Reliability Of Bioelectrical Impedance Analysis Research Articles

Within- and between-day reliability of bioelectrical impedance analysis using a novel Tanita multi-frequency body composition analyzer (MC-780PMA) in healthy young adults

Within- and between-day reliability of bioelectrical impedance analysis using a novel Tanita multi-frequency body composition analyzer (MC-780PMA) in healthy young adults

Body composition assessment before and after weight loss following a Roux-en-Y gastric bypass. Are bioimpedanciometry estimations reliable?

Introduction: in patients with severe and morbid obesity it has been observed that bioimpedance (BIA) assessment generates an underestimation of fat mass (FM) and weight loss as FM after bariatric surgery, overestimating the loss of fat-free mass (FFM) and muscle mass. Objective: to evaluate the reliability of bioelectrical impedance analysis (BIA) to estimate total body water (TBW), fat-free mass (FFM), fat mass (FM), and its changes after 6 months of a Roux-en-Y gastric bypass (RYGBP), in patients with severe and morbid obesity. Methods: thirty-six patients approved for RYGBP were prospectively studied. TBW was measured by deuterium (D), and FM and FFM were calculated. A dual-frequency BIA device (5 and 200 kHz) (Bodystat Dualscan®) was used to estimate FM, FFM, TBW, extracellular water (ECW), intracellular water (ICW), and ECW/ICW ratio. Results: before RYGBP, BIA overestimated TBW by 2.6 ± 4.3 L (p = 0.002) and FFM by 3.5 ± 5.7 kg (p = 0.002), and underestimated FM% by 2.98 ± 4.7% (p = 0.002). The ECW/ICW ratio showed a significant and positive correlation with the difference BIA-D for FFM (r = 0.49; p = 0.002). After surgery, the differences between BIA and D were not significant, and the estimation error of FFM did not correlate with the ECW/ICW ratio. Conclusions: BIA generates an underestimation of FM as reported in patients with severe and morbid obesity, which is attenuated after weight reduction, underestimating weight loss as FM and overestimating FFM loss. Future research may assess whether these errors are reproduced by other BIA devices.

Establishment of muscle mass diagnostic standard of sarcopenia using a bioelectrical impedance analysis and epidemiological investigation of the elderly in Shanghai

Objective To establish diagnostic standard of sarcopenia using bioelectrical impedance analysis (BIA) and to obtain the prevalence of sarcopenia in the elderly in Shanghai. Methods 40 volunteers aged 20-77 years were enrolled and received BIA and dual-energy X-ray absorptiometry (DEXA) measurements in order to verify the reliability of BIA for measuring lean mass. 219 healthy young volunteers aged 20 to 40 years with ratio of gender men: women 100: 119 had BIA measurements to obtain peak muscle mass and sarcopenia diagnostic cut-off point of the elderly. 657 elderly aged ≥ 60 years with ratio of gendermen: women 318: 339 took BIA measurements to obtain the prevalence of sarcopenia in the elderly in Shanghai. Results No statistical difference between BIA-measured and DEXA-measured LM was observed (P=0.307). The appendicular skeletal muscle mass/height2 (ASM/h2) was (7.90±0.62) kg/m2 in young men, and (6.12±0.44) kg/m2 in young women, the cut off in elderly men and women were ≤6.66 kg/m2 and ≤ 5.24 kg/m2 respectively. Elderly people were divided into three age groups: aged60-69 years group, aged 70-69 years group, aged ≥ 80 years group, The prevalence of sarcopenia were 14.6%, 25.0% and 36.0% in men and 6.8%, 12.6% and 27.9% in women in aged 60-69 years, aged 70-69 years, aged ≥ 80 years groups, respectively. The overall prevalence in elderly men and women were 23.6% and 11.8% respectively. Conclusions Measurement of LM by BIA is validated in Shanghai volunteers. The prevalence of sarcopenia in the elderly is increased with age, which is higher in elderly men than in elderly women. Key words: Muscular diseases; Electric impedance; Body composition

Validity and reliability of bioelectrical impedance analysis to estimate body fat percentage against air displacement plethysmography and dual‐energy X‐ray absorptiometry

