RAS Blockade for Every Diabetic Patient: Pro and Con

Luis M Ruilope, MD, and Anna Solini, MD, PhD, presented a pro/con argument article in the May 2011 edition of Diabetes Care.  They were tackling the question of whether renin-angiotensin system (RAS) inhibitors should be used in every patient with type 1 diabetes or type 2 diabetes.  The suggestion that this could be done comes from the known role of RAS blockade in blood pressure regulation and organ protection.

The counter argument to this is that RAS inhibitors should not necessarily be used in every patient; there could be better options for achieving the same goal, including calcium-channel blockers—alone or in combination with ACE inhibitors.

The arguments will be summarized here.

Pro Argument

Con Argument

Commentary by Colleen Flynn MD

The most important aspect of blood pressure control in patients with diabetes is actually lowering the blood pressure to goal. Most physicians will reflexively place a diabetic patient on a RAS-inhibitor at the first sign of hypertension. However, the first step should be measuring kidney function and albuminuria.

Microalbuminuria (30-300 mcg/mg) is not a surrogate for diabetic nephropathy, but rather a marker of inflammation. Other causes of microabluminuria include poor glucose control, poorly controlled blood pressure, elevated cholesterol, a high salt diet, and infection. Physicians should address these other etiologies of microalbuminuria and monitor for improvement.

Rather than assuming the patient has early signs of diabetic nephropathy and automatically treating with a RAS blocker, patients should be assessed for other causes of microalbuminuria. If a diabetic patient has macroalbuminuria (>300 mcg/mg), then there is an indication to treat with an ACE or ARB.