Plasma angiotensin II and aldosterone in unselected diabetic patients

The concentrations of angiotensin II and aldosterone in plasma were measured in 101 consecutive unselected out-patient diabetic patients and in fifty-three normal controls. The concentration of angiotensin II was similar in diabetics without complications and controls, but was significantly lower in patients with hypertension or peripheral neuropathy. In contrast, plasma aldosterone was not reduced in any sub-group. The concentrations of angiotensin II and aldosterone were positively correlated in controls, in diabetes without complications and in hypertensive diabetics, but this relationship was not found in patients with peripheral neuropathy, retinopathy or nephropathy. There was no evidence of overt hypoaldosteronism in any of the diabetic patients. No individual aldosterone concentration was below the range found in controls and no plasma angiotensin II concentration is reduced in patients with specific diabetic complications such as neuropathy, plasma aldosterone may be maintained by factors other than the renin-angiotensin system. This would explain why hypoaldosteronism is rare among unselected diabetics.