Effects of a Ketogenic Diet on Body Composition in Healthy, Young, Normal-Weight Women: A Randomized Controlled Feeding Trial.

This study investigates the effects of a ketogenic low-carbohydrate high-fat (LCHF) diet on body composition in healthy, young, normal-weight women. With the increasing interest in ketogenic diets for their various health benefits, this research aims to understand their impact on body composition, focusing on women who are often underrepresented in such studies. Conducting a randomized controlled feeding trial with a crossover design, this study compares a ketogenic LCHF diet to a Swedish National Food Agency (NFA)-recommended control diet over four weeks. Seventeen healthy, young, normal-weight women adhered strictly to the provided diets, with ketosis confirmed through blood ß-hydroxybutyrate concentrations. Dual-energy X-ray absorptiometry (DXA) was utilized for precise body composition measurements. To avoid bias, all statistical analyses were performed blind. The findings reveal that the ketogenic LCHF diet led to a significant reduction in both lean mass (-1.45 kg 95% CI: [-1.90;-1.00]; p < 0.001) and fat mass (-0.66 kg 95% CI: [-1.00;-0.32]; p < 0.001) compared to the control diet, despite similar energy intake and physical activity levels. This study concludes that while the ketogenic LCHF diet is effective for weight loss, it disproportionately reduces lean mass over fat mass, suggesting the need for concurrent strength training to mitigate muscle loss in women following this diet.

Adjustments of iodinated contrast media using lean body weight for abdominopelvic computed tomography: A systematic review and meta-analysis.

PURPOSE: This systematic review aimed to compare the effect of contrast media (CM) dose adjustment based on lean body weight (LBW) method versus other calculation protocols for abdominopelvic CT examinations. METHOD: Studies published from 2002 onwards were systematically searched in June 2024 across Medline, Embase, CINAHL, Cochrane CENTRAL, Web of Science, Google Scholar and four other grey literature sources, with no language limit. Randomised controlled trials (RCT) and quasi-RCT of abdominopelvic or abdominal CT examinations in adults with contrast media injection for oncological and acute diseases were included. The comparators were other contrast dose calculation methods such as total body weight (TBW), fixed volume (FV), body surface area (BSA), and blood volume. The main outcomes considered were liver and aortic enhancement. Titles, abstracts and full texts were independently screened by two reviewers. RESULTS: Eight studies were included from a total of 2029 articles identified. Liver parenchyma and aorta contrast enhancement did not significantly differ between LBW and TBW protocols (p = 0.07, p = 0.06, respectively). However, the meta-analysis revealed significantly lower contrast volume injected with LBW protocol when compared to TBW protocol (p = 0.003). No statistical differences were found for contrast enhancement and contrast volume between LBW and the other strategies. CONCLUSION: Calculation of the CM dosage based on LBW allows a reduction in the injected volume for abdominopelvic CT examination, ensuring the same image quality in terms of contrast enhancement.

Advancing body composition assessment in patients with cancer: First comparisons of traditional versus multicompartment models.

