Body composition analysis in chronic dialysis patients: a longitudinal study

AbstractObjectiveNutritional status is an important determinant of morbidity and mortality in dialysis patients. Body composition analysis bioelectrical impedance techniques are becoming commonplace in the clinical setting. Our objective is to report our clinical experience using bioelectrical impedance analysis for the prospective nutritional surveillance of dialysis patients.MethodsA total of 204 patients, 157 on hemodialysis and 47 on peritoneal dialysis were followed for a median of 21 months. Values from the first trimester were averaged and compared to those obtained in the last trimester. Bioelectrical impedance values were obtained using a single frequency (50 kHz) bioimpedance analyzer.ResultsBaseline values for body weight, height, body mass index and body surface area were similar in both treatment modalities. Hemodialysis patients lost a discreet amount of body weight (1.5%, p=0.0334). Body weight did not change in peritoneal dialysis patients. Significant decreases in resistance (p=0.l0023) and phase angle (p=0.0481) were noted in hemodialysis but not peritoneal dialysis patients. A small but significant decrease in fat free (1.8%; p=0.0028) and body cell free (3.3%; p=0.0036) mass was noted in hemodialysis but not peritoneal dialysis patients.Conclusions1. Bioelectrical impedance analysis may detect losses in fat free mass and body cell mass that are not apparent by body weight monitoring. 2. Bioelectrical impedance analysis is a practical clinical tool for evaluating body composition in dialysis patients