Ask the Doctors March 2012 Issue

Ask The Doctors: March 2012

I have diabetes and am on an ACE-inhibitor, because my doctor says it also helps protect the kidneys. I’ve developed a cough. My doctor said something about trying an ARB instead, but I’m doing well on this drug, except for the cough. Any thoughts?

Angiotensin-converting enyzme (ACE) inhibitors such as lisinopril, enalapril, and ramipril are valuable medications used in the treatment of high blood pressure, heart failure, and coronary artery disease (CAD). They lower blood pressure by blocking conversion of the small inactive protein angiotensin I to its active form, angiotensin II. When angiotensin II binds to its receptors on blood vessels, they contract, raising blood pressure. Angiotensin II receptor blockers (ARB’s) such as losartan, valsartan, and candesartan can reduce blood pressure by blocking this last step in the pathway. Many large, randomized clinical trials have shown conclusively that both ACE inhibitors and ARB’s help lower the risk of heart attack, stroke, and worsened cardiac function. In some situations, they may even increase longevity. And as your doctor mentioned, ACE inhibitors are “renoprotective,” helping to prevent kidney damage from diabetes. This quality is not unique to ACE inhibitors, though, since renal benefits are seen