BACKGROUND AND AIMS: Measurement of body composition using computed tomography (CT) scans may be a viable clinical tool for low muscle mass assessment in oncology. However, longitudinal assessments are often infeasible with CT. Clinically accessible body composition technologies can be used to track changes in fat-free mass (FFM) or muscle, though their accuracy may be impacted by cancer-related physiological changes. The purpose of this study was to examine the agreement among accessible body composition method with criterion methods for measures of whole-body FFM measurements and, when possible, muscle mass for the classification of low muscle in patients with cancer. METHODS: Patients with colorectal cancer were recruited to complete measures of whole-body DXA, air displacement plethysmography (ADP), and bioelectrical impedance analysis (BIA). These measures were used alone, or in combination to construct the criterion multicompartment (4C) mode for estimating FFM. Patients also underwent abdominal CT scans as part of routine clinical assessment. Agreement of each method with 4C model was analyzed using mean constant error (CE = criterion - alternative), linear regression including root mean square error (RMSE), Bland-Altman limits of agreement (LoA) and mean percentage difference (MPD). Additionally, appendicular lean soft tissue index (ALSTI) measured by DXA and predicted by CT were compared for the absolute agreement, while the ALSTI values and skeletal muscle index by CT were assessed for agreement on the classification of low muscle mass. RESULTS: Forty-five patients received all measures for the 4C model and 25 had measures within proximity of clinical CT measures. Compared to 4C, DXA outperformed ADP and BIA by showing the strongest overall agreement (CE = 1.96 kg, RMSE = 2.45 kg, MPD = 98.15 ± 2.38%), supporting its use for body composition assessment in patients with cancer. However, CT cutoffs for skeletal muscle index or CT-estimated ALSTI were lower than DXA ALSTI (average 1.0 ± 1.2 kg/m2) with 24.0% to 32.0% of patients having a different low muscle classification by CT when compared to DXA. CONCLUSIONS: Despite discrepancies between clinical body composition assessment and the criterion multicompartment model, DXA demonstrates the strongest agreement with 4C. Disagreement between DXA and CT for low muscle mass classification prompts further evaluation of the measures and cutoffs used with each technique. Multicompartment models may enhance our understanding of body composition variations at the individual patient level and improve the applicability of clinically accessible technologies for classification and monitoring change over time.

Vitamin D Status and Longitudinal Changes in Body Composition in Patients with Chronic Obstructive Pulmonary Disease - A Prospective Observational Study.

Background: Alterations in body weight and composition are common in patients with chronic obstructive pulmonary disease (COPD) and are independent predictors for morbidity and mortality. Low vitamin D status is also more prevalent in patients with COPD compared to controls and has been related to lower lung function, muscle atrophy and impaired musculoskeletal function. This study aimed to evaluate the association between vitamin D levels and status with body composition (BC), as well as with its changes over time. Patients and Methods: Patients with COPD and controls without COPD, participating in the Individualized COPD Evaluation in relation to Ageing (ICE-Age) study, a prospective observational study, were included. Plasma 25-hydroxyvitamin D (25(OH)D) was measured at baseline and BC was measured by dual-energy X-ray absorptiometry scan, at baseline and after two years of follow-up. Multiple linear regression analyses were performed to assess the relationships between 25(OH)D (nmol/l) and longitudinal changes in BMI, fat-free mass index (FFMI), fat mas index (FMI) and bone mineral density (BMD). Results: A total of 192 patients with COPD (57% males, mean ± SD age, 62 ± 7, FEV1, 49 ± 16% predicted) and 199 controls (45% males, mean ± SD age 61 ± 7) were included in this study. Vitamin D levels were significantly lower in patients with COPD (64 ± 26 nmol/L, 95% CI 60-68 nmol/L versus 75 ± 25 nmol/L, 95% CI 72-79 nmol/L) compared to controls. Both patients and controls presented a significant decline in FFMI and T-score hip, but vitamin D level or status did not determine differences in BC or changes in BC over time in either COPD or controls. Conclusion: Vitamin D status was not associated with BC or longitudinal changes in BC. However, vitamin D insufficiency and low BMD were more prevalent in patients with COPD compared to controls.

Body Composition in Patients With Metabolic Dysfunction-associated Steatotic Liver Disease: Impact of Body Surface Area.

