Validating InBody® 570 Multi-frequency Bioelectrical Impedance Analyzer versus DXA for Body Fat Percentage Analysis

A school-based physical activity intervention in primary school: effects on physical activity, sleep, aerobic fitness, and motor competence

Objective

The "Super Quinas" project evaluated the effectiveness of an intervention program to improve physical activity, aerobic fitness, sleep, and motor competence on children in primary school.

Methods

The experimental group (n = 19) enrolled in a 12-week intervention program (one more extra-curricular activity class of 60 min per week) compared to the CG (n = 19), all aged 9-10 years. Physical activity (PA) and sleep were measured by accelerometry, and aerobic fitness was measured by Children's Yo-Yo test (YYIR1C) during the 1st week (PRE), the 6th week (DUR), and the 12th week (POST) of the intervention program. Motor Competence in PRE and POST intervention was also assessed by the Motor Competence Assessment (MCA) instrument. Heart rate (HR, assessed using HR monitors), and enjoyment level were recorded during all intervention program classes. A linear mixed model analysis (i.e., within-subject analyses) was performed.

Results

Comparing the EG and CG in DUR and POST, the EG spent ~18 min and ~ 34 min more time in moderate to vigorous physical activity (MVPA) per day (p < 0.001); had ~44 min and ~ 203 min less sedentary time per day (p < 0.001); performed more 44 and 128 m in the Children's Yo-Yo test compared to CG (p < 0.001) and slept more 17 and 114 min per night (p < 0.001). In POST motor competence was significantly better (27%) in the EG compared to CG (p < 0.001). The %HRmax during the extra-curricular classes ranged between 65 and 81% (i.e., light to moderate intensities), and the enjoyment between fun and great fun.

Conclusion

Our findings suggest that adding one more extra-curricular activity class of 60 min per week for 12 weeks effectively increased the levels of physical activity, aerobic fitness, sleep duration, and motor competence in children aged 9-10 years.

A comparative study on the reliability and validity of body composition results by impedance method measurement device

The purpose of this study was to analyze the reliability and validity of the body composition results for each impedance device and use them as primary data for body composition research. Total of 58 participants, including 24 men and 34 women, were recruited. The correlation was analyzed by measuring two repetitive measurements for each device. Dual energy x-ray absorptiometry (DEXA) equipment was used as reference equipment for body composition research. All data were analyzed as IBM SPSS Statistics ver. 25.0, and the validity and reliability were estimated by calculating the timely correlation coefficient. As a result of the study, repeated measurements of the measuring instrument showed high reliability by gender and age, especially in the child age group, with relatively higher reliability than those in their 50s or older. In the validity analysis between DEXA, in the case of the male group, the validity of the fat mass amount was relatively higher than the body fat amount and body fat rate. In the case of the women's group, the validity of the body fat amount and body fat rate was relatively higher than that of the fat mass amount. The company B had the highest validity for body fat rate and body fat amount in both men and women. However, the validity for men's fat mass amount was the lowest. In subsequent studies, it is believed that studies that have expanded the population further and studies targeting special groups such as athletes should be conducted.

Association of body anthropometry and obstructive sleep apnea in children: Variations observed in Hispanic children

Objectives

Obesity is a risk factor for obstructive sleep apnea (OSA) in children. Childhood obesity rates vary amongst different ethnic groups. Here the interaction of Hispanic ethnicity and obesity on OSA risk was evaluated.

Methods

Retrospective cross-sectional analysis of consecutive children undergoing polysomnography and anthropometry using bioelectrical impedance from 2017 to 2020. Demographics obtained from the medical chart. Children who had also undergone cardiometabolic testing were identified and the relationship of cardiometabolic markers with OSA and anthropometry was assessed.

Results

Data from 1217 children revealed Hispanic children were more likely to have moderate-severe OSA (36.0%) compared to Non-Hispanic children (26.5%), p < 0.001. Hispanic children had greater Body mass index (BMI), BMI percentile and percent body fat, p < 0.0001. In children that underwent cardiometabolic testing, Hispanic children had significantly greater serum alanine aminotransferase levels (ALT) levels. Following adjustment of age and sex, Hispanic ethnicity was not found to moderate the association of anthropometry with OSA, anthropometry with cardiometabolic markers, and OSA with cardiometabolic markers.

