The relationship between active renin concentration and plasma renin activity in Type 1 diabetes

Aims Circulating activity of the renin‐angiotensin‐aldosterone system (RAAS) can be assessed by measuring plasma active renin concentration (ARE), as well as by measuring plasma renin activity (PRA). We aimed to assess the relationships between ARE and PRA in Type 1 diabetic compared with non‐diabetic control subjects. We also assessed concentrations of the active renin precursor, prorenin. Patients and methods Thirty‐five Type 1 diabetic subjects and 34 non‐diabetic control subjects were assessed. Groups had similar ages, sex distributions, body mass indices, systolic and diastolic blood pressures. PRA was measured by radioimmunoassay of angiotensin I generation from endogenous substrate. ARE and total renin concentration (TRE) were measured by immunoradiometric assay (Nichols Institute Diagnostics, USA). Prorenin concentration was calculated as the difference between ARE and TRE. Results PRA was significantly lower in Type 1 diabetic than in control subjects (0.8 (0.4–1.1) vs. 1.1 (0.9–1.9) pmol/ml per h; P