This study examined how different sequences of concurrent training impacted physical activity (PA), body composition, and physical fitness in young obese males. We also investigated whether the effectiveness of these interventions in reducing body fat percentage (BF%) was influenced by PA levels.

A 12-week randomized controlled trial involving a cohort of 45 obese young males (mean age: 22.42 ± 1.96 years, mean BMI: 29.78 ± 3.37) was conducted. Participants were randomly assigned to three groups: the CRE group (Resistance Training (RT) followed by Endurance Training (ET)), the CER group (ET followed by RT), and the control group (Con). The training sessions were held three times a week. Measurements, including PA level, body composition, bone density, VO2max, and muscle strength, were assessed before and after the intervention.

Compared to those at baseline, following the intervention, both the CRE and CER groups showed significant improvements in various parameters, including PA level, body composition, bone density, VO2max, and muscle strength (p < 0.05), whereas no significant changes were observed in the Con group (p > 0.05). Specifically, the CRE group demonstrated remarkable progress, as evidenced by an increase in MVPA level (η2 p = 0.37, p < 0.001), a reduction in fat mass (η2 p = 0.28, p < 0.001), BF% (η2 p = 0.28, p < 0.001), android fat (%) (η2 p = 0.21, p < 0.001), gynoid fat (%) (η2 p = 0.30, p < 0.001), and various physical fitness indices, such as maximum strength (η2 p = 0.20, p = 0.008), explosive strength (η2 p = 0.38, p < 0.001), and muscular endurance (η2 p = 0.55, p < 0.001), surpassing the improvements observed in the CER and Con groups. Changes in PA levels during the intervention influence the efficacy of CT in reducing BF%.

CT, particularly when RT precedes ET, had the potential to improve PA levels, overall physical fitness, body composition, and bone health in obese young males. Moreover, changes in PA levels during the intervention impacted the effectiveness of CT in reducing BF%.

ChiCTR, ChiCTR2200063892.

Muscle wasting is a prevalent issue among long-term critically ill patients and is associated with adverse clinical outcomes. Evaluating muscle mass in the ICU presents challenges due to the lack of a consistent methodology and the significant impact of fluid balance range in ICU patients. This prospective study aimed to compare the utility of bioelectrical impedance analysis (BIA) and ultrasound (US) for monitoring muscle wasting in critically ill patients over an initial seven-day period of critical illness.

Conducted in a tertiary teaching hospital's mixed ICU, the study included adult patients with ICU stays exceeding seven days. Measurements were taken on Day 1 (within 24 hours of ICU admission), Day 5, and Day 7.

Out of 101 enrolled patients, 74 were male, with a mean age of 55.3 (SD 14.8) years. The mean APACHE II score was 18.2 (SD 7.2), and the Day 1 SOFA score was 7.9 (SD 3.2). The ICU survival rate was 65%, and the mean ICU length of stay was 19.2 (SD 19.2) days. Statistically significant muscle mass loss was detected by US measurement, demonstrating the relative change in general muscle thickness: -2.5% (SD 11.8) by Day 5 and -6.5% (SD 12.4) by Day 7 (P < 0.001). BIA demonstrated no significant change in phase angle, as the relative change by Day 5 was -3.3% (SD 19.9) and by Day 7 it was -1.9% (SD 21.9), with no significant difference (P = 0.374).

Ultrasound was a more suitable method for assessing and monitoring muscle wasting during ICU stays, while bioelectrical impedance analysis failed to demonstrate a comparable degree of muscle loss at Days 5 and 7. This study highlights the importance of selecting an appropriate assessment method based on the specific clinical context, emphasizing the reliability of US in evaluating muscle wasting among critically ill patients.

Diagnosing sarcopenia necessitates the measurement of skeletal muscle mass. However, guidelines lack a standardized imaging modality with thresholds validated among Asians. This systematic review compared ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), and bioelectrical impedance analysis (BIA)/body composition monitoring in the detection of sarcopenia within Asian populations.

PubMed and Embase were systematically searched for studies analyzing ultrasonography, CT, MRI, and BIA in diagnosing sarcopenia among Asians. Study quality was assessed using the Newcastle-Ottawa scale.

Pooled findings from 21,598 patients across 25 studies were examined. In receiver operating characteristic analysis, ultrasound displayed a pooled mean area under the curve (AUC) of 0.767 (95% confidence interval [CI], 0.709-0.806), with mean sensitivity of 81.1% (95% CI, 0.744-0.846) and specificity of 73.1% (95% CI, 0.648-0.774), for detecting sarcopenia in Asian populations. CT exhibited an AUC of 0.720 (sensitivity, 54.0%; specificity, 92.0%). MRI demonstrated an AUC of 0.839 (sensitivity, 67.0%; specificity, 66.0%). BIA displayed an AUC of 0.905 (95% CI, 0.842-0.968), 80.7% sensitivity (95% CI, 0.129-0.679), and 82.4% specificity (95% CI, 0.191-0.633).

Various modalities aid in diagnosing sarcopenia, and selection should be individualized. Although only BIA and dual-energy x-ray absorptiometry are recommended by the Asian Working Group for Sarcopenia and the European Working Group on Sarcopenia in Older People, ultrasound imaging may hold diagnostic value for sarcopenia in the Asian population. In certain groups, diagnostic use of CT and MRI is warranted. Future research can standardize and validate modality-specific thresholds and protocols within Asian populations.

Obesity is a public health problem worldwide, and body composition assessment is a very important diagnostic tool. Bioelectrical Impedance Analysis (BIA) is a fast, non-invasive, relatively low-cost, and user-friendly technique; however, to obtain greater validity of the estimates, the predictive equations used must be population specific. Thus, the objectives of this study were: (1) to test the validity of four BIA equations used for fat-free mass (FFM) estimation and one model for fat mass (FM) estimation in adults with overweight or obesity; (2) develop and cross-validate new equations to estimate FFM to adults with overweight or obesity, and specific for those with obesity.

