Validating Body Fat Assessment by Bioelectric Impedance Spectroscopy in Taiwanese Hemodialysis Patients.
Obesity is becoming increasingly common in hemodialysis (HD) patients and is associated with inflammation and increased mortality. The primary aim of the present study was to evaluate the accuracy and variability of the bioimpedance device in measuring body fat in Taiwanese dialysis patients.



Cross-sectional study.



One hundred twenty-two adult patients receiving HD in a single hospital in Taiwan.



We compared the results of fat mass (FM) measured by dual-energy x-ray absorptiometry (DEXA) and bioelectrical impedance spectroscopy device (Body composition monitor, BCM).



FM measured by BCM was calculated by subtracting fat-free mass (FFM) from body mass assuming fractional hydration of FFM of 0.73 or the proprietary prediction equations from the BCM model.



Assessment of whole-body composition showed that percentage FM measured using the 2 techniques was highly correlated when using the BCM model or estimating from total body water using constant (0.73) hydration (r = 0.87, P < .001). There was no evident difference in measurement between patients gender. The Bland-Altman plot also showed good agreement of percentage of FM (t = 3.82; P < .001). In female patients, it was found that BCM significantly underestimated mean FM as compared to DEXA. However, the mean differences of the estimates between the methods were small (0.35 ± 3.00 kg) and with Bland-Altman plot the limits of agreements were -5.5 to 6.2 kg (P = .40) for FM in female patients.



Using DEXA as the reference test, BCM is a valid tool for the assessment of total body fat in HD patients. Hence, it may provide a more accessible tool for early detection of changes in body composition in these high-risk patients.
Division of Renal Medicine, Department of Internal Medicine, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan; Department of Internal Medicine, Taipei Medical University, Taipei, Taiwan; Department of Rehabilitation, Jenteh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan. Electronic address: jamespslim@gmail.com.
Paik Seong
PS
Lim
Division of Renal Medicine, Department of Internal Medicine, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan.
Chang Hsu
CH
Chen
Research Division, Renal Research Institute, New York, New York.
Fansan
F
Zhu
Research Division, Renal Research Institute, New York, New York.
Peter
P
Kotanko
Department of Rehabilitation, Jenteh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan; Division of Biostatistics and Epidemiology, Department of Medical Research, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan.
Yachung
Y
Jeng
Division of Renal Medicine, Department of Internal Medicine, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan.
Chun Yu
CY
Hu
Division of Renal Medicine, Department of Internal Medicine, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan.
Li Shu
LS
Chiu
Division of Renal Medicine, Department of Internal Medicine, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan.
Hui-Chen
HC
Chang
D015502:Absorptiometry, Photon; D000368:Aged; D044466:Asian People; D001823:Body Composition; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D006435:Renal Dialysis / Q000009:adverse effects*; D013624:Taiwan