Tetrapolar Bioelectrical Impedance Research Articles

Association between muscle-localized bioelectrical impedance analysis parameters and performance in a multi-set exercise on the isokinetic dynamometer in young women.

This study aimed to verify the relationship between changes in thigh muscle-localized bioelectrical impedance analysis (ML-BIA) parameters and performance in a multiple-set exercise. The sample consisted of 30 female university students (22.1±3.2years). The ML-BIA parameters, including localized muscle resistance (ML-R), reactance (ML-Xc), and phase angle (ML-AngF), were evaluated using a tetrapolar bioelectric impedance device operating at a frequency of 50KHz. The multiple sets protocol was performed with an isokinetic dynamometer. For body composition, total and leg lean soft tissue (LST) were evaluated using dual X-ray absortiometry. Student's t-test for paired samples was used to compare the ML-BIA parameters and thigh circumference pre and postexercise. Linear regression analysis was performed to verify the ∆ML-PhA as a predictor of peak torque for the three sets alone while controlling for total and leg LST. There were differences in the ML-R (∆=0.02±1.45Ω; p=0.001; and E.S=0.19), ML-Xc (∆=2.90±4.12Ω; p=0.043; and E.S=0.36), and thigh circumference (∆=0.82±0.60cm; p<0.001; and E.S=0.16) pre- and post-multiple sets. ΔML-PhA was a predictor of performance in the first set (p=0.002), regardless of total and leg LST. However, the ΔML-PhA lost its explanatory power in the other sets (second and third), and the variables that best explained performance were total and leg LST. The ML-BIA (ML-R and ML-Xc) parameters were sensitive and changed after the multiple sets protocol, and the ΔML-PhA was a predictor of performance in the first set regardless of the total and leg LST.

Obese Women Have a High Carbohydrate Intake without Changes in the Resting Metabolic Rate in the Luteal Phase.

Hormonal changes are caused by the menstrual cycle phases, which influence resting metabolic rate and eating behavior. The aim of the study was to determine resting metabolic rate (RMR) and its association with dietary intake according to the menstrual cycle phase in lean and obese Chilean women. This cross-sectional analytical study included 30 adult women (15 lean and 15 with obesity). Body composition was measured with a tetrapolar bioelectrical impedance meter. Nutritional status was determined by adiposity. A 24-h recall of three nonconsecutive days verifies dietary intake. The RMR was measured by indirect calorimetry. All measurements were performed in both the follicular and luteal phases of the menstrual cycle. Statistical analyses were performed with STATA software at a significance level, which was α = 0.05. The RMR (β = 121.6 kcal/d), temperature (β = 0.36 °C), calorie intake (β = 317.1 kcal/d), and intake of lipids (β = 13.8 g/d) were associated with the luteal phase in lean women. Only extracellular water (β = 1.11%) and carbohydrate consumption (β = 45.2 g/d) were associated in women with obesity. Lean women showed increased RMR, caloric intake, and lipid intake during the luteal phase. For women with obesity, carbohydrate intake increased but not RMR.

Proposal of a Normative Table for Classification of Body Fat Percentage in Brazilian Jiu-Jitsu Athletes

