Cardiovascular outcomes in diabetic nephropathy studies

Diabetes is associated with a high risk of the development of cardiovascular disease and renal disease, and in patients with microalbuminuria this risk is further increased. Inhibition of the renin‐angiotensin system with angiotensin‐converting enzyme (ACE) inhibitors and angiotensin‐receptor blockers (ARBs) is proven to reduce the level of microalbuminuria and slow the rate of deterioration in renal function, an effect independent of the antihypertensive effect of these drugs. Analysis of diabetic patients in the MICRO‐HOPE study demonstrated that the ACE inhibitor ramipril reduced major cardiovascular outcomes and also reduced the development of nephropathy as a secondary endpoint. Cardiovascular outcomes have been secondary endpoints in several recent studies of ARBs in patients with type 2 diabetes and proteinuria; a reduction in the risk of congestive cardiac failure has been demonstrated, but none of the other main cardiovascular outcomes has been improved. Thus, when a patient with type 2 diabetes has microalbuminuria renin‐angiotensin blockade with an ACE inhibitor may be of considerable cardiovascular benefit, and any cardiovascular benefit of ARBs is yet to be proven. Once overt diabetic nephropathy has developed, the cardiovascular benefits offered by ACE inhibitors and ARBs are restricted to preventing cardiac failure.