BACKGROUND/AIM: To examine the relationship between the body surface area (BSA) and body composition in patients with metabolic dysfunction-associated steatotic liver disease (MASLD, 2,141 men and 986 women). MATERIALS AND METHODS: BSA and body composition parameters were examined. RESULTS: The median body mass index (BMI) was 25.0 kg/m2 for both men and women (p=0.7754). The median body surface area (BSA) was 1.854 m2 for men and 1.618 m2 for women (p<0.0001). In men, the median fat mass was 17.7 kg, whereas in women, it was 22.1 kg (p<0.0001). Additionally, the median fat-free mass was 55.4 kg in men and 39.3 kg in women (p<0.0001).). In male cases, BSA significantly correlated with fat mass (r=0.82, p<0.0001) and fat-free mass (r=0.95, p<0.0001). In female cases, BSA significantly correlated with fat mass (r=0.87, p<0.0001) and fat-free mass (r=0.94, p<0.0001). CONCLUSION: BSA could be a useful marker for the estimation of body composition in patients with MASLD.

Changes in alanine aminotransferase and body composition and metabolic factors among individuals receiving medical health checkups.

AIM: To examine the relationship between changes in alanine aminotransferase (ALT) and those in body composition and metabolic factors in participants receiving medical health checkups (4350 men [mean age 52.5 years] and 5398 women [mean age 50.5 years]) METHODS: We divided the participants into four types based on their ALT value at baseline and 1 year: A, ALT ≤30 (baseline) and ≤30 (1 year); B, ALT ≥31 (baseline) and ≤30 (1 year); C, ALT ≤30 (baseline) and ≥31 (1 year); and D, ALT ≥31 (baseline) and ≥31 (1 year). The change in each body composition-related parameter (waist circumference, fat mass, fat-free mass, fat mass to fat-free mass ratio, etc.) after 1-year was defined as Δ. RESULTS: The mean changes in waist circumference (cm) in the four types (A, B, C, and D) were -0.33, -1.54, 0.66, and -0.29 (overall p < 0.0001) in men, and -0.19, -0.90, 0.30, and 0.090 (overall p < 0.0001) in women. The mean changes in fat mass (kg) in the four types were -0.027, -0.86, 0.62, and 0.092 (overall p < 0.0001) in men, and 0.0067, -0.48, 0.39, and 0.063 (overall p < 0.0001) in women. The mean changes in fat-free mass (kg) in the four types were -0.028, -0.55, 0.42, and -0.034 (overall p < 0.0001) in men, and -0.0091, -0.34, 0.12, and -0.045 (overall p = 0.0012) in women. The mean changes in fat mass to fat-free mass ratio in the four types were -0.00042, -0.0120, 0.00837, and 0.00171 (overall p < 0.0001) in men, and -0.00013, -0.00817, 0.00730, and 0.00628 (overall p < 0.0001) in women. CONCLUSION: A decrease in ALT to ≤30 IU/L may be associated with improved body composition balance, but caution should be exercised for the decrease in muscle mass.

Evaluation of Nutrition and Performance Parameters in Division 1 Collegiate Athletes.

BACKGROUND: Testing and evaluating athletes is necessary and should include performance, body composition, and nutrition. The purpose of this study was to report assessments of dietary intake, V˙O2max, and body composition in D1 collegiate athletes and examine relationships between these assessments. METHODS: Dietary intake was assessed with 3-day recalls and compared to recommendations, and body composition was assessed via bioelectrical impedance analysis (BIA) (n = 48). V˙O2max was evaluated using a graded exercise test (GXT) with a verification bout (n = 35). Reliability between "true" V˙O2max and verification was determined. Correlations and regressions were performed. RESULTS: Energy, carbohydrate, and micronutrient intake was lower than recommendations. Mean V˙O2max was 47.3 and 47.4 mL·kg-1·min-1 for GXT and verification, respectively. While correlations were apparent among dietary intake, V˙O2max, and body composition, percent fat-free mass (%FFM) predicted 36% of V˙O2max. CONCLUSIONS: Collegiate athletes are not meeting energy and carbohydrate recommendations and exceed fat recommendations. Vitamin D and magnesium were low in all sports, and iron and calcium were low in females. V˙O2max ranged from 35.6 to 63.0 mL·kg-1·min-1, with females below average and males meeting typical values for their designated sport. Assessing D1 athletes can provide guidance for sports dietitians, coaches, and strength and conditioning specialists to track and monitor nutrition in athletes.