Conclusions

OSA was more likely in Hispanic children; this relationship was likely driven by obesity status rather than ethnicity. Among children undergoing cardiometabolic testing, Hispanic children were observed to have greater ALT concentrations however ethnicity did not impact the association of anthropometry and ALT or other cardiometabolic markers.

Human Serum Betaine and Associated Biomarker Concentrations Following a 14 Day Supplemental Betaine Loading Protocol and during a 28 Day Washout Period: A Pilot Investigation

Several previous investigations have employed betaine supplementation in randomized controlled crossover designs to assess its ostensible ergogenic potential. Nevertheless, prior methodology is predicated on limited pharmacokinetic data and an appropriate betaine-specific washout period is hitherto undescribed. The purpose of the present pilot investigation was therein to determine whether a 28 day washout period was sufficient to return serum betaine concentrations to baseline following a supplementation protocol. Five resistance-trained men (26 ± 6 y) supplemented with 6 g/day betaine anhydrous for 14 days and subsequently visited the lab 10 additional times during a 28 day washout period. Participants underwent venipuncture to assess serum betaine and several other parameters before (PRE) and periodically throughout the washout timeframe (POST0, -4, -7, -10, -13, -16, -19, -22, -25 and -28). All analyses were performed at a significance level of p < 0.05. While analyses failed to detect any differences in any other serum biomarker (p > 0.05), serum betaine was significantly elevated from PRE-to-POST0 (p = 0.047; 2.31 ± 1.05 to 11.1 ± 4.91 µg·mL−1) and was statistically indistinguishable from baseline at POST4 (p = 1.00). Nevertheless, visual data assessment and an inability to assess skeletal muscle concentrations would otherwise suggest that a more conservative 7 day washout period is sufficient to truly return both serum-and-skeletal muscle betaine content to pre-supplementation levels.

The Determination of Step Frequency in 3-min Incremental Step-in-Place Tests for Predicting Maximal Oxygen Uptake from Heart Rate Response in Taiwanese Adults

The maximal oxygen uptake (VO_2max) prediction models established by step tests are often used for evaluating cardiorespiratory fitness (CRF). However, it is unclear which type of stepping frequency sequence is more suitable for the public to assess the CRF. Therefore, the main purpose of this study was to test the effectiveness of two 3-min incremental step-in-place (3MISP) tests (i.e., 3MISP_30s and 3MISP_60s) with the same total number of steps but different step-frequency sequences in predicting VO_2max. In this cross-sectional study, a total of 200 healthy adults in Taiwan completed 3MISP_30s and 3MISP_60s tests, as well as cardiopulmonary exercise testing. The 3MISP_30s and 3MISP_60s models were established through multiple stepwise regression analysis by gender, age, percent body fat, and 3MISP-heart rate. The statistical analysis included Pearson's correlations, the standard errors of estimate, the predicted residual error sum of squares, and the Bland-Altman plot to compare the measured VO_2max values and those estimated. The results of the study showed that the exercise intensity of the 3MISP_30s test was higher than that of the 3MISP_60s test (% heart rate reserve (HRR) during 3MISP_30s vs. %HRR during 3MISP_60s = 81.00% vs. 76.81%, p < 0.001). Both the 3MISP_30s model and the 3MISP_60s model explained 64.4% of VO_2max, and the standard errors of the estimates were 4.2043 and 4.2090 mL·kg^-1·min^-1, respectively. The cross-validation results also indicated that the measured VO_2max values and those predicted by the 3MISP_30s and 3MISP_60s models were highly correlated (3MISP_30s model: r = 0.804, 3MISP_60s model: r = 0.807, both p < 0.001). There was no significant difference between the measured VO_2max values and those predicted by the 3MISP_30s and 3MISP_60s models in the testing group (p > 0.05). The results of the study showed that when the 3MISP_60s test was used, the exercise intensity was significantly reduced, but the predictive effectiveness of VO_2max did not change. We concluded that the 3MISP_60s test was physiologically less stressful than the 3MISP_30s test, and it could be a better choice for CRF evaluation.