Previous evidence indicates that body fat can distinguish Brazilian jiu-jitsu (BJJ) athletes according to the competitive level. However, propositions of cut-off points for establishing classifications of body fat percentage for combat sports athletes and, specifically, for BJJ athletes are still incipient in the literature. In this sense, the main aim of the present study was to establish a normative table for the classification of body fat percentage in BJJ athletes. As a secondary aim, athletes were compared according to competitive level. Ninety male BJJ athletes (aged: 29.0 ± 8.2 years; practice time: 6.0 ± 2.1 years; body mass: 82.1 ± 12.7 kg; height: 175.9 ± 6.5 cm; fat mass: 16.0 ± 8.9 kg; bone mineral content: 3.7 ± 0.6 kg; muscle mass: 37.9 ± 5.4 kg; body fat percentage: 17.3 ± 6.8 %; basal metabolic rate: 1811.4 ± 193.4 kcal) from different competitive levels: state (n= 42), national (n= 26) and international (n= 22) took part in this study. All athletes had their body composition measured via tetrapolar bioelectrical impedance. Percentiles p10, p25, p50, p75, and p90 were used to establish the classification. As a result, the following classification was obtained: <7.7 % (very low); ≥7.7-11.5 % (low); 11.6-17.0 % (medium); 17.1-24.0 % (high) and ≥24.1 % (very high). State-level athletes had a higher fat percentage than national and international-level athletes (p<0.05). The proposed cut-off points can help professionals responsible for sports training and nutritional prescription in monitoring the body fat of BJJ athletes.

Phase angle as a screening method for sarcopenia in community-dwelling older adults

ABSTRACT Objective We investigated the utility of the phase angle as a screening tool for sarcopenia. Methods We performed a cross-sectional study that included 169 active community-dwelling elderly women. The phase angle was determined using tetrapolar bioelectrical impedance, and sarcopenia was diagnosed based on skeletal muscle mass, muscle strength, and physical performance using bioelectrical impedance analysis, a handheld dynamometer, and the gait speed test, respectively. Receiver operating characteristic curve analysis was performed to investigate the role of the phase angle as a predictor of sarcopenia. Results The prevalence of sarcopenia was 12.4%. The median phase angle was 5.30°; elderly women with sarcopenia had lower phase angles than those without sarcopenia (p=0.006). The phase angle cutoff for the detection of sarcopenia was ?5.15°, with an area under the curve of 0.685, sensitivity 81.0%, specificity 60.8%, and accuracy 63.31%. Elderly women with a low phase angle show a high risk of presenting with reduced muscle mass. Conclusions The phase angle was shown to be a useful screening tool in elderly women with sarcopenia.

Appetitive behaviors and body composition in school-age years: Bi-directional analyses in a population-based birth cohort

Cross-sectional studies have consistently associated appetitive behaviors with child body mass index. However, few prospective studies have investigated the association between appetite and other measures of body composition and its directionality. We aimed to investigate the bi-directional relationship between appetitive behaviors and body composition in school-aged children. Data from 3668 children of the Generation XXI birth cohort were analyzed. Appetitive behaviors were assessed at 7 and 10 years through the Children's Eating Behavior Questionnaire. Higher fat mass and fat-free mass were measured through tetrapolar bioelectric impedance and waist-to-weight and waist-to-height ratios were calculated. Fat and fat-free mass indexes, waist-to-weight and waist-to-height age- and sex-specific z-scores were then calculated. Cross-lagged analyses were performed (body composition at 7 to appetitive behaviors at 10 and the reverse) to measure the magnitude and direction of associations. Fat mass and waist-to-height ratio at 7y predicted greater food approach behaviors at 10y (Enjoyment of Food, Food Responsiveness, Desire to Drink and Emotional Overeating), but not waist-to-weight, which seems to be consequence of child's avid appetite (e.g. Enjoyment of Food at 7y: βstandardized = 0.085, 95%CI = 0.041; 0.128, p < 0.001). Child scores on food avoidant behaviors, such as Satiety Responsiveness (βstandardized = -0.073, 95%CI = −0.110;-0.034, p < 0.001) and Slowness in Eating (βstandardized = −0.080, 95% CI = −0.120;-0.041, p < 0.001) at 7y predicted lower fat-free mass at 10. Appetitive behaviors may not solely predict weight status, but the path of association between body composition and later appetitive behavior may also be true, especially for food approaching behaviors and adipose tissue. Interventions aiming to prevent excess weight should focus on appetitive behaviors. Moreover, in children with higher adiposity, other pathways also seem to regulate appetite and need to be considered in interventions.

