An evaluation of the influence of therapeutic interventions on serum trace element levels in groups of patients

Abstract The aim of the study was to propose a method of large amount data evaluation. A new graphical method for data evaluation was suggested: the data were ranked according to the initial values and both the initial values and final values were intersected by polynomial curves. This method was used in the following situations: 1. Serum levels of Mg and Zn were measured just before and after hemodialysis (HD) in 87 patients in chronic renal failure. 2. Mg levels in serum, red blood cells and urine were estimated in 20 patients before and after administration of a Mg containing drug. Three basic graphic forms of curves were established: 1. Significant decrease of serum Mg levels during HD resulted in two uncrossed lines, the initial-values line being higher than terminal-values one (the higher the initial level the more pronounced was its decrease during HD). 2. Balanced effect of HD on the serum levels of Zn (low values increased, high levels decreased) represented two crossing-lines. 3. Significant increase of urine Mg in patients supplemented by Mg demonstrated two uncrossed lines. The position of initial-values curve was lower than the terminal-values one. The proposed graphical method of the evaluation of large amounts of data is simple and enables a quick orientation in the assessment of the effects of therapeutic interventions (trace elements, drugs and other relevant substances).