Reduction of blood pressure retards the progression of chronic renal failure in man

The effect of blood pressure reduction on the progression rate of chronic renal failure (CRF) was studied in 28 patients with CRF of diverse aetiology entering a prospective study (observation time 7-24 months, mean 16 months). Endogenous creatinine clearance was 12-66 ml/min (mean 30 +/- 3 ml/min). We aimed to keep the blood pressure below 160/90 mmHg. Dietary protein was not restricted. The progression rate of CRF was assessed from the regression coefficients of the regressions of creatinine clearance and the inverse of s-creatinine, respectively, on time. Progression rate and the means of all recordings of mean arterial blood pressure (MAP) and urinary protein excretion, respectively, in each patient during the prospective phase were compared with retrospective data from the proceeding period (observation time 4-25 months, mean 19 months). The patients received various combinations of antihypertensive drugs including diuretics, beta-blockers and vasodilatory drugs. In 19 patients MAP decreased from 109 +/- 2 to 102 +/- 2 mmHg (group I), whereas MAP increased from 105 +/- 2 to 108 +/- 2 mmHg in nine patients (group II). In group I proteinuria was significantly lower (P less than 0.05) and the progression of CRF was approximately 50% slower (P less than 0.01) in the prospective phase than in the retrospective phase; no changes were observed in group II. Calculated for all patients, significant correlations were observed between the change in MAP and the change in progression rate and protein excretion, respectively. These results indicate that lowering of blood pressure results in decreased proteinuria and retardation of the progression of CRF irrespective of the aetiology.