Influence of sodium intake and sociodemographic, lifestyle and anthropometric variables on blood cholesterol of hypertensive women

The restriction of sodium intake, one of the pillars of antihypertensive treatment, has been associated with the increase in cholesterol levels. Given this, we hypothesize that a sodium intake restriction may increase cholesterol levels in hypertensive women. The present study aimed to evaluate the influence of sodium intake, sociodemographic, lifestyle and anthropometric variables on the blood cholesterol levels of hypertensive women. This was a cross-sectional study with hypertensive and nondiabetic women aged 20 to 59 years, recruited from the primary healthcare units of Maceio, Alagoas, in the Brazilian Northeast. Sodium intake was estimated by the 24-hour urinary excretion of sodium; and blood cholesterol was estimated by capillary blood. Age (years), education level (&lt;4 or ≥4 years), race (white or nonwhite), smoking and alcohol consumption were evaluated. The weight, height and waist circumference were measured and body mass index, conicity index and waist-to-height ratio were quantified. The percentage of body fat was measured using a tetrapolar bioelectrical impedance device. The relationship between blood cholesterol and other variables was assessed by multiple regression analysis. A significance level of 5% was used in the final model. This study included 165 hypertensive women. In linear regression, blood cholesterol wasdirectly proportional to age (p&lt;0.001), education level (p=0.01) and race (p=0.04). These variables, as well assodium intake (p = 0.07) and conicity index (p = 0.12), were included in the multiple regression analysis. Sodium intake (p=0.03) and age (p=0.001) were related, in an inverse and a direct way, respectively, to the blood cholesterol in the hypertensive women studied.

Effects of Continuous Yoga on Body Composition in Obese Adolescents.

Overweight/obesity is a pressing international health concern, and conventional treatments demonstrate poor long-term efficacy. Several studies have shown that yoga can control risk factors for cardiovascular disease, obesity, and psychosocial stress. The present study aimed to assess the effect of continuous yoga (asanas, pranayama, and Surya Namaskar yoga) on body composition in overweight participants. Forty adolescents with obesity were enrolled in this study. The study was conceived as a prospective, single-center, single-blinded randomized controlled trial. The participants were divided into 2 groups: the intervention group (n = 20), which undertook a continuous yoga practice, and the control group (n = 20). Body composition, including body weight (BW), body mass index (BMI), body fat mass (BFM), and muscle mass, was evaluated using tetrapolar bioelectrical impedance (BIA). Our results showed that the mean BMI and BFM of the yoga intervention group were significantly decreased at week 8 and week 12. The muscle mass of the yoga group continued to improve at a rate of 0.515 per week, which was statistically significant. In conclusion, a continuous yoga practice had a tendency to decrease BMI and BFM and increase muscle mass. These findings demonstrate intervention effectiveness similar to that observed in other clinical research and indicate that continuous yoga practice may be used as an alternative therapy for obesity prevention and health promotion in adolescents with obesity.

Bioelectrical impedance vector analysis evaluates cellularity and hydration in cirrhotic patients.

BACKGROUNDMalnutrition in cirrhotic patients is correlated with mortality and a better response to liver transplantation. However, recovery of the nutritional status in these patients is a challenge due to the difficulty in establishing a reliable nutritional diagnosis. The bioelectrical impedance vector analysis (BIVA) method appears as a feasible tool in clinical practice to define the physiological state of cirrhotic patients by assessing hydration and body cellularity.AIMTo evaluate body composition in cirrhotic patients using BIVA.METHODSThis retrospective cross-sectional study was carried out by following cirrhotic outpatients at a hospital in Porto Alegre, Brazil. A tetrapolar bioelectrical impedance analysis device was used to evaluate cellularity and hydration and to perform the BIVA. The BIVA graphic was elaborated by software and for statistical analysis a significance level of 5% (P ≤ 0.05) was considered.RESULTSOne hundred and ninety patients, 61.1% males, with a mean age of 56.6 ± 11.0 years, were evaluated. Of these, 56.3% had Child-Turcotte-Pugh (CTP) A score, and the prevalent etiology was hepatitis C virus (47.4%). The patients were classified according to cellularity and hydration by the quadrants and ellipses of the BIVA method, quadrant 1 (47.9%); quadrant 2 (18.9%); quadrant 3 (14.2%); and quadrant 4 (18.9%). Those classified in quadrant 1 and 2 had a higher phase angle compared to those in quadrants 3 and 4 (P < 0.001). Quadrant 2 patients had a lower average age than the other groups. The association with CTP score showed that patients in quadrant 2 had a higher proportion of CTP A, and those in quadrant 4 had a higher proportion of CTP C (P < 0.052).CONCLUSIONThe BIVA method allows identification of the cellularity and hydration status of cirrhotic patients, and its association with clinical factors determines the disease severity, age and prognostic index.