AbstractAir displacement plethysmography (ADP) and dual‐energy X‐ray absorptiometry (DXA) are well‐regarded methods for predicting body fat percentage (BF%). Bioelectrical impedance analysis (BIA) also predicts BF% and has distinct advantages in research settings.AimTo assess the validity of BIA against ADP and DXA to measure BF%, and to test the reliability of each method.MethodsAdults (n = 166) with a wide range of body mass index (19–38 kg/m2) were tested twice during a 5‐day period. ADP was conducted in a BodPod (Life Measurement Inc, Concord, CA, USA); DXA measurements on a QDR Discovery A (Hologic) and BIA measurements used the InBody 230 (Biospace Ltd., Seoul, Korea). Agreement between measurements was analysed using t‐tests, effect size, linear regression models and method of triads (estimating true value).ResultsBIA showed excellent relative agreement to the estimated true value (ρ = 0.97 (0.96, 0.98)) and to ADP (R2 = 0.88) and DXA (R2 = 0.92), but wide limits of agreement (−4.25 to 8.37%). BIA underestimated BF% by 2%, across all values. DXA showed excellent relative agreement to the estimated true value (ρ = 0.97 (0.96, 0.98)) and with ADP (R2 = 0.92), good absolute agreement but wide limits of agreement (−6.13 to 6.91%) and under‐ and overestimation at high and low BF% levels, respectively. All methods showed excellent reliability with repeat measurements differing by less than 0.2% with very small 95% CIs.ConclusionsBIA may be a valid method in research and population samples. All three methods showed excellent reliability.

Validity and Reliability of Bioelectrical Impedance Analysis and Skinfold Thickness in Predicting Body Fat in Military Personnel

Previous studies show that body composition is related to injury risk and physical performance in soldiers. Thus, valid methods for measuring body composition in military personnel are needed. The frequently used body mass index method is not a valid measure of body composition in soldiers, but reliability and validity of alternative field methods are less investigated in military personnel. Thus, we carried out test and retest of skinfold (SKF), single frequency bioelectrical impedance analysis (SF-BIA), and multifrequency bioelectrical impedance analysis measurements in 65 male and female soldiers. Several validated equations were used to predict percent body fat from these methods. Dual-energy X-ray absorptiometry was also measured, and acted as the criterion method. Results showed that SF-BIA was the most reliable method in both genders. In women, SF-BIA was also the most valid method, whereas SKF or a combination of SKF and SF-BIA produced the highest validity in men. Reliability and validity varied substantially among the equations examined. The best methods and equations produced test-retest 95% limits of agreement below ±1% points, whereas the corresponding validity figures were ±3.5% points. Each investigator and practitioner must consider whether such measurement errors are acceptable for its specific use.

Reliability of Bioelectrical Impedance Analysis in the Evaluation of the Nutritional Status of Hemodialysis Patients — A Comparison With Mini Nutritional Assessment

IntroductionProtein-energy wasting (PEW) is a strong predictive factor for morbidity and mortality in patients who have end-stage renal disease (ESRD). Mini Nutritional Assessment (MNA) is an important and confirmed tool to evaluate PEW that has been recommended by many guidelines. Bioelectrical impedance analysis (BIA) is a noninvasive technique for assessing body composition. The aim of the present study was to analyze the reliability of BIA in malnutrition diagnosis by comparing it with standard MNA in a group of 100 ESRD patients. MethodsOne hundred ESRD patients who were medically stable and under dialysis treatment for at least 6 months were enrolled to the study. Monthly assessed serum creatinine, albumin, C-reactive protein (CRP), and lipid profiles from the last 6 months prior to the study were retrospectively collected. A standard Full-MNA and body composition analyses were applied to all patients. Body compositions were analyzed with the BIA technique using the Body Composition Analyzer (Tanita BC-420MA; Tanita, Tokyo, Japan). Patients were classified into three groups according to MNA scores as PEW (n = 15, score <17), moderate PEW or risk group (n = 49, score 17–23.5), and well-nourished (n = 36, score ≥24) patients. ResultsMean duration of maintenance hemodialysis treatment was significantly shorter in the PEW group compared to both of the other groups described (P = .015). Well-nourished and risk groups had lower CRP and higher albumin levels compared to PEW patients; however, these values were statistically similar in these two groups (P = .018, .01, respectively). According to BIA findings, well-nourished patients had the highest fat ratio, fat mass, muscle mass, visceral fat mass, and fat-free mass compared to both moderate the PEW/risk and the PEW groups (P < .05). Risk group patients also had higher muscle mass, visceral fat mass, and fat-free mass values compared to the PEW group (P < .05). A correlation analysis revealed that MNA scores were positively correlated with albumin (P = .005), creatinine (P = .049), fat mass (P = .045), muscle mass (P = .001), visceral fat ratio (P = .007), and BMI (P = .047) and in negative correlation with CRP (r = −0.357, P = .0001) levels. ConclusionsWe recommend BIA as a complementary diagnostic tool to evaluate nutritional status of ESRD along with MNA, anthropometric measures, and classical biochemical markers.