Central obesity and fat-free mass are associated with a larger spleen volume in the general population.

Background and aim: As the spleen plays a significant role in immunity, the aim was to investigate the associations of different body composition markers derived from various sources with spleen volume in a general population sample. Materials and methods: Cross-sectional data of 1095 individuals (570 women; 52%) aged between 30 and 90 years were collected in the Study of Health in Pomerania (SHIP-START-2). We measured spleen volume by magnetic resonance imaging (MRI).Body composition markers were derived from classic anthropometry, bioelectrical impedance analysis, including absolute fat mass (FM) and fat-free mass (FFM), as well as from MRI, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and liver fat content. Sex-stratified-adjusted linear regression models were used to analyze the associations of body composition markers with spleen volumes. Results: We observed positive associations of body mass index, body weight, waist circumference, hip circumference, waist-to-height ratio, absolute FM, absolute FFM, and VAT and SAT with spleen volume in men and women. An 8.12 kg higher absolute FFM was associated with a 38.4 mL (95% confidence interval [CI]: 26.7-50.1) higher spleen volume in men and a 5.21 kg higher absolute FFM with a 42.6 mL (95% CI: 26.2-59.0) higher spleen volume in women. Conclusion: Our findings indicate that obesity-related body composition markers and FFM are associated with a higher spleen volume. Particularly, higher absolute FFM showed a strong association with a larger spleen volume in both men and women. Further studies are warranted to understand the clinical significance of body composition markers on large spleen volume.

Assessment of body mass-related covariates for rifampicin pharmacokinetics in healthy Caucasian volunteers.

PURPOSE: Currently, body weight-based dosing of rifampicin is recommended. But lately, fat-free mass (FFM) was reported to be superior to body weight (BW). The present evaluation aimed to assess the influence of body mass-related covariates on rifampicin's pharmacokinetics (PK) parameters in more detail using non-linear mixed effects modeling (NLMEM). METHODS: Twenty-four healthy Caucasian volunteers were enrolled in a bioequivalence study, each receiving a test and a reference tablet of 600 mg of rifampicin separated by a wash-out period of at least 9 days. Monolix version 2023R1 was used for NLMEM. Monte Carlo simulations (MCS) were performed to visualize the relationship of body size descriptors to the exposure to rifampicin. RESULTS: A one-compartment model with nonlinear (Michaelis-Menten) elimination and zero-order absorption kinetics with a lag time best described the data. The covariate model including fat-free mass (FFM) on volume of distribution (V/F) and on maximum elimination rate (Vmax/F) lowered the objective function value (OFV) by 56.4. The second-best covariate model of sex on V/F and Vmax/F and BW on V/F reduced the OFV by 51.2. The decrease in unexplained inter-individual variability on Vmax/F in both covariate models was similar. For a given dose, MCS showed lower exposure to rifampicin with higher FFM and accordingly in males compared to females with the same BW and body height. CONCLUSION: Our results indicate that beyond BW, body composition as reflected by FFM could also be relevant for optimized dosing of rifampicin. This assumption needs to be studied further in patients treated with rifampicin.

Lower-Body Power, Body Composition, Speed, and Agility Performance among Youth Soccer Players.