C-reactive protein is inversely and independently associated with maximal oxygen uptake in adolescents with obesity

The purposes of this study were: 1) investigate whether different markers of infl ammation (CRP and TNF-alpha) are correlated to cardiorespiratory fi tness in adolescents with obesity; 2) examine the association of these variables when adjusted by parameters of body composition. Were selected 57 individuals, 34 girls and 23 boys, with 16.4±1.56 years and body mass index 36.0±4.3 kg/m2. Anthropometric measurements (weight, height and abdominal circunference) and body composition (BMI, visceral fat, body fat) were assessment. Body composition was estimated by analyzer of tetrapolar bioelectrical impedance. Obesity was defi ned as BMI&gt;95th percentile of the curve proposed by the Center for Diseases Control. Plasma TNF-alpha was measured by a quantitative two-site high-sensitivity enzyme immunoassay and CRP was measured by high-sensitivityimmunoturbidimetric assay. Graded maximal exercise testing was performed to obtain the maximum oxygen consumption (VO2max) and velocity associated with the VO2max (vVO2max). Signifi cant correlations of CRP with VO2max and vVO2max were found (r=-0.40 and r=-0,36, respectively). No correlations were observed between TNF-alpha and VO2max e vVO2max. CRP was associated to the VO2max and vVO2max independently of measurements of body composition. The CRP was independently and inversely associated with direct measurement of VO2max and the indirect variable of cardiorespiratory fitness vVO2max, in obese adolescents, even after adjustments in body composition, a potential confounding factor. No association was found between TNF-alpha and the parameters of cardiorespiratory fitness.

C-reactive protein is inversely and independently associated with maximal oxygen uptake in adolescents with obesity

The purposes of this study were: 1) investigate whether different markers of infl ammation (CRP and TNF-alpha) are correlated to cardiorespiratory fi tness in adolescents with obesity; 2) examine the association of these variables when adjusted by parameters of body composition. Were selected 57 individuals, 34 girls and 23 boys, with 16.4±1.56 years and body mass index 36.0±4.3 kg/m2. Anthropometric measurements (weight, height and abdominal circunference) and body composition (BMI, visceral fat, body fat) were assessment. Body composition was estimated by analyzer of tetrapolar bioelectrical impedance. Obesity was defi ned as BMI&gt;95th percentile of the curve proposed by the Center for Diseases Control. Plasma TNF-alpha was measured by a quantitative two-site high-sensitivity enzyme immunoassay and CRP was measured by high-sensitivityimmunoturbidimetric assay. Graded maximal exercise testing was performed to obtain the maximum oxygen consumption (VO2max) and velocity associated with the VO2max (vVO2max). Signifi cant correlations of CRP with VO2max and vVO2max were found (r=-0.40 and r=-0,36, respectively). No correlations were observed between TNF-alpha and VO2max e vVO2max. CRP was associated to the VO2max and vVO2max independently of measurements of body composition. The CRP was independently and inversely associated with direct measurement of VO2max and the indirect variable of cardiorespiratory fitness vVO2max, in obese adolescents, even after adjustments in body composition, a potential confounding factor. No association was found between TNF-alpha and the parameters of cardiorespiratory fitness.

