Bioelectrical impedance analysis as an alternative to dual-energy x-ray absorptiometry in the assessment of fat mass and appendicular lean mass in patients with obesity

Normative Values and Anthropometric Prediction Models for Lean Mass and Fat Mass in the Northeastern Thai Population

Background: Data on reference values for lean mass (LM) and fat mass (FM) in the Southeast Asian populations are currently lacking. Therefore, we aimed to estimate the normative values and generate anthropometric prediction models for LM and FM in the Thai population. Methods: Consecutive community-dwelling individuals aged 20-90 years were recruited from Srinagarind Hospital, Khon Kaen, Thailand, between 2010 and 2015. LM and FM were measured using dual energy X-ray absorptiometry. Age and sex stratified percentile of LM and FM were presented. Anthropometric prediction models for LM and FM were developed by using linear regression to generate competing models. Results: A total of 832 individuals (334 males and 498 females) were included in the study. The mean ± SD age, LM, and FM were 50.0 ± 16.2 years, 38.9 ± 8.0 kg, and 15.5 ± 7.7 kg, respectively. LM decreased with age from 49.4 kg in 20-29 years group to 42.3 kg in ≥70 years group in male and 34.6 kg in 30-39 years group to 30.8 kg in ≥70 years group in females. FM has an inverse U-shaped association with age, which peaked at 11.9 kg in 60-69 years group in males and 20.7 kg in 50-59 years group in females. Among the various anthropometric models, the models incorporating age, sex, weight, and height were considered the best fit for predicting both LM and FM. Conclusion: In the Thai population, peak LM was reached during early adulthood and decline with age, whereas FM showed an inverse U-shaped association with age. The prediction models incorporating age, sex, weight, and height were proposed as practical tools for assessing LM and FM in clinical practice.

Association between systemic immune-inflammation index and sarcopenic obesity in middle-aged and elderly Chinese adults: a cross-sectional study and mediation analysis

BACKGROUND

Despite the known association between chronic inflammation and reduced muscle mass, there is a gap in research regarding the association between the systemic immune-inflammation index (SII) and sarcopenic obesity (SO). This study aims to assess the relationship between SII and SO in middle-aged and elderly adults and the mediating role of triglyceride-glucose index (TyG).

METHODS

This cross-sectional study involved 2,719 participants aged 45-90 years who underwent health check-ups. SO was evaluated by combining sarcopenia [assessed by handgrip strength and appendicular skeletal muscle index (ASMI)] with obesity (determined by body fat percentage). Association between SII and SO, sarcopenia, and obesity in middle-aged and elderly individuals was examined using multivariable logistic regression, restricted cubic spline analysis, and subgroup analysis. Bidirectional mediation analysis was conducted to determine the direct and indirect effects through SII and TyG.

RESULTS

The study included 2,719 participants, of which 228 had SO (8.4%). SO prevalence increased as the SII quartiles rose (Pfor trend <0.001). SII (per SD increase) had a significantly positive association with SO in both middle-aged individuals (OR = 1.69, 95% CI: 1.43 ~ 1.99) and older adults (OR = 2.52, 95% CI: 1.68 ~ 3.77). The relationship between SII and SO was found to be non-linear (Pnonlinear<0.05). In addition, SII showed a strong negative relationship with both handgrip strength and ASMI across all participants. In subgroup analysis, SII was still shown to significantly increase the risk of SO in all subgroups by gender, body mass index, waist circumference, smoking, drinking, hypertension, diabetes, dyslipidemia. TyG was found to mediate 21.36%, 11.78%, and 9.94% of the associations between SII and SO, sarcopenia, and obesity, respectively. SII had no mediation effect on the association between TyG and SO, sarcopenia, and obesity (P>0.05).

CONCLUSIONS

Elevated levels of SII were associated with an increased risk of SO in middle-aged and elderly adults, especially in the elderly population, and elevated TyG levels played a role in this relationship.

