Body composition assessment using bioelectrical impedance analysis (BIA) in a wide cohort of patients affected with mild to severe obesity

Association between phase angle and body composition: New equations to predict fat mass and skeletal muscle mass

OBJECTIVE

The aim of this cross-sectional study was to develop new regression equations for estimating fat mass (FM) and skeletal muscle mass (SMM) in a heterogeneous Caucasian population, using the phase angle (PhA) as a bioelectrical parameter and DXA as the reference method. We also aimed to cross-validate the new equations, and to compare them with the manufacturers' equations.

METHODS

The 212 healthy Caucasian participants aged 20-65 years were randomly distributed into two groups: development group (n = 141) and validation group (n = 71). Bioelectrical parameters were obtained with a 50 kHz foot-to-hand phase-sensitive body composition analyzer. The new FM percentage (FM%) and SMM percentage (SMM%) equations were developed by performing multiple forward regression analyses. Agreement between DXA and the different equations was assessed by mean differences, coefficient of determination, standard error of the estimate (SEE), concordance correlation coefficient (CCC), and Bland-Altman plots.

RESULTS

The proposed equations explained 89.2% of the variance in the DXA-derived FM% and 91.8% in the DXA-derived SMM%, with low random errors (SEE = 3.04% and 1.92%, respectively), and a very strong agreement (CCC = 0.93 and 0.94, respectively). In addition, they demonstrated no fixed bias and a relatively low individual variability. However, the manufacturer's equations described a lower percentage of the variance, with higher random errors, obtained fixed bias of -5.77% for FM% and 4.91% for SMM%, as well as higher individual variability.

CONCLUSIONS

The new regression equations, which include the PhA as a bioelectrical parameter, can accurately predict DXA-derived FM% and SMM% in a heterogeneous Caucasian population, and are better options than the manufacturer's equations.

U-Shaped Association of Visceral Fat Area With Diabetic Peripheral Neuropathy

Background: The impact of visceral fat area (VFA) on diabetic peripheral neuropathy (DPN) remains controversial in Type 2 diabetes mellitus (T2DM), with conflicting evidence. Methods: We conducted a cross-sectional study at the National Metabolic Management Center of Beijing Luhe Hospital between October 2017 and May 2024. VFA was quantified using bioelectrical impedance analysis, and DPN was diagnosed according to standardized clinical criteria. The association between VFA and DPN was examined using multiple logistic regression models with comprehensive confounder adjustment. Nonlinear relationships were investigated through generalized additive models and threshold effect analyses. Results: Among 7436 T2DM patients (3044 females), the median VFA was 104 cm2 (interquartile range: 79.5-132 cm2), with DPN present in 26.55% of participants. Generalized additive models revealed a significant U-shaped association between VFA and DPN, with an inflection point at 133 cm2 (log-likelihood ratio test, p < 0.001). In the segmented regression analysis, each 10 cm2 increase in VFA below this threshold was associated with decreased DPN risk (OR: 0.95, 95% CI: 0.93-0.97, p < 0.05), while increases above the threshold were associated with elevated risk (OR: 1.06, 95% CI: 1.03-1.09, p < 0.05). Conclusions: A U-shaped association exists between VFA and DPN prevalence in T2DM patients, suggesting clinical relevance of moderate visceral adiposity.

Intertrigo in Severe Obesity: Clinical Insights and Outcomes With a New Antimicrobial Silver-Infused Breathable Fabric

BACKGROUND

Intertrigo is often underdiagnosed in obesity.

OBJECTIVES

To investigate the incidence of intertrigo in obesity and assess the efficacy of a moisture-wicking fabric (MWF) with antimicrobial silver.

METHODS

Intertrigo symptoms were evaluated in patients with severe obesity, and the effect of MWF application was assessed in a subset of these patients after 5 or 10 days of use.

RESULTS

In inpatients with obesity (n = 2.778, mean age 63.9 ± 13.3 years, BMI 43.4 ± 6.8 kg/m2), intertrigo lesions were found in 15.9% under the breast (37.4%), abdomen (19.0%), and inguinal area (9.6%). It was more prevalent in women (12.3%), especially among patients older than 65 years (50.9%), with a mean BMI of 46.4 ± 7.3 kg/m2, waist circumference of 129.6 ± 15.2 cm, and mean fat mass of 51.1% ± 6.2%. A subset of 40 patients with intertrigo was randomly divided into two groups: one treated with MWF (mean age 57.0 ± 14.2 years, BMI 46.4 ± 8.2 kg/m2) and the other with traditional treatment (mean age 62.0 ± 14.1 years, BMI 49.9 ± 7.5 kg/m2). The MWF treatment resulted in significantly faster symptom resolution (6.0 ± 2.4 days for MWF vs. 11.0 ± 3.9 days in control group; p < 0.001).

CONCLUSIONS

We underline the need for intertrigo screening in patients with obesity, especially in those with risk factors, such as female, older, and higher BMI. The use of a novel MWF effectively alleviates symptoms within a short treatment period and should be considered as an optional intertrigo treatment.

Raw bioelectrical impedance parameters and vector analysis in the screening of low muscle mass and low muscle mass associated with obesity in adult healthy subjects

The aim was to estimate the prevalence of low muscle mass (LMM) and low muscle mass associated with obesity (LMM-O) in healthy adult, and to verify the performance of raw bioelectrical impedance parameters (BIA) and vector analysis (BIVA) in the screening of this tow conditions. This is a cross-sectional study including 1025 healthy adults. Body composition was assessed by the BIA technique. The appendicular skeletal muscle mass index (ASMMI) and body fat percentage (BF%) were used for the screening of LMM and LMM-O. The raw BIA parameters were: resistance (R), reactance (Xc), phase angle (PhA), and impedance (Z). The vectors, R and Xc, were adjusted for height and projected on the RXc graph. Associations were checked by the correlation test, binary logistic regression, adjusted for age and body water, and ROC curve. LMM was found in 30.8% of the subjects, and 20.9 and 21.4% of the men and women were with LMM-O. PhA and R/H were the most powerful discriminators of LMM with a sensitivity of 62-100% and a specificity of 71-90%. Cutoff values of PhA ranged between 4.95° and 5.75° for women and men. The RXc graph was able to identify LMM subjects, with clustering on the right side: area of low cellularity, high R/H and low-phase angle. Traditional anthropometric indices were the least effective in identifying LMM-O. The BIVA approach, PhA, R and R/H are effective in the screening of LMM and LMM-O, irrespective of age, gender, intra- and extracellular hydration status.

Stronger associations of the phase angle than the TyG index with micro- and macrovascular complications in patients with type 2 diabetes

BACKGROUND

Identifying micro- and macrovascular damage through microalbuminuria and arterial stiffness is essential for preventing renal and cardiovascular complications in patients with type 2 diabetes mellitus (T2D). The primary goal of this research is to investigate the association of the phase angle (PA), triglyceride‒glucose (TyG) index, and homeostasis model assessment for insulin resistance (HOMA-IR) with microalbuminuria and arterial stiffness in patients with T2D.

METHODS

In this retrospective cross-sectional study, 938 participants with T2D were enrolled. The PA was calculated from bioelectrical impedance analysis. Logistic regression was used to analyze the association of PA, the TyG index and HOMA-IR with microalbuminuria (urinary albumin-to-creatinine ratio [UACR] > 30 mg/g using overnight urine) and increased arterial stiffness (brachial-ankle pulse wave velocity [baPWV] > 1400 cm/s), respectively. Potential nonlinear relationships between PA, the TyG index, and the prevalence of microalbuminuria and increased arterial stiffness were assessed via restricted cubic splines (RCS). Subgroup analysis evaluated the robustness of the association.

RESULTS

PA was inversely correlated with the UACR (r = -0.29, P < 0.001) and baPWV (r = -0.37, P < 0.001). Confounder-adjusted analyses revealed that the highest tertile of PA was significantly associated with lower prevalences of both microalbuminuria and increased arterial stiffness than the lowest tertile, with ORs of 0.305 and 0.467 and P trends < 0.001 and 0.017, respectively. Conversely, the highest TyG tertile was associated with increased prevalences of microalbuminuria and increased arterial stiffness, with ORs of 1.727 and 1.625, respectively, but the P trends were not statistically significant. There were no significant associations between HOMA-IR and microalbuminuria and increased arterial stiffness. RCS analysis further confirmed a significant linear relationship between PA and both vascular complications. Subgroup analyses consistently demonstrated the association between PA and microalbuminuria across all subgroups stratified by sex, age, BMI, HbA1c, and duration of diabetes (all P < 0.01).