Can Phase Angle in Newborns at Neonatal Intensive Care Units Be an Indicator of Mortality and Prognosis?

The bioelectrical impedance (BI) phase angle (PA), analyzed directly through BI analysis (BIA), is determined by tissue cellularity, representing a direct measure of cellular stability and, for this reason, has been studied and considered as an indicator of prognosis and nutrition status in adults and children. We aimed to determine if PA can be an indicator of mortality and prognosis in newborns admitted to the neonatal intensive care unit (NICU). Transversal study conducted at a public NICU in Curitiba, Paraná, Brazil. All newborns, preterm and term, were considered eligible for the study if admission to the NICU occurred by the first hour of life. The Score for Neonatal Acute Physiology II, as well as the Perinatal Extension version, were developed to assess the risk of mortality for all newborns, measured within 12hours of admission. BIA measurements were conducted using the tetrapolar BioScan Maltron 916, with single-frequency (50 kHz) tetrapolar BI. PA was calculated as the arc tangent: (Xc/R) x 180°/π. BIA was measured during the first 24hours of admission for all newborns (n = 93), repeated between 24 and 48hours (n = 79) and again after 7 days (n = 55), always when possible. PA measurements decreased in the first 48hours in premature newborns, particularly among those who died. The premature newborns also showed a significant decrease from the first to the last PA measurement (P = .001). In addition, whereas full-term newborns showed an increase of PA at 1week of life, preterm infants continued to have a decrease in values. For preterm newborns, PA measurements decreased and more sharply so for those who died. This result should be viewed with caution given the small number of deaths, but it should be investigated to understand the role of PA in the prognosis of NICU newborns. The absolute value of PA during the first 24hours of life was not a good marker for severity or mortality. However, the decrease of PA between different moments of evaluation was a good marker of severity. The decrease of PA in the first 48hours in premature newborns, and that when the decrease is more pronounced, may be indicative of mortality. The difference in PA values between these newborns is probably a significant variable for mortality and prognosis and not a cutoff value.

Resistance Training, Regardless Of Protein Supplementation, Improves Muscular Phenotypes In Women Long-term After Bariatric Surgery

PURPOSE: This double-blind placebo-controlled study investigated the effects of resistance training (RT), with and without protein supplementation (PRO), on body composition, muscle strength and physical function in long term Roux-en-Y bypass (RYGB) female patients. METHODS: A total of 45 women (age 40.4 ± 8.5 yrs, BMI 29.0 ± 4.7 kg/m2) with 4.1 ± 1.4 yrs after RYGB surgery were divided into four groups: Control + Placebo (CON+PL; n = 11), Control + PRO (CON+PRO; n = 10), RT+PL (n = 12), and RT+PRO (n = 12). Patients were evaluated before and after the 12-weeks study protocol for body composition (Tetrapolar Bioelectrical Impedance), knee extensors isokinetic strength and physical function (timed up and go [TUG], 30-seconds sit to stand, and 6-minutes walking). PRO and PL were administrated in a double-blind fashion and respectively consisted of daily 0.5 g of whey protein powder per kg of ideal body weight and an isocaloric placebo powder, both throughout the study period. Training protocol comprised 3 sets of 8-12 reps for 8 exercises targeting all major muscle groups and with progressive loads. ANOVA was used to assess time by group interactions. RESULTS: No significant between-groups differences were observed for any variable at baseline (all P > .05). Significant improvements were observed in the exercised groups, but not in the nonexercised groups, for skeletal muscle mass (RT+PL 0.6 ± 0.3, P = .02; RT+PRO 0.8 ± 0.2, P <.01; CON+PL -0.1 ± 0.3, P = .68; and CON+PRO 0.3 ± 0.3 kgs, P = .31), isokinetic peak torque (RT+PL 12.9 ± 3.1, P<.01; RT+PRO 8.7 ± 2.6, P < .01; CON+PL -4.4 ± 2.9, P = .15; and CON+PRO -3.1 ± 2.9 Nm, P = .30), TUG (RT+PL -1.1 ± 0.2, P < .01; RT+PRO -0.7 ± 0.2, P < .01; CON+PL -0.2 ± 0.2, P = .38; and CON+PRO -0.3 ± 0.2 seconds, P = .23), six-minutes walking (RT+PL 48.4 ± 20.6, P = .02; RT+PRO 37.4 ± 17.8, P = .04; CON+PL -0.9 ± 21.9, P = .97; and 4.4 ± 19.5 meters, P = .82) and seat to stand test (RT+PL 3.2±0.7, P<.01; RT+PRO 1.7±0.6, P<.01; CON+PL 1.1±0.7, P=.13; and CON+PRO 0.7 ± 0.6 repetitions, P = .25). No differences for the improvements were observed between exercised groups (all P > .05). Also, no significant alteration occurred for percent body fat in any group (all P > .05). CONCLUSIONS: A 12-weeks RT program, regardless of PRO, improves muscle mass, knee extensors isokinetic strength and physical function in long term RYGB female patients.