The non-probabilistic sample included 269 individuals, 53.2% with overweight and 46.8% with obesity, aged 18-79 years, randomly divided into two groups: development (n = 178) and cross-validation (n = 91), stratified by sex and classification as overweight or obese. The criterion technique was dual-energy-x-ray absorptiometry (DXA), whereas a tetrapolar single-frequency BIA equipment was used as the alternative method. Paired t-test, multiple regression, concordance correlation coefficient, and Bland-Altman analysis were used.

Most existing equations were not valid and new equations were derived: (1) for individuals with overweight or obesity: CCC = 0.982; r2 = 0.95; standard error of estimate (SEE) = 2.50 kg; limits of agreement (LOA) = -5.0 to 4.8; and (2) specific for individuals with obesity: CCC = 0.968; r2 = 0.94; SEE = 2.53 kg; LOA = -5.3 to 5.2. No FFM differences were observed between the new models and the reference method (p > 0.05).

The new proposed models provide valid options to estimate FFM in an adult population with overweight/obesity.

Individually tailored contrast medium (CM) may improve vascular image quality in chest computed tomography (CT).

To evaluate vascular attenuation in chest CT by comparing CM dose calculations using lean body mass (LBM) and body surface area (BSA) with a fixed-dose protocol.

Patients referred for contrast-enhanced chest CT were categorized as either normal, muscular, or overweight. Patients were accordingly randomized into three CM dosing protocols: fixed-dose group (n = 87), LBM group (n = 92), and BSA group (n = 93).

Of the patients, 94% in the fixed-dose group, 99% in the LBM group, and 98% in the BSA group achieved optimal vascular attenuation. In the overweight category, lower attenuation was demonstrated in the fixed-dose group compared to the LBM group (P = 0.032) and the BSA group (P = 0.010). In the fixed-dose group, vascular attenuation showed a negative correlation with total body weight for all body composition categories. In the LBM group, a positive correlation was observed between attenuation and total body weight in the muscular category (P = 0.041), while a negative correlation was noted for the overweight category in the BSA group (P = 0.049).

Fixed-dose CM protocol exhibited larger variations in vascular attenuation between patients of various body weights and body compositions compared to tailored CM doses based on LBM and BSA.

The aim of this study was to identify preoperative predictors for 1-year posttotal knee arthroplasty (TKA) pain and pre- to post-TKA pain difference in knee osteoarthritis (KOA) patients.

From March 2018 to July 2023, this prospective longitudinal cohort study enrolled KOA patients awaiting TKA from four hospitals in Belgium and the Netherlands. Different biopsychosocial predictors were assessed preoperatively by questionnaires and physical examinations (input variables). The Knee injury and Osteoarthritis Outcome Score (KOOS) subscale pain was used to measure pain intensity. The absolute KOOS subscale pain score 1-year post-TKA and the difference score (ΔKOOS = 1-year postoperative - preoperative) were used as primary outcome measures (output variables). Two multivariable linear regression analyses were performed.

Two hundred and twenty-three participants were included after multiple imputation. Worse absolute KOOS subscale pain scores 1-year post-TKA and negative or closer to zero ΔKOOS subscale pain scores were predicted by self-reported central sensitisation, lower KOA grade and preoperative satisfaction, and higher glycated haemoglobin, number of pain locations and personal control (adjusted R2 = 0.25). Additional predictors of negative or closer to zero ΔKOOS subscale pain scores were being self-employed, higher preoperative pain and function (adjusted R2 = 0.37).

This study reports different biopsychosocial predictors for both outcomes that have filtered out other potential predictors and provide value for future studies on developing risk assessment tools for the prediction of chronic TKA pain.

The protocol is registered at clinicaltrials.gov (NCT05380648) on 13 May 2022.

Level II.

Obesity is a global issue, with over 1.9 billion adults overweight. Disruption of circadian rhythms (CR) leads to obesity and metabolic disorders. Dietary nutrition significantly impacts sleep disorders and disruption in CR, influencing hormones and inflammation, which can contribute to insomnia. The dietary insulin index (DII) and dietary insulin load (DIL) are important factors in determining sleep quality. The current study aims to investigate the association between DII and DIL with CR and sleep quality among with overweight and obesity women.

A case-control study involved 280 overweight/obese women aged 25-40 from Tehran University Medical Science. They were assessed for dietary intake, physical activity, and sleep using validated questionnaires. The study also assessed body composition, bioelectrical impedance analysis, biochemical components, anthropometric components, and blood pressure. Socio-demographic and lifestyle characteristics, such as age, educational level, physical activity, and smoking habits, were also assessed through questionnaires.

In the crude and adjustment models, high adherence of DII compared with lower adherence increased the odds of poor sleep quality index among participants. This significant association remained even after adjustment for confounding variables (P < 0.05), such that the odds of poor sleep quality index was 1.92 times higher.

This study showed high adherence to DII and DIL may cause CR disruption. Furthermore, higher adherence to DII lead to poor sleep quality in women.

This study aimed to evaluate the body composition of the Khisêdjê, an Indigenous people residing in the Xingu Indigenous Territory, and compare it to the results obtained by anthropometry. One hundred seventy-nine individuals aged above 20 of both genders were included. The nutritional status was classified per the cutoff proposed by the WHO (1995). The body composition was identified using measures derived directly from a bioelectrical impedance device (resistance - R, reactance - Xc, and phase angle - PA). Data were analyzed using the Student t-test, chi-square, Pearson correlation, and analysis of variance, and 57% of the sample was male. The mean age of the population was 37.5 years, and 48% of subjects had some overweight level (BMI ≥ 25,0 kg/m2). We identified a positive correlation between BMI with waist (WC) and arm (AC) circumference, and PA measurements, and an inverse correlation between BMI and R and Xc measurements. R and Xc mean values decreased with increasing BMI. In contrast, mean PA increased with greater weight. The results suggest that being overweight among the Khisêdjê Indigenous people was associated with higher muscle mass amounts.

This cross-sectional study investigated the association between metabolic syndrome (MetS) and handgrip strength (HGS) with respect to sex and adiposity in Saudi men (n = 287) and women (n = 268).