Inter-Individual Variability of a High-Intensity Interval Training With Specific Techniques vs. Repeated Sprints Program in Sport-Related Fitness of Taekwondo Athletes

This study investigated the effect of 4 weeks of high-intensity interval training (HIIT) with specific techniques (TS-G) vs. repeated sprints (RS-G) and analyzed the inter-individual variability [classified into responders (Rs) and non-responders (NRs)] on sport-related fitness in taekwondo (TKD) athletes. Athletes of both genders (n = 12) were randomly assigned into TS-G and RS-G groups. Both groups trained 3 days/week for 4 weeks [two blocks of three rounds of 2 min of activity (4-s of all-out efforts with 28-s dynamical pauses) with 1 min of recovery in between and 5 min between blocks] during their regular training. The related sport fitness assessments included squat jump (SJ), countermovement jump (CMJ), multiple frequency speed of kick test (FSKT_MULT), specifically total kicks and Kick Decrement Index (KDI), and 20-m shuttle run (20MSR). Relevant results indicate a significant effect of the time factor in both groups for SJ performance and a significant decrease for KDI in RS-G. In addition, an improvement in performance according to the effect size analysis in the TS-G in total kicks, KDI, and 20MSR. Complementarily, a higher proportion of athlete Rs was reported in TS-G vs. RS-G for SJ (50% vs. 30.3%, respectively), CMJ, and total kicks (16.6% vs. 0%). In conclusion, the addition to the regular training of a HIIT with specific-techniques and repeated-sprints associated with intervals and similar structure of the combat during 4 weeks of training can improve the concentric characteristics of lower limb performance, although they were not the sufficient stimuli in the other components of TKD-related fitness.

Development and Validation of 3 Min Incremental Step-In-Place Test for Predicting Maximal Oxygen Uptake in Home Settings: A Submaximal Exercise Study to Assess Cardiorespiratory Fitness

The purpose of this research was to develop the 3 min incremental step-in-place (3MISP) test for predicting maximal oxygen uptake (V.O_2max). A total of 205 adults (20–64 years) completed the 3MISP and V.O_2max tests. Using age, gender, body composition (BC) including percent body fat (PBF) or body mass index (BMI), and with or without heart rate (HR) at the beginning of exercise (HR0) or difference between HR at the third minute during the exercise and the first minute post exercise (ΔHR3 − HR4) in the 3MISP test, six V.O_2max prediction models were derived from multiple linear regression. Age (r = −0.239), gender (r = 0.430), BMI (r = −0.191), PBF (r = −0.706), HR0 (r = −0.516), and ΔHR3 − HR4 (r = 0.563) were significantly correlated to V.O_2max. Among the six V.O_2max prediction models, the PBF model^{∆HR3 − HR4} has the highest accuracy. The simplest models with age, gender, and PBF/BMI explained 54.5% of the V.O_2max in the PBF model^BC and 39.8% of that in the BMI model^BC. The addition of HR0 and ∆HR3 − HR4 increases the variance of V.O_2max explained by the PBF and BMI models^{∆HR3 − HR4} by 17.98% and 45.23%, respectively, while standard errors of estimate decrease by 10.73% and 15.61%. These data demonstrate that the models established using 3MISP-HR data can enhance the accuracy of V.O_2max prediction.

Bayesian Estimation of the Variation in Strength and Aerobic Physical Performances in Young Eumenorrheic Female College Students during a Menstrual Cycle

