title: Corticosteroids Significantly Increase Serum Cystatin C Concentration without Affecting Renal Function in Symptomatic Heart Failure.
abstract: BACKGROUND
  Human cystatin C is a single non-glycosylated polypeptide chain consisting of 120 amino acid residues. Its concentration in the circulation is mainly determined by glomerular filtration rate. However, non-renal factors, i.e., drugs, may dramatically affect its levels in the circulation. The aim of this study was to evaluate the effect of corticosteroid treatment on serum cystatin C concentration in patients with symptomatic heart failure.
  
  
  METHODS
  Fifty-six symptomatic heart failure patients were treated with prednisone. Concentrations of serum cystatin C and serum creatinine were recorded at baseline, and after about 2 weeks of treatment. Twenty-four hour urinary creatinine was also measured to directly calculate glomerular filtration rate.
  
  
  RESULTS
  Prednisone treatment significantly increased serum cystatin C concentration from 1.24 +/- 0.40 mg/L at baseline to 1.61 +/- 0.80 mg/L at the end of study (p < 0.05). However, the elevation in serum cystatin C concentration was not associated with renal function impairment. Prednisone not only significantly decreased serum creatinine concentrations from 89.66 +/- 28.63 pmol/L at baseline to 76.55 +/- 20.80 micromol/L after prednisone treatment (p < 0.05), but also significantly increased fractional excretion of sodium and urine flow rate. The data also showed there was a slight and but nonstatistically significant increase in glomerular filtration rate in such patients after prednisone treatment.
  
  
  CONCLUSIONS
  Important non-renal factors, such as corticosteroids, can influence cystatin C concentration. Thus, it needs to be considered when interpreting cystatin C values in patients with heart failure receiving corticosteroid therapy.
authors.forename: Jian-Long
authors.initials: JL
authors.lastname: Zhai
authors.forename: Ning
authors.initials: N
authors.lastname: Ge
authors.forename: Yuzhi
authors.initials: Y
authors.lastname: Zhen
authors.forename: Qingzhen
authors.initials: Q
authors.lastname: Zhao
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D007668:Kidney / Q000187:drug effects* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009318:Natriuresis / Q000187:drug effects; D011241:Prednisone / Q000627:therapeutic use*; D012964:Sodium / Q000097:blood; D013997:Time Factors; D016896:Treatment Outcome; D015854:Up-Regulation; D014563:Urodynamics / Q000187:drug effects
chemical_list: D000305:Adrenal Cortex Hormones; D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D012964:Sodium; D003404:Creatinine; D011241:Prednisone