title: Resting energy expenditure of chronic kidney disease patients: influence of renal function and subclinical inflammation.
abstract: BACKGROUND
  The resting energy expenditure (REE) of patients with chronic kidney disease (CKD) might be influenced by the degree of renal function and by a subclinical inflammatory condition. The aim of this study is to evaluate the impact of these 2 variables on the REE of patients with CKD.
  
  
  METHODS
  A cross-sectional study was performed on 91 nondialyzed and nondiabetic patients with CKD with no clinical signs of inflammation. Patients were divided into quartiles of creatinine clearance (CrCl) and tertiles of C-reactive protein (CRP) level. REE was measured by means of indirect calorimetry, and the presence of a subclinical inflammatory condition was assessed by means of serum CRP concentration.
  
  
  RESULTS
  CrCl interquartile ranges calculated were: quartile 1 (CrCl < or = 18 mL/min [< or =0.30 mL/s]; n = 24); quartile 2 (CrCl, 19 to 29 mL/min [0.31 to 0.48 mL/s]; n = 22); quartile 3 (CrCl, 30 to 42 mL/min [0.49 to 0.70 mL/s]; n = 23), and quartile 4 (CrCl > or = 43 mL/min [> or =0.71 mL/s]; n = 22). Nonadjusted REE and REE adjusted for sex, age, and lean body mass did not differ among the 4 CrCl quartiles. The following ranges were calculated for CRP tertiles: tertile 1 (CRP < or = 0.14 mg/dL; n = 30), tertile 2 (CRP, 0.15 to 0.49 mg/dL; n = 31), and tertile 3 (CRP > or = 0.50 mg/dL; n = 30). The nonadjusted REE in CRP tertile 3 was significantly greater than those in tertiles 1 and 2. REE adjusted for sex, age, and lean body mass was greater in CRP tertile 3 than tertile 1, a difference equivalent to 123.7 kcal/d (P = 0.003; 95% confidence interval, 42.9 to 204.5). A borderline difference was observed between CRP tertiles 3 and 2. When analyzing the entire group, REE did not correlate with either serum creatinine level or CrCl, and a borderline correlation between REE and log of CRP was observed (r = 0.19; P = 0.07).
  
  
  CONCLUSIONS
  This study suggests that REE is not influenced by degree of renal function, but it may be elevated during a condition of subclinical inflammation.
authors.affiliation: Division of Nephrology, Dialysis Unit of the Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Carla Maria
authors.initials: CM
authors.lastname: Avesani
authors.forename: Sergio Antonio
authors.initials: SA
authors.lastname: Draibe
authors.forename: Maria Ayako
authors.initials: MA
authors.lastname: Kamimura
authors.forename: Fernando Antonio Basile
authors.initials: FA
authors.lastname: Colugnati
authors.forename: Lilian
authors.initials: L
authors.lastname: Cuppari
mesh_terms: D002908:Chronic Disease; D003430:Cross-Sectional Studies; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000503:physiopathology; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012146:Rest / Q000502:physiology*