CONCLUSIONS

Compared with the TyG index and HOMA-IR, PA is independently and more strongly associated with microalbuminuria and increased arterial stiffness in patients with T2D.

Independent Predictors of Circulating Trimethylamine N-Oxide (TMAO) and Resistin Levels in Subjects with Obesity: Associations with Carotid Intima-Media Thickness and Metabolic Parameters

Background: Obesity contributes to cardiometabolic risk, including subclinical atherosclerosis and insulin resistance. This study examines the predictive roles of trimethylamine N-oxide (TMAO) and resistin in relation to carotid intima-media thickness and metabolic parameters; Methods: Sixty adults (18-71 years) with varying body weights were assessed for body composition, subclinical atherosclerosis, and blood biomarkers, including TMAO and resistin; Results: TMAO correlated strongly with CIMT (r = 0.674, p < 0.001), indicating its role in subclinical atherosclerosis. Logistic regression identified TMAO (threshold 380; AUC = 0.880, accuracy = 91.7%) as a predictor of cardiometabolic risk. Resistin was associated with CIMT, WHR, and total cholesterol, inversely linked to LDL cholesterol (p = 0.003). Less active participants exhibited higher TMAO (p = 0.001) and resistin (p = 0.02). Family histories of obesity and diabetes correlated with elevated TMAO, while resistin linked to shorter sleep duration and diabetes history, highlighting their importance in obesity-related cardiometabolic risks; Conclusions: TMAO is strongly linked to abdominal fat, insulin resistance, and subclinical atherosclerosis, while resistin is associated with lipid metabolism and aging. Their combined assessment enhances the prediction of obesity-related cardiometabolic risk, supporting their role in risk stratification and targeted interventions.

Association Between Phase Angle and Tongue Pressure in Older Inpatients with Connective Tissue Diseases

To investigate the association between tongue pressure (TP) and phase angle (PhA) in patients with connective tissue diseases (CTDs) aged 65 years or older. This retrospective cross-sectional study was conducted on 189 patients with CTDs who underwent hospital rehabilitation. TP was measured using a tongue pressure measuring device, and PhA was calculated from the bioimpedance analysis readings. Statistical analyses included multivariate linear regression with TP and receiver operating characteristic curves to determine PhA cutoff values indicative of low TP, defined as < 24.3 kPa for men and < 23.7 kPa for women. A total of 189 patients with CTDs (mean age 75 years; 49 men and 140 women; mean PhA 4.0°; mean TP 27.7 kPa) were included in the analysis. Fifty-five patients had low TP. Patients with low TP had lower PhA values than those with normal TP (mean PhA values 3.5° versus 4.3°). After adjusting for confounding factors, PhA (β = 0.387, p < 0.001) was significantly associated with TP. Cutoff values for PhA predicting low TP were identified as 3.9° for men and 3.5° for women. PhA is associated with TP, independent of other factors, in older inpatients with CTDs. The identified PhA cutoff values could enable the early detection of declining TP.

Poor muscle quality: A hidden and detrimental health condition in obesity

Poor muscle quality (MQ) is a hidden health condition in obesity, commonly disregarded and underdiagnosed, associated with poor health-related outcomes. This narrative review provides an in-depth exploration of MQ in obesity, including definitions, available assessment methods and challenges, pathophysiology, association with health outcomes, and potential interventions. MQ is a broad term that can include imaging, histological, functional, or metabolic assessments, evaluating beyond muscle quantity. MQ assessment is highly heterogeneous and requires further standardization. Common definitions of MQ include 1) muscle-specific strength (or functional MQ), the ratio between muscle strength and muscle quantity, and 2) muscle composition (or morphological MQ), mainly evaluating muscle fat infiltration. An individual with obesity might still have normal or higher muscle quantity despite having poor MQ, and techniques for direct measurements are needed. However, the use of body composition and physical function assessments is still limited in clinical practice. Thus, more accessible techniques for assessing strength, muscle mass, and composition should be further explored. Obesity leads to adipocyte dysfunction, generating a low-grade chronic inflammatory state, which leads to mitochondrial dysfunction. Adipocyte and mitochondrial dysfunction result in metabolic dysfunction manifesting clinically as insulin resistance, dyslipidemia, and fat infiltration into organs such as muscle, which in excess is termed myosteatosis. Myosteatosis decreases muscle cell function and insulin sensitivity, creating a vicious cycle of inflammation and metabolic derangements. Myosteatosis increases the risk of poor muscle function, systemic metabolic complications, and mortality, presenting prognostic potential. Interventions shown to improve MQ include nutrition, physical activity/exercise, pharmacology, and metabolic and bariatric surgery.

Effectiveness of Early Versus Late Time-Restricted Eating Combined with Physical Activity in Overweight or Obese Women

AIMS

To evaluate the effectiveness of a dual approach involving time-restricted eating (TRE) at different times of the day combined with physical activity (PA) on functional capacity and metabolic health in overweight or obese women.

METHODS

Random allocation of sixty-one participants into four groups: early time-restricted eating plus physical activity (ETRE-PA, n = 15, 31.8 ± 10.76 years, 89.68 ± 13.40 kg, 33.5 ± 5.53 kg/m2), late time-restricted eating with physical activity (LTRE-PA, n = 15, 30.60 ± 7.94 years, 94.45 ± 15.36 kg, 34.37 ± 7.09 kg/m2), late time-restricted eating only (LTRE, n = 15, 27.93 ± 9.79 years, 88.32 ± 10.36 kg, 32.71 ± 5.15 kg/m2) and a control group (CG, n = 15, 36.25 ± 11.52 years, 89.01 ± 11.68 kg, 33.66 ± 6.18 kg/m2). The intervention lasted for 12 weeks in all groups. Both the ETRE-PA and LTRE-PA groups engaged in a rigorous combined aerobic and resistance-training program.

RESULTS

Significant reductions in body weight and body mass index were observed in the ETRE-PA and LTRE-PA groups compared to the CG and LTRE groups post-intervention (p < 0.0005). Only the ETRE-PA group exhibited a significant decrease in fat mass (p = 0.02), low-density lipoprotein cholesterol (p = 0.01), and aspartate aminotransferase (p = 0.002). Significant reductions in alanine aminotransferase levels were observed in the ETRE-PA (p = 0.004) and LTRE-PA (p = 0.02) groups. These two latter groups achieved higher performances in the 6-min walking test, bench press, 30-s squat, crunch test, vertical jump (p < 0.0005 for both), and leg extension (p < 0.02 for both) when compared to the LTRE and CG groups.

CONCLUSION

The integration of TRE with PA leads to greater improvements in body composition, lipid profile, and physical performance, with no significant differences between the ETRE-PA and LTRE-PA approaches. This combined strategy offers a promising solution for overweight and obese women.

Quantitative analysis of the caloric restriction versus isocaloric diets models based on macronutrients composition: impacts on body weight regulation, anthropometric, and bioimpedance parameters in women with obesity

Introduction

Obesity is a growing public health issue, especially among young adults, with long-term management strategies still under debate. This prospective study compares the effects of caloric restriction and isocaloric diets with different macronutrient distributions on body composition and anthropometric parameters in obese women during a 12-week weight loss program, aiming to identify the most effective dietary strategies for managing obesity-related health outcomes.

Methods

A certified clinical nutritionist assigned specific diets over a 12-week period to 150 participants, distributed as follows: hypocaloric diets-low-energy diet (LED, 31 subjects) and very low-energy diet (VLED, 13 subjects); isocaloric diets with macronutrient distribution-low-carbohydrate diet (LCD, 48 subjects), ketogenic diet (KD, 23 subjects), and high-protein diet (HPD, 24 subjects); and isocaloric diet without macronutrient distribution-time-restricted eating (TRE, 11 subjects). Participants were dynamically monitored using anthropometric parameters: body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) and bioelectrical impedance analysis (BIA) using the TANITA Body Composition Analyzer BC-418 MA III (T5896, Tokyo, Japan) at three key intervals-baseline, 6 weeks, and 12 weeks. The following parameters were evaluated: body weight, basal metabolic rate (BMR), percentage of total body fat, trunk fat, muscle mass, fat-free mass, and hydration status.

