Background: Vascular injury at the microvascular and macrovascular levels plays a crucial role in the patient with diabetes mellitus. Evidence for renin-system activation in many patients with type 1 diabetes mellitus has raised the possibility that aldosterone-widely recognized as a contributor to vascular injury-could play a role.
Methods: We examined the state of the renin-angiotensin-aldosterone system (RAAS) in 58 subjects with type 1 diabetes mellitus and 64 age-matched normal control subjects. All studies were performed on a fixed sodium (200 mmol/day) and potassium (100 mmol/day intake), and samples were drawn at 8:00 a.m. to avoid the influence of circadian rhythms.
Results: The patient with diabetes mellitus showed an increase in plasma renin activity (PRA) (P < 0.01), plasma angiotensin II concentration (P < 0.01), and plasma aldosterone concentration (P < 0.001). A striking influence of the angiotensin receptor blocker, candesartan, on plasma aldosterone concentration in the patients with diabetes mellitus suggested strongly that renin-system activation is responsible for the elevated plasma aldosterone concentration.
Conclusion: Pharmacologic interruption of the effects of aldosterone at the tissue level could be especially useful in patients with diabetes mellitus. The dose of agents that block the renin-angiotensin system (RAS) should be adjusted to maximize the fall in plasma aldosterone concentration.