Exercise snacks are a time-efficient alternative to moderate-intensity continuous training for improving cardiorespiratory fitness but not maximal fat oxidation in inactive adults: a randomized controlled trial

The aims of this study were (1) to determine how stair-climbing-based exercise snacks (ES) compared to moderate-intensity continuous training (MICT) for improving cardiorespiratory fitness (CRF), and (2) to explore whether ES could improve maximal fat oxidation rate (MFO) in inactive adults. Healthy, young, inactive adults (n: 42, age: 21.6 ± 2.3 years, BMI: 22.5 ± 3.6 kg·m-2, peak oxygen uptake (VO2peak): 33.6 ± 6.3 mL·kg-1·min-1) were randomly assigned to ES, MICT, or Control. ES (n = 14) and MICT (n = 13) groups performed three sessions per week over 6 weeks, while the control group (n = 15) maintained their habitual lifestyle. ES involved 3 × 30 s "all-out" stair-climbing (6 flight, 126 steps, and 18.9 m total height) bouts separated by >1 h rest, and MICT involved 40 min × 60%-70% HRmax stationary cycling. A significant group × time interaction was found for relative VO2peak (p < 0.05) with ES significantly increasing by 7% compared to baseline (MD = 2.5 mL·kg-1·min-1 (95% CI = 1.2, 3.7), Cohen's d = 0.44), while MICT had no significant effects (MD = 1.0 mL·kg-1·min-1 (-1.1, 3.2), Cohen's d = 0.17), and Control experienced a significant decrease (MD = -1.7 mL·kg-1·min-1 (-2.9, -0.4), Cohen's d = 0.26). MFO was unchanged among the three groups (group × time interaction, p > 0.05 for all). Stair climbing-based ES are a time-efficient alternative to MICT for improving CRF among inactive adults, but the tested ES intervention appears to have limited potential to increase MFO.

CT imaging-derived phenotypes for abdominal muscle and their association with age and sex in a medical biobank

The study of muscle mass as an imaging-derived phenotype (IDP) may yield new insights into determining the normal and pathologic variations in muscle mass in the population. This can be done by determining 3D abdominal muscle mass from 12 distinct abdominal muscle regions and groups using computed tomography (CT) in a racially diverse medical biobank. To develop a fully automatic technique for assessment of CT abdominal muscle IDPs and preliminarily determine abdominal muscle IDP variations with age and sex in a clinically and racially diverse medical biobank. This retrospective study was conducted using the Penn Medicine BioBank (PMBB), a research protocol that recruits adult participants during outpatient visits at hospitals in the Penn Medicine network. We developed a deep residual U-Net (ResUNet) to segment 12 abdominal muscle groups including the left and right psoas, quadratus lumborum, erector spinae, gluteus medius, rectus abdominis, and lateral abdominals. 110 CT studies were randomly selected for training, validation, and testing. 44 of the 110 CT studies were selected to enrich the dataset with representative cases of intra-abdominal and abdominal wall pathology. The studies were divided into non-overlapping training, validation and testing sets. Model performance was evaluated using the Sørensen-Dice coefficient. Volumes of individual muscle groups were plotted to distribution curves. To investigate associations between muscle IDPs, age, and sex, deep learning model segmentations were performed on a larger abdominal CT dataset from PMBB consisting of 295 studies. Multivariable models were used to determine relationships between muscle mass, age and sex. The model's performance (Dice scores) on the test data was the following: psoas: 0.85 ± 0.12, quadratus lumborum: 0.72 ± 0.14, erector spinae: 0.92 ± 0.07, gluteus medius: 0.90 ± 0.08, rectus abdominis: 0.85 ± 0.08, lateral abdominals: 0.85 ± 0.09. The average Dice score across all muscle groups was 0.86 ± 0.11. Average total muscle mass for females was 2041 ± 560.7 g with a high of 2256 ± 560.1 g (41-50 year old cohort) and a change of - 0.96 g/year, declining to an average mass of 1579 ± 408.8 g (81-100 year old cohort). Average total muscle mass for males was 3086 ± 769.1 g with a high of 3385 ± 819.3 g (51-60 year old cohort) and a change of - 1.73 g/year, declining to an average mass of 2629 ± 536.7 g (81-100 year old cohort). Quadratus lumborum was most highly correlated with age for both sexes (correlation coefficient of - 0.5). Gluteus medius mass in females was positively correlated with age with a coefficient of 0.22. These preliminary findings show that our CNN can automate detailed abdominal muscle volume measurement. Unlike prior efforts, this technique provides 3D muscle segmentations of individual muscles. This technique will dramatically impact sarcopenia diagnosis and research, elucidating its clinical and public health implications. Our results suggest a peak age range for muscle mass and an expected rate of decline, both of which vary between genders. Future goals are to investigate genetic variants for sarcopenia and malnutrition, while describing genotype-phenotype associations of muscle mass in healthy humans using imaging-derived phenotypes. It is feasible to obtain 3D abdominal muscle IDPs with high accuracy from patients in a medical biobank using fully automated machine learning methods. Abdominal muscle IDPs showed significant variations in lean mass by age and sex. In the future, this tool can be leveraged to perform a genome-wide association study across the medical biobank and determine genetic variants associated with early or accelerated muscle wasting.

