title: p-Cresyl sulphate and indoxyl sulphate predict progression of chronic kidney disease.
abstract: BACKGROUND
  Indoxyl sulphate (IS) and p-cresyl sulphate (PCS) are uraemic toxins that have similar protein binding, dialytic clearance and proinflammatory features. However, only a few prospective studies have evaluated possible associations between these two retained solutes and renal disease progression in chronic kidney disease (CKD) patients.
  
  
  METHODS
  This prospective observational study evaluated independent associations between serum total IS and PCS with renal progression in a selected cohort of patients having different stages of CKD. Baseline PCS and IS were correlated with renal progression [defined as decrements in estimated glomerular filtration rate (eGFR) > 50% from baseline or progression to end-stage renal disease (ESRD)] and death during a follow-up period of 24 months.
  
  
  RESULTS
  Of 268 patients, 35 (13.1%) had renal progression and 14 (5.2%) died after a mean follow-up of 21 ± 3 months. Univariate Cox regression analysis followed by multivariate analysis showed that high-serum PCS levels were associated with renal progression and all-cause mortality independent of age, gender, diabetes status, albumin levels, serum IS, serum creatinine, Ca × P product, intact parathyroid hormone, haemoglobin or high-sensitivity C-reactive protein level. Serum IS was only associated with renal progression; however, the predictive power of serum IS was weakened when serum PCS was also present in the analytical model.
  
  
  CONCLUSIONS
  In addition to traditional and uraemia-related risk factors such as renal function, serum IS and PCS levels may help in predicting the risk of renal progression in patients having different stages of CKD.
authors.affiliation: Department of Nephrology, Chang Gung Memorial Hospital, Keelung, Taiwan.
authors.forename: I-Wen
authors.initials: IW
authors.lastname: Wu
authors.forename: Kuang-Hung
authors.initials: KH
authors.lastname: Hsu
authors.forename: Chin-Chan
authors.initials: CC
authors.lastname: Lee
authors.forename: Chiao-Yin
authors.initials: CY
authors.lastname: Sun
authors.forename: Heng-Jung
authors.initials: HJ
authors.lastname: Hsu
authors.forename: Chi-Jen
authors.initials: CJ
authors.lastname: Tsai
authors.forename: Chin-Yuan
authors.initials: CY
authors.lastname: Tzen
authors.forename: Yen-Chih
authors.initials: YC
authors.lastname: Wang
authors.forename: Ching-Yuang
authors.initials: CY
authors.lastname: Lin
authors.forename: Mai-Szu
authors.initials: MS
authors.lastname: Wu
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood; D003408:Cresols / Q000097:blood*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007200:Indican / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000097:blood*; D007677:Kidney Function Tests; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D013463:Sulfuric Acid Esters / Q000097:blood*; D015996:Survival Rate; D014511:Uremia / Q000097:blood*
chemical_list: D015415:Biomarkers; D003408:Cresols; D013463:Sulfuric Acid Esters; C408690:4-cresol sulfate; D003404:Creatinine; D007200:Indican