A critical evaluation of bioimpedance spectroscopy analysis in estimating body composition during GH treatment: comparison with bromide dilution and dual X-ray absorptiometry

Abstract

Objective: To compare estimates by bioimpedance spectroscopy analysis (BIS) of extracellular water (ECW), fat mass (FM), and fat-free mass (FFM) against standard techniques of bromide dilution and dual energy X-ray absorptiometry (DXA) during intervention that causes significant changes in water compartments and body composition. Methods: Body composition analysis using BIS, bromide dilution, and DXA was performed in 71 healthy recreational athletes (43 men, 28 women; aged 18-40 years; BMI 24G0.4 kg/m 2 ) who participated in a double-blinded, randomized, placebocontrolled study of GH and testosterone treatment. The comparison of BIS with bromide dilution and DXA was analyzed using linear regression and the Bland-Altman method. Results: At baseline, there was a significant correlation between BIS and bromide dilution-derived estimates for ECW, and DXA for FM and FFM (P!0.001). ECW by BIS was 3.5G8.1% lower compared with bromide dilution, while FM was 22.4G26.8% lower and FFM 13.7G7.5% higher compared with DXA (P!0.01). During treatment, the change in ECW was similar between BIS and bromide dilution, whereas BIS gave a significantly greater reduction in FM (19.4G44.8%) and a greater increase in FFM (5.6G3.0%) compared with DXA (P!0.01). Significant differences in body composition estimates between the BIS and DXA were observed only in men, particularly during the treatment that caused greatest change in water compartments and body composition. Conclusion: In healthy adults, bioimpedance spectroscopy is an acceptable tool for measuring ECW; however, BIS overestimates FFM and substantially underestimates FM compared with DXA.

Comparison of regional fat mass measurement by whole body DXA scans and anthropometric measures to predict insulin resistance in women with polycystic ovary syndrome and controls

“…In the present study, age and central fat mass were positively associated and recent studies supported that increasing age in PCOS is associated with more metabolic risk factors, whereas hyperandrogenemia decreases with increasing age . The use of bioelectrical impedance to establish fat and lean body mass may also have affected study results . Our findings are supported by a study by Comerford et al.…”

Effects of Graded Whey Supplementation During Extreme-Volume Resistance Training

“…The SFB7 device measures whole-body bioelectrical impedance at more than 200 frequencies, and uses complex Cole models to estimate TBW, ICW and ECW. Moreover, the SFB7 device: (a) has excellent agreement with TBW assessed via deuterium oxide ( 21 ), (b) has excellent agreement with ECW assessed via sodium bromide dilution ( 22 ), and (c) has been posited to be the best non-invasive methodology for the determination of fluid compartmentalization ( 23 ). This test involved the participant resting in a supine position for 5–10 min, after which TBW, ICW, and ECW estimates were determined while the participants laid supine on a table with his arms ≥30° away from the torso and legs separated.…”

Fluid balance concepts in medicine: Principles and practice

“…The methodologies for measuring TBW and ECFV by these newer techniques were developed by comparing their performance to measurements from the older dilution techniques, mostly the 2 H 2 O and bromide dilution techniques[ 116 , 117 , 126 , 130 , 134 , 148 - 156 ]. Figure 3 shows average ECFV values obtained by the older dilution techniques (Table 3 ) and several frequently used newer techniques (Table 4 ).…”