Background: The purpose of the present investigation was to examine changes in strength and aerobic physical performances in young eumenorrheic female college students during the menstruation phase and different testing occasions within a menstrual cycle. Methods: A repeated measure experimental design used to investigate the variation in physical performance from different testing occasions compared to the menstruation phase. Twelve eumenorrhea female college students volunteered to participate in this study. The participants were 19.8 ± 0.8 (±SD) years old, with the body mass of 61.4 ± 11.6 kg, the height of 162.6 ± 5.1 cm, and BMI of 23.2 ± 3.8. All participants reported regular monthly menstrual cycles of 26–33 days, none of whom reported taking oral contraceptives in their entire life. None of the participants was an athlete, and their level of activity was limited to physical education classes and recreational activities. The menstrual cycles during the two cycles before testing had to be between 26 and 35 days to participate in this study. Second, there had to be no current or ongoing neuromuscular diseases or musculoskeletal injuries. Third, no one should be taking any dietary or performance-enhancing supplements that could have affected testing results during this study. The participants tested on one-repetition maximum (1RM) bench press, 1RM leg press, push-up to failure, leg press with 60% of 1RM to failure, and running 1600 m time trial. The participants were tested on four occasions based on the classical model of the menstrual cycle (i.e., 28 days; early follicular phase (menstruation phase) on day 2 (T1), late follicular phase on day 8 (T2), ovulation phase on day 14 (T3), and mid-luteal phase on day 21 (T4)). Data were analyzed using the Bayesian hierarchical model (Bayesian Estimation) with Markov Chain Monte Carlo simulation using the decision-theoretic properties of the high-density interval (HDI) + ROPE decision rule. Results: The Bayesian estimated difference from the four testing occasions neither showed that the most credible parameter values (95% HDI) were sufficiently away from the null value nor showed that the most credible parameter values are close to the null value (Rope odds ratio among all tests were spread in 12.7% < 0 < 87.3% with an effect size ranging between d = −0.01 and 0.44). Hence, no decision can be made as to whether strength and aerobic physical performances change during the menstruation phase compared to the other testing occasions within a menstrual cycle. Conclusions: It was noticed that different studies concluded different results, which make the research in menstrual cycle difficult. However, the results from this study and published studies suggest that future research should investigate and profile motivation and autonomic nervous system activity during the menstruation phase and examine the interaction effect of the three on performance compared to other testing occasions within a menstrual cycle.

Assessment of Body Composition, Lower Limbs Power, and Anaerobic Power of Senior Soccer Players in Portugal: Differences According to the Competitive Level

BACKGROUND

During a soccer game, the most diversified stimuli occur all the time, the physical condition level plays a determinant role, and there may be variations according to the competitive level. In this sense, the present study aimed to verify differences in body composition, lower limbs power, and anaerobic power, comparing senior soccer players of different competitive levels.

METHODS

Participants were 81 players belonging to six soccer teams, aged between 18 and 35 years, with a mean age of 23.14 ± 4.23 years, who were divided into three distinct competitive levels: Elite, Sub-Elite and Non-Elite. The players performed bioimpedance evaluations on a tetrapolarInbody270 scale (body composition), the Countermovement Jump (CMJ) through the ChronoJump (lower limbs power), and Running Anaerobic Sprint Test (RAST) (anaerobic power).

RESULTS

Based on the competitive level analysis, we verified that the players present body composition values similar to each other regardless of the competitive level in which they play. Concerning the performance evaluations, we verified that the elite players present higher values of highest jump (p = 0.012; d = 0.76, moderate; and p = 0.022; d = 0.71, moderate) and maximum force produced (p = 0.05; d = 0.64, moderate; and p = 0.002; d = 1.00, moderate), together with higher values of anaerobic power (p < 0.001; d = 2.43, very large; and p < 0.001; d = 2.22, very large), compared to the others.

CONCLUSIONS

We can thus conclude that there is a homogeneity regarding the body composition of soccer players, regardless of their competitive level; in turn, elite players show better performance indicators in all variables.

Changes in Body Composition, Energy Expenditure, and Energy Intake during Four Years of University-A Follow-Up Study

Purpose: The transition to university is often accompanied by the adoption of negative lifestyle habits, which may result in weight and fat gain. While this has been demonstrated during 1st year, little is known about subsequent years. We investigated changes in body composition, energy expenditure, and dietary/energy intake from 1st to 4th year university. Methods: Thirty-eight students (14 males, 24 females) completed a lifestyle questionnaire and had their body mass, fat mass, lean body mass (LBM), and body fat percentage (%BF) measured three times: at the beginning and end of 1st year, and end of 4th year. Results: During 1st year, body mass, fat mass, LBM, and %BF increased (+3.2 ± 3.8 kg, +2.5 ± 3.0 kg, +0.7 ± 2.1 kg, +2.3 ± 4.9%, respectively; p < 0.01), while daily energy intake and expenditure decreased (-359 ± 1019 kcal·d-1 and -434 ± 786 kcal·d-1, respectively; p < 0.01). Between the end of 1st year and end of 4th year, body mass, LBM, and energy expenditure increased (+3.2 ± 3.8 kg, +1.3 ± 2.9 kg, +209 ± 703 kcal·d-1, respectively; p ≤ 0.05), while %BF, fat mass, and energy intake did not change. Conclusions: Although %BF and fat mass remained stable from the end of 1st year to the end of 4th year in this group of university students, the positive increase in energy expenditure was not enough to reverse the weight and fat gained during 1st year.

