Antihypertensive treatment inhibiting the progression of diabetic nephropathy.

In 6 male insulin-dependent proteinuric long-term diabetics aged 26-35 years the rate of progression of nephropathy was followed for an initial control period of 2.0 years and subsequently for 4.1 years during antihypertensive therapy with a beta-receptor blocker combined with Hydralazine and Furosemide. GFR and urinary albumin excretion was measured 3-4 times before and 9-14 times during treatment. Systolic blood pressure was reduced significantly from 162 +/- 14 (SD) mm Hg before treatment to 146 +/- 9 (SD) as a mean during the whole treatment period (2p = 0.002). Diastolic pressure was also reduced significantly, from 103 +/- 9 (SD) mm Hg to 95 +/- 8 (SD), (2p = 0.025). After 49 days of treatment there was a significant fall in albumin clearance as a per cent of GFR from 0.243 +/- 0.28 (SD) to 0.170 +/- 0.20 (SD), (2p < 0.001 for percentage change) with no change in GFR. In five patients the fall rate of GFR was in the initial control period 1.24 ml/min/month +/- 0.8 (SD). In the period when antihypertensive therapy was given it was reduced to 0.45 ml/min/month +/- 0.5 (SD) (2p = 0.037). In the 6th patient there was no decline in GFR neither before, nor during treatment. Before treatment there was a mean yearly percentage increase in albumin excretion of 107 per cent. During treatment this yearly increase was reduced to--7 per cent (2p = 0.002 for differences in slope). The results indicate that the state of renal insufficiency in diabetic patients with nephropathy and moderately increased blood pressure can be postponed by antihypertensive treatment. Other trials should be carried out to define the optimal scheme of treatment.