Body Fat Analysis in Predialysis Chronic Kidney Disease: Multifrequency Bioimpedance Assay and Anthropometry Compared With Dual-Energy X-Ray Absorptiometry.

Body composition analysis is required for accurate assessment of nutritional status in patients with predialysis chronic kidney disease (CKD). The reference method for assessing body fat is dual-energy X-ray absorptiometry (DXA), but it is relatively expensive and often not available for widespread clinical use. There is only limited data on the utility of less expensive and easily available alternatives such as multifrequency bioimpedance assay (BIA) and skinfold thickness (SFT) measurements for assessing body fat in predialysis CKD. The study intends to assess the utility of BIA and SFT in measuring body fat compared to the reference method DXA in subjects with predialysis CKD. Body composition analysis was done in 50 subjects with predialysis CKD using multifrequency BIA, SFT, and DXA. The agreement between the body fat percentages measured by reference method DXA and BIA/SFT was assessed by paired t-test, intraclass correlation coefficients (ICCs), regression, and Bland-Altman plots. Percentage of body fat measured by BIA was higher compared to the measurements by DXA, but the difference was not significant (30.44 ± 9.34 vs. 28.62 ± 9.00; P = .071). The ICC between DXA and BIA was 0.822 (confidence interval: 0.688, 0.899; P = .000). The mean values of body fat percentages measured by anthropometry (SFT) was considerably lower when compared to DXA (23.62 ± 8.18 vs. 28.62 ± 9.00; P = .000). The ICC between DXA and SFT was .851 (confidence interval: 0.739, 0.915; P = .000). Bland-Altman plots showed that BIA overestimated body fat by a mean of 1.8% (standard deviation, 6.98), whereas SFT underestimated body fat by 5% (standard deviation, 4.01). Regression plots showed a better agreement between SFT and DXA (R(2) = .79) than BIA (R(2) = .50). Overall, SFT showed better agreement with the DXA. Body mass index (BMI) showed a moderate positive correlation with body fat measured by DXA whereas serum albumin failed to show good correlation. SFT showed relatively better agreement with the reference method DXA, compared to BIA. SFT can be used as a tool for assessing nutritional status in predialysis patients with CKD.

Ravindranath J ，Pillai PP ，Parameswaran S ，Kamalanathan SK ，Pal GK ... -  《-》

Reliability of Anthropometry-Based Equations Compared to Dual Energy Absorptiometry for Assessing Body Composition in Predialysis Chronic Kidney Disease-A Longitudinal Study.

Skinfold thickness measurements for assessing body composition are reported to have good reproducibility compared to the reference method of dual energy absorptiometry (DXA). In the current study, we compared the level of agreement between body composition measured with DXA and skinfold thickness (SFT) in CKD Stage 3 and 4, at 2 occasions, 6 months apart. Body composition was assessed in 177 Indian patients with CKD Stage 3 and 4 using DXA and anthropometry (SFT). The body fat mass obtained by the 2 methods was compared by paired t-test, intraclass correlation coefficients, regression analysis, and Bland-Altman plots. A linear regression analysis was done to identify the patient-related parameters which would account for the intermethod differences between DXA and SFT. Compared to DXA, SFT underestimated the fat mass at baseline as well as 6 months [DXA vs. SFT at entry: 15.85 kg (95% confidence interval, CI 15.07-16.65) vs. 13.71 kg (95% CI 13.21-14.32), P < .001; at 6 months: 16.13 (95% CI 15.33-16.93) vs. 13.85 (95% CI 13.25-14.45), P < .001]. The intraclass correlation coefficients at entry and 6 months were 0.894 (0.857-0.921) and 0.896 (0.860-0.923), respectively. The intermethod differences between DXA and SFT at baseline and 6 months were comparable: 2.08 kg (95% CI 1.66-2.5) at baseline versus 2.27 kg (95% CI 1.83-2.71) at 6 months, P = 0.200. Gender and body mass index turned out to be the significant predictors of intermethod differences at base line and exit (P < .001). SFT-based measurements show good reproducibility compared to DXA over a period of 6 months. However, SFT systematically underestimates the fat mass by 2 Kg compared to DXA.

Dubey AK ，Priyamvada PS ，Sahoo J ，Vairappan B ，Haridasan S ，Parameswaran S ... -  《-》

Comparison of Body Mass Index, Skinfold Thickness, and Bioelectrical Impedance Analysis With Dual-Energy X-Ray Absorptiometry in Hemodialysis Patients.

