Four-site skinfold anthropometry (FSA) versus body impedance analysis (BIA) in assessing nutritional status of patients on maintenance hemodialysis: which method is to be preferred in routine patient care?
BACKGROUND
Both four-site skinfold anthropometry (FSA) and bioelectrical impedance analysis (BIA) claim to be useful in routine clinical practice of maintenance dialysis as easy methods to assess nutritional status. The purpose of this study was to investigate which of these two methods is to be preferred.


METHODS
Both before and after dialysis nutritional and hydration status were evaluated by BIA in 20 stable hemodialysis patients. Variables of nutritional status as lean body mass (LBM) and body fat (BF) were assessed by four-site skinfold anthropometry (LBM-FSA and BF-FSA) and BIA (LBM-BIA and BF-BIA). Variables of hydration status were total body water (TBW), its distribution into intracellular and extracellular compartments (ICW and ECW, respectively) and ICW/ECW.


RESULTS
Weight loss during dialysis correlated with a change of LBM-FSA (r = 0.75, p <0.005) and also with that of LBM-BIA (r = 0.69, p < 0.005). To promote reliability of follow-up measurements in intervention studies it is warranted to evaluate nutritional status in an unchanged hydration status. The highly significant correlation (r = 0.93, p < 0.005) between the two techniques and the comparability between means and SD indicate that both techniques were almost equivalent to each other, although, compared to LBM-BIA, LBM-FSA was less affected by changes in fluid status. The sam held true for BF-BIA and BF-FSA. BF-FSA correlated significantly with BF-BIA (r = 0.65, p <0.005), whereas no difference of mean +/- SD was found between BF-FSA and BF-BIA.


CONCLUSIONS
FSA and BIA are almost comparable techniques to assess both LBM and BF, although FSA is less affected by changes in fluid status. However, assessing LBM in normohydration is mandatory. Compared with FSA, BIA is able to establish hydration status and lacks depency on operator interpretation. Therefore, in routine patient care the BIA technique is the one to be preferred.
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Department of Internal Medicine, Academic Hospital Free University, Amsterdam, The Netherlands.
de Fijter
C W
CW
Oe
P L
PL
Stevens
P
P
de Vries
P M
PM
D001823:Body Composition; D001834:Body Water / Q000378:metabolism; D017097:Electric Impedance; D006801:Humans; D009748:Nutrition Disorders / Q000175:diagnosis / Q000209:etiology; D009752:Nutritional Status; D006435:Renal Dialysis / Q000009:adverse effects; D012885:Skinfold Thickness; D015431:Weight Loss