Association of phase angle and running performance

A high phase angle derived from bioelectrical impedance analysis has been linked to a high level of physical activity. However, it is unknown whether a high phase angle is related to running performance. We included all subjects who participated for the first time to the Course de l'Escalade between 1999 and 2016, a yearly city run occurring in Geneva. The subjects underwent a measurement by 50-kHz tetrapolar bioelectrical impedance analysis (Nutriguard®). Running time was converted to running speed in km/h. Results are shown as mean (SD) and as frequencies. We performed sex-specific univariate and multivariate regressions, adjusted for age, body mass index, categories of running distance and year of measurement, to evaluate whether the phase angle is associated with running speed. We analyzed 2264 subjects (1025 women and 1239 men). In univariate regressions, phase angle was significantly related to running speed in women (coeff 0.52, 95% CI 0.35-0.67, p<0.001, adjusted R2 0.037) and men (coeff 0.57, 95% CI 0.42-0.73, p<0.001, adjusted R2 0.039). Multivariate regressions showed that the phase angle was still significantly associated with running speed in women and men (p<0.001 for both models), with an adjusted R2 of 0.262 and 0.282, respectively. The phase angle is positively associated with running performance in men and women. It remains to be demonstrated if this association reflects the benefit of regular training and whether the phase angle might be suitable to monitor improvements in running performance. CLINICAL TRIAL REGISTRY: clinicaltrials.gov, identifier: NCT03400761.

Field study of anthropomorphic and muscle performance changes among elite skippers following a transoceanic race.

Ocean racing has become increasingly demanding, both physically and psychologically. The aim of the study was to assess global changes after a transoceanic race. Eight male sailors were evaluated pre- and post-race through anthropometric measurements (weight, skinfold, girth at different level and estimated body fat percentage), multifrequency tetrapolar bioelectrical impedance, muscular performance, visual analogic scale for perceived fatigue and Critical Flicker Fusion Frequencies for cerebral arousal. Compared to pre-race values, a significant decrease in body weight (-3.6 ± 1.4%, p = 0.0002) and body composition with reduction of body fat percentage (-15.1 ± 3.5%, p < 0.0001) and fat mass (-36.4 ± 31.4%, p = 0.022) was observed. Muscle performance of the upper limb was preserved. In the lower limb, monohulls skippers showed a significant reduction of jump height (-6.6 ± 4.8%, p = 0.022), power (-11.7 ± 7.3%, p = 0.011) and speed (-14.6 ± 7.4%, p = 0.0006) while a multihulls skipper showed a gain in speed (+0.87%), power (+8.52%), force (+11%) resulting in a higher jump height (+1.12%). These changes were inversely correlated with sea days (Pearson r of -0.81, -0.96 and -0.90, respectively, p < 0.01). Changes in body weight and composition are consistent with previous data indicating a probable negative energy balance. The main finding demonstrates a difference in muscular conditioning between upper and lower limbs that might be explained by differential workload related to boat architecture (trampolines) or handling.