Effects of 4 Weeks of a Technique-Specific Protocol with High-Intensity Intervals on General and Specific Physical Fitness in Taekwondo Athletes: An Inter-Individual Analysis

The aim of this research was to compare the effects of a technique-specific high-intensity interval training (HIIT) protocol vs. traditional taekwondo training on physical fitness and body composition in taekwondo athletes, as well as to analyse the inter-individual response. Utilising a parallel controlled design, sixteen male and female athletes (five females and 11 males) were randomly divided into an experimental group (EG) that participated in the technique-specific HIIT and a control group (CG) that participated in traditional taekwondo training. Both groups trained three days/week for four weeks. Squat jump (SJ), countermovement jump (CMJ), 5-metre sprint (5M), 20-metre shuttle run (20MSR), taekwondo specific agility test (TSAT), multiple frequency speed of kick test (FSKT_MULT), total kicks, and kick decrement index (KDI), as well as body composition were evaluated. Results indicate that there are no significant differences (p > 0.05) in the factors group and time factor and group by time interaction (p > 0.05). Although percentage and effect size increases were documented for post-intervention fitness components in TSAT, total kicks, KDI, and 20MSR, responders and non-responders were also documented. In conclusion, a HIIT protocol based on taekwondo-specific technical movements does not report significant differences in fitness and body composition compared to traditional taekwondo training, nor inter-individual differences between athletes.

Impact of Ketogenic Diet on Body Composition during Resistance Training among Untrained Individuals

Background:

Resistance training (RT) has been established as the most efficient approach for lean body mass maintenance required for preserving a sufficiently high metabolism during weight loss.

Objective:

This study aimed to evaluate the impacts of the ketogenic diet (KD) and regular diet (RE) in combination with 8-week resistance exercise (RT), on body weight, body fat mass (BFM), and lean body mass (LBM) of untrained individuals.

Methods:

Twenty untrained participants were randomly assigned to the RE+RT and KD+RT as control and experimental groups, respectively. Sixty to ninety minutes of diversified resistance exercise were performed by both groups, three sessions weekly, and diet was self-administered with a recommended daily energy and protein intakes. Body composition was measured using a Bioelectrical Impedance Analyzer. One-way Analysis of Covariance (ANCOVA) was applied to analyze the data.

Results:

The results showed a greater post-intervention adjusted mean for body weight and LBM in the normal dietary group in comparison with the experimental group. After controlling for baseline measurements, there was a statistically significant difference in body weight (p < .0005) and BFM (p =.001) between groups.

Conclusion:

Resistance training along with a ketogenic diet may decrease BFM without notable changes in LBM, whilst RT on a normal diet might increase LBM without remarkably influencing BFM.

Barriers and enablers to physical activity and aerobic fitness deficits among childhood cancer survivors

BACKGROUND

Physical activity and aerobic fitness are modifiable risk factors for cardiovascular disease (CVD) after childhood cancer. How survivors engage in physical activity remains unclear, potentially increasing CVD risk. We assessed survivors' physical activity levels, barriers and enablers, fitness, and identified predictors of fitness and physical activity stage of change.

METHODS

Childhood cancer survivors (CCS; 8-18 years old) ≥1 year post-treatment were assessed for aerobic fitness (6-min walk test), used to extrapolate VO_2max , and body composition (InBody 570). Survivors self-reported physical activity to determine stage of change (Patient-Centered Assessment and Counselling for Exercise). Physical activity and fitness were compared with guidelines and CVD-risk cut-points (VO_2max  < 42 mL/kg/min: males; VO_2max  < 35 mL/kg/min: females). Multiple regression and mediator-moderator analysis were used to identify fitness predictors and stage of change.

RESULTS

One hundred two survivors (12.8 ± 3.3 years) participated (46% acute lymphoblastic leukaemia). Forty percent of males (VO_2max  = 43.3 ± 6.3 mL/kg/min) and 28% of females (VO_2max  = 36.5 ± 5.9 mL/kg/min) were in the CVD-risk category, while 25% met physical activity guidelines. Most prevalent physical activity barriers were fatigue (52%), preferring television instead of exercise (38%), and lacking time (34%). Predictive factors for reduced fitness included being older, female, higher waist-to-height ratio, higher screen time, and moderated by lower physical activity (r²  = 0.91, P < .001). Survivors with higher physical activity stage of change were male, lower body fat percentage, lower screen time, and lived with both parents (r = 0.42, P = .003).