Prevalence of Sarcopenia and Its Defining Components in Non-alcoholic Fatty Liver Disease Varies According to the Method of Assessment and Adjustment: Findings from the UK Biobank

Sarcopenia may increase non-alcoholic fatty liver disease (NAFLD) risk, but prevalence likely varies with different diagnostic criteria. This study examined the prevalence of sarcopenia and its defining components in adults with and without NAFLD and whether it varied by the method of muscle mass assessment [bioelectrical impedance (BIA) versus dual-energy X-ray absorptiometry (DXA)] and adjustment (height2 versus BMI). Adults (n = 7266) in the UK Biobank study (45-79 years) with and without NAFLD diagnosed by MRI, were included. Sarcopenia was defined by the 2018 European Working Group on Sarcopenia in Older People definition, with low appendicular skeletal muscle mass (ASM) assessed by BIA and DXA and adjusted for height2 or BMI. Overall, 21% of participants had NAFLD and the sex-specific prevalence of low muscle strength (3.6-7.2%) and sarcopenia (0.1-1.4%) did not differ by NAFLD status. However, NAFLD was associated with 74% (males) and 370% (females) higher prevalence of low ASM when adjusted for BMI but an 82% (males) to 89% (females) lower prevalence when adjusted for height2 (all P < 0.05). The prevalence of impaired physical function was 40% (males, P = 0.08) to 123% (females, P < 0.001) higher in NAFLD. In middle-aged and older adults, NAFLD was not associated with a higher prevalence of low muscle strength or sarcopenia but was associated with an increased risk of impaired physical function and low muscle mass when adjusted for BMI. These findings support the use of adiposity-based adjustments when assessing low muscle mass and the assessment of physical function in NAFLD.

Prevalence of sarcopenic obesity according to different diagnostic methods and cut-off points in candidates for bariatric surgery

BACKGROUND AND AIMS

Sarcopenic obesity (SO) is defined as a combination of low strength and muscle mass along with excess adiposity. Our study aimed to determine the prevalence of sarcopenic obesity in candidates for bariatric surgery, according to ESPEN/EASO criteria using bioimpedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA).

METHODS

Retrospective study of adult patients (18-60 years) candidates for bariatric surgery (BMI ≥40 kg/m2 or ≥35 kg/m2 with associated complications). Adiposity was assessed by the percentage of fat mass by DXA, according to Gallagher's cut-off points. Muscle strength was measured by hand grip according to Sánchez-Torralvo, Dodds, and <-2SD cut-off points of healthy reference population. Muscle mass was determined by DXA (ALM/weight according to Batsis) and by BIA (SMM/weight according to Janssen and according to reference population). In addition, the agreement of the different diagnostic methods of sarcopenic obesity was analyzed.

RESULTS

A total of 124 subjects were included in the study, with 71.8 % being women. The overall mean age was 42.6 (SD 8.9) years. SO prevalence was found to be 13 %-22 % applying BIA with the SMM/weight equation according to Janssen, 14 %-23 % utilizing BIA with the SMM/weight equation according to the reference population, and 13 %-23 % employing DXA with the ALM/weight equation following Batsis criteria, depending on the specific hand grip strength cut-off points used. In general, we found good or very good concordances with the different diagnostic methods (with kappa values between 0.6 and 0.97).

CONCLUSIONS

The prevalence of SO according to ESPEN/EASO criteria in candidates for bariatric surgery was 13 %-23 % based on the diagnostic method and cut-off points used.

Comparison between Discrete Multi-Wavelength Near-Infrared Spectroscopy and Bioelectrical Impedance Analysis in the Assessment of Muscle Mass for Community-Dwelling Older People

(1) Background: This study evaluated the clinical implications of a new measurement technique for muscle mass using discrete multi-wavelength near-infrared spectroscopy (DMW-NIRS) compared with multifrequency bioelectrical impedance analysis (BIA) in older adults. (2) Methods: In a cross-sectional study involving 91 participants aged 65 years, the agreement of total lean mass for each measurement was assessed using the intraclass correlation coefficient (ICC) and Pearson's correlation analysis. The study was conducted at a university hospital from 10 July 2023 to 1 November 2023. (3) Results: A total of 45 men (mean age, 74.1) and 46 women (mean age, 73.6) were analyzed. In the comparisons of total lean mass between DMW-NIRS and BIA, ICC (2.1) was 0.943 and Cronbach's α coefficient was 0.949 (p < 0.001). Across all segments of lean mass, we found excellent agreement with the ICCs (>0.90) and acceptable values of the correlation coefficients (>0.6) between DMW-NIRS and BIA. (4) Conclusions: This study confirmed agreement in the measurements of muscle mass between portable devices using DMW-NIRS and BIA among community-dwelling older adults. A simple screening of muscle mass in a home setting would help to detect early decreases in muscle mass.

Increased visceral fat area to skeletal muscle mass ratio is positively associated with the risk of metabolic dysfunction-associated steatotic liver disease in a Chinese population

BACKGROUND

The diagnosis and comprehension of nonalcoholic fatty liver disease (NAFLD), recently redefined as metabolic dysfunction-associated steatotic liver disease (MASLD) are gaining a better understanding. In this study, we examined the association between visceral fat area and skeletal muscle mass ratio (VSR) and the prevalence of MASLD in a Chinese population.

METHODS

A cross-sectional study was conducted involving 10,916 individuals who underwent bioelectrical impedance analysis, along with anthropometric and biochemical measurements, from January 2022 to June 2023. According to the VSR distribution, sex-specific quartiles of VSR within the study population were defined. Linear trend tests were performed for the categorized VSR variables. Logistic regression models were performed to estimate the odds ratio and 95% confidence intervals between VSR distribution and MASLD prevalence stratified by sex.

RESULTS

The prevalence of MASLD was 37.94% in the overall population (56.34% male), and it gradually increased with higher VSR levels in both genders (P < 0.001). Logistic regression analysis demonstrated a significant association between VSR and MASLD prevalence after adjusting for confounders. The odds ratio (95% confidence interval) for MASLD, comparing the lowest to the highest VSR quartile, was 3.159 (2.671, 3.736) for men and 2.230 (1.764, 2.819) for women (all P < 0.001). Restricted cubic splines also indicated significant non-linear relationships between VSR and MASLD prevalence.

CONCLUSIONS

VSR is positively associated with the prevalence of MASLD in this Chinese population, with a notably higher risk for men as VSR increases compared to women.

Fat and fat-free mass measurement agreement by dual-energy X-ray absorptiometry versus bioelectrical impedance analysis: Effects of posture and waist circumference

Background

Bioelectrical impedance analysis (BIA) operates under the assumption that the conductor has a uniform cylindrical shape. However, this assumption may be violated if measures are taken in the seated position, especially in people with a high waist circumference (WC).

Aims

The aims of this research were to determine whether posture (supine, standing, and seated) and WC affect agreement between BIA and dual-energy X-ray absorptiometry (DXA) measures of fat mass (FM) and fat-free mass (FFM).

Materials & Methods

Baseline data were collected from 28 adults (mean = 61.4 ± 6.9 years, 64.3% female) with obesity (BMI 38.6 ± 5.0 kg/m2). Body composition was measured using BIA in the supine, standing, and seated positions and by DXA while supine. Intraclass correlation coefficient (ICC) analyses with two-way mixed effects and absolute agreement were performed to determine agreement.

Results

Point estimates were excellent for FM and FFM while supine, excellent for FM and good for FFM while standing, and moderate for FM and good for FFM while seated. BIA measures in the supine position resulted in the narrowest 95% confidence intervals compared with other positions. Better agreement was observed across all positions in participants with a WC below the median (118.3 cm).

Discussion

Despite the potential pragmatic value of measuring with BIA in a seated position, the results of this analysis demonstrate the poorest agreement between DXA and BIA methods, especially in individuals with high WC.

Conclusion

Findings from this study demonstrate that BIA, particularly when measured in a supine position, can serve as a viable alternative to DXA for measuring body composition in people with obesity.

The Effects of an Eight-Week Swimming Program on Body Composition and Assessment of Dietary Intake in Post-COVID-19 Patients

COVID-19 infection and its consequences (long-term COVID-19 syndrome) have implications for weight loss, body composition, and diet quality. In the context of the "PostCovSwim" project, which is part of a broader international study, the impact of an eight-week swimming program on post-COVID-19 patients' nutritional status (i.e., body composition and dietary intake) was evaluated. Body composition and dietary intake were assessed by medically approved and calibrated bioelectrical impedance (Tanita 780 S MA) and food frequency questionnaires. At the baseline, most participants were classified as overweight based on their body mass index (BMI). However, their body fat percentage (BF%) classification indicated normal weight, although females were near obesity thresholds. Furthermore, at the baseline, according to the BMI classification, 62% of females and 61% of males were female, whereas according to the BF% for obesity classification, 44% of females and 43% of males were considered overweight or obese. Surprisingly, despite the eight-week program, there were no significant changes in body composition. Additionally, the assessment of dietary intake, which remained consistent throughout the study, revealed dietary imbalances characterized by an unhealthy low-carbohydrate, high-fat dietary pattern. This dietary pattern entailed excessive consumption of ultraprocessed foods; reduced carbohydrate intake (39% E vs. 37% E); increased total fat intake (46% E vs. 47% E); increased saturated fatty acids (14% E vs. 13% E); increased cholesterol (412 mg/d vs. 425 mg/d); increased free sugars (7% E vs. 7% E); and inadequate intake of fibre (24 g/d vs. 20 g/d), polyunsaturated fatty acids (6.6% E vs. 7.7% E), vitamin B12 (in females: 3.1 µg/d), vitamin C (86 mg/d vs. 66 mg/d), vitamin D (2 µg/d vs. 3.2 µg/d), folate (in males: 258 µg/d), calcium (777 mg/d vs. 743 mg/d), and selenium (in males: 66 µg/d). After an eight-week swimming program following COVID-19, no significant changes were observed in the subjects' body composition. Their dietary intake was found to not align with the dietary recommendations. These findings underscore the urgency of implementing comprehensive dietary and lifestyle interventions for post-COVID-19 patients to optimize their recovery and overall well-being. Physical activity, like a swimming program, may positively affect various aspects of human well-being.

Obesity - Standards, trends and advances

Obesity continues to be a significant global health concern, giving rise to various complications. This review article explores the current standards and emerging innovations in diagnosing and treating obesity, including recent disease name change, staging system or therapeutic goals. This narrative review has been based on recent scientific articles from PubMed database, limiting the scope of topics to current standards and upcoming developments and breakthroughs in the diagnosis and treatment of obesity. The educational and informative nature of the review has been maintained in order to make the information presented accessible to both researchers and clinical practitioners. The recognition of diverse obesity phenotypes has prompted a paradigm shift towards a complex and patient-centered approach to diagnosis and therapy. Pharmacotherapy for obesity is evolving rapidly, with ongoing research focusing on novel molecular targets and metabolic pathways. Promising developments include dual or triple incretin analogs, oral incretin drugs, neurotransmitter-based therapies, muscle mass-increasing treatments, and therapies targeting visceral adipose tissue browning. Despite current evidence-based international standards, the field of obesity diagnosis and treatment continues to expand, with new diagnostic tools and pharmacotherapies potentially replacing current practices. Therapeutic management should be tailored to individual patients, considering obesity phenotype, health status, lifestyle, and preferences. Looking ahead, the future holds promising opportunities for obesity management, but further research is required to assess the efficacy and safety of emerging therapies. A multifactorial and personalized approach will be pivotal in addressing the diverse challenges posed by obesity.

[Body composition models based on anthropometry, systematic literature review]

Introduction

The body composition determination is carried out through measurement methods that require the use of specialized equipment that is difficult to acquire and manipulate. Therefore, different authors have developed mathematical models for its calculation. The target of this review was to analyze the work carried out on mathematical models of body composition variables from different anthropometric measurements, answering the following questions: what is the corporal variable that the model predicts?, what are the input variables for model development?, how is the patients typification in each model?, what data analysis method has been used?, and how has been the model evaluated? The search was limited to journals found in repositories in the areas of Medicine, Nursing, Biochemistry, Biology, Health, Pharmacology, Immunology, Engineering, and Mathematics. Four hundred and twenty-four articles were found, which were reduced to 30 by applying the systematic literature review process. The analyzed studies are oriented to the prediction of variables related to body fat mass. The evaluation results found for fat-free mass, fat mass and metabolic rate differ according to the comparison technique and the body segments analyzed. The evaluation is mainly based on the intraclass correlation, the Pearson correlation and the coefficient of determination (r2), and they present a good correlation for the population under study.

Obesity and diabetes

Obesity, which has currently reached pandemic dimensions, is usually accompanied by diabetes mellitus type 2 (T2DM). These two conditions share common pathophysiological mechanisms. Adipose tissue secretes cytokines which are involved in inflammation and various endocrine functions. As for T2DM, it is characterized also by inflammation, mitochondrial dysfunction, and hyperinsulinemia. These conditions occur also in other diseases related to obesity and T2DM, like cardiovascular disease (CVD) and nonalcoholic fatty liver disease (NAFLD). Thus, management of obesity-related complications with lifestyle modification, anti-obesity drugs, and bariatric surgery, all contribute to improvement in any of these conditions. This review provides an overview of the literature addressing the association between obesity and T2DM, briefly discussing the pathophysiological mechanisms linking these conditions and outlining the management approach at the overlap of obesity and T2DM.

Sarcopenic obesity research perspectives outlined by the sarcopenic obesity global leadership initiative (SOGLI) - Proceedings from the SOGLI consortium meeting in rome November 2022

The European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO) launched the Sarcopenic Obesity Global Leadership Initiative (SOGLI) to reach expert consensus on a definition and diagnostic criteria for Sarcopenic Obesity (SO). The present paper describes the proceeding of the Sarcopenic Obesity Global Leadership Initiative (SOGLI) meeting that was held on November 25th and 26th, 2022 in Rome, Italy. This consortium involved the participation of 50 researchers from different geographic regions and countries. The document outlines an agenda advocated by the SOGLI expert panel regarding the pathophysiology, screening, diagnosis, staging and treatment of SO that needs to be prioritized for future research in the field.

Change in skeletal muscle mass is associated with hepatic steatosis in nonalcoholic fatty liver disease

The association between nonalcoholic fatty liver disease (NAFLD) and sarcopenia is known. We aimed to determine the association between skeletal muscle mass changes and NAFLD status. This retrospective single-center study analyzed patients who underwent health screening twice between November 2009 and December 2017, with a temporal gap of 6 ± 0.5 years. The degree of sarcopenia was assessed using appendicular skeletal muscle mass (ASM) adjusted for weight and body mass index (BMI). Changes in hepatic steatosis and fibrosis status were evaluated using noninvasive serum markers. Patients with a decrease in ASM/BMI (n = 353) had increased hepatic steatosis index (HSI) and fatty liver index (FLI) scores during 6 years (p < 0.05). The baseline sarcopenia group had a greater elevation in NAFLD fibrosis score (NFS) over 6 years than those without baseline sarcopenia. ASM changes over 6 years showed a negative correlation with variations in HSI (β = - 0.96 in ASM/Weight and -28.93 in ASM/BMI) and FLI (β = - 5.44 in ASM/Weight and - 167.12 in ASM/BMI). Subgroup analyses showed similar results according to sex and age. Sarcopenia may worsen steatosis and vice versa. Skeletal muscle status can be used to predict the course of NAFLD and establish individualized treatment strategies.

[Assessment of low muscle mass and strength in a control population]

Introduction

Background and aims: low muscle mass (LMM) conditions the nutritional status of an individual and has implications for quality of life and prognosis. The aim of this study was to evaluate body composition and determine normal values in the diagnosis of LMM in a control group of healthy individuals. Methods: a cross-sectional study of healthy volunteers aged 18 to 45 years with body mass index (BMI) < 30 kg/m2. A descriptive study was performed including demographic, clinical, anthropometric, and body composition variables (by bioimpedance, TANITA MC 780 MA; TANITA, Tokyo, Japan), stratified by age, sex and BMI. Values corresponding to -1/-2 standard deviations (SD) were determined to consider low muscle mass/function. Results: we included 67 patients, 71,60 % women, with a median age of 28.29 (IQR 4.05) years. Males presented higher weight, BMI, fat-free mass (FFM), muscle mass (MM), appendicular lean mass (ALM), appendicular lean mass index (ALMI), and dynamometry values when compared to females. The -1/-2 SD values of the various muscle parameters were determined according to sex. Conclusion: this study determined normal LMM values in healthy and young people, and the most commonly used indexes to express it, which will allow the diagnosis of LMM in disease-related situations using the corresponding -2 DS value.

Effectiveness of Fecal Microbiota Transplantation for Weight Loss in Patients With Obesity Undergoing Bariatric Surgery: A Randomized Clinical Trial

IMPORTANCE

Severe obesity is a major health concern. However, a few patients remain resistant to bariatric surgery and other treatments. Animal studies suggest that weight may be altered by fecal microbiota transplantation (FMT) from a lean donor.

OBJECTIVE

To determine whether FMT from a lean donor reduces body weight and further improves the results of bariatric surgery.

DESIGN, SETTING, AND PARTICIPANTS

This double-blinded, placebo-controlled, multicenter, randomized clinical trial was conducted in 2018 to 2021 among adult individuals with severe obesity treated at 2 bariatric surgery centers in Finland and included 18 months of follow-up. Patients eligible for bariatric surgery were recruited for the study. Data were analyzed from March 2021 to May 2022.

INTERVENTIONS

FMT from a lean donor or from the patient (autologous placebo) was administered by gastroscopy into the duodenum. Bariatric surgery was performed 6 months after the baseline intervention using laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG).

MAIN OUTCOMES AND MEASURES

The main outcome was weight reduction measured as the percentage of total weight loss (TWL).

RESULTS

Forty-one patients were recruited to participate in the study and were included in the final analysis (29 women [71.1%]; mean [SD] age, 48.7 [8.7] years; mean [SD] body mass index, 42.5 [6.0]). A total of 21 patients received FMT from a lean donor, and 20 received an autologous placebo. Six months after FMT, 34 patients underwent LRYGB and 4 underwent LSG. Thirty-four patients (82.9%) attended the last visit 18 months after the baseline visit. The percentage of TWL at 6 months was 4.8% (95% CI, 2.7% to 7.0%; P < .001) in the FMT group and 4.6% (95% CI, 1.5% to 7.6%; P = .006) in the placebo group, but no difference was observed between the groups. At 18 months from the baseline (ie, 12 months after surgery), the percentage of TWL was 25.3% (95% CI, 19.5 to 31.1; P < .001) in the FMT group and 25.2% (95% CI, 20.2 to 30.3; P < .001) in the placebo group; however, no difference was observed between the groups.

CONCLUSIONS AND RELEVANCE

FMT did not affect presurgical and postsurgical weight loss. Further studies are needed to elucidate the possible role of FMT in obesity.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03391817.

External validation of BIA equations to estimate appendicular skeletal muscle mass in older adults: Importance of the bias analysis and derivation of correction factors to achieve agreement

There are several equations based on bioelectrical impedance analysis (BIA) to estimate with high precision appendicular skeletal muscle mass (ASM). However, most of the external validation studies have reported that these equations are inaccurate or biased when applied to different populations. Furthermore, none of the published studies has derived correction factors (CFs) in samples of community-dwelling older adults, and none of the published studies have assessed the influence of the dual-energy X-ray absorptiometry (DXA) model on the validation process. This study assessed the agreement between six BIA equations and DXA to estimate ASM in non-Caucasian older adults considering the DXA model and proposed a CF for three of them. This analysis included 547 non-institutionalized subjects over 60 years old from the northwest of Mexico who were physically independent and without cognitive impairment: 192 subjects were measured using DXA Hologic, while 355 were measured by DXA Lunar. The agreement between each of the equations and DXA was tested considering the DXA model used as a reference method for the design of each equation, using the Bland and Altman procedure, a paired t test, and simple linear regression as objective tests. This process was supported by the differences reported in the literature and confirmed in a subsample of 70 subjects measured with both models. Only six published BIA equations were included. The results showed that four equations overestimated ASM_DXA, and two underestimated it (p < 0.001, 95% CI for Kim's equation:−5.86-−5.45, Toselli's:−0.51-−0.15, Kyle's: 1.43–1.84, Rangel-Peniche's: 0.32–0.74, Sergi's: 0.83–1.23, and Yoshida's: 4.16–4.63 kg). However, Toselli's, Kyle's and Rangel-Peniche's equations were the only ones that complied with having a homogeneous bias. This finding allowed the derivation of CFs, which consisted of subtracting or adding the mean of the differences from the original equation. After estimating ASM applying the respective CF, the new ASM estimations showed no significant bias and its distribution remained homogeneously distributed. Therefore, agreement with DXA in the sample of non-Caucasian was achieved. Adding valid CFs to some BIA equations allowed to reduce the bias of some equations, making them valid to estimate the mean values of ASM at group level.

Bio-Electrical Impedance Analysis: A Valid Assessment Tool for Diagnosis of Low Appendicular Lean Mass in Older Adults?

Background

The diagnosis of sarcopenia is essential for early treatment of sarcopenia in older adults, for which assessment of appendicular lean mass (ALM) is needed. Multi-frequency bio-electrical impedance analysis (MF-BIA) may be a valid assessment tool to assess ALM in older adults, but the evidences are limited. Therefore, we validated the BIA to diagnose low ALM in older adults.

Methods

ALM was assessed by a standing-posture 8 electrode MF-BIA (Tanita MC-780) in 202 community-dwelling older adults (age ≥ 55 years), and compared with dual-energy X-ray absorptiometry (DXA) (Hologic Inc., Marlborough, MA, United States; DXA). The validity for assessing the absolute values of ALM was evaluated by: (1) bias (mean difference), (2) percentage of accurate predictions (within 5% of DXA values), (3) the mean absolute error (MAE), and (4) limits of agreement (Bland–Altman analysis). The lowest quintile of ALM by DXA was used as proxy for low ALM (< 22.8 kg for men, < 16.1 kg for women). Sensitivity and specificity of diagnosing low ALM by BIA were assessed.

Results

The mean age of the subjects was 72.1 ± 6.4 years, with a BMI of 25.4 ± 3.6 kg/m², and 71% were women. BIA slightly underestimated ALM compared to DXA with a mean bias of −0.6 ± 1.2 kg. The percentage of accurate predictions was 54% with a MAE of 1.1 kg, and limits of agreement were −3.0 to + 1.8 kg. The sensitivity for ALM was 80%, indicating that 80% of subjects who were diagnosed as low ALM according to DXA were also diagnosed low ALM by BIA. The specificity was 90%, indicating that 90% of subjects who were diagnosed as normal ALM by DXA were also diagnosed as normal ALM by the BIA.

Conclusion

This comparison showed a poor validity of MF-BIA to assess the absolute values of ALM, but a reasonable sensitivity and specificity to recognize the community-dwelling older adults with the lowest muscle mass.

Usefulness of Muscle Ultrasound to Study Sarcopenic Obesity: A Pilot Case-Control Study

Background and objectives: Sarcopenic obesity (SO) is an emerging problem, especially in candidates for bariatric surgery (BS). We hypothesized that musculoskeletal ultrasound (MUS), a simple and accessible method, could be a reliable index of SO. Materials and Methods: A cross-sectional pilot study including 122 subjects (90 cases and 32 controls, 73% female, mean age: 51.2 years) who underwent BS was conducted at University Hospital Mútua Terrassa. The lean mass (LM) was calculated by bioelectrical impedance analysis (BIA) and the thigh muscle thickness (TMT) by MUS. To identify the subjects with SO by BIA, we used skeletal muscle index (SMI). The validity of MUS was determined using the ROC curve. Results: The mean BMI in the obesity group was 44.22 kg/m2. We observed a correlation between the LM and SMI assessed by BIA and the TMT assessed by MUS (R = 0.46, p < 0.001). This correlation was maintained at significant levels in the SO group (n = 40): R = 0.79; p = 0.003). The TMT assessed by MUS was able to predict SMI using BIA (AUC 0.77; 95% CI: 0.68242 to 0.84281). The optimal cut-off point for maximum efficiency was 1.57 cm in TMT (sensitivity = 75.6% and specificity = 71.1%). Conclusions: The TMT of the quadriceps assessed by US is a useful tool for identifying subjects with SO. Larger studies to validate this simple low-cost screening strategy are warranted.

Longitudinal Assessment of Physical Activity, Fitness, Body Composition, Immunological Biomarkers, and Psychological Parameters During the First Year After Diagnosis in Women With Non-Metastatic Breast Cancer: The BEGYN Study Protocol

Background

Moderate physical activity is associated with an improved prognosis and psychosocial outcome in breast cancer patients. Although exercise and physical activity are associated with multiple physiological and psychological effects, many of the underlying mechanisms remain obscure. The BEGYN study (Influence of physical activity in breast cancer patients on physiological and psychological parameters and on biomarkers) aims at identifying potential associations between the extent of physical activity, fitness, body composition, immunological biomarkers, psycho-emotional parameters, and the course of treatment during the first year after diagnosis of breast cancer.

Methods

The prospective observational BEGYN study will include 110 non-metastatic breast cancer patients. The patients will be assessed during a base line visit prior to the initiation of the antineoplastic therapy and after 3, 6, 9 and 12 months. The physical activity will be measured using a fitness tracker and a self-assessment diary during the entire study. Each visit will include the assessment of (i) cardiorespiratory fitness measured by spiroergometry, (ii) body composition, (iii) psycho-emotional parameters (quality of life, mental health, fatigue, depression, distress, anxiety, well-being), and (iv) extensive blood tests including routine laboratory, vitamin D, selenium and immunologically relevant biomarkers (e.g., leukocyte subpopulations and cytokine profiles).

Discussion

Whereas most studies investigating the influence of physical activity in breast cancer patients focus on specific activities for three months or less, the BEGYN study will quantify the daily physical activity and cardiorespiratory fitness of breast cancer patients based on objective measurements in the context of the oncological therapy for 12 months after diagnosis. The study will reveal potential associations between exercise, immune status and physical as well as psycho-emotional outcome and the clinical course of the disease. Moreover, complementary therapies such as Vit D and Selenium supplementation and parameters investigating the motivation of the patients are part of the study. Due to this holistic approach, the BEGYN study will guide towards confirmatory studies on the role of physical activity in breast cancer patients to develop individualized counselling regarding the recommended type and extent of exercise.

Trial Registration

This study has been registered at the German Clinical Trials Register DRKS00024829.