Reliability of Bioelectrical Impedance Analysis for Estimating Whole‐Fish Energy Density and Percent Lipids

AbstractWe evaluated bioelectrical impedance analysis (BIA) as a nonlethal means of predicting energy density and percent lipids for three fish species: Yellow perch Perca flavescens, walleye Sander vitreus, and lake whitefish Coregonus clupeaformis. Although models that combined BIA measures with fish wet mass provided strong predictions of total energy, total lipids, and total dry mass for whole fish, including BIA provided only slightly better predictions than using fish mass alone. Regression models that used BIA measures to directly predict the energy density or percent lipids of whole fish were generally better than those using body mass alone (based on Akaike's information criterion). However, the goodness of fit of models that used BIA measures varied widely across species and at best explained only slightly more than one‐half the variation observed in fish energy density or percent lipids. Models that combined BIA measures with body mass for prediction had the strongest correlations between predicted and observed energy density or percent lipids for a validation group of fish, but there were significant biases in these predictions. For example, the models underestimated energy density and percent lipids for lipid‐rich fish and overestimated energy density and percent lipids for lipid‐poor fish. A comparison of observed versus predicted whole‐fish energy densities and percent lipids demonstrated that models that incorporated BIA measures had lower maximum percent error than models without BIA measures in them, although the errors for the BIA models were still generally high (energy density: 15‐18%; percent lipids: 82‐89%). Considerable work is still required before BIA can provide reliable predictions of whole‐fish energy density and percent lipids, including understanding how temperature, electrode placement, and the variation in lipid distribution within a fish affect BIA measures.

Reliability of bioelectrical impedance methods in detecting body fluids in elderly patients with congestive heart failure

Objective. To investigate the reliability of bioelectrical impedance analysis (BIA) in estimating total body water (TBW) and extracellular water (ECW) in elderly patients suffering from congestive heart failure (CHF). Material and methods. In 72 elderly subjects, 34 with CHF (aged 83.9±6.9 years) and 38 healthy controls (78.7±7.5 years), TBW and ECW values were assessed using dilution methods, and bioelectrical variables were measured using single frequency BIA (SF‐BIA) at 1 and 50 kHz, and bioelectrical spectroscopy (BIS). Results. In CHF patients, Ht2/R1 correlated weakly with TBW (r = 0.56) and ECW (0.47). In both healthy controls and CHF patients, TBW correlated strongly with Ht2/R50, Ht2/R0, Ht2/R∞ and Ht2/Zc. Using multiple regression analysis and the Bland–Altmann approach, SF‐BIA at 50 kHz and BIS proved similar in predicting TBW for both the explained variance (R2∼0.89) and the limits of agreement. In all subjects, ECW was estimated best by including height, weight and Ht2/R0 (R2 0.75) or Ht2/Zc (R2 0.77) in multivariate models, while SF‐BIA at 50 kHz did not explain more than 71 % of ECW variability. The SEE % was nonetheless about twice the SEE % for estimating TBW. Conclusions. SF‐BIA at 1 kHz is unreliable in predicting body fluids in elderly people with CHF. SF‐BIA at 50 kHz and BIS are useful for estimating TBW in healthy elderly people and in cases of water imbalance, but both methods are less reliable in estimating ECW, particularly in conditions of fluid overload.