Malnutrition is a consistent finding in hemodialysis (HD) patients and is associated with high mortality. The aim was to compare nutrition status indicators using dual-energy x-ray absorptiometry (DXA) as reference in HD patients. Observational cross-sectional study with 42 patients, 55.8 years (±14.6) old, 60% male, HD 2-3 times per week for ≥3 months. HD ranged from 3 months to 28 years (median, 17.3; interquartile range, 8.73-39.0). We used body mass index (BMI) and fat mass (FM) by skinfold thickness (SFT), bioelectrical impedance analysis (BIA), and DXA. Statistical analyses used Bland-Altman plots, Lin's concordance correlation coefficient, the paired t-test, and Pearson or Spearman correlation. P < .05 was significant. SFT and DXA presented the lowest prevalence of malnutrition (2.4%) and BMI the highest (28.6%). BMI, BIA FM, and SFT FM presented strong positive correlations with DXA FM (r = 0.915; r = 0.976; r = 0.910, P < .001, respectively). BIA FM and fat-free mass (FFM) demonstrated substantial agreement with DXA values (ρ = 0.974 and 0.960, P < .001). Thus, the measurement procedures used, SFT and BIA, underestimated %FM (-4.65% and -2.13%) and overestimated FFM (3.12 kg and 1.0 kg) according to DXA. No differences were found between mean values of BIA FM and DXA (P = .178). Compared with DXA, BIA was the most appropriate nutrition indicator for measuring body composition.

de Abreu AM ，Wilvert LC ，Wazlawik E 《-》

Comparison of Skinfold Thicknesses and Bioimpedance Spectroscopy to Dual-Energy X-Ray Absorptiometry for the Body Fat Measurement in Patients With Chronic Kidney Disease.

Rymarz A ，Szamotulska K ，Niemczyk S 《-》

Body Composition Measurement in Bronchiectasis: Comparison between Bioelectrical Impedance Analysis, Skinfold Thickness Measurement, and Dual-Energy X-ray Absorptiometry before and after Pulmonary Rehabilitation.

In individuals with bronchiectasis, fat-free mass depletion may be common despite a low prevalence of underweight and is considered a risk factor for increased morbidity and mortality. Techniques to adequately estimate fat-free mass and its changes over time are needed. The purpose of this study was to assess agreement among values obtained with three different body composition techniques: skinfold thickness measurement (STM), bioelectrical impedance analysis (BIA), and dual-energy x-ray absorptiometry (DXA). The study was a secondary analysis of data from a randomized controlled trial. A respiratory rehabilitation program was administered for 3 months to individuals with bronchiectasis from the bronchiectasis unit of the Regional University Hospital in Malaga, Spain, from September 2013 to September 2014. Individuals with a body mass index (calculated as kg/m2) >18.5 who were aged 65 years or younger and those with a body mass index >20 who were older than 65 years were included. At baseline and at 3 and 6 months, body composition was determined by DXA and STM. Statistical concordance was assessed with the intraclass correlation coefficient (ICC), kappa coefficient, and the degree of agreement using the Bland Altman method. For comparison of the quantitative variables at baseline vs at 3 months and 6 months, the paired sample t test (or the Wilcoxon test) was used. Thirty participants were included. Strong agreement was observed between body composition values determined by BIA and DXA in fat mass (ICC: 0.92) and fat-free mass (ICC: 0.87). Strong agreement was observed between STM and DXA in the values for fat-free mass (ICC: 0.91) and fat mass (ICC: 0.94), and lower agreement was observed for the longitudinal data and in the regional values. The mean difference between fat-free mass determined by BIA and DXA was + 4.7 with a standard deviation of 2.4 kg in favor of BIA. The mean difference between fat-free mass determined by STM and DXA was +2.3 with a standard deviation of 2.7 kg in favor of STM. Six individuals were classified as having a low fat-free mass index (20%) by DXA vs four by STM (13%; kappa: 0.76) and only two by BIA (6.6%; kappa: 0.44) compared with DXA. Despite good statistical agreement among values obtained with DXA, STM, and BIA, the study findings indicate that STM and BIA, above all, tended to overestimate fat-free mass compared with DXA.

Doña E ，Olveira C ，Palenque FJ ，Porras N ，Dorado A ，Martín-Valero R ，Godoy AM ，Espíldora F ，Contreras V ，Olveira G ... -  《Journal of the Academy of Nutrition and Dietetics》