Speed and agility have been described as crucial abilities for soccer players. The purpose of this study was to analyze, in detail, the variance in speed and agility tasks explained by lower-body power after controlling for age and body composition. The participants were 96 male soccer players aged 16.1 ± 1.6 years. Body composition (stature, body fat percentage-BF%, body mass, and fat-free mass-FFM), lower-body power (countermovement jump-CMJ, and squat jump-SJ), speed (5-, 10-, and 35 m sprints), and agility (t-test) were assessed. Among body composition parameters, BF% presented the highest number of significant relationships with speed and agility, with the strength of correlations ranging from small (5 m sprint, r = 0.25) to large (35 m sprint, r = 0.52). The strongest correlation coefficient emerged between FFM and the 35 m sprint (r = -0.65). Significant correlations were found between vertical jump performance and the 35 m sprint (CMJ: r = -0.68; SJ: r = -0.69), followed by the t-test (CMJ: r = -0.35; SJ: r = -0.47). The hierarchical multiple regression model could explain 22% to 67% of the variance observed in agility scores and speed. BF% remained the most statistically significant negative predictor of all regression models. The CMJ remained a statistically significant positive predictor of the 35 m sprint (ß = -0.581, p ≤ 0.01) after controlling for age and body composition. Integrating programs targeting lower-body power might be important to enhance speed and agility performance in youth soccer. On the other hand, future research based on multidisciplinary approaches to investigate the effects of nutritional strategies in reducing or preventing gains in BF% is still needed, which remained a significant predictor of sprint and agility performance in the final models.

Inulin supplementation exhibits increased muscle mass via gut-muscle axis in children with obesity: double evidence from clinical and in vitro studies.

Gut microbiota manipulation may reverse metabolic abnormalities in obesity. Our previous studies demonstrated that inulin supplementation significantly promoted Bifidobacterium and fat-free mass in obese children. We aimed to study gut-muscle axis from inulin supplementation in these children. In clinical phase, the plasma samples from 46 participants aged 7-15 years, were analyzed for muscle biomarkers before and after 6-month inulin supplementation. In parallel, the plausible mechanism of muscle production via gut-muscle axis was examined using macrophage cell line. Bifidobacterium was cultured in semi-refined medium with inulin used in the clinical phase. Cell-free supernatant was collected and used in lipopolysaccharide (LPS)-induced macrophage cell line to determine inflammatory and anti-inflammatory gene expression. In clinical phase, IL-15 and creatinine/cystatin C ratio significantly increased from baseline to the 6th month. In vitro study showed that metabolites derived from Bifidobacterium capable of utilizing inulin contained the abundance of SCFAs. In the presence of LPS, treatment from Bifidobacterium + inulin downregulated TNF-α, IL-6, IL-1ß, and iNOS, but upregulated FIZZ-1 and TGF-ß expression. Inulin supplementation promoted the muscle biomarkers in agreement with fat-free mass gain, elucidating by Bifidobacterium metabolites derived from inulin digestion showed in vitro anti-inflammatory activity and decreased systemic pro-inflammation, thus promoting muscle production via gut-muscle axis response.Clinical Trial Registry number: NCT03968003.

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.

Phase angle as an indicator of sarcopenia and malnutrition in patients with chronic obstructive pulmonary disease.

BACKGROUND: Phase angle (PhA), which is measured using bioelectrical impedance analysis, is an indicator of muscle quality and malnutrition. PhA has been shown to be correlated with sarcopenia and malnutrition; however, studies on patients with chronic obstructive pulmonary disease (COPD) are limited. In this study, we investigated the correlation between PhA and sarcopenia and malnutrition and determined the cutoff values of PhA for those in patients with COPD. METHODS: This study included 105 male patients with COPD (mean age 75.7 ± 7.7 years, mean forced expiratory volume in 1s % predicted [%FEV1] 57.0 ± 20.1%) and 12 male controls (mean age 74.1 ± 3.8 years) who were outpatients between December 2019 and March 2024. PhA was measured using the InBody S10, and its correlation with sarcopenia and malnutrition was assessed. The cutoff PhA values for sarcopenia and malnutrition were determined using receiver operating characteristic curves. RESULTS: The prevalence rates of sarcopenia and malnutrition were 31% and 22%, respectively, in patients with COPD. PhA significantly correlated with sarcopenia- and malnutrition-related indicators. Multivariate logistic regression analysis independently correlated PhA with sarcopenia and malnutrition. The cutoff values of the PhA for sarcopenia and malnutrition were 4.75° (AUC = 0.78, 95% CI = 0.68-0.88) and 4.25° (AUC = 0.75, 95% CI = 0.63-0.86), respectively. CONCLUSIONS: PhA was significantly correlated with sarcopenia and malnutrition in Japanese patients with COPD and may be a useful diagnostic indicator.

