Body Composition Changes in Hemodialysis Patients: Implications for Prognosis

Abstract

Background: Overhydration, inflammation and protein-energy wasting have been related to all-cause mortality in dialysis patients, being lean mass loss, a poor prognostic factor. Objective: to monitor body composition changes (BCC) in hemodialysis (HD) patients and to relate BCC to mortality. Methods: Prospective follow up study: Bioimpedance spectroscopy (BIS) and nutritional parameters were performed every 6 months during three years. Results : Overall data show a significant loss of weight at 12m, 24m, and 36m, with decrease of lean tissue index and phase angle (PA) in each period measured. Fat tissue index (FTI) diminished in the third year's measurements. End of first year, 41 % of patients gain weight, them at baseline had lower age, higher serum albumin, lower Extracelular/intracellular water index (ECW/ICW) and higher PA, showing a significant FTI increase. Higher baseline PA was gain weight predictor by binary logistic regression. Cox regression analyses: Age, diabetes, HD technique, albumin, ECW/ICW, and PA were mortality predictors in univariate analysis; being PA the main mortality predictor in multivariate analysis. BCC were not associated with mortality. ROC curve: PA higher than 4.85° is protective for mortality. Conclusions: Lean mass loss was the most important change during follow up; we have not observed association between BCC with mortality. PA was the main mortality predictor.