Hypertension in diabetes as related to nephropathy. Early blood pressure changes.

We measured the blood pressure under standardized conditions in three groups of patients with type I (insulin-dependent) diabetes: group 1, patients with Albustix-negative urine and normal urinary albumin excretion rate below 20 micrograms/min; group 2, patients with Albustix-negative urine and elevated urinary albumin excretion rate 20 to 200 micrograms/min; and group 3, patients with Albustix-positive urine at the time of diagnosis of diabetic nephropathy, that is, proteinuria greater than 0.5 g/24 hr on four consecutive visits with an interval of more than 1 month. We also studied blood pressure data at the time of diagnosis of diabetes in patients with type I diabetes who later died with severe nephropathy (n = 84), and in those who survived their disease for more than 40 years (n = 256). Patients subsequently developing diabetic nephropathy could not be identified on the basis of systolic and/or diastolic blood pressure during the first 2 to 10 years of diabetes. Our study also demonstrated that the blood pressure in group 3 (147/93 mm Hg) was significantly higher than that in group 2 (135/86 mm Hg), which again was higher than that in group 1 (128/79 mm Hg). We concluded that arterial hypertension is an early feature in the developing of diabetic nephropathy, with blood pressure rising before the presence of clinical proteinuria.