High-standard predictive equations for estimating body composition using bioelectrical impedance analysis: a systematic review.

The appropriate use of predictive equations in estimating body composition through bioelectrical impedance analysis (BIA) depends on the device used and the subject's age, geographical ancestry, healthy status, physical activity level and sex. However, the presence of many isolated predictive equations in the literature makes the correct choice challenging, since the user may not distinguish its appropriateness. Therefore, the present systematic review aimed to classify each predictive equation in accordance with the independent parameters used. Sixty-four studies published between 1988 and 2023 were identified through a systematic search of international electronic databases. We included studies providing predictive equations derived from criterion methods, such as multi-compartment models for fat, fat-free and lean soft mass, dilution techniques for total-body water and extracellular water, total-body potassium for body cell mass, and magnetic resonance imaging or computerized tomography for skeletal muscle mass. The studies were excluded if non-criterion methods were employed or if the developed predictive equations involved mixed populations without specific codes or variables in the regression model. A total of 106 predictive equations were retrieved; 86 predictive equations were based on foot-to-hand and 20 on segmental technology, with no equations used the hand-to-hand and leg-to-leg. Classifying the subject's characteristics, 19 were for underaged, 26 for adults, 19 for athletes, 26 for elderly and 16 for individuals with diseases, encompassing both sexes. Practitioners now have an updated list of predictive equations for assessing body composition using BIA. Researchers are encouraged to generate novel predictive equations for scenarios not covered by the current literature.Registration code in PROSPERO: CRD42023467894.

Defining malnutrition in persons with spinal cord injury - does the Global Criteria for Malnutrition work?

Background and aims: Physiologic and metabolic changes following spinal cord injury (SCI) lead to an increased risk of malnutrition. The Global Leadership Initiative on Malnutrition (GLIM) is a three-step approach to diagnose malnutrition: 1) screening; 2) phenotypic and etiological criteria; and 3) malnutrition severity. The main aim of this study was to assess malnutrition in patients with SCI, according to the GLIM criteria. Methods: Patients with SCI (≥ 18 years) admitted to rehabilitation were included. Anthropometrics, food intake, and inflammation were assessed on admission. Fat-free mass index (FFMI) was estimated from bioimpedance analysis. Malnutrition was diagnosed by the GLIM criteria, using the Malnutrition Universal Screening Tool (MUST) as the first step screening tool. Sensitivity and specificity analyses were performed. Results: In total, 66 patients were assessed (50 men) with a mean age of 51.4 (± 17.4) years and median time since injury was 37.5 (10-450) days. The mean body mass index was 24.7 (± 4.2) kg/m2, and 1-month involuntary weight loss was 5.7 (± 4.4)%. FFMI for men was 17.3 (± 1.9) and for women 15.3 (± 1.6) kg/m2. Forty-one patients (62%) were malnourished according to the GLIM criteria: 27 moderately and 14 severely malnourished. MUST was not able to detect malnutrition risk of nine patients, giving a moderate agreement (kappa 0.66), with a sensitivity of 0.78 and a specificity of 0.92 compared to the GLIM diagnosis. Conclusions: In this cross-sectional study, 62% of subacute SCI patients were malnourished according to the GLIM criteria. The screening tool MUST showed moderate agreement with the GLIM criteria and did not detect risk of all patients with a malnutrition diagnosis. The clinical implications of these findings need further investigation.

Appendicular Muscle Mass Index as the Most Important Determinant of Bone Mineral Content and Density in Small for Gestational Age Children.

