Abnormalities of bioimpedance measures in overweight and obese hemodialyzed patients

Abstract

BACKGROUND:The body composition in overweight and obese hemodialyzed patients (HD) remains ill-de®ned. This study evaluates in HD patients the in¯uence of body size, as indicated by body mass index (BMI, kgam 2 ), on body composition by measuring bioimpedance analysis (BIA)-derived variables (phase angle (PA), fat-free mass (FFM) and body cell mass (BCM). METHODS: We studied 50 Caucasian patients (mean age 62.8 AE 9.2 y) on standard bicarbonate hemodialysis for at least 12 months who regularly achieved dry weight in post-HD, received similar dialysis doses and were free from in¯ammationainfec-tion. Thirty-eight gender-and age-matched healthy subjects were included as controls (CON). Both HD and CON were divided into three groups on the basis of their BMI(kgam 2 ) 18.5 ± 24.9, normal-weight (NW); 25 ± 29.9, overweight (OW); and !30, obese (OB). In HD patients, BIA was performed 30 min after the end of dialysis. RESULTS: Seven patients were obese (12%) while 16 were overweight (32%); in CON, 12 were obese (31%) and 12 overweight (31%). BIA-measured extracellular water was comparable in all groups. PA, which was similar in normal-weight HD and CON (6.2 AE 0.9 and 6.3 AE 0.8 ), decreased in OW-and OB-HD patients (5.3 AE 1.0 and 5.2 AE 0.6 , respectively; P`0.05 vs NW-HD) while it was unchanged in OW-and OB-CON (6.1 AE 0.8 and 5.9 AE 0.5 , P`0.05 vs respective HD groups). In OW and OB patients, the lower PA values were coupled with a major reduction of BIA-derived percentage BCM and FFM (P`0.05 vs NW-HD, and vs OW-and OB-CON). In patients, PA and BCM correlated with anthropometry-measured FFM. Of note, serum albumin and protein catabolic rate were signi®cantly reduced in OB patients. CONCLUSION: In overweight and obese HD patients, BIA-derived FFM, BCM and PA are signi®cantly lower with respect to normal-weight patients and BMI-matched controls. These abnormalities of body composition are coupled with reduction of anthropometric measures of lean mass and a decrease of protein intake that, however, becomes signi®cant only in the obese. We therefore suggest that overweight and obese HD patients are at risk of protein malnutrition in spite of excessive energy intake. BIA may be considered as a useful diagnostic tool to detect such a condition early.

Physical methods for evaluating the nutrition status of hemodialysis patients

“…the angular transformation of the ratio between reactance and resistance), one can anticipate the change in biochemical nutritional parameters [35]. Accordingly, by using single frequency BIA it was possible to unveil the risk of malnutrition also in apparently healthy overweight and obese patients on hemodialysis [36], including also those on the waiting list for kidney transplantation [37]. The bioimpedance vector Table 3 Comparison of different scores with subjective components for the assessment of protein energy wasting (PEW) analysis (BIVA) is a more advanced methodology.…”

Benefits of dietary sodium restriction in the management of chronic kidney disease

“…Of note, volume expansion is common in renal patients, even in the absence of edema [53]. The effect of dietary sodium restriction with or without RAAS blockade is illustrated in Fig.…”

Desnutrição na insuficiência renal crônica: qual o melhor método diagnóstico na prática clínica?

“…By using bioimpedance measures, Guida et al 30 have detected a reduction in BCM and phase angle in overweight and obese HD patients, suggesting that even patients with BMI values above normal may be at risk for malnutrition.…”