Results

All diets led to weight loss, but differences emerged over time. The TRE model resulted in significantly less weight loss compared to LED at the final follow-up (6.30 kg, p < 0.001), similar to the VLED (4.69 kg, p < 0.001). Isocaloric diets with varied macronutrient distributions showed significant weight loss compared to LED (p < 0.001). The KD reduced waist circumference at both 6 and 12 weeks (-4.08 cm, p < 0.001), while significant differences in waist-to-hip ratio reduction were observed across diet groups at 12 weeks (p = 0.01). Post-hoc analysis revealed significant fat mass differences at 12 weeks, with HPD outperforming IF (p = 0.01) and VLED (p = 0.003). LCD reduced trunk fat at 6 weeks (-2.36%, p = 0.001) and 12 weeks (-3.79%, p < 0.001). HPD increased muscle mass at 12 weeks (2.95%, p = 0.001), while VLED decreased it (-2.02%, p = 0.031). TRE showed a smaller BMR reduction at 12 weeks compared to LED.

Conclusion

This study highlights the superior long-term benefits of isocaloric diets with macronutrients distribution over calorie-restrictive diets in optimizing weight, BMI, body composition, and central adiposity.

Sex and Body Mass Index Differences in Changes in Skin Temperature After Repeated Sessions of Whole-Body Cryostimulation

Background: Whole-body cryostimulation (WBC) involves exposure to extremely low temperatures to reduce inflammation and pain and to enhance recovery. Despite its growing popularity and the importance of the magnitude of WBC-induced skin cooling in triggering the cascade of effects, limited research has focused on skin temperature changes in individuals with severe obesity, where body composition and sex may influence outcomes. Objective: To examine differences in the cooling response based on sex and BMI, we conducted an observational study comparing patients with obesity to normal-weight individuals after repeated WBC sessions. The goal was to identify differences in skin temperature drops linked to sex and BMI. Methods: A total of 149 adults participated in the study: 119 with obesity (body mass Index, BMI ≥ 30 kg/m2) and 30 with normal weight (BMI ≤ 25 kg/m2). Participants underwent 10 WBC sessions at -110 °C for 2 min over two weeks. Skin temperatures were measured before and after each session. Results: While the overall drop in skin temperature after 10 sessions of WBC was similar between the patients with obesity and normal-weight subjects, significant differences emerged after adjustment for body surface area. Females exhibited a greater decrease in temperature than males in both groups irrespective of BMI. However, among males, normal-weight individuals experienced a significantly greater temperature drop compared to those with obesity. Conclusions: The study shows that sex and BMI influence WBC-induced skin temperature changes. The results of this study suggest that WBC protocols should be personalized.

Predictive model for abdominal liposuction volume in patients with obesity using machine learning in a longitudinal multi-center study in Korea

This study aimed to develop and validate a machine learning (ML)-based model for predicting liposuction volumes in patients with obesity. This study used longitudinal cohort data from 2018 to 2023 from five nationwide centers affiliated with 365MC Liposuction Hospital, the largest liposuction hospitals in Korea. Fifteen variables related to patient profiles were integrated and applied to various ML algorithms, including random forest, support vector, XGBoost, decision tree, and AdaBoost regressors. Performance evaluation employed mean absolute error (MAE), root mean square error (RMSE), and R-squared (R2) score. Feature importance and RMSE importance analyses were performed to compare the influence of each feature on prediction performance. A total of 9,856 were included in the final analysis. The random forest regressor model best predicted the liposuction volume (MAE, 0.197, RMSE, 0.249, R2, 0.792). Body fat mass and waist circumference were the most important features of the random forest regressor model (feature importance 71.55 and 13.21, RMSE importance 0.201 and 0.221, respectively). Leveraging this model, a web-based application was developed to suggest ideal liposuction volumes. These findings could be used in clinical practice to enhance decision-making and tailor surgical interventions to individual patient needs, thereby improving overall surgical efficacy and patient satisfaction.

Design and Development of Portable Body Composition Analyzer for Children

OBJECTIVES

The aim of this study was (i) to design and develop a portable BCA device for measuring body composition parameters such as body weight, body fat (BF) %, total body water (TBW), fat-free mass (FFM), muscle mass (MM), and bone mass (BM); (ii) to validate the developed portable BCA with the Tanita MC 980 MA BCA device.

METHODS

For this current study, two hundred healthy and obese subjects, whose ages ranged from 8 to 12 years (8.4 ± 1.7), were considered.

RESULTS

The highest percentage difference between the two study groups was found to be in BFat (50.39%), followed by body mass index (BMI) (41.73 kg), FFM (38.32 kg), and MM (37.89 kg), and this was found to be statistically significant. The results obtained from the designed prototype of the body composition analyzer were validated using Tanita MC 980MA BCA. The overall error% was calculated as ±3% for measuring the different body composition parameters.

CONCLUSIONS

Due to its low standard error and high overall accuracy, the BCA prototype demonstrates the potential to be a dependable instrument for evaluating and tracking the body composition of children.

Fat Mass Index Predicts the Effect of Weight Loss and Quality of Life Early After Laparoscopic Sleeve Gastrectomy

BACKGROUND

Fat mass index (FMI) is a body composition indicator that reflects body fat content. Laparoscopic sleeve gastrectomy (LSG) is widely performed in patients with obesity.

OBJECTIVE

This study aimed to evaluate the value of the FMI in predicting weight loss effect and quality of life early after LSG.

MATERIAL AND METHODS

From January 2014 to July 2022, the clinical data and computed tomography (CT) images of patients who underwent LSG at a tertiary referral teaching hospital were analyzed. Body composition indicators were calculated using the SliceOmatic software. Achieving initial body mass index within 6 months postoperatively was defined as early eligible weight loss (EEWL). The relationship between body composition and EEWL was analyzed.

RESULTS

A total of 243 patients were included. Receiver operating characteristic (ROC) curve analysis showed that the predictive value of the FMI for EEWL in patients after LSG was higher than that of other indicators (all P < 0.05; area under the curve = 0.813). The best FMI cut-off point was 13.662. Accordingly, the patients were divided into the high-FMI group and low-FMI group. The %EWL and BMI of patients in the low-FMI group at 1, 3, 6, 9, 12, and 24 months after surgery were better than those in the high-FMI group (all P < 0.001). Patients in the low-FMI group had higher BAROS (Bariatric Analysis and Reporting Outcome System) scores than those in the high-FMI group (P < 0.001).

CONCLUSION

Compared with other body composition indicators, FMI can effectively predict the early effect of weight loss and quality of life after LSG.

Body composition assessment in individuals with class II/III obesity: a narrative review

BACKGROUND

Individuals with class II/III obesity have a high percentage of body fat. Assessing body composition in cases of severe obesity can be difficult and controversial both in clinical practice and scientific research. Thus, it is essential to explore the different aspects of evaluating body composition and to discuss the available methods to assess it in this population.

AIMS

To summarise and discuss the methods used to measure body composition in adults with class II/III obesity and their potential in clinical practice and scientific research.

METHODS

This is a narrative review using data from PubMed, Scielo, and Lilacs databases. Original articles on body composition analysis in adults with class II/III obesity i.e., a BMI ≥ 35 kg/m2 were eligible. Body composition assessment methods were analysed and described.

RESULTS

Some imaging methods produced significantly accurate results. Dual-energy X-ray absorptiometry (DXA) significantly produces accurate results and has been used in clinical studies. However, due to its high cost, it is not applicable in clinical practice. Multifrequency bioelectrical impedance analysis (BIA) has good accuracy and is more appropriate for clinical practice than other methods. We have highlighted several aspects of the importance and applicability of performing body composition analysis in individuals with class II/III obesity.

CONCLUSION

DXA has been considered the most adequate method for clinical research. Multifrequency BIA may be a viable alternative to DXA for use in clinical practice. Assessing body composition and its components is important for people with class II/III obesity. It can help improve the effectiveness of interventions and clinical treatments, especially in reducing the risk of losing muscle mass. Muscle loss can cause sarcopenic obesity and other clinical complications, so understanding body composition is crucial. Assessing body composition can also help understand the impact of interventions on bones and avoid clinical complications.

The challenges of assessing adiposity in a clinical setting

To tackle the burden of obesity-induced cardiometabolic disease, the scientific community relies on accurate and reproducible adiposity measurements in the clinic. These measurements guide our understanding of underlying biological mechanisms and clinical outcomes of human trials. However, measuring adiposity and adipose tissue distribution in a clinical setting can be challenging, and different measurement methods pose important limitations. BMI is a simple and high-throughput measurement, but it is associated relatively poorly with clinical outcomes when compared with waist-to-hip and sagittal abdominal diameter measurements. Body composition measurements by dual energy X-ray absorptiometry or MRI scans would be ideal due to their high accuracy, but are not high-throughput. Another important consideration is that adiposity measurements vary between men and women, between adults and children, and between people of different ethnic backgrounds. In this Perspective article, we discuss how these critical challenges can affect our interpretation of research data in the field of obesity and the design and implementation of clinical guidelines.

