Comparative effect of captopril and nifedipine in normotensive patients with incipient diabetic nephropathy

The effect of a six-week treatment by placebo, the calcium channel blocker nifedipine or the converting enzyme inhibitor captopril was assessed in normotensive patients with insulin-dependent diabetes and incipient nephropathy. In response to captopril and nifedipine, arterial pressure decreased slightly and to a similar extent. These drugs resulted in opposite effects on urinary albumin excretion (increase in urinary albumin excretion by 40% during nifedipine and decrease by 40% during captopril treatment). No change in urinary albumin excretion was observed in the placebo group. This observation of opposite changes in urinary albumin excretion in the presence of a similar fall in arterial pressure suggests that the effect of captopril and nifedipine on urinary albumin excretion results from some difference in their intrarenal action.