Undergoing Hemodialysis: The Q-Cohort Study

Hemodialysis patients are at increased risk for bone fracture and sarcopenia. There is close interplay between skeletal muscle and bone. However, it is still unclear whether lower skeletal muscle mass increases the risk for bone fracture. Cross-sectional study and prospective longitudinal cohort study. An independent cohort of 78 hemodialysis patients in the cross-sectional study and 3,030 prevalent patients undergoing maintenance hemodialysis prospectively followed up for 4 years. Skeletal muscle mass measured by bioelectrical impedance analysis (BIA) and modified creatinine index, an estimate of skeletal muscle mass based on age, sex, Kt/V for urea, and serum creatinine level. Bone fracture at any site. In the cross-sectional study, modified creatinine index was significantly correlated with skeletal muscle mass measured by BIA. During a median follow-up of 3.9 years, 140 patients had bone fracture. When patients were divided into sex-specific quartiles based on modified creatinine index, risk for bone fracture estimated by a Fine-Gray proportional subdistribution hazards model with all-cause death as a competing risk was significantly higher in the lower modified creatinine index quartiles (Q1 and Q2) compared to the highest modified creatinine index quartile (Q4) as the reference value in both sexes (multivariable-adjusted HRs for men were 7.81 [95% CI, 2.63-23.26], 5.48 [95% CI, 2.08-14.40], 2.24 [95%CI, 0.72-7.00], and 1.00 [P for trend< 0.001], and for women were 4.44 [95% CI, 1.50-13.11], 2.33 [95% CI, 0.86-6.31], 1.96 [95% CI, 0.82-4.65], and 1.00 [P for trend= 0.007] for Q1, Q2, Q3, and Q4, respectively). One-time assessment of modified creatinine index; no data for residual kidney function and fracture sites and causes. Modified creatinine index was correlated with skeletal muscle mass measured by BIA. Lower modified creatinine index was associated with increased risk for bone fracture in male and female hemodialysis patients.

Measurement of muscle mass in sarcopenia: from imaging to biochemical markers.

Sarcopenia encompasses the loss of muscle mass and strength/function during aging. Several methods are available for the estimation of muscle or lean body mass. Popular assessment tools include body imaging techniques (e.g., magnetic resonance imaging, computed tomography, dual X-ray absorptiometry, ultrasonography), bioelectric impedance analysis, anthropometric parameters (e.g., calf circumference, mid-arm muscle circumference), and biochemical markers (total or partial body potassium, serum and urinary creatinine, deuterated creatine dilution method). The heterogeneity of the populations to be evaluated as well as the setting in which sarcopenia is investigated impacts the definition of "gold standard" assessment techniques. The aim of this article is to critically review available methods for muscle mass estimation, highlighting strengths and weaknesses of each of them as well as their proposed field of application.

Involvement of oxidative stress in atherosclerosis development in subjects with sarcopenic obesity.

SummaryIntroduction Co-existing decreased muscle mass and increased visceral fat, an age-associated change called sarcopenic obesity, results in fragility and cardiovascular disease. To assess the pathogenesis of sarcopenic obesity, we assessed the associations of clinical parameters with psoas muscle mass in elderly male subjects with obesity and type 2 diabetes. Methods The subjects were 55 patients, over 65 years of age and with a visceral fat area exceeding 100 cm2, with type 2 diabetes. The cross-sectional area of the psoas muscle is considered to provide an estimation of overall muscle mass. Sarcopenia was considered to be present when the total psoas muscle area was low, defined as a value below 500 mm2 m−2 on a computed tomographic scan. Results The maximum intima-media thickness (max IMT) and urinary 8-isoprostane values were significantly higher in the sarcopenic group. Multiple linear regression analysis revealed max IMT to be an independent variable related to muscle mass decline. In addition, logistic analysis showed max IMT and urinary 8-isoprostane to be variables independently contributing to total psoas muscle area <500 mm2 m−2. Conclusion Worsening surrogate markers for systemic oxidative stress and atherosclerosis were associated with declining muscle mass in elderly subjects with obesity and type 2 diabetes. These results indicate that systemic oxidative stress is among the mechanisms underlying atherosclerosis development in subjects with sarcopenic obesity.