Classic Bioelectrical Impedance Vector Reference Values for Assessing Body Composition in Male and Female Athletes.

Bioimpedance standards are well established for the normal healthy population and in clinical settings, but they are not available for many sports categories. The aim of this study was to develop reference values for male and female athletes using classic bioimpedance vector analysis (BIVA). In this study, 1556 athletes engaged in different sports were evaluated during their off-season period. A tetrapolar bioelectrical impedance analyzer was used to determine measurements of resistance (R) and reactance (Xc). The classic BIVA procedure, which corrects bioelectrical values for body height, was applied, and fat-free mass, fat mass, and total body water were estimated. In order to verify the need for specific references, classic bioelectrical values were compared to the reference values for the general male and female populations. Additionally, athletes were divided into three groups: endurance, velocity/power, and team sports. In comparison with the general healthy male and female populations, the mean vectors of the athletes showed a shift to the left on the R–Xc graph. Considering the same set of modalities, BIVA confidence graphs showed that male and female endurance athletes presented lower body fluids, fat mass, and fat-free mass than other sets of modalities. This study provides BIVA reference values for an athletic population that can be used as a standard for assessing body composition in male and female athletes.

Cross-validation of prediction equations for estimating body composition in ballet dancers

IntroductionIn sports related to low body weight, such as classical ballet, the assessment of body composition is important for monitoring performance and health status. This study aimed to cross-validate anthropometry and bioelectrical impedance (BIA) predictive equations for estimating body composition of non-professional classical ballet dancers, using dual-energy-X-ray absorptiometry (DXA) as a reference method.Materials and methodsThirty-seven female non-professional classical dancers (median age of 19 years), at intermediate/advanced level, were evaluated in a cross-sectional study. Body composition was evaluated by DXA, anthropometry and tetrapolar BIA. Twenty different predictive equations of anthropometry (n = 8) and BIA (n = 12) were used to estimate Body Fat (BF) and Fat-Free Mass (FFM), testing their validity against DXA using the Bland-Altman statistics.ResultsFor BF estimated by anthropometry equations, just one equation showed agreement with DXA (r = 0.852, p < 0.0005; p = 0.600 for one sample T-test). According to the Bland-Altman analysis, this equation also showed validity, with the absence of proportional bias. Regarding the predictive BIA equations tested, none were valid for our study group.ConclusionOnly one of the anthropometric equations, the one proposed by Durnin and Womerley (1974), but none of the BIA equations analyzed, was valid for the evaluation of body composition of the studied classical dancers. Our results emphasize the importance of previous cross-validation of existing equations or the development of specific equations for body composition assessment in specific populations.

Assessment of Changes in Body Composition During the First Postoperative Year After Bariatric Surgery

The potential effect of bariatric surgery on weight reduction and improvement of associated comorbidities is known, but the ratio obtained between the components of body weight, including lean body mass, body fat mass, and bone mass, is still not determined. This study aims to verify the changes in body composition during the first year after bariatric surgery. We conducted a prospective observational cohort study. Fifty patients who underwent bariatric surgery and maintained follow-ups were selected. Patients were assessed preoperatively and postoperatively for periods of 1, 3, 6, and 12months using tetrapolar bioelectrical impedance analysis and laboratory testing of lipids and serum albumin levels. Data were statistically analyzed. Statistically significant differences (p < 0.001) were obtained between the preoperative and 12-month evaluation respectively, for body mass index (BMI) (45.8 ± 7.5 to 30.0 ± 4.8kg/m2), FM (64.7 ± 15.5 to 30.6 ± 9.8kg), PFM (51.6 ± 4.17 to 37.3 ± 7.6%), and total cholesterol levels (197.1 ± 49.8 to 169.8 ± 31.0mg/dL). The decrease in PFM shows a better proportion between the body components. PFM showed significantly higher decrease in males than in females (p = 0.012). Lean body mass (p = 0.000) reduction was highest for patients operated by the Unified Health System (SUS, Government of Brazil) probably because of its few financial resources to maintain postoperative care. The change in body composition of patients who underwent Roux-en-Y gastric bypass was statistically significant for all variables examined during the first year postoperatively. This shows the effectiveness of the surgical procedure and clinical protocol set, which tends to favor a better health prognosis and weight maintenance in the long term.

