Stockholm clinical study on progression of chronic renal failure--an interim report

Fifty-seven patients with chronic renal failure (CRF) of diverse etiology entered a prospective, randomized study to evaluate the effect of a low protein diet on the progression rate of CRF. All patients were followed for a control period of 12 or 24 months before randomization into two groups, one permitted unrestricted protein intake and the other prescribed a diet containing 0.4 g/kg body wt/day of protein and 0.1 g/kg body wt/day of essential amino acids, (LPD + EAA). During both the control and study periods, patients were clinically evaluated and had serum biochemistry and 24-hour clearance of creatinine, urea and protein excretion checked monthly. The 51Cr-EDTA clearance (plasma slope and urinary clearance) was determined every third month. The progression of renal failure was evaluated from the regressions of the reciprocal of serum creatinine (SCr-1), creatinine clearance and urinary 51Cr-EDTA clearance against time. Having defined criteria for progression, only patients in whom renal failure had progressed over 12 or 24 months were randomized. In 28 patients, data were available, permitting a comparison of the progression of renal failure (estimated from regression of SCr-1 and of creatinine clearance against time) during the retrospective and prospective periods. There was a significant correlation between the change in progression rate and the change in mean arterial pressure, a relationship which was also present in patients with mild hypertension or those with blood pressure within the "normal" range. The urinary protein excretion also correlated with the change in mean arterial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)