title: Metabolic acidosis components in advanced chronic kidney disease: association with serum albumin and parathyroid hormone.
abstract: OBJECTIVE
  To investigate the associations between the 2 main components of metabolic acidosis (unmeasured anions [UA] and hyperchloremia) with serum albumin and intact parathormone (iPTH) in patients with advanced chronic kidney disease.
  
  
  METHODS
  Cross-sectional study with advanced chronic kidney disease patients (estimated glomerular filtration rate <30 mL/minute/1.73 m(2)) not receiving phosphate binders, alkali therapy, or vitamin D analogs. Arterial blood sample was collected for biochemical and blood gas analysis. UA and strong ion difference (SID) were calculated according to quantitative acid-base analysis. Reduced SID was used as a measure of hyperchloremia.
  
  
  METHODS
  Serum albumin and parathormone (iPTH).
  
  
  RESULTS
  A total of 383 patients were included with a mean age of 64.7 ± 16.3 year and a mean estimated glomerular filtration rate of 19.9 ± 12.1 mL/minute/1.73 m(2). Among patients with metabolic acidosis, 45.7% had metabolic acidosis exclusively because of UA and 53.7% had a hyperchloremic component (either mixed metabolic acidosis or pure hyperchloremic metabolic acidosis). Considering the main acid-base status determinants, only UA had a significant correlation with serum albumin (r = -0.278, P < .001). There was no correlation between serum albumin and SID (r = 0.083, P = .156). This is in opposition to serum iPTH, where there was no correlation with UA (r = 0.082, P = .114), but an inverse correlation between iPTH and SID was observed (r = -0.228, P < .001). Multiple linear regressions with all acid-base determinants confirmed these findings.
  
  
  CONCLUSIONS
  Our data brings further knowledge on the associations between metabolic acidosis with bone disorders and nutritional status, suggesting that the two main metabolic acidosis components (UA and hyperchloremia) have different effects on serum parathormone and serum albumin.
authors.affiliation: Internal Medicine Department, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil.
authors.forename: Daniele Pinto
authors.initials: DP
authors.lastname: Vasconcelos
authors.affiliation: Medical Course, University of Fortaleza, UNIFOR, Fortaleza, Ceará, Brazil; Clinical Emergency Post-Graduate Program, University of São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Rafaela Elizabeth
authors.initials: RE
authors.lastname: Bayas de Queiroz
authors.affiliation: Medical Course, University of Fortaleza, UNIFOR, Fortaleza, Ceará, Brazil.
authors.forename: Tandara Maria
authors.initials: TM
authors.lastname: Ponte Costa
authors.affiliation: Medical Course, University of Fortaleza, UNIFOR, Fortaleza, Ceará, Brazil.
authors.forename: Monique Queiroz
authors.initials: MQ
authors.lastname: Rocha Guerreiro
authors.affiliation: General Hospital of Fortaleza, Fortaleza, Ceará, Brazil.
authors.forename: Maria Alessandra
authors.initials: MA
authors.lastname: Oliveira Leitão
authors.affiliation: Medical Course, University of Fortaleza, UNIFOR, Fortaleza, Ceará, Brazil.
authors.forename: Larissa Chagas
authors.initials: LC
authors.lastname: Corrêa
authors.affiliation: Internal Medicine Department, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil. Electronic address: alexandreliborio@yahoo.com.br.
authors.forename: Alexandre Braga
authors.initials: AB
authors.lastname: Libório
mesh_terms: D000138:Acidosis / Q000097:blood*; D000368:Aged; D000369:Aged, 80 and over; D000838:Anions / Q000097:blood; D002712:Chlorides / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000503:physiopathology; D012709:Serum Albumin / Q000032:analysis*
chemical_list: D000838:Anions; D002712:Chlorides; D010281:Parathyroid Hormone; D012709:Serum Albumin