Body composition in underweight elderly subjects: reliability of bioelectrical impedance analysis

Background & aims: In underweight elderly subjects it is important to estimate body composition and particularly fat-free mass (FFM). Bioelectrical impedance analysis (BIA) is a non-invasive method in determining FFM, but its usefulness in these frail subjects should be verified. The aim of this study is to verify in underweight elderly people the reliability of previously published BIA formulas in detecting FFM.Methods: Fifty-seven hospitalized elderly subjects (27 males and 30 females) with body mass index <20kg/m2 were selected. In all subjects, FFM was detected by dual energy X-ray absorptiometry. Moreover, BIA measurements were performed at standard frequency (50kHz and 800μA) and FFM was derived using the main previous published BIA equations.Results: In men, Kyle and Rising equations gave acceptable estimates of FFM with a mean error, respectively, of 1±1.9 and 1.4±1.7kg. Also RJL formula could be used after adjusting for a correction factor. In women, no equation seemed sufficiently reliable to estimate FFM.Conclusions: BIA method seems useful to evaluate body composition in underweight elderly men but it seems to have intrinsic limits in women. Nevertheless, the variability in behavior of the different equations suggests to be careful in adopting BIA equations.

Análisis de la composición corporal por parámetros antropométricos y bioeléctricos

Interest in the study of body composition in childhood is increasing. Bioelectrical impedance analysis (BIA) is an accurate and reliable method. To determine anthropometric parameters, fat-free body mass and fat body mass using BIA and anthropometry, and to establish their relationship. A total of 365 healthy children (188 boys, 177 girls) aged 6.0 to 14.9 years were studied. Weight, height, arm circumference, skinfolds (bicipital, tricipital, subscapular and suprailiac) and bioelectrical parameters were measured. Body density was calculated from the four skinfold measurements using Brook's formula. Bioelectrical impedance was measured with a BIA-101 S (RJL Systems) using a fixed frequency (50 kHz). Fat-free body mass from BIA was calculated using Deurenberg's equation (FFM = 0.82 x height2/resistance). We present the mean, standard deviation and 3rd, 5th, 10th, 25th, 50th, 75th, 90th, 95th and 97th percentiles of anthropometric variables and fat mass and fat-free mass estimated using BIA. Correlations were found between fat-free mass estimated using BIA and anthropometric variables. The reliability of BIA in estimating fat mass was assessed with intraclass correlation coefficients, which were excellent (0.948 in boys, and 0.945 in girls). BIA is an easy, low-cost, and highly reliable method, making it a useful technique for studying human body composition. This method shows excellent correlation with anthropometric variables.

Role of bioelectrical impedance analysis in acutely dehydrated subjects

15 young healthy volunteers were studied to assess the reliability of bioelectrical impedance analysis (BIA) to determine body composition during acute dehydration. Body weight (BW), resistance and reactance measurements were performed before and 4h after a 40 mg intravenous administration of furosemide. BW decreased on average from 69.09 ± 9.83 kg to 67.43 ± 9.72 kg (p < 0·001), while resistance, reactance, and phase angle showed significant increases. The individual variations in bioelectrical parameters were not related to the BW loss. Formulae to derive body composition predicted poorly the true water loss (mean individual error: 40% of real loss). The errors in body composition prediction were unrelated to basal percentage of fat free mass, to body mass index, or to BW loss after furosemide administration. In conclusion, BIA proved unreliable in calculating the body composition of acutely dehydrated subjects.

Reliability of bioelectrical impedance analysis in dehydrated subjects

Reliability of bioelectrical impedance analysis in dehydrated subjects

Validity and Reliability of Bioelectrical Impedance Analysis of Body Composition in Obese and Normal Female Subjects

Validity and Reliability of Bioelectrical Impedance Analysis of Body Composition in Obese and Normal Female Subjects