Studies on change in serum creatinine concentration in polycystic kidney disease

Abstract

We analysed the changes in serum creatinine concentration (Scr) in 24 patients with polycystic kidney disease whose Scr is higher than 1.5 mg/dl for over 3 times. Using the linear regression analysis, time and the reciprocal of Scr (1/Scr) as well as time and the logarithm of Scr (logScr) showed significant correlation in 19 patients, correlation coefficient (r) ranged from -0.8031 to -0.9912 and from 0.81576 to 0.99115, respectively. When predicting the time at which dialysis would be required, frequent determination of Scr is recommended after Scr begins to elevate. LogScr and 1/Scr are plotted against time, and prediction of the time is carried out as follows: (1) When a single straight line is described either on reciprocal or on logarithmic plot, the time is calculated using the single straight line. (2) When a straight line is not evident, the time is calculated on reciprocal plot as a single straight line, and (3) when a new line can be easily recognized, using the new line. Assessing the effect of therapy on progression of the disease remains to be defined.