Full-dose rivaroxaban in patients with a history of bariatric surgery: bridging the knowledge gap through a phase 1 study

BACKGROUND

Bariatric surgery (BS) induces significant changes in gastrointestinal anatomy, potentially influencing the pharmacokinetics of orally administered drugs such as rivaroxaban.

OBJECTIVES

This phase 1 study aimed to assess the pharmacokinetics and safety of full-dose rivaroxaban in post-BS patients.

METHODS

The ABSORB (Rivaroxaban Pharmacokinetics and Pharmacodynamics After Bariatric Surgery and in Morbid Obesity) study was a single-center, nonrandomized, multiple-dose, parallel-design bioequivalence trial. Adult patients with stable weight after Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) were compared with subjects with class III obesity and healthy controls. Participants received 20 mg of rivaroxaban daily for 8 days.

RESULTS

Post-BS patients exhibited altered rivaroxaban pharmacokinetics, suggesting reduced absorption. Mean area under the concentration-time curve from time 0 to 24 hours after the first dose (RYGB, 1806.8 ng.h/mL; SG, 1648.9 ng.h/mL) was lower compared with that in controls (1893.5 ng.h/mL). At steady state, the area under the concentration-time curve values remained lower in BS groups (RYGB, 2129.9 ng.h/mL; SG, 1946.4 ng.h/mL) than in controls (2224.8 ng.h/mL). The maximum concentration after the first dose was lower in post-RYGB subjects (214.9 ng/mL) than in controls (264.1 ng/mL). This difference was less pronounced at steady state (RYGB, 256.9 ng/mL vs controls, 288.8 ng/mL). Neither BS group met bioequivalence criteria compared with controls, whereas the group with class III obesity met bioequivalence criteria compared with controls at steady state.

CONCLUSION

Rivaroxaban displayed minor pharmacokinetic variations in post-BS patients. Given reported interindividual variability in the general population, these variations are unlikely to be of clinical significance. Our findings support rivaroxaban use in BS patients, emphasizing the need for further research in this area.

Comparative Analysis of Dietary Habits and Obesity Prediction: Body Mass Index versus Body Fat Percentage Classification Using Bioelectrical Impedance Analysis

Background: Obesity remains a widely debated issue, often criticized for the limitations in its identification and classification. This study aims to compare two distinct systems for classifying obesity: body mass index (BMI) and body fat percentage (BFP) as assessed by bioelectrical impedance analysis (BIA). By examining these measures, the study seeks to clarify how different metrics of body composition influence the identification of obesity-related risk factors. Methods: The study enrolled 1255 adults, comprising 471 males and 784 females, with a mean age of 36 ± 12 years. Participants exhibited varying degrees of weight status, including optimal weight, overweight, and obesity. Body composition analysis was conducted using the TANITA Body Composition Analyzer BC-418 MA III device (T5896, Tokyo, Japan), evaluating the following parameters: current weight, basal metabolic rate (BMR), adipose tissue (%), muscle mass (%), and hydration status (%). Results: Age and psychological factors like cravings, fatigue, stress, and compulsive eating were significant predictors of obesity in the BMI model but not in the BFP model. Additionally, having a family history of diabetes was protective in the BMI model (OR: 0.33, 0.11-0.87) but increased risk in the BFP model (OR: 1.66, 1.01-2.76). The BMI model demonstrates exceptional predictive ability (AUC = 0.998). In contrast, the BFP model, while still performing well, exhibits a lower AUC (0.975), indicating slightly reduced discriminative power compared to the BMI model. Conclusions: BMI classification demonstrates superior predictive accuracy, specificity, and sensitivity. This suggests that BMI remains a more reliable measure for identifying obesity-related risk factors compared to the BFP model.

Muscle Strength and Phase Angle Are Potential Markers for the Efficacy of Multidisciplinary Weight-Loss Program in Patients with Sarcopenic Obesity

Background/Objectives: Traditional weight-loss methods often result in the loss of both fat and muscle mass. For individuals with sarcopenic obesity (SO), additional muscle loss can exacerbate sarcopenia, leading to further declines in muscle strength and function, ultimately worsening quality of life. To mitigate this risk, weight-loss strategies should emphasize the preservation and building of muscle mass through adequate protein intake and tailored resistance training. This study aimed to evaluate changes in SO status following a 4-week multidisciplinary weight-loss intervention program in hospitalized patients with obesity. Methods: This study included adult patients with obesity (BMI > 30 kg/m2, aged 18-90 years). The SO diagnosis was performed using the handgrip strength (HGS) test and skeletal muscle mass (SMM) by bioelectrical impedance analysis (BIA) according to ESPEN/EASO-2022 guidelines. Results: A total of 2004 patients were enrolled, 64.8% female, with a mean age of 56 (±14) years and a BMI of 40.7 (±6.48) kg/m2. SO was present in 9.38% (188 patients) at baseline. At discharge, 80 patients (42.55%) were no longer classified as sarcopenic and showed significant improvements in HGS. The likelihood of resolving SO was not modified in patients with only phase angle (PhA) improvement (p-value = 0.141). Patients with HGS increment had a 65% probability to be No-SO at discharge and this probability, with the concomitant PhA increment, rose to 93% (p-value < 0.0001), indicating that functional changes and good nutrition status are crucial in improvement of SO. Muscle mass (MM) and SMMI remained unchanged in the studied cohort. Conclusions: Improvements in HGS and the PhA are potential markers for the efficacy of weight-loss programs tailored to patients with SO. These findings suggest that specific interventions focusing on these markers could be beneficial in managing SO patients.

Development of a comprehensive risk prediction model for arterial stiffness assessment in individuals with obesity

Introduction

Obesity in adults is a known risk factor for cardiovascular events and is associated with a decline in arterial elasticity. This study aims to evaluate the utility of pulse wave analysis (PWA) parameters in routine clinical practice for the primary prevention of cardiovascular events by developing a prediction model for arterial stiffness among obese and overweight individuals.

Methods

The study enrolled 84 adult patients, aged 18 to 85 years, with varying degrees of weight status, including optimal weight, overweight, and obesity. The lifestyle habits, the personal and family history of cardiometabolic diseases, as well the clinical evaluation that included BMI (body mass index), WHR (waist-to-hip ratio), WC (waist circumferance) were performed. PWA evaluation was conducted using the Mobil-O-Graph device, assessing the following parameters: pulse wave velocity (PWV), augmentation index (AIx), heart rate (HR), central pulse pressure (cPP), peripheral and central blood pressure (SBP, DBP, cSBP, cDBP). Body composition analysis was performed using the TANITA BC-418 body analyzer. Laboratory results from the past 3 months were also collected during initial nutritional consultations for each patient.

Results

Family history of cardiovascular events showed positive correlations with all PWA parameters, while diabetes history only with PWV and family history of obesity with PWV, DBP, and cSBP. Insufficient sleep duration showed positive associations with all arterial stiffness parameters except cDBP. Smoking status correlated with significantly elevated PWV and Aix values, while insufficient physical activity was associated solely with PWV. Positive correlations were showed between current weight and PWV, while WC demonstrated positive associations with PWV, SBP, and cSBP. Body composition analysis revealed significant associations between trunk adipose tissue mass (%) and PWV, SBP, and cSBP. Hydration status (%) emerged as an independent predictor for PWV, exhibiting an inverse relationship. HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) showed a strong positive correlation with PWV. Negative associations were observed with HDL-c and vitamin D. Threshold values for age, cDBP and Cardiac Index providing positive diagnostic for vascular impairment.

Conclusion

The assessment of arterial stiffness can be considered a reliable approach to prevent obesity-related cardiovascular events and facilitate the comprehensive management of such pathologies.

