Changes in body composition parameters in patients on haemodialysis and peritoneal dialysis del sumario

Introduction: Proper hydration is one of the major aims in haemodialysis (HD) and peritoneal dialysis (PD). Bioimpedance spectroscopy appears to be a promising method for the evaluation and follow up of the hydration status in dialysis patients (P). Objectives: We compared body composition between stable patients on HD and PD after six months. Patients and method: An observational study with 62 P on HD and 19 P on PD was performed. Clinical, biochemical and bioimpedance parameters were analysed. Results: In the comparative study, PD P were younger (50 +/- 10 vs 57 +/- 14 years, P=.031). The Charlson Comorbidity Index (4.8 +/- 3 vs 7.5 +/- 3, P <.001), time on dialysis (16.9 +/- 18.01 vs 51.88 +/- 68.79 months, P=.020) and C-Reactive Protein [3 (3-9.3) vs 5.25 (1-76.4)] were lower. Total protein levels (7.46 +/- 0.44 vs 7.04 +/- 0.55 g/dl, P=.005) and transferrin levels (205 +/- 41 vs 185 +/- 29 mg/dl, P=.024) were higher. BIS: Intracellular water (19.67 +/- 3.61 vs 16.51 +/- 3.36 litres, P=.010), lean tissue mass (LTM) (37.20 +/- 8.65 vs 32.57 +/- 8.72 kg, P=.029), total cellular mass (TCM) (20.53 +/- 5.65 vs 17.56 +/- 5.91 kg, P=.033), and bioelectrical impedance phase angle (Phi 50) (5.81 +/- 0.86 vs 4.74 +/- 0.98, P=.000) were higher than in HD P. Overhydration: 22% in HD y 10% in PD, in conditions referred to in methods. Six months later, PD P increased in weight (73.75 +/- 12.27 vs 75.22 +/- 11.87 kg, P=.027), total fat (FAT) (26.88 +/- 10 vs 30.02 +/- 10 kg, P=.011) and relative fat (Rel FAT) (35.75 +/- 9.87 vs 39.34 +/- 9.12, P=.010); and decreased in ICW (18.56 +/- 3.45 vs 17.65 +/- 3.69 I, P=.009), LTM (36.95 +/- 8.88 vs 34 +/- 9.70 kg, P=.008) and relative LTM (Rel LTM) (50.85 +/- 12.33 vs 45.40 +/- 11.95%, P=.012). In the multivariate analysis, weight variation (Delta) was related to Delta FAT (P<.001). We found a correlation between fat increase and lean tissue mass decrease. Six months later, in HD P. we observed a reduction in ECW (15.11 +/- 2.45 vs 14.00 +/- 2.45, P.001), without changes in other parameters. Conclusions: Bioelectrical impedance analysis facilitates the assessment of changes in body composition so as to correct dry weight and to introduce changes in treatment schedule.