Anthropometry, body composition, HGS, and blood biochemistry were measured. The average age of the study population was 57.65 ± 9.3 years (men = 55.1 ± 9.3 years, women = 60.4 ± 9.3 years). We report that HGS/body mass index (BMI), HGS/weight, and HGS/fat (%) were significantly higher in controls than in patients with MetS in men but not in women. According to the ROC analysis, relative HGS (RHGS) was higher than HGS alone in the association with MetS, which was significant for men (p < 0.01). At lower quartiles of HGS, the probability of MetS was higher in women, and the same was found in men in the lower quartiles of HGS/%Fat. Multinomial regression revealed significant associations between age and adiposity and MetS in men and HGS in women. Additionally, the linear regression of age, HGS, and weight exhibited significant associations between HGS with WC in both sexes.

A higher risk of MetS in the lower quartiles of HGS was found in women, and adiposity moderated the relationship between HGS and MetS in men.

Low muscle mass (MM) is significant in cancer patients, and computed tomography (CT) is considered the reference standard for MM assessment. We investigated the consistency of CT and multifrequency bioelectrical impedance analysis (mBIA) in detecting body composition at baseline and during anticancer treatment and the relationship between MM and malnutrition as well as complications in lung and cervical cancer patients.

Abdominal CT and mBIA were conducted to assess body composition at baseline for all patients and repeated for patients with cervical cancer after 4 wk of chemoradiotherapy. Concordance was compared by intraclass correlation coefficient and Bland-Altman plots. Receiver operating characteristic analysis was used to assess the diagnostic efficacy of mBIA for low MM. Correlation analysis was conducted to assess the relationship between MM and Nutritional Risk Screening 2002 and Global Leadership Initiative on Malnutrition. Furthermore, we assessed whether there was a difference in the incidence of chemoradiotherapy side effects in the low MM group derived by CT or mBIA.

A total of 77 cervical and 73 lung cancer patients were enrolled. mBIA showed fair discriminative capacity (area under the curve = 0.651) for detecting low MM, the concordance of skeletal MM and visceral fat area between CT and mBIA was good (intraclass correlation coefficient = 0.712 and 0.698, respectively), and mBIA and CT had consistent observations of muscle and fat changes (P = 0.051 and 0.124, respectively). There was no difference in the incidence of chemoradiotherapy side effects in the low MM group compared with controls regardless of whether derived by CT or mBIA (P > 0.05). MM was correlated with Nutritional Risk Screening 2002 and Global Leadership Initiative on Malnutrition but showed unsatisfactory prediction of malnutrition (area under the curve <0.7).

mBIA- and CT-derived body composition was highly correlated, and agreement was reached on body composition changes during treatment.

This study aimed to compare cervical proprioception and related biomechanical factors among patients with Obstructive Sleep Apnea (OSA) and asymptomatic controls.

In this case-control study, polysomnography scores (apnea-hypopnea index-AHI) were examined to determine the disease severity of the OSA group. Also, we evaluated cervical proprioception by using a laser pointer to detect joint repositioning error sense in cervical rotational movements. Comparison statistics were also conducted for the cervical musculoskeletal variables such as range of motion (ROM) with bubble inclinometer, cranio-cervical (CVA), and thoracic posture (TKA) through photometric analysis, neck flexor muscle endurance test, and pain pressure thresholds of trapezius (PPT).

This case-control study included 59 male participants: patients with OSA (n = 29; mean age = 49.10 years; mean BMI = 28.41 kg/m2) and asymptomatic controls (n = 30; mean age = 49.73 years; mean BMI = 26.89 ± 3.60 kg/m2). The mean AHI score was 26.06 events/hour, categorizing the severity of OSA as mild (31.03%), moderate (31.03%), and severe (37.94%). Patients with OSA demonstrated significantly poorer cervical proprioception compared to controls for both sides of cervical rotation with larger effect sizes (d:1.36-1.45; p < 0.05). Also, cervical ROM, CVA, TKA, neck flexor muscle endurance test, and PPT values were altered in the OSA group compared to the control group (p < 0.05).

Impaired cervical proprioception may be a previously unrecognized factor associated with OSA. This finding has implications for understanding the mechanisms underlying cervical musculoskeletal changes in OSA and for developing potential new interventions or exercise designs targeting postural control.

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.

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

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.

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.

Obesity is associated with the development of polycystic ovarian syndrome (PCOS), a complex endocrine disorder. However, the correlation between body composition and PCOS in women has not been thoroughly investigated. This study aimed to examine body composition using bioelectrical impedance analysis (BIA) in women with and without PCOS in a population-based study within the Tehran Lipid and Glucose Study (TLGS).

We conducted a cross-sectional study among non-menopausal women aged 18-45 who underwent BIA in phase VII of the TLGS. A total of 150 participants with PCOS and 240 without PCOS were included based on the Rotterdam criteria. Baseline demographic, anthropometric, laboratory, and body composition parameters were compared between the two groups.

The mean age was 33.7 ± 7.45 years in the PCOS group and 35.49 ± 7.05 years in the control group. The mean BMI was 27.0 ± 4.0 kg/m2 in the PCOS group and 27.1 ± 4.4 kg/m2 in the control group. No significant differences were found in body composition parameters between the two groups as assessed by BIA. Additionally, there were no correlations between body composition and hormone parameters in PCOS patients.

In this sample of non-referral patients with PCOS, the use of BIA did not provide added value beyond conventional anthropometric measures for assessing body composition. Further longitudinal research is needed to determine whether body composition analysis can enhance PCOS evaluation.

Bioelectrical impedance analysis (BIA) is a widely used method for estimating body composition, and its accuracy may be influenced by various factors, including bladder filling. This study aims to investigate the impact of bladder filling on the accuracy of BIA measurements. An experimental crossover study was conducted with sedentary young adults. The influence of bladder filling on total body water (TBW), fat mass (FM), fat-free mass (FFM), and basal metabolic rate (BMR) was assessed. Participant in underwear followed an overnight fast. They were instructed to abstain from vigorous physical activity and alcohol for at least 24 h prior to the session. The results obtained from single-frequency and multi-frequency BIA devices were compared. The findings suggest that bladder filling does not affect measured impedance; however, changes in weight following bladder voiding influenced derived BIA results. Specifically, TBW, FM, and BMR values significantly reduced after voiding (p < 0.05). Furthermore, the study found poor agreement between single-frequency and multi-frequency BIA devices, indicating that they are not interchangeable. Bladder filling does affect BIA measurements, not clinically meaningful. Further research is needed to explore the implications of these findings for clinical practice and research protocols.