Preterm small for gestational age (SGA) children are at increased risk for low bone mineral content later in life; however, data on SGA children born at term are scarce. We included 44 SGA and 57 adequate for gestational age (AGA) children aged 6 to 11 years to compare bone mineral density (BMD) and bone mineral content (BMC) and to identify which anthropometric and biochemical values influence bone mineralization in these children. Fat mass, appendicular skeletal muscle mass index (ASMMI), BMC, and BMD were significantly lower in SGA children than in AGA (P ≤ .005). Appendicular muscle mass index correlated with BMC(TBLH,FN,L1-L4) and BMD(TBLH,FN,L1-L4) in both groups (r2 = 0.7, P < .05). In multivariate analysis, ASMMI was strongly associated with BMC and BMD in both groups. There were no differences in clinical biomarkers, calcium intake, and physical activity between the groups. Achieving adequate muscle mass contributes to adequate bone mineralization and a lower risk for low BMC and BMD in SGA children.

The Association between Circulating Cytokines and Body Composition in Frail Patients with Cardiovascular Disease.

The burden of cardiovascular disease and the percentage of frail patients in the aging population will increase. This study aims to assess the circulating levels of several cytokines in frail patients. This is an ancillary analysis of the FRAPICA trial. The ratio of men/women changed from robust through frail groups from 3:1 to 1:2. The groups are comparable in terms of age and body measurements analysis (weight, height, and BMI), yet the frail patients have significantly reduced fat-free mass, and more often have been diagnosed with diabetes. Frail patients have higher fibroblast growth factor basic (FGF basic) and follistatin levels (borderline significance). In multiple linear regression modeling of fat-free mass, we identified FGF basic, osteopontin, stem cell factor, soluble suppression of tumorigenicity 2, soluble epidermal growth factor receptor, soluble human epidermal growth factor receptor 2, follistatin, prolactin, soluble interleukin 6 receptor alfa, platelet endothelial cell adhesion molecule 1, soluble vascular endothelial cell growth factor receptor 1, leptin, soluble angiopoietin/tyrosine kinase 2, and granulocyte colony-stimulating factor. We have identified a few cytokines that correlate with fat-free mass, a hallmark of frailty. They comprise the kinins implicated in bone and muscle metabolism, fibrosis, vascular wall function, inflammation, endocrine function, or regulation of bone marrow integrity.

Associations between 47 anthropometric markers derived from a body scanner and relative fat-free mass in a population-based study.

BACKGROUND: Low relative fat free mass (FFM) is associated with a greater risk of chronic diseases and mortality. Unfortunately, FFM is currently not being measured regularly to allow for individuals therapy. OBJECTIVE: One reason why FFM is not being used may be related to additional equipment and resources, thus we aimed to identify easily accessible anthropometric markers related with FFM. MATERIALS AND METHODS: We analyzed data of 1,593 individuals (784 women; 49.2%, age range 28-88 years) enrolled in the population-based Study of Health in Pomerania (SHIP-TREND 1). Forty-seven anthropometric markers were derived from a 3D optical body-scanner. FFM was assessed by bioelectrical impedance analysis (FFMBIA) or air displacement plethysmography (FFMADP). In sex-stratified linear regression models, FFM was regressed on anthropometric measurements adjusted for body height and age. Anthropometric markers were ranked according to the coefficient of determination (R2) derived from these regression models. RESULTS: Circumferences of high hip, belly, middle hip, waist and high waist showed the strongest inverse associations with FFM. These relations were stronger in females than in males. Associations of anthropometric markers with FFMAPD were greater compared to FFMBIA. CONCLUSION: Anthropometric measures were more strongly associated with FFMADP compared to FFMBIA. Anthropometric markers like circumferences of the high or middle hip, belly or waist may be appropriate surrogates for FFM to aid in individualized therapy. Given that the identified markers are representative of visceral adipose tissue, the connection between whole body strength as surrogate for FFM and fat mass should be explored in more detail.