Strength training improves body composition, muscle strength and increases CD4+ T lymphocyte levels in people living with HIV/AIDS.

The establishment of physical training programs for people living with HIV/AIDS (PLWHA) has several benefits. The study aimed to analyze the effect of resistance training using prediction of intensity by subjective perception of effort (SPE) on body composition, muscle strength, and TCD4+ lymphocyte levels in PLWHA. This a randomized controlled trial study. Participants (11 men and 8 women), were divided in two groups: exercise group (EG) and control group (CG). The EG was submitted to 12 weeks of a resistance-training program based in the prediction of intensity by SPE. Body mass percentages were evaluated using tetrapolar bioelectrical impedance and skinfold methods. We used Flow Cytometry to quantify CD4+ T lymphocytes. Patients showed significant changes in Body Fat Percentage (Δ%=-6.23%), Lean Body Mass (Δ%=2.45%), and CD4T lymphocytes levels (Δ%=15.77%). They also showed significant increase in muscular strength presented in the test for one repetition maximum in all the evaluated exercises. Our data suggest that exercising program prescribed by SPE is capable of improving immune function, body composition, and muscular strength in PLWHA.

Abnormal sympathetic functioning is linked to familial hypertension in nonathletic young males.

BACKGROUND:Sympathetic overactivity mediates abnormal cardiovascular outcome that is affected by stress, lack of physical activity (PA), and familial hypertension (HTN). It can be assessed by blood pressure-based sympathetic function tests.OBJECTIVE:We studied sympathetic function tests in young nonathletic males in relation to measures of obesity, PA, and familial HTN.METHODOLOGY:We recruited 100 males (mean age: 19 years) and measured body mass index (BMI) and body composition parameters by tetrapolar bioelectrical impedance such as total body fat, visceral fat, subcutaneous fat, and skeletal muscle mass. Using instrument cardiac autonomic neuropathy system of Recorders and Medicare System Company, India, blood pressures (supine, standing, and post hand grip) were recorded and studied quantitatively and qualitatively.RESULTS:Physically active and inactive individuals (n = 50 each) had comparable age, BMI, measures of obesity, and sympathetic function tests. However, individuals with familial HTN (n = 37) showed significantly higher obesity measures and blood pressures (supine: systolic blood pressure [SBP] – 133 vs. 115 and diastolic blood pressure [DBP] – 79 vs. 76; standing: SBP – 136 vs. 122 and DBP – 80 vs. 76; post hand grip: SBP – 136 vs. 125 and DBP – 86 vs. 81). Qualitatively, postural hypotension was seen in only two individuals, while worst grading was in post hand grip test significantly and more so in physically inactive group (30%, 28%, and 42% vs. 16%, 20%, and 64%) and individuals with positive familial HTN (32%, 38%, and 30% vs. 17%, 13%, and 70%).CONCLUSION:Familial HTN, but not physical inactivity, affects sympathetic functioning in nonathletic young male medical personnel. It asks for other lifestyle modifications for better cardiovascular health as primary prevention.

Girl Body Composition according to pubertal status. Methodology variation

The objective of the present paper is to analyze the differences in body composition among pre and post-menarche girls of the same chronological age using anthropometry and tetrapolar bioelectrical impedance.