Central and general obesity are commonly measured using tools like waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR). However, the universally recognized cutoffs for these measures may be inadequate for individuals of Ethiopian descent. Due to the lack of universally applicable cutoffs, studies recommend tailoring the optimal screening thresholds to each population's specific characteristics. Therefore, this study aimed to determine body composition-based WC, WHR, and WHtR cutoffs for the healthy adult population of Ethiopia.

A population based cross-sectional study was conducted in the Amhara region of Ethiopia from June to August 2023, collecting anthropometric and body composition data from 838 adult participants. Data were analyzed using Stata, and MedCalc software. The cut-off values were determined using ROC analysis, and performance was assessed using area under the curve (AUC), Youden index, sensitivity, and specificity.

The optimal cut-off values for WC, HC, WHR, and WHtR to define obesity in men were 85.0 cm, 93.5 cm, 0.89, and 0.53 respectively. Correspondingly, these values in women were 81.1 cm, 97.2 cm, 0.84, and 0.5. These cutoff values showed the highest effectiveness in defining obesity especially for WC and WHtR. The new proposed cutoff values for waist circumference, hip circumference, and waist-to-height ratio had sensitivity ranging 76-93% and specificity of 83-94% in accurately identifying obesity. The current study also determined the cut-off values for underweight, normal weight, and overweight body weight categories. Accordingly, for men, the WC cut-offs were: ≤ 74.55 cm (underweight), 74.56-78.95 cm (normal), and 79.0-85.0 cm (overweight). For women, the cut-offs were: ≤ 68.25 cm (underweight), 68.26-79.59 cm (normal), and 79.60-81.10 cm (overweight). The WHtR thresholds were: ≤0.43 (underweight), 0.44-0.47 (normal), and 0.48-0.53 (overweight) in men; ≤0.43 (underweight), 0.44-0.50 (normal), and 0.50-0.51 (overweight) in women.

The findings indicate that the WC, WHR, and WHtR cutoff values for defining obesity in Ethiopian adults are lower than international standards. The newly proposed cutoff values showed improved sensitivity and specificity, suggesting their potential diagnostic relevance. Considering these country-specific cutoffs may be beneficial for clinical practice and obesity-related research in Ethiopia.

Background: FIR therapy is used in various medical settings to treat diseases associated with inflammation and edema. Unlike conventional FIR lamp therapy, this study investigated how body fluids change depending on the intensity and duration of FIR irradiation to the whole body. Method: Subjects in group A (n = 27) were exposed to FIR emitted from a loess bio-ball mat set at 40 °C for 30 min, and subjects in group B (n = 27) were exposed to FIR emitted from a loess bio-ball mat set at 30 °C for 7 h during sleep. Changes in bioimpedance parameters and fluid-related values were measured using a body fluid analyzer before and after exposure to FIR. Results: Changes in bioimpedance parameters associated with inflammatory fluids were quantitatively confirmed. In group A, there was a minimal change in fluid-related measurements. However, significant changes in bioimpedance parameters associated with inflammatory fluids were observed in group B exposure to FIR for 7 h during sleep. Conclusions: FIR emitted from loess bio-balls activates biological tissues and lymphatic circulation, gradually reducing the levels of inflammatory fluids over time.

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.

Bioelectrical impedance analysis (BIA) for body composition estimation is increasingly used in clinical and field settings to guide nutrition and training programs. Due to variations among BIA devices and the proprietary prediction equations used, studies have recommended the use of raw measures of resistance (R) and reactance (Xc) within population-specific equations to predict body composition.

We compared raw measures from three BIA devices to assess inter-device variation and the impact of differences on body composition estimations.

Raw R, Xc, impedance (Z) parameters were measured on a calibrated phantom and athletes using tetrapolar supine (BIASUP4), octapolar supine (BIASUP8), and octapolar standing (BIASTA8) devices. Measures of R and Xc were compared across devices and graphed using BIA vector analysis (BIVA) and raw parameters were entered into recommended athlete-specific equations for predicting fat-free mass (FFM) and appendicular lean soft tissue (ALST). Whole-body FFM and regional ALST were compared across devices and to a criterion five-compartment (5C) model and dual energy X-ray absorptiometry for ALST.

Data from 73 (23.2 ± 4.8 y) athletes were included in the analyses. Technical differences were observed between Z (range 12.2-50.1Ω) measures on the calibrated phantom. Differences in whole-body impedance were apparent due to posture (technological) and electrode placement (biological) factors. This resulted in raw measures for all three devices showing greater dehydration on BIVA compared to published norms for athletes using a separate BIA device. Compared to the 5C FFM, significant differences (p < 0.05) were observed on all three equations for BIASUP8 and BIASTA8, with constant error (CE) from -2.7 to -4.6 kg; no difference was observed for BIASUP4 or when device-specific algorithms were used. Published equations resulted in differences as large as 8.8 kg FFM among BIA devices. For ALST, even after a correction in the error of the published empirical equation, all three devices showed significant (p < 0.01) CE from -1.6 to -2.9 kg.

Raw bioimpedance measurements differ among devices due to technical, technological, and biological factors, limiting interchangeability of data across BIA systems. Professionals should be aware of these factors when purchasing systems, comparing data to published reference ranges, or when applying published empirical body composition prediction equations.

Bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) serves as common modalities for body composition assessment. This study was aimed to evaluate the agreement between BIA and DXA measures in UK Biobank.

UK Biobank participants with body fat mass (FM) and fat-free mass (FFM) estimates obtained through BIA (Tanita BC418MA) and DXA concurrently were included. Correlation between BIA and DXA-derived estimates were assessed with Lin's concordance correlation coefficients. Bland-Altman and Passing-Boblok analyses were performed to quantify the difference and agreement between BIA and DXA. Multivariable linear regression was used to identify predictors influencing the differences. Finally, prediction models were developed to calibrate BIA measures against DXA.