Body composition and associated factors among 5-7-year-old children with moderate acute malnutrition in Jimma town in southwest Ethiopia: A comparative cross-sectional study.

Acute malnutrition affects not only the growth and development but also the body composition of children. However, its specific effects have not yet been characterized. This study aims to compare the body composition of 5-7-year-old children with moderate acute malnutrition (MAM) to that of their well-nourished (WN) peers and identify associated factors. A school-based comparative cross-sectional study was conducted from June to July 2022 in Jimma town, southwest Ethiopia. The study participants were selected from eight kindergartens and eight primary schools using a simple random sampling technique based on the proportional allocation of the sample to the size of the population in the respective school. Descriptive statistics and multivariable linear regression analyses were used to assess the mean differences and associations between variables and isolate independent predictors of body composition, respectively. The statistical significance was determined using ß-coefficients with 95% confidence intervals and a p value of ≤ 0.05. Data were captured from 388 (194 MAM and 194 WN) children with a response rate of 97.9%. The mean fat-free mass of WN children was significantly higher compared with those with MAM (p < 0.001). The mean (SD) of fat mass of MAM children was 4.23 ± 0.72 kg, 4.36 ± 0.88 kg and 4.08 ± 0.89 kg for 5, 6 and 7-year-olds, respectively. For WN children, the mean (SD) of fat mass was 4.92 ± 0.88 kg for 5 years old, 5.64 ± 1.01 kg for 6 years old and 5.75 ± 1.26 kg for 7 years old (p < 0.001). On the multivariable linear regression analysis after controlling for background variables, WN children exhibited 1.51 times higher fat-free mass compared with MAM children (ß = 1.51, p = 0.003). A unit increase in age of the study participants was associated with a 1.37 increment in fat-free mass (ß = 1.37, p < 0.001). WN children had 1.07 times higher fat mass compared with children with MAM (ß = 1.07, p < 0.001). A unit increase in the age of the child resulted in 0.15 times increment in fat mass (ß = 0.15, p = 0.020), and being female was associated with a 0.37 increase in fat mass (ß = 0.37, p < 0.001). The results showed that the mean fat mass and fat-free mass were significantly lower among moderately acute malnourished children than in WN children showing the loss of both body compartments due to malnutrition. The body mass index for age, age of the child and sex of the child were significantly linked to both fat-free mass and fat mass.

Fat-free mass predictive equation using bioelectrical impedance and maturity offset in adolescent athletes: Development and cross-validation.

OBJECTIVES: This is a cross-sectional study, aimed to develop and cross-validate a fat-free mass (FFM) predictive equation using single-frequency bioelectrical impedance (BIA), considering the predicted age at peak height velocity (PHV) as a variable. Additionally, the study aims to test the FFM-BIA obtained using a previous predictive equation that used skeletal maturity as a variable. METHOD: The participants (n = 169 male adolescent athletes) were randomly divided into two groups: development of a new predictive equation (n = 113), and cross-validation (n = 56). The concordance test between the FFM values obtained by Koury et al. predictive equation and DXA data was determined (n = 169). Bioelectrical data was obtained using a single-frequency analyzer. RESULTS: Among the models tested, the new predictive equation has resistance index (height2/resistance) and predictive age at PHV as variables and presented R2 = 0.918. The frequency of maturity status using skeletal maturity and PHV diagnosis was inadequate (Kappa = 0.4257; 95%CI = 0.298-0.553). Bland-Altman plots and concordance correlation coefficient showed substantial concordance between the FFM-DXA values (48.8 ± 11.2 kg) and the new predictive equation (CCC = 0.960). The results showed that the new equation performed better than the equation developed by Koury et al. (CCC = 0.901). CONCLUSIONS: Our results show that it is feasible to predict FFM in male adolescent athletes using predictive age at PHV, with moderate concordance. The calculation of FFM using more economical and less complex variables is viable and should be further explored.