Computer program for iterative evaluation of fractional turnover rates by exponential regression: application to the turnover of VLDL-triglycerides in blood.
A microcomputer program ('EXREG') in GW BASIC was developed for fitting experimental data of A(T) to the equation A = A0 + A1.exp(-K.T) by exponential regression. In an iterative procedure K-values are tested to yield the maximum coefficient of determination. The accuracy of K is further improved in consecutive steps. The program is used to obtain the fractional turnover rate K of radiolabelled very low density lipoprotein (VLDL)-triglycerides in patients suffering from disturbances of lipid metabolism. A is the radioactivity of VLDL-triglycerides which is measured after isolation from blood. Seventeen consecutive blood samples are taken within a period of 24 h after injection of radioactive glycerol. T is the time after injection. The production rate of VLDL-triglycerides is calculated using K, the VLDL-triglyceride concentration, the body weight and height.
Leonhardt
W
W
Lipid Research Unit, Medical Academy Dresden, G.D.R.
Lüthke
C
C
Leonhardt
F
F
Julius
U
U
D003198:Computer Simulation; D006801:Humans; D008079:Lipoproteins, VLDL / Q000097:blood*; D008659:Metabolic Diseases / Q000097:blood*; D008838:Microcomputers; D008954:Models, Biological; D012044:Regression Analysis; D012984:Software; D014280:Triglycerides / Q000097:blood*
D008079:Lipoproteins, VLDL; D014280:Triglycerides; C030106:very low density lipoprotein triglyceride