The analysis included 34437 participants (female 51.4%, mean age 64.1 years at imaging assessment). BIA and DXA measurements were highly correlated (Lin's concordance correlation coefficient 0.94 for FM and 0.94 for FFM). BIA (Tanita BC418MA) underestimates FM overall by 1.84 kg (23.77 vs. 25.61, p < 0.01), and overestimated FFM overall by 2.56 kg (52.49 vs. 49.93, p < 0.01). The BIA-DXA differences were associated with FM, FFM, BMI and waist circumference. The developed prediction models showed overall good performance in calibrating BIA data.

Our analysis exhibited strong correlation between BIA (Tanita BC418MA)- and DXA-derived body composition measures at a population level in UK Biobank. However, the BIA-DXA differences were observed at individual level and associated with individual anthropometric measures. Future studies may explore the use of prediction models to enhance the calibration of BIA measures for more accurate assessments in UK Biobank.

Patients living with and beyond breast cancer frequently exhibit several side effects that can impact quality of life and physical functioning way beyond diagnosis and cancer therapies. Traditional on-land exercise has shown to be effective in reducing several symptoms of BC but little is known about the role of water-based exercise in improving physical and psychological well-being.

To compare land- vs. water-based exercise training for BC survivors to improve Health-Related Quality of Life (HRQoL), cancer-related fatigue (CRF), physical functioning, body composition and physical activity in patients with BC.

A randomised, parallel group (1:1) controlled trial was conducted between 2020 and 2022. Patients were randomly allocated to complete a similar exercise training twice weekly during 12 weeks either on land (LG) using traditional gym equipment or in a swimming pool (WG) using body-weight exercises and water-suitable accessories. Both groups were supervised and monitored by an experienced physiotherapist. Main outcome was HRQoL (EORTC QLQ C30 and B23 module) and CRF measured with the Piper Scale. Secondary variables included functional capacity with the 6 Minutes Walking Test (6MWT), upper and lower body strength (handgrip strength and 30″ Sit-to-Stand (STS) test), body composition and objectively measured physical activity.

28 patients were assessed and randomised during the study period. One patient did not receive the allocated intervention due to skin issues and one patient was dropped out during the intervention. A significant effect of time was found for both symptom severity (F(2,52) = 6.46, p = 0.003) and overall functioning (F1.67,43.45 = 5.215, p =0 .013) but no interaction was found between group and time. No effects were reported for CRF. Similar findings were reported for functional capacity (time effect F1.231,32.019 = 16.818, p < 0.001) and lower body strength (time effect F2,52 = 15.120, p < 0.001) as well as fat mass (time effect F2,52 = 4.38, p = 0.017). Notably, a significant time per group interaction was reported for physical activity (F2,52 = 6.349, p =0.003) with patients in the WG significantly improving PA levels over time while patients in the LG exhibited a marked decreased.

Exercise training either in water or on land can decrease symptom severity and improve functionality and body composition. Water-based training seems more effecting than land-based exercise to improve physical activity patterns over time.

The relationship between tinnitus and body composition in specific regions has not been extensively investigated. This study aimed to identify associations between tinnitus and body composition. Individuals with data on physical and otological examination findings, and bioelectrical impedance analysis were included from the ninth Korea National Health and Nutritional Examination Survey. They were divided into a tinnitus group and a non-tinnitus group. Participants with tinnitus were further classified into acute or chronic tinnitus group. The tinnitus group showed significantly higher body fat percentages in each region (arms: P = 0.014; legs: P = 0.029; trunk: P = 0.008; whole body: P = 0.010) and waist circumference (P = 0.007) than the non-tinnitus group, and exhibited lower leg muscle percentage (P = 0.038), total body fluid percentage (P = 0.010), and intracellular fluid percentage (P = 0.009) than the non-tinnitus group in men. Furthermore, men with chronic tinnitus showed a significantly higher trunk fat percentage (P = 0.015) and waist circumference (P = 0.043), and lower intracellular fluid percentage (P = 0.042) than their counterparts without tinnitus. No significant differences in body composition were observed among the groups in the female population. In men, body composition may be associated with tinnitus.

The rising prevalence of obesity has become a global public health crisis. Traditional screening tools like body mass index (BMI) and waist circumference (WC) have limitations, prompting the need for simpler, more effective alternatives. Neck circumference (NC) has emerged as a promising tool due to its simplicity, affordability, and reliability. The study aimed to evaluate neck circumference as a screening tool for obesity among female adults, alongside measuring BMI, waist-to-hip ratio (WHR), WC, and NC, and establishing NC cut-off values using body fat percentage as the gold standard. Additionally, it sought to compare the predictive accuracy of these measures for assessing obesity.

This cross-sectional study, conducted from March 2023 to October 2023, involved 362 female students from a health sciences university in Western Maharashtra, India. The participants provided informed consent and underwent anthropometric measurements, including height, weight, waist circumference, hip circumference, body fat percentage, and neck circumference. Body fat percentage, measured using a bioimpedance analyzer, served as the reference standard.

The study identified a neck circumference (NC) cut-off of 31.3 cm using receiver operating characteristic (ROC) analysis, showing robust sensitivity (71.23%) and specificity (79.02%) for detecting obesity defined by body fat percentage. Waist circumference (WC) showed the highest sensitivity (73.97%) for diagnosing obesity in females, followed by NC (71.23%).

Neck circumference is a practical, cost-effective, and reliable screening tool for obesity, offering advantages over traditional methods. Its noninvasive nature and ease of measurement make it suitable for large-scale screening, contributing to the early detection and management of obesity-related health risks. This study supports the inclusion of NC in routine clinical assessments and public health initiatives.

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.

The use of androgenic anabolic steroids (AASs) among recreational athletes is steadily increasing. However, knowledge regarding the potentially harmful effects of AAS primarily originates from case reports and small observational studies. This large-scale study aims to investigate the impact of AAS use on vascular plaque formation, preclinical coronary disease, cardiac function, circulating cardiovascular risk markers, quality of life (QoL) and mental health in a broad population of illicit AAS users.