CONCLUSION

Aerobic fitness and physical activity of CCS is low compared with population norms, potentially increasing CVD risk. Addressing physical activity barriers and enablers, including reducing screen time, could promote regular physical activity, reducing CVD risk.

Circulating miRNA Signatures Associated with Insulin Resistance in Adolescents with Obesity

PURPOSE

MicroRNAs (miRNAs) are implicated in metabolic changes accompanying progression of obesity, insulin resistance (IR), and metabolic disorders in children. Identifying circulating miRNAs that uniquely associate with these disorders may be useful in early identification and prevention of obesity-related complications. We aimed to identify circulating miRNA signatures that distinguish adolescents with obesity and IR from those with obesity unaccompanied by IR.

METHODS

Adolescents (aged 10-17 years) with obesity were recruited from a weight management clinic. Fasting serum samples were obtained from 33 participants. A total of 179 miRNAs were queried by a quantitative RT-PCR-based miRNA focus panel. Differentially expressed miRNAs were compared between groups using Student's t-test or one-way ANOVA analysis, and the association between IR evaluated by homeostatic model assessment model (HOMA-IR > 4) and body mass index (BMI) status was assessed using Pearson's correlation analysis.

RESULTS

We found an expression pattern consisting of 12 elevated miRNAs linked to IR in obese adolescents. miR-30d, -221, and -122 were significantly correlated with clinical and biochemical markers of obesity and IR, suggestive of IR in adolescents at risk.

CONCLUSION

Specific signatures of circulating miRNAs reflected metabolic phenotypes and predicted the presence of IR in adolescents with obesity, suggesting that miRNA indicators may identify obesity-associated complications in childhood. Further studies will be needed to understand cause versus effect and the mechanisms by which IR status links to changes in blood miRNA profiles.

Fibroblast Growth Factor-21 to Adiponectin Ratio: A Potential Biomarker to Monitor Liver Fat in Children With Obesity

Background: There is a pressing need for effective and non-invasive biomarkers to track intrahepatic triglyceride (IHTG) in children at-risk for non-alcoholic fatty liver disease (NAFLD), as standard-of-care reference tools, liver biopsy and magnetic resonance imaging (MRI), are impractical to monitor the course disease. Objective: We aimed to examine the association between serum fibroblast growth factor (FGF)-21 to adiponectin ratio (FAR) and IHTG as assessed by MRI in children with obesity. Methods: Serum FGF21 and adiponectin levels and IHTG were measured at two time points (baseline, 6 months) in obese children enrolled in a clinical weight loss program. The association between percent change in FAR and IHTG at final visit was examined using a multiple linear regression model. Results: At baseline, FAR was higher in the subjects with NAFLD (n = 23, 35.8 ± 41.9 pg/ng) than without NAFLD (n = 35, 19.8 ± 13.7 pg/ng; p = 0.042). Forty-eight subjects completed both visits and were divided into IHTG loss (≥1% reduction than baseline), no change (within ±1% change), and gain (≥1% increase than baseline) groups. At 6 months, the percent change in FAR was different among the three groups (p = 0.005). Multiple linear regression showed a positive relationship between percent change in FAR and the final liver fat percent in sex and pubertal stage-similar subjects with NAFLD at baseline (slope coefficient 6.18, 95% CI 1.90-10.47, P = 0.007), but not in those without NAFLD. Conclusions: Higher value in percent increase in FAR is positively associated with higher level of IHTG percent value at 6 months in children with baseline NAFLD. FAR could be a potential biomarker to monitor the changes in IHTG in children with NAFLD.

