title: Low lean tissue mass is an independent risk factor for mortality in patients with stages 4 and 5 non-dialysis chronic kidney disease.
abstract: Background:Mortality in patients with stages 4 and 5 chronic kidney disease (CKD) is higher than in the general population. Body composition predicts mortality. Our objective was to evaluate the effect of body composition on mortality in patients with stages 4 and 5 non-dialysis CKD.Methods:We performed a prospective study of 356 patients with stages 4 and 5 non-dialysis CKD. At baseline, we recorded general characteristics, history of cardiovascular events, body composition, serum inflammatory markers, nutrition and cardiac biomarkers. Body composition was analysed using bioimpedance spectroscopy. We recorded the lean tissue index (LTI), fat tissue index (FTI) and overhydration (OH). During a median (range) follow-up of 22 (3-49) months, we recorded mortality, cardiovascular events and progress to renal replacement therapy.Results:At baseline, mean (± standard deviation) age was 67 ± 13 years (men 64%; diabetes 36%). Mean body mass index was 28.2 ± 12.8 kg/m2, the FTI was 12.3 ± 5.6 kg/m2, the LTI was 15.7 ± 3.4 kg/m2and median (interquartile range) OH was 0.6 (-0.4 to 1.5) L. Sixty-four (18%) patients died during follow-up. The univariate Cox analysis showed an association between mortality and age, low LTI, high Charlson comorbidity index, previous cardiovascular events, OH, low albumin and prealbumin levels, and high C-reactive protein levels. Kaplan-Meier analysis revealed higher survival in patients with a higher LTI (log-rank, 9.47; P = 0.002). The multivariate Cox analysis confirmed an association between mortality and low LTI (P = 0.031), previous cardiovascular events (P = 0.003) and high Charlson comorbidity index (P = 0.01). We did not find any association between body composition and cardiovascular events or renal replacement therapy.Conclusions:A low LTI is an independent factor for mortality in patients with stages 4 and 5 CKD.
authors.affiliation: Nephrology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Almudena
authors.initials: A
authors.lastname: Vega
authors.affiliation: Nephrology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Soraya
authors.initials: S
authors.lastname: Abad
authors.affiliation: Nephrology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Macías
authors.affiliation: Nephrology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Inés
authors.initials: I
authors.lastname: Aragoncillo
authors.affiliation: Nephrology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Alba
authors.initials: A
authors.lastname: Santos
authors.affiliation: Nephrology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Galán
authors.affiliation: Nephrology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Cedeño
authors.affiliation: Nephrology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Manuel López-Gómez
keywords: bioimpedance; body mass index; chronic renal failure; nutrition; survival