A nationwide cross-sectional cohort study including a diverse population of men and women aged ≥18 years, with current or previous illicit AAS use for at least 3 months. Conducted at Odense University Hospital, Denmark, the study comprises two parts. In part A (the pilot study), 120 recreational athletes with an AAS history will be compared with a sex-matched and age-matched control population of 60 recreational athletes with no previous AAS use. Cardiovascular outcomes include examination of non-calcified coronary plaque volume and calcium score using coronary CT angiography, myocardial structure and function via echocardiography, and assessing carotid and femoral artery plaques using ultrasonography. Retinal microvascular status is evaluated through fundus photography. Cardiovascular risk markers are measured in blood. Mental health outcomes include health-related QoL, interpersonal difficulties, body image concerns, aggression dimensions, anxiety symptoms, depressive severity and cognitive function assessed through validated questionnaires. The findings of our comprehensive study will be used to compose a less intensive investigatory cohort study of cardiovascular and mental health (part B) involving a larger group of recreational athletes with a history of illicit AAS use.

The study received approval from the Regional Committee on Health Research Ethics for Southern Denmark (S-20210078) and the Danish Data Protection Agency (21/28259). All participants will provide signed informed consent. Research outcomes will be disseminated through peer-reviewed journals and scientific conferences.

NCT05178537.

In 2020, 38% of adults were affected by obesity, while infertility globally affected 1 in 6 people at some stage of their lives.Body mass index (BMI) provides an easy but occasionally inaccurate estimation of body composition. To achieve a more precise assessment, bioelectric impedance analysis serves as a validated tool that administers electrical energy through surface electrodes. Phase angle as a function of the relationship between tissues resistance and reactance, is a trustworthy predictor of body composition and cell membrane integrity.

We aim to assess whether there is an association between phase angle and seminal parameters, as well as sperm DNA fragmentation percentage.

Semen samples of 520 idiopathic infertile patients were analyzed according to 2021 World Health Organization guidelines and evaluated for sperm DNA fragmentation rate. Each participants underwent bioelectric impedance analysis.

Median age was 40 years old, median BMI was 26.3 kg/m2, median phase angle was 6.2°. In the logistic regression analysis adjusted for age and total intracorporeal water, phase angle (continuous) was significantly associated with oligozoospermia (odds ratio [OR]:0.4; p<0.01) and sperm morphology (OR: 0.65; p=0.05) and slightly with sperm DNA fragmentation (OR: 0.98; p=0.07). In subgroup analysis, the logistic regression analysis adjusted for the mentioned parameters showed that a phase angle between 6.2 and 7 (°) (OR: 0.63; p=0.02) and >7 (°) (OR: 0.12; p<0.01) were associated with a reduced risk of oligozoospermia compared to values <6.2 (°). Similarly, a phase angle between 6.2 and 7 (°) (OR: 0.57; p< 0.01 and OR: 0.58; p= 0.01) and PA > 7 (°) (OR: 0.12; p= 0.03 and OR: 0.21; p< 0.01) were associated with a reduced risk of lower sperm concentration and lower total sperm count, respectively, compared to a phase angle < 6.2 (°).

Our study suggests a negative association between phase angle and detrimental sperm parameters in male idiopathic infertility.

Occult hemorrhages after trauma can be present insidiously, and if not detected early enough can result in patient death. This study evaluated a hemorrhage model on 18 human subjects, comparing the performance of traditional vital signs to multiple off-the-shelf non-invasive biomarkers. A validated lower body negative pressure (LBNP) model was used to induce progression towards hypovolemic cardiovascular instability. Traditional vital signs included mean arterial pressure (MAP), electrocardiography (ECG), plethysmography (Pleth), and the test systems utilized electrical impedance via commercial electrical impedance tomography (EIT) and multifrequency electrical impedance spectroscopy (EIS) devices. Absolute and relative metrics were used to evaluate the performance in addition to machine learning-based modeling. Relative EIT-based metrics measured on the thorax outperformed vital sign metrics (MAP, ECG, and Pleth) achieving an area-under-the-curve (AUC) of 0.99 (CI 0.95-1.00, 100% sensitivity, 87.5% specificity) at the smallest LBNP change (0-15 mmHg). The best vital sign metric (MAP) at this LBNP change yielded an AUC of 0.6 (CI 0.38-0.79, 100% sensitivity, 25% specificity). Out-of-sample predictive performance from machine learning models were strong, especially when combining signals from multiple technologies simultaneously. EIT, alone or in machine learning-based combination, appears promising as a technology for early detection of progression toward hemodynamic instability.

This study aimed at evaluating the agreement between bioelectrical impedance analysis (BIA) using ABC-02 Medas and A-mode ultrasound (AUS) using BodyMetrix™ BX2000 for fat mass (FM), fat free mass (FFM), and body fat percentage (%BF) in females.

The cross-sectional, single-center, observational study was performed in 206 female subjects aged 18-67 years. The examination program included measurements of body height and weight along with waist, hip circumferences, and body composition analysis. The measurements were performed by ultrasound scanner and bioimpedance analyzer.

We found that 20.9% of women were obese based on BMI (≥30 kg/m2), which was significantly lower when using a criterion based on body fat percentage (%BF ≥ 30%) measured with US (53.4%, p = .0056) or BIA (54.8%, p = .0051). At the group level, both methods were found interchangeable and showed practically negligible differences (0.1% for %BF, 0.5 kg for FM, and 0.4 kg for FFM). Agreement analysis conducted in the whole sample revealed a low level of agreement in estimating %BF (CCC = 0.72 0.77 0.82) and FFM (CCC = 0.81 0.84 0.86), and medium level of agreement in estimating FM (CCC = 0.91 0.93 0.94). The level of agreement in estimating %BF and FFM was improved to the medium level with the use of newly generated prediction equations.

Thus, the proposed equations can be used for conversion of body composition results obtained by AUS into the BIA data.