Characterization of the Texas Instruments Inc AFE4500 analog front end chip for wearable bioimpedance applications

The proliferation of wearable health monitors has prompted the investigation of bioimpedance (BioZ) to deliver meaningful health data. The Texas Instruments Analog Front End 4500 (AFE4500) is equipped with BioZ functionality but has not been characterized. This study provides an initial characterization of the AFE4500's BioZ function in RC loads. We evaluate and report the performance of the AFE4500 for wearable body composition monitoring. The AFE4500 exhibits the greatest precision with higher excitation currents and low BioZ sampling frequency. The lowest standard deviation (0.20 Ω) was achieved at 6.67 samples per second. AFE4500 measurements showed the lowest root mean square error of 4.37 Ω compared to ground truth at 50 kHz excitation. The AFE4500 measurement precision and small form factor prepare it for physiological monitoring in wearable body composition assessment using smartwatches and rings.

Is phase angle associated with visceral adiposity and cardiometabolic risk in cardiology outpatients?

BACKGROUND/OBJECTIVES

Phase angle (PhA) serves as a prognostic marker in various clinical scenarios, reflecting oxidative stress and cellular damage. Despite its clinical relevance, its connection with adiposity and cardiovascular risk markers remains underexplored. Hence, our study sought to investigate the relationship between PhA and metabolic, adiposity, and cardiovascular risk parameters among outpatients with cardiology diagnosis.

SUBJECTS/METHODS

Adults aged between 26 and 59 years, under the care of a cardiology unit, were included. Ultrasound imaging was used to assess visceral adipose tissue (VAT). Single-frequency bioelectrical impedance analysis (BIA) [50 kHz] was employed to calculate PhA, from BIA's resistance and reactance measurements. Muscle strength, body mass index, waist circumference, and waist-to-height ratio were also evaluated. Framingham's risk score was calculated to estimate the cardiovascular risk events. Metabolic blood samples' results were obtained from medical records.

RESULTS

One hundred and five participants were included in our study. Low PhA was observed in 29.5% of our sample. Higher PhA values were independently and inversely associated with both higher VAT and cardiovascular risk (adjusted OR: 0.79 [95% CI 0.69;0.91], OR: 0.74 [95% CI 0.60;0.89], respectively). Lower PhA values (≤5.59) were goodly associated with high VAT (AUC: 0.82 p < 0.001). Lower PhA values (≤5.06) were fairly associated with higher cardiovascular risk (AUC: 0.70 p = 0.003).

CONCLUSION

Our study provides evidence that PhA is independently and inversely associated with elevated VAT and cardiovascular risk. These findings underscore the potential of PhA as a valuable complementary marker in assessing cardiometabolic health.

Unexpectedly Rapid Onset of Severe Sarcopenia in an Elderly Diabetic Man following SGLT2i Administration: A Case Report

Sarcopenia is characterized by the progressive loss of muscle mass, strength, and function and poses a significant health challenge among people with diabetes. Sodium-glucose cotransporter-2 inhibitors (SGLT2is) are the backbone of type 2 diabetes treatment. The interplay between SGLT2is and sarcopenia is an area of active research with inconclusive results. This article presents an unexpectedly rapid weight reduction, along with physical performance deterioration, in an elderly patient with type 2 diabetes, which led to treatment discontinuation. A bioelectrical impedance analysis confirmed severe sarcopenia development. Until more data are available, sarcopenia and body composition screening and monitoring may be warranted whenever SGLT2is are prescribed.

Nutritional and Body Composition Changes in Paediatric β-Thalassemia Patients Undergoing Hematopoietic Stem Cell Transplantation: A Retrospective Study Using Bioelectrical Impedance Analysis

Objective

This retrospective study evaluated nutritional status and body composition changes in paediatric β-thalassemia (β-TM) patients before and after hematopoietic stem cell transplantation (HSCT), using bioelectrical impedance analysis (BIA), and explored their relationship with HSCT outcomes.

Methods

A cohort of 40 paediatric β-TM patients undergoing allogeneic HSCT was assessed for their nutritional status, anthropometric parameters, including body mass index (BMI), weight, and height, and body composition parameters pre-and post-HSCT, focusing on BIA measurements, including intracellular water (ICW), extracellular water (ECW), fat mass (FAT), fat-free mass (FFM), Skeletal Muscle Mass (SMM), soft Lean Mass (SLM), percent body fat (PBF), Body Cell Mass (BCM), Phase angle (PA) and muscle balance pre- and post-HSCT. Post-HSCT clinical outcomes, including acute graft-vs-host disease (aGVHD), engraftment time, oral mucositis (OM), sinusoidal obstruction syndrome (SOS), and diarrhoea in relation to nutrition status after HSCT were analysed.

Results

After HSCT, 28.21% experienced diminished nutritional status, with 71.43% of those who were wasting before HSCT showing diminished nutritional status, significantly higher than the normal group (18.75%, P = 0.012). Anthropometric changes included significant weight reduction (87.5%, 22.15 ± 7.46 vs 20.74 ± 6.57, P < 0.001) and BMI decrease (90%, 15.19 ± 1.70 vs 14.05 ± 1.48, P < 0.001). Body composition parameters, which are FFM, SMM, SLM, ICW, ECW, BCM, and PA (18.26 ± 5.71 vs 17.27 ± 5.19, 8.68 ± 3.30 vs 7.93 ± 3.02, 17.11 ± 5.28 vs 16.06 ± 4.84, 8.19 ± 2.54 vs 7.62 ± 2.31, 5.15 ± 1.58 vs 4.94 ± 1.47, 11.74 ± 3.63 vs 10.92 ± 3.32, 4.42 ± 0.50 vs 3.90 ± 0.57, respectively, P < 0.001) analysis revealed significant decreases. No significant differences in clinical outcomes were observed based on nutritional status.

Conclusion

Paediatric β-TM patients undergoing HSCT exhibit significant changes in nutrition status and body composition, emphasizing the need for focused attention on malnourished children who are more prone to diminished nutritional status. Comprehensive BIA aids in understanding the impact, urging consideration for extended follow-up and larger cohorts in future research.

The role of various physiological and bioelectrical parameters for estimating the weight status in infants and juveniles cohort from the Southern Cuba region: a machine learning study

OBJECTIVE

The search for other indicators to assess the weight status of individuals is important as it may provide more accurate information and assist in personalized medicine.This work is aimed to develop a machine learning predictions of weigh status derived from bioimpedance measurements and other physical parameters of healthy infant juvenile cohort from the Southern Cuba Region, Santiago de Cuba.

METHODS

The volunteers were selected between 2002 and 2008, ranging in age between 2 and 18 years old. In total, 393 female and male infant and juvenile individuals are studied. The bioimpedance parameters are obtained by measuring standard tetrapolar whole-body configuration. A classification model are performed, followed by a prediction of other bioparameters influencing the weight status.

RESULTS

The results obtained from the classification model indicate that fat-free mass, reactance, and corrected resistance primarily influence the weight status of the studied population. Specifically, the regression model demonstrates that other bioparameters derived from impedance measurements can be highly accurate in estimating weight status.

CONCLUSION

The classification and regression predictive models developed in this work are of the great importance for accessing to the weigh status with high accuracy of younger individuals at the Oncological Hospital in Santiago de Cuba, Cuba.

Myocardial mechano-energetic efficiency is not impaired in patients with metabolically healthy overweight and obesity

OBJECTIVE

Reduced myocardial mechano-energetic efficiency (MEE) was associated with BMI. Subgroups of individuals with increased BMI but favorable cardiovascular risk profile were identified as individuals with "metabolically healthy overweight" (MHOW) and "metabolically healthy obesity" (MHO), respectively. We aim to investigate whether those with MHOW/MHO, defined as those having none of the components of metabolic syndrome, exhibit impaired MEE compared with their unhealthy counterparts.

METHODS

Myocardial MEE per gram of left ventricular mass (MEEi) was assessed by echocardiography in 2190 nondiabetic individuals participating in the CATAnzaro MEtabolic RIsk factors (CATAMERI) study who were divided, according to BMI and metabolic status, into groups of individuals with metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW), MHOW, metabolically unhealthy overweight (MUOW), MHO, and metabolically unhealthy obesity (MUO).

RESULTS

After adjusting for age and sex, no differences in myocardial MEEi were observed among individuals with MHNW, MHOW, and MHO (p = 0.56). Myocardial MEEi was comparable among individuals with MUNW, MUOW, and MUO (p = 0.21). Individuals with MHNW, MHOW, and MHO displayed significantly higher myocardial MEEi compared with their unhealthy counterparts.

CONCLUSIONS

Increased BMI is not an obligate determinant for reduced myocardial MEEi. Other known components of metabolic syndrome rather than increased BMI contributed to reduced myocardial MEEi.

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.