Assessment of Plasma Resistivity as a Surrogate for Extracellular Fluid Resistivity: Analytical Performance and Impact of Fluid Composition

Bio-electrical impedance analysis (BIA) is frequently used to assess body composition in man. Its accuracy in patients is limited, possibly because the employed algorithms are based on the assumption that total body electrical resistance (TBER) is exclusively related to body water volume, and that variation in fluid composition and its effect on fluid resistivity can be ignored. This may introduce substantial calculation errors. The aim of this study was to develop an objective method to assess plasma resistivity (ρ_plasma) based on measurements by a conductivity probe, as a surrogate for extracellular fluid resistivity (ρ_e). Sample measurements were standardized at body temperature. Analytical variation was 0.6% within runs and 0.9% between runs. The critical difference, i.e. the smallest difference needed to consider changes within individuals significant, was 1.8% for measurements within runs and 4.3% for measurements between runs. The normal range was defined by a mean ± SD of 66.9 ± 1.8 Ω cm. Multiple regression demonstrated that ρ_plasma was inversely related to plasma sodium and chloride concentrations, and positively related to total protein (overall R² = 0.92, p < 0.001). In conclusion, ρ_plasma measurements were sufficiently robust to be useful as a tool to examine and improve the validity of BIA in clinical settings.

Proposal of a normative table for body fat percentages of Brazilian young adults through bioimpedanciometry

Identification of the body fat (BF) percentage allows health professionals to detect healthy or risky patterns in a population. However, no studies have elaborated BF cutoff points using the bioelectrical impedance method in young Brazilian adults. Thus, the objective of the present study was to elaborate normative tables for BF in Brazilian men and women (sedentary and physically active) between 18 and 39 years of age. A total of 3,111 adults (958 men and 2,153 women) were evaluated using bioimpedance measurements with the InBody 520 device. The data were distributed normally and divided into percentiles (P₃, P₁₀, P₂₅, P₅₀, P₇₅, P₉₀, and P₉₇). The following values were observed: for men: P₃=8.9%–12.5%; P₁₀=12.6%–17.5%; P₂₅=17.6%–25.3%; P₅₀=25.4%–35.1%; P₇₅=35.2%–43.0%; P₉₀=43.1%–49.4% and P₉₇=49.5%; for women: P₃=18.7%–23.1%; P₁₀=23.2%–28.7%; P₂₅=28.8%–35.7%; P₅₀=35.8%–42.9%; P₇₅=43.0%–49.1%; P₉₀=49.2%–52.1% and P₉₇≥52.2%. These percentiles can be used to classify the adiposity of sedentary and physically active individuals evaluated by bioimpedanciometry.

Aggressive clinical approach to obesity improves metabolic and clinical outcomes and can prevent bariatric surgery: a single center experience

BACKGROUND

The number of bariatric procedures has exponentially increased in the past decade, as a result of the lack of successful clinical weight-loss interventions. The main reasons for the failure of clinical obesity management are: (1) anti-obesity medications are administered as monotherapies (or pre-combined drugs); (2) lack of combination between pharmacotherapy and non-pharmacological modalities; (3) short duration of pharmacotherapy for obesity; (4) lack of weight-loss maintenance strategies; (5) misunderstanding of the complex pathophysiology of obesity; and (6) underprescription of anti-obesity medications. We developed a protocol that can potentially overcome the drawbacks that may lead to the failure of clinical therapy for obesity. The aim of this study is therefore to report the clinical and metabolic effects of our proposed obesity-management protocol over a 2-year period, and to determine whether this more intensive approach to obesity management is feasible and a possible alternative to bariatric surgery in patients with moderate-to-severe obesity.

METHODS

This retrospective study involved 43 patients in whom bariatric surgery was indicated. Patients underwent an intensive anti-obesity protocol that included pharmacotherapy with multiple drugs; intense surveillance with monthly body analysis by air-displacement plethysmography, electrical bioimpedance, and 3D body scans; weekly psychotherapy; diet planning with a dietician every 2 months; and exercises at least 3 times a week with exercises prescribed by a personal trainer at least once a month. Body weight (BW), total weight excess (TWE), obesity class, body mass index, fat weight, muscle weight, waist circumference, and visceral fat were analyzed. Markers of lipid and glucose metabolism, liver function, and inflammation were also evaluated. Therapeutic success was defined as >20% BW loss or >50% decrease in TWE after 1 year.

RESULTS

Significant improvements were observed in all clinical and metabolic parameters. Thirty-eight (88.4%) patients achieved 10% BW loss, and 32 (74.4%) achieved 20% BW loss. TWE decreased by >50% in 35 (81.4%) patients. Forty (93.0%) patients were able to avoid bariatric surgery.

CONCLUSION

An intensive clinical approach to obesity management can be an effective alternative to bariatric surgery, although further randomized controlled studies are necessary to validate our findings.