Cancer risk is associated with the widely debated measure body mass index (BMI). Fat mass and fat-free mass measurements from bioelectrical impedance may further clarify this association. The UK Biobank is a rare resource in which bioelectrical impedance and BMI data was collected on ~ 500,000 individuals. Using this dataset, a comprehensive analysis using regression, principal component and genome-wide genetic association, provided multiple levels of evidence that increasing whole body fat (WBFM) and fat-free mass (WBFFM) are both associated with increased post-menopausal breast cancer risk, and colorectal cancer risk in men. WBFM was inversely associated with prostate cancer. We also identified rs615029[T] and rs1485995[G] as associated in independent analyses with both PMBC (p = 1.56E-17 and 1.78E-11) and WBFFM (p = 2.88E-08 and 8.24E-12), highlighting splice variants of the intriguing long non-coding RNA CUPID1 (LINC01488) as a potential link between PMBC risk and fat-free mass.

This study examines the maturity status and relative age effect in elite youth taekwondo Croatian National Team athletes. Measurements of biological age, maturity offset, and body composition were taken from a sample of 17 junior athletes. Differences in maturity status were observed among athletes of the same chronological age, with variations in sitting height and age at peak height velocity. Male athletes generally exhibited higher values in body height, percentage of body fat, muscle mass, and total body water. No significant relative age effect was found. These findings highlight the importance of considering individual biological age and maturity status for talent development and training program adjustments. Further research involving athletes from different countries is recommended to validate these results and enhance the understanding of youth taekwondo athlete development.

A Crataegus Extract Mixture (CEM) is a combination of extracts from Crataegus pinnatifida leaves and Citrus unshiu peels, well-known herbs used for treating obesity and dyslipidemia. We aimed to investigate the efficacy and safety of a CEM on the body fat and lipid profiles in overweight adults. A 12-week, randomized, double-blind, placebo-controlled, parallel-group trial was conducted on 105 subjects aged 20-60 years with body mass indexes between 25 and 30 kg/m2. Eligible subjects were randomly assigned in a 1:1:1 ratio to receive either a high dose of the CEM (400 mg tid), a low dose of the CEM (280 mg tid), or a placebo. Body fat was evaluated using dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), and anthropometric measurements. The blood lipid and adipokine profiles were measured before and after the administration. After 12 weeks, the reductions in the fat percentages measured by DXA and BIA were significantly greater in the CEM groups than in the placebo group. The CEM also significantly decreased the body weights, body mass indexes, and blood leptin levels. An additional per-protocol analysis revealed that the high dose of the CEM also lowered the blood levels of triglycerides and very low-density lipoprotein cholesterol. No adverse events occurred after the CEM treatment. Our results suggest that CEMs are safe and effective for reducing the body fat and body weight and regulating the blood lipid and leptin levels in overweight or mildly obese individuals.

The main aim of this research is to study the protective effects of tryptophan on the histomorphological and biochemical abnormalities in the liver caused by a high-calorie diet (HCD), as well as its ability to normalize mitochondrial functions in order to prevent the development of non-alcoholic fatty liver disease (NAFLD).

The study was conducted in male Wistar rats aged 3 months at the start of the experiment. Control animals (group I) were fed a standard diet. Group II experimental animals were fed a diet with an excess of fat (45%) and carbohydrates (31%) for 12 weeks. Group III experimental animals also received L-tryptophan at a dose of 80 mg/kg body weight in addition to the HCD. The presence of NAFLD, functional activity, physiological regeneration, and the state of the liver parenchyma and connective tissue were assessed using physiological, morphological, histo-morphometric, biochemical, and biophysical research methods.

HCD induced the development of NAFLD, which is characterized by an increase in liver weight, hypertrophy of hepatocytes and an increase in the concentration of lipids, cholesterol and triglycerides in liver tissue. Increased alanine aminotransferase activity in the liver of obese rats also confirm hepatocytes damage. Tryptophan added to the diet lowered the severity of NAFLD by reducing fat accumulation and violations of bioelectric properties, and prevented a decrease in mitochondrial ATP synthesis.

The addition of tryptophan can have a potential positive effect on the liver, reducing the severity of structural, biochemical, mitochondrial and bioelectric damage caused by HCD.

Adiposity and insulin resistance (IR) are closely associated with hypertension; however, the role of interactions between obesity phenotypes and IR in hypertension is unclear. This study aimed to evaluate the interactions of body mass index (BMI), waist circumference (WC), and body fat percentage (BF%) with IR on hypertension risk.

We analyzed data from 4888 participants (mean age 57 years, 41.2% men) in the China Northwest Natural Population Cohort, Ningxia Project. BMI, WC, and BF% were determined using bioelectrical impedance analysis devices. IR was estimated using a homeostasis model assessment index (HOMA-IR). Multivariable-adjusted logistic regression was used to evaluate the association between HOMA-IR and hypertension risk. We calculated the relative excess risk and attributable proportion with their 95% confidence intervals (CIs) to assess whether adiposity phenotypes modified the effect of HOMA-IR on hypertension risk.

The crude prevalence of hypertension was 52.2%. The multivariable-adjusted odds ratio of HOMA-IR was 1.80 (95% CI: 1.23-2.65) for the risk of hypertension in the highest versus the lowest quartiles, but this association became marginal in models further adjusting for BMI, WC, and BF% (P for trend = 0.056). Relative excess risk and attributable proportion for interaction between high HOMA-IR and high BF% were 0.32 (0.04-0.59) and 0.33 (0.06-0.60), respectively. Additionally, high truncal and leg BF% and high HOMA-IR accounted for the hypertension risk in women, but not in men. We did not observe any significant interactions between BMI or WC and HOMA-IR on hypertension.

BF% modified the association between IR and increased risk of hypertension in women with high truncal and leg BF%, but not in men.

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.

Physiological ageing is associated with major and progressive changes in body composition, particularly in the decline of fat-free mass, which puts older individuals at risk of geriatric syndromes such as sarcopenia and sarcopenic obesity. Bioimpedance analysis noninvasively allows the determination of body composition, thus being able to rapidly assess primary risk factors leading to sarcopenia prediction.

We conducted a study of 180 probands, 120 females (66.7%) with a mean age of 76.23 (SD = 9.29) years and 60 males (33.3%) with a mean age of 74.01 (SD = 8.99) years in cooperation with facilities for the elderly and with the inpatient department of the clinics of J.A. Reimann Hospital in Prešov. Body height, body weight, hip circumference, and waist circumference were determined by the anthropometric method, from which the values of the body mass index and waist-to-hip ratio were calculated. Active body mass, total body water, extracellular body water, intracellular body water, cell mass, body mass fat, body fat index, fat-free mass index, impedance at frequencies of 50 kHz, resistance, reactance, and phase angle were determined using the Quadscan 4000 Touch bioimpedance instrument. Appendicular skeletal muscle mass (ASMM) and muscle mass (ASMM/Ht2) were calculated. The data obtained from anthropometric and bioimpedance measurements were processed in MS Excel 2000 and STATISTICA ver. 12. The difference of means in the studied groups was tested by the t-test.

Presarcopenia was diagnosed in 12 (6.66%) probands out of 180 probands, of which were 3 (5%) men and 9 women (7.5%). Phase angle, ASMM and ASMM/Ht2 values were significantly lower (p < 0.001) in men and women with presarcopenia.

By introducing bioimpedance measurements into practice, it is possible to obtain results in a non-invasive way revealing possible presarcopenia in the elderly.

We aim to compare the efficacies of the bioelectrical indices (percentage of body fat, PBF; visceral fat area, VFA) with the conventional anthropometric measures (body mass index, BMI; waist-hip ratio, WHR) for predicting type 2 diabetes (T2D) risk by sex and to determine the sex-specific optimal adiposity indices to predict the T2D risk.

Cross-sectional design.

Tianjin First Central Hospital and Tianjin Union Medical Center, Tianjin, China.

A total of 9,332 adults (41.35% men) undergoing physical examination.

T2D was defined using the WHO's criteria: fasting blood glucose (FBG) ≥7.0 mmol/L and/or previous diagnosis of T2D. Height, weight, waist, hip, PBF, VFA, and fasting plasma glucose were measured.

All studied adiposity indices were associated with T2D among both males and females, and the observed associations differed by sex. The standardized aORs of BMI, WHR, PBF and VFA for T2D were 1.60 (95% CI 1.42-1.81), 1.43 (95% CI 1.25-1.64), 1.42 (95% CI 1.23-1.62) and 1.53 (95% CI 1.35-1.75) for females, and 1.47 (95% CI 1.31-1.66), 1.40 (95% CI 1.25-1.58), 1.54 (95% CI 1.36-1.74) and 1.47 (95% CI 1.31-1.65) for males, respectively. The AUCs of VFA, WHR and BMI were 0.743, 0.742 and 0.717 in women, respectively, whereas none of the indices had AUC larger than 0.70 in men. The AUCs were not significantly different between VFA and WHR, while both demonstrate larger AUCs than BMI and PBF in females (all p < 0.05). The optimal cutoff values of VFA, WHR, and BMI for T2D in women were 103.55 cm2, 0.905, and 24.15 kg/m2, respectively.

Although BMI, WHR, and PBF and VFA as measured by bioelectrical impedance analysis (BIA) were all positively associated with T2D, their efficacy for predicting the risk of T2D differed by sex. VFA, WHR and BMI could be used as biomarkers to predict T2D risk in women, however none of the study indicators demonstrated favorable efficacy of predicting T2D risk in men.

The optimal intra-set rest for cluster sets (CLS) during plyometric-jump training (PJT) to improve physical fitness remains unclear. The objective of this quasi-experimental study was to compare the effects of PJT with traditional (TRS) vs. CLS structures, using different intra-set rests, on the physical fitness of healthy participants. Forty-seven recreationally active young men performed 3-5 sets of 10-12 repetitions of upper- and lower-body PJT exercises twice a week for six weeks using different set configurations: TRS group (no intra-set rest), and the CLS10, CLS20 and CLS30 groups with 10, 20 and 30 s of intra-set rest, respectively, while the total rest period was equated. Pretest-posttest measurements were carried out 48 h before and after the intervention and the rating of fatigue (ROF) was also assessed using a numerical scale (0-10 points) 20 min after the first and last (i.e., 12th) session. There was no significant difference in the mean energy intake between groups (p > 0.05). The repeated measures ANOVA revealed that all groups showed similar improvements (p < 0.05) in body mass, body mass index, fat-free mass, one repetition maximum (dynamic strength) and repetitions to failure (muscular endurance) in back squat and chest press, handgrip strength, standing long jump, 20 m sprint, 9-m shuttle run (change of direction speed), and ROF. Of note, the ROF was lower for the CLS20 and CLS30 groups, independent from the training effect. The physical fitness of recreationally active young men improved after 6 weeks of PJT involving intra-set rest intervals of 0 s, 10 s, 20 s, or 30 s. However, an intra-set rest of 20 s and 30 s seems to induce lower exercise-induced fatigue perception.

Multi-frequency bioelectrical impedance (MF-BIA) provides an estimate of total body water. However, it is unknown if MF-BIA detects body water increases due to acute hydration, thus affecting the validity of MF-BIA body composition measurements. The purpose of this study was to compare the effects of pre-testing fluid ingestion on body composition estimation using single-frequency bioelectrical impedance (SF-BIA) and MF-BIA.

Thirty-nine subjects (20 male, 19 female) were tested for body composition using DXA, SF-BIA and MF-BIA before and after consumption of 2 L of water.

Hydration significantly increased fat percentage in men and women for MF-BIA (+2.1±0.7% for men, +2.6±0.7% for women) and SF-BIA (+1.3±0.7% for men, +2.1±0.9% for women). Additionally, hydration significantly increased fat-free mass (FFM) for DXA (+1.4±0.8 kg for men, +1.7±0.4 kg for women) and SF-BIA (+0.5±0.6 kg) in men. Hydration significantly increased fat mass (FM) for all modes (DXA +0.3±0.3 kg, MF-BIA +2.0±0.7 kg, SF-BIA +1.3±0.6 kg) in males, and only for MF-BIA (+2.2±0.3 kg) and SF-BIA (+1.7±0.5 kg) in females. Increases in FM were highest for MF-BIA for both males and females. Total body water was unchanged in males and significantly decreased with acute hydration in females.

MF-BIA improperly categorizes increased mass due to acute hydration as fat mass, resulting in an increase in measured body fat percentage. These findings confirm the need to standardize hydration status for body composition measurements using MF-BIA.