Plasma renin activity (PRA) in type I diabetes mellitus: PRA and metabolic control in diabetes.

Plasma renin activity (PRA) and aldosterone were evaluated in 39 diabetic children and adolescents and in 39 healthy subjects. The mean values of PRA in the diabetics were higher than in controls not only basal (means +/- SD: 2.7 +/- 1.1 vs. 1.3 +/- 0.6 ng/ml/h) but also after physical exercise (5.2 +/- 3.84 vs. 2.8 +/- 0.7 ng/ml/h). Aldosterone was similar in diabetics and controls (basal: 18.1 +/- 6.6 vs. 16.9 +/- 5.1 pmol/l; after physical exercise: 5.3 +/- 14.1 vs. 39.9 +/- 7.1 pmol/l). There was a significant correlation between HbA1c and PRA after exercise (p less than 0.01). The diabetic children were subdivided into 3 groups according to their stable HbA1c values (group A: less than 8.5%; group B: 8.5-10.9%; group C: greater than 11.0%). A group of diabetics (group C) were re-evaluated after a long period of a good metabolic control. The values of PRA were decreased and similar to the controls (PRA basal values: 1.7 +/- 1.9 ng/ml/h; after exercise: 3.2 +/- 2.9 ng/ml/h). Our study suggests that PRA abnormalities present in diabetic patients can be reversible if a good metabolic control is achieved.