title: [Nonlinear regression analysis of cardiac enzyme kinetic model with modified simplex method and DUD method using SAS software].
abstract: OBJECTIVE
  To compare the efficacy of modified simplex method and DUD method using SAS software for nonlinear regression analysis of cardiac enzyme kinetic model.
  
  
  METHODS
  By using cardiac enzyme kinetic one-compartment mathematical model, nonlinear regression results obtained from DUD methods using SAS software and modified simplex method were compared with the same starting values to fit the creatine kinase curves in 22 patients with acute myocardial infarction.
  
  
  RESULTS
  The parameters calculated by DUD method and modified simplex method were the same in 4 cases, and smaller least square was resulted from DUD method in 4 cases. In the other 14 cases, modified simplex method yielded smaller least square. The mean value of the least square calculated by modified simplex method was less than that by DUD method (867 747 vs 6 712 989, P=0.013).
  
  
  CONCLUSIONS
  Modified simplex method appears to be more adequate than DUD method in estimating circulatory parameters of the one-compartment model.
authors.affiliation: Department of Cardiology, Zhujiang Hospital, First Military Medical University, Guangzhou 510282, China. liulei@1010.com
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.forename: Zhan-yu
authors.initials: ZY
authors.lastname: Cai
authors.forename: Bin-hui
authors.initials: BH
authors.lastname: Wang
mesh_terms: D006801:Humans; D007700:Kinetics; D008433:Mathematics; D009203:Myocardial Infarction / Q000201:enzymology*; D009206:Myocardium / Q000201:enzymology*; D012044:Regression Analysis