Assessment of Changes in Body Composition After 3 Months of Dulaglutide Treatment

Background

Changes in body composition accompanied by glucagon-like peptide 1 receptor agonist (GLP-1RA) induced weight loss have drawn much attention. However, fewer studies have reported body composition changes in patients receiving dulaglutide therapy in Chinese population.

Methods

A total of 70 overweight/obese type 2 diabetes mellitus (T2DM) patients who received dulaglutide therapy were included. Clinical data were collected. Visceral fat area (VFA) and body composition were also measured. Changes in clinical indicators and body composition of patients before and after intervention were also analyzed. Correlation analysis and multiple linear regression model were used to evaluate the association between hemoglobin A1C (HbA1c) and body composition.

Results

The results showed that body weight (BW), VFA, body fat (BF), lean body mass (LBM), skeletal muscle mass (SMM) and water content were reduced after 3 months dulaglutide intervention. The lean body mass percentage (LBMP) and skeletal muscle mass percentage (SMMP) significantly increased. Moreover, there was no significant difference in bone mineral quality (BMQ) after the intervention. The multiple linear regression model revealed that the % change in BF was independently associated with % change in HbA1c (β = 0.449, t = 3.148, p=0.002).

Conclusion

These results indicate that dulaglutide intervention does not cause muscle and bone mass loss while inducing weight loss, and % change in BF was independently associated with improved glucose control during dulaglutide therapy. This study offers some positive results to support the clinical application of dulaglutide.

Unraveling Adipose Tissue Dysfunction: Molecular Mechanisms, Novel Biomarkers, and Therapeutic Targets for Liver Fat Deposition

Adipose tissue (AT), once considered a mere fat storage organ, is now recognized as a dynamic and complex entity crucial for regulating human physiology, including metabolic processes, energy balance, and immune responses. It comprises mainly two types: white adipose tissue (WAT) for energy storage and brown adipose tissue (BAT) for thermogenesis, with beige adipocytes demonstrating the plasticity of these cells. WAT, beyond lipid storage, is involved in various metabolic activities, notably lipogenesis and lipolysis, critical for maintaining energy homeostasis. It also functions as an endocrine organ, secreting adipokines that influence metabolic, inflammatory, and immune processes. However, dysfunction in WAT, especially related to obesity, leads to metabolic disturbances, including the inability to properly store excess lipids, resulting in ectopic fat deposition in organs like the liver, contributing to non-alcoholic fatty liver disease (NAFLD). This narrative review delves into the multifaceted roles of WAT, its composition, metabolic functions, and the pathophysiology of WAT dysfunction. It also explores diagnostic approaches for adipose-related disorders, emphasizing the importance of accurately assessing AT distribution and understanding the complex relationships between fat compartments and metabolic health. Furthermore, it discusses various therapeutic strategies, including innovative therapeutics like adipose-derived mesenchymal stem cells (ADMSCs)-based treatments and gene therapy, highlighting the potential of precision medicine in targeting obesity and its associated complications.

Causal associations between modifiable risk factors and isolated REM sleep behavior disorder: a mendelian randomization study

Objectives

This Mendelian randomization (MR) study identified modifiable risk factors for isolated rapid eye movement sleep behavior disorder (iRBD).

Methods

Genome-wide association study (GWAS) datasets for 29 modifiable risk factors for iRBD in discovery and replication stages were used. GWAS data for iRBD cases were obtained from the International RBD Study Group. The inverse variance weighted (IVW) method was primarily employed to explore causality, with supplementary analyses used to verify the robustness of IVW findings. Co-localization analysis further substantiated causal associations identified via MR. Genetic correlations between mental illness and iRBD were identified using trait covariance, linkage disequilibrium score regression, and co-localization analyses.

Results

Our study revealed causal associations between sun exposure-related factors and iRBD. Utilizing sun protection (odds ratio [OR] = 0.31 [0.14, 0.69], p = 0.004), ease of sunburn (OR = 0.70 [0.57, 0.87], p = 0.001), childhood sunburn occasions (OR = 0.58 [0.39, 0.87], p = 0.008), and phototoxic dermatitis (OR = 0.78 [0.66, 0.92], p = 0.003) decreased iRBD risk. Conversely, a deep skin color increased risk (OR = 1.42 [1.04, 1.93], p = 0.026). Smoking, alcohol consumption, low education levels, and mental illness were not risk factors for iRBD. Anxiety disorders and iRBD were genetically correlated.

Conclusion

Our study does not corroborate previous findings that identified smoking, alcohol use, low education, and mental illness as risk factors for iRBD. Moreover, we found that excessive sun exposure elevates iRBD risk. These findings offer new insights for screening high-risk populations and devising preventive measures.

Associations between adiposity and white matter hyperintensities: Cross-sectional and longitudinal analyses of 34,653 participants

OBJECTIVES

White matter hyperintensities (WMH) increase the risk of stroke and cognitive impairment. This study aims to determine the cross-sectional and longitudinal associations between adiposity and WMH.

METHODS

Participants were enrolled from the UK Biobank cohort. Associations of concurrent, past, and changes in overall and central adiposity with WMH were investigated by linear and nonlinear regression models. The association of longitudinal adiposity and WMH volume changes was determined by a linear mixed model. Mediation analysis investigated the potential mediating effect of blood pressure.

RESULTS

In 34,653 participants with available adiposity measures and imaging data, the concurrent obese group had a 25.3% (β [95% CI] = 0.253 [0.222-0.284]) higher WMH volume than the ideal weight group. Increment in all adiposity measures was associated with a higher WMH volume. Among them, waist circumference demonstrated the strongest effect (β [95% CI] = 0.113 [0.101-0.125]). Past adiposity also demonstrated similar effects. Among the subset of 2664 participants with available WMH follow-up data, adiposity measures were predictive of WMH change. Regarding changes of adiposity, compared with ideal weight stable group, those who turned from ideal weight to overweight/obese had a 8.1% higher WMH volume (β [95% CI] = 0.081 [0.039-0.123]), while participants who turned from overweight/obese to ideal weight demonstrated no significant WMH volume change. Blood pressure partly meditates the associations between adiposity and WMH.

CONCLUSIONS

Both concurrent and past adiposity were associated with a higher WMH volume. The detrimental effects of adiposity on WMH occurred throughout midlife and in the elderly and may still exist after changes in obesity status.

The Effects of Sodium-Glucose Cotransporter 2 Inhibitors on Body Composition in Type 2 Diabetes Mellitus: A Narrative Review

Body composition is related to cardiometabolic disorders and is a major driver of the growing incidence of type 2 diabetes mellitus (T2DM). Altered fat distribution and decreased muscle mass are related to dysglycemia and impose adverse health-related outcomes in people with T2DM. Hence, improving body composition and maintaining muscle mass is crucial in T2DM. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are novel glucose-lowering medications gaining popularity because of their cardiorenal-protective effects and weight-lowering characteristics. However, reports on myopathy secondary to SGLT2 inhibitor treatment raised a safety concern. The importance of maintaining muscle mass in people with T2DM necessitates further investigation to explore the impact of novel medications on body composition. In this review, we discussed current evidence on the impact of SGLT2 inhibitors on body composition in people with T2DM.

Perioperative Nutritional Management in Enhanced Recovery after Bariatric Surgery

Obesity is a crucial health problem because it leads to several chronic diseases with an increased risk of mortality and it is very hard to reverse with conventional treatment including changes in lifestyle and pharmacotherapy. Bariatric surgery (BS), comprising a range of various surgical procedures that modify the digestive tract favouring weight loss, is considered the most effective medical intervention to counteract severe obesity, especially in the presence of metabolic comorbidities. The Enhanced Recovery After Bariatric Surgery (ERABS) protocols include a set of recommendations that can be applied before and after BS. The primary aim of ERABS protocols is to facilitate and expedite the recovery process while enhancing the overall effectiveness of bariatric procedures. ERABS protocols include indications about preoperative fasting as well as on how to feed the patient on the day of the intervention, and how to nourish and hydrate in the days after BS. This narrative review examines the application, the feasibility and the efficacy of ERABS protocols applied to the field of nutrition. We found that ERABS protocols, in particular not fasting the patient before the surgery, are often not correctly applied for reasons that are not evidence-based. Furthermore, we identified some gaps in the research about some practises that could be implemented in the presence of additional evidence.

Association between Maternal Body Composition in Second Trimester and Risk of Fetal Macrosomia: A Population-Based Retrospective Study in China

(1) Background: Female body composition undergoes significant changes to support fetal growth and development during pregnancy. This study investigated the association of maternal body composition in the second trimester and macrosomia and explored whether body-composition-related indicators could be used to predict macrosomia. (2) Methods: This study was conducted in China from December 2016 to December 2021. Women with singleton pregnancies, gestational ages between 37 and 42 weeks, and an absence of pregnancy complications were included. In the second trimester, bioelectric impedance analysis (BIA) was used to measure body-composition-related indicators. Logistic regression analysis was performed to explore the risk factors for macrosomia. The predictive performance of maternal body composition and clinical indicators for macrosomia were assessed using the area under the receiver-operating-characteristics curve (AUC). (3) Results: This retrospective study involved 43,020 pregnant women; we collected 2008 cases of macrosomia. Gravidity, gestational age, body mass index (BMI), gestational weight gain (GWG), total body water, fat mass, fat-free mass (FFM), skeletal muscle mass, and visceral fat level were risk factors for macrosomia (p < 0.05 for all). In the prediction model, the AUC of FFM for predicting macrosomia was the largest (0.742). (4) Conclusions: Body-composition-related indicators associated with macrosomia and body composition measurements in the second trimester can predict the risk of macrosomia, enabling clinicians to implement interventions earlier to reduce adverse perinatal outcomes.

Distribution of Bioelectrical Impedance Vector Analysis and Phase Angle in Korean Elderly and Sarcopenia

PURPOSE

This study aimed to verify whether bioelectrical impedance vector analysis (BIVA) can support the clinical evaluation of sarcopenia in elderly individuals and evaluate the relationships between phase angle (PhA), physical performance, and muscle mass.

METHODS

The sample comprised 134 free-living elderly individuals of both sexes aged 69-91 years. Anthropometric parameters, grip strength, dual-energy X-ray absorptiometry findings, bioimpedance analysis results, and physical performance were also measured. The impedance vector distributions were evaluated in elderly individuals using BIVA.

RESULTS

BIVA revealed significant differences between the sarcopenia and non-sarcopenia groups (both sexes). The sarcopenia group had a significantly lower PhA than the non-sarcopenia group in both sexes (p < 0.05). PhA was significantly correlated with age, appendicular skeletal muscle (ASM), handgrip strength (HGS), and muscle quality in both sexes and significantly correlated with ASM/Height2 and physical performance in males.

CONCLUSION

BIVA can be used as a field assessment method in elderly Koreans with sarcopenia. PhA is a good indicator of muscle strength, muscle quality, and physical performance in males. These methods can help diagnose sarcopenia in elderly individuals with reduced mobility.

Changes in Fat-Free Mass, Protein Intake and Habitual Physical Activity Following Roux-en-Y Gastric Bypass Surgery: A Prospective Study

PURPOSE

Large inter-individual variations in post-bariatric fat-free mass loss (FFML) are observed, which might relate to differences in protein intake and physical activity across patients. We performed repetitive assessments of protein intake and physical activity before and after banded Roux-en-Y gastric bypass surgery, and examined its relations to FFML during 6 months of follow-up.

MATERIALS AND METHODS

FFML (bio-impedance analyses), protein intake (24-h dietary recalls) and moderate-to-vigorous physical activity (MVPA; activPAL) were assessed in 28 patients (4 males, age 42 ± 12 years) before surgery and at 1-, 3- and 6-months post-surgery. Changes in protein intake and MVPA were evaluated with mixed model analysis, whereas associations with FFML were assessed by univariate regression analysis.

RESULTS

Six-month FFML was -7.3 ± 3.6 kg. Protein intake decreased from 80 ± 29 g/day (pre-surgery) to 45 ± 26 g/day (1 month post-surgery (P < 0.001)) and did not improve thereafter (51 ± 21 g/day; P > 0.05). Seven participants (25%) consumed ≥ 60 g protein/day at 6 months post-surgery. Participants performed 7394 ± 2420 steps/day in 54 ± 20 min/day of MVPA, which did not change from pre- to post-surgery (P > 0.05). A higher step count (B = -0.002; 95%CI = [-0.004 - 0.000]; P = 0.048) and higher level of MVPA (B = -0.29; 95%CI = [-0.54 - -0.03]; P = 0.018) were related to a lower FFML.

CONCLUSION

A lower post-surgery FFML was attributable to higher MVPA levels but not protein intake. This may be due to the low total protein intake and the observation that only a minority of patients achieved a protein intake ≥ 60 g/day. Future studies should focus on interventions to increase post-bariatric protein intake and MVPA levels.

Differences in calculated body fat percentage estimated from published equations based on bioelectric impedance analysis in healthy young South African adults

Background

Adult overweight and obesity, in addition to the intake of saturated fat and total serum cholesterol must be monitored as biological risk factors for non-communicable diseases (NCDs). Bioelectric impedance analysis (BIA) provides data on body fat for use in epidemiological settings. However, optimized equations should be used to calculate percentage body fat (%BF). The purpose of this study was to assess the differences between %BF calculated using different published BIA equations and %BF measured by BIA in young South African adults.

Design and methods

In this observational study, differences in calculated %BF were assessed, with different BIA equations retrieved from the literature used in 1128 healthy young adults aged 20-30 years. The %BF (measured by BIA) was compared between equations, between Black and White men and women, respectively.

Results

The results showed statistically significant differences in the %BF calculated from published BIA equations when used in young South African adults (χ² = 946, χ² = 2528, χ² = 2088, respectively, p < 0.0001). In Black and White men and women, respectively, %BF levels were significantly higher when calculated by equations, than when measured by BIA (p < 0.0001).

Conclusion

There seem to be large discrepancies in estimating %BF by BIA equations and these values cannot be used interchangeably for young South African adults. A South African age, ethnicity and sex-specific BIA equation needs to be developed to accurately estimate %BF in young South African adults.

Population Pharmacokinetic Analysis of Perampanel in Portuguese Patients Diagnosed with Refractory Epilepsy

Perampanel is a promising antiepileptic drug (AED) for refractory epilepsy treatment due to its innovative mechanism of action. This study aimed to develop a population pharmacokinetic (PopPK) model to be further used in initial dose optimization of perampanel in patients diagnosed with refractory epilepsy. A total of seventy-two plasma concentrations of perampanel obtained from forty-four patients were analyzed through a population pharmacokinetic approach by means of nonlinear mixed effects modeling (NONMEM). A one-compartment model with first-order elimination best described the pharmacokinetic profiles of perampanel. Interpatient variability (IPV) was entered on clearance (CL), while the residual error (RE) was modeled as proportional. The presence of enzyme-inducing AEDs (EIAEDs) and body mass index (BMI) were found as significant covariates for CL and volume of distribution (V), respectively. The mean (relative standard error) estimates for CL and V of the final model were 0.419 L/h (5.56%) and 29.50 (6.41%), respectively. IPV was 30.84% and the proportional RE was 6.44%. Internal validation demonstrated an acceptable predictive performance of the final model. A reliable population pharmacokinetic model was successfully developed, and it is the first enrolling real-life adults diagnosed with refractory epilepsy.

Comparison of bioelectrical impedance analysis-derived phase angle in individuals with different weight status

OBJECTIVE

Obesity is characterized not only by an increase of fat mass but also by alterations in skeletal muscle. Bioimpedance analysis (BIA)-derived phase angle (PhA) may provide specific information on the inherent characteristics of fat-free mass, and is widely used as an index of poor nutritional status. The aim of this study was to describe whether and to what extent PhA varies depending on age, sex, and body mass index (BMI) in individuals with different weight status.

METHODS

We selected 1877 participants for this retrospective study (two weight status groups): 983 individuals with obesity (age 40 ± 13.9 y; BMI 39.5 ± 7.2 kg/m²) and 894 controls (age 40 ± 13.3 y; BMI 24.6 ± 2.7 kg/m²). Anthropometry and PhA at 50 kHz for the whole body were performed in all participants.

RESULTS

PhA was greater in men than in women, although a decline of PhA was observed with age, which was linear in women and occurred in men after 40 y of age. On the other hand, no significant differences were observed with increasing BMI in either sex; lower values might be observed when BMI >50 kg/m².

CONCLUSIONS

A more detailed appraisal of BIA-derived PhA in obesity is reported in the present study, providing basic data that might be taken into consideration in prevention and clinical nutrition. Further studies are needed to explore differences of PhA in individuals with different weight status.

Normal values for body composition in adults are better represented by continuous reference ranges dependent on age and BMI

BACKGROUND & AIMS

Reference values for body composition parameters like skeletal muscle mass index (SMI) depend on age and BMI. To ensure reference intervals reflect these changes, they have traditionally been separated into groups of young adults based on sex and BMI. However, this static stratification oversimplifies the dynamic and gradual changes of body composition with increasing age and BMI. The aim was therefore to provide continuous reference ranges for body composition parameters.

METHODS

Cross-sectional data of 1958 healthy men and women with an age between 18 and 97 years and a BMI between 17.1 und 45.6 kg/m² were obtained between 2011 and 2019. Multiple regression analyses stratified by sex with age, age² and BMI as independent variables were conducted to predict fat mass index (FMI), visceral adipose tissue (VAT), SMI, appendicular lean soft tissue index (ALSTI) and the ratio between extracellular to total body water (ECW/TBW).

RESULTS

The regression models explained between 61 (VAT in women and ALSTI in men) and 93% of the variance in the respective body composition parameters (FMI in women). Age had only a minor impact (2-16%) whereas BMI substantially increased the explained variance of reference models for FMI, VAT and ALSTI (total explained variance 61-93%). In SMI, age is a major determinant of the explained variance (36% in men and 38% in women) with BMI equally contributing to the explained variance (total explained variance 72% in men and 75% in women). For ECW/TBW-ratio, age nearly completely explained the variance (79% in men and 74% in women) whereas BMI added only 2-3% to the explained variance.

CONCLUSIONS

In conclusion, the derived continuous reference ranges are expected to improve body composition evaluation especially in very overweight and very old persons. Future studies applying these reference equations need to validate these assumptions. STUDY REGISTRATION, CLINICALTRIALS.GOV: NCT01368640, NCT01481285, NCT03779932, NCT04028648.

[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.

Phase angle (PhA) in overweight and obesity: evidence of applicability from diagnosis to weight changes in obesity treatment

Phase angle (PhA) is a recently proposed marker of nutritional status in many clinical conditions. Its use in patients with obesity presents different critical concerns due to the higher variability of the two measured parameters (resistance, R, and reactance, Xc) that contribute to the determination of PhA. Controversial is the relation between PhA and BMI that might vary with graded levels of obesity due to the variation in fat and free fat mass. Obesity is frequently associated with metabolic, hepatic, cardiovascular and kidney diseases that introduce variations in PhA values, in relation to multimorbidity and severity degree of these diseases. It is reported that the improvement of clinical condition is associated with a positive change in PhA. Also, the treatment of obesity with weight loss might confirm this effect, but with different responses in relation to the type and duration of the intervention applied. In fact, the effect appears not only related to the percentage of weight loss but also the possible loss of free fat mass and the nutritional, metabolic and structural modifications that might follow each therapeutic approach to decrease body weight. We can conclude that the PhA could be used as marker of health status in patients with obesity supporting an appropriate weight loss intervention to monitor efficacy and fat free mass preservation.

Phase angle and cellular health: inflammation and oxidative damage

Phase angle is a composite measure that combines two raw bioelectrical impedance analysis measures: resistance and reactance. Phase angle has been considered an indicator of cellular health, integrity, and hydration. As inflammation and oxidative stress can damage cellular structures, phase angle has potential utility in early detecting inflammatory and oxidative status. Herein, we aimed to critically review the current understanding on the determinants of phase angle and its relationship with markers of inflammation and oxidative stress. We also discussed the potential role of phase angle in detecting chronic inflammation and related adverse outcomes. Several factors have been identified as predictors of phase angle, including age, sex, extracellular to intracellular water ratio, and fat-free mass. In addition to these factors, body mass index (BMI) also seems to influence phase angle. Available data also show that lower phase angle values are correlated (negligible to high correlation coefficients) with higher c-reactive protein, tumour necrosis factor-α, interleukin-6, and interleukin-10 in studies involving the general and aging populations, as well as patients with chronic conditions. Although fewer studies have evaluated the relationship between phase angle and markers of oxidative stress, available data also suggest that phase angle has potential to be used as an indicator (for screening) of oxidative damage. Future studies including diverse populations and bioelectrical impedance devices are required to confirm the validity and accuracy of phase angle as a marker of inflammation and oxidative stress for clinical use.

The Role of Dietary Patterns and Dietary Quality on Body Composition of Adolescents in Chinese College

There is limited evidence regarding the effects of dietary pattern and dietary quality on the risk of unhealthy weight status and related body composition in Chinese adolescence. In particular, studies using bioelectrical impedance analyzer (BIA) in these subjects are rare. The aim of this study was to evaluate the role of diet in body composition, to find a healthy dietary pattern for Chinese youth, and to promote the application of BIA among this population. A total of 498 participants aged from 18 to 22 years old were included. Dietary patterns were identified by principal components analysis. Energy-adjusted dietary inflammatory index (DII) and diet balance index (DBI) were calculated based on semi-quantitative food frequency questionnaire. Multivariate linear regression and logistic regression analysis were used to examine the relationship of dietary patterns, dietary quality with body mass index (BMI), fat mass index (FMI), fat-free mass index (FFMI), and the effect of dietary factors on BMI levels. The majority of participants with overweight and obesity had abdominal obesity, and there was 3.7% abdominal obesity in normal BMI individuals. Four dietary patterns were detected in the subjects. The pattern with the higher energy intake, which was close to the Western diet, was positively correlated with BMI (β = 0.326, p = 0.018) and FMI (β = 0.201, p = 0.043), while being negatively correlated with FFMI (β = −0.183, p = 0.021). Individuals who followed the pattern similar to the Mediterranean diet had a higher basal metabolic rate (BMR), and the highest fat free mass, soft lean mass, and skeletal muscle mass (p < 0.05) but the lowest FMI, visceral fat area (VFA), waist−hip ratio, and FMI/FFMI ratio (p < 0.05). Higher energy-adjusted DII was associated with high BMI. Higher bound score (HBS) (β = −0.018, p = 0.010) and diet quality distance (DQD) (β = −0.012, p = 0.015) were both negatively correlated with FFMI. In conclusion, fat or muscle indexes, such as BMR, FMI, and FFMI, had an important role in predicting overweight and obesity, which suggested the importance of applying BIA among Chinese college students. Students who followed healthful dietary patterns or the high-quality diet that is similar to the Mediterranean diet but not close to the Western diet were more likely to have a healthy BMI and normal body composition.

Frailty Is Associated with Oxidative Stress in Older Patients with Type 2 Diabetes

Aging has increased the prevalence of frailty, and type 2 diabetes (T2D) has also increased in prevalence. Diabetes and oxidative stress (OS) have been shown to be related to frailty. However, the exact mechanism by which it occurs is not fully known. Our aim was to analyze body composition in community-dwelling older diabetic people treated in our center and to evaluate the possible relation between OS, frailty, and body composition. We included 100 adults older than 65 years with T2D. We found that 15% were frail and 57% were prefrail. The patients included in the nonrobust group showed increased levels of OS. Our study shows that the presence of T2D in the geriatric population is associated with a high prevalence of frailty and high OS levels, conditions that cause greater morbidity and mortality and that highlight the importance of the diagnosis of frailty in this population.

Identification of Sarcopenic Obesity in German Nursing Home Residents-The Role of Body Composition and Malnutrition in the BaSAlt Cohort-Study

Background: Sarcopenic obesity (SO) is a phenotype, which is defined by reduced muscle strength, muscle mass, and obesity. Limited mobility leads to increased sedentary behavior and decreased physical activity. Both sarcopenia and obesity are aggravated by these factors. In combination, SO is an additional challenge for the setting nursing home (NH). Previous studies have shown a low prevalence of residents with SO in comparable settings, such as community-dwelling. We hypothesize that the BaSAlt cohort also has a small proportion of residents with SO. Methods: For the analysis, 66 residents (women: 74.2%) aged ≥ 65 years from NH, were screened for SO based on EWGSOP2 specifications and cut-off values to classify obesity. Results: Severe sarcopenia was quantified in eleven residents (16.7%). The majority of sarcopenic residents were women (n = 10) compared to men (n = 1). However, no SO could be identified by assessment of body mass index, fat mass in percentage, and fat mass index. Conclusion: As expected, the setting-specific cohort showed a low number of SO. Furthermore, no case of SO was identified in our study. Sarcopenia was associated with an increased fat-free mass in NH residents. Nevertheless, sarcopenia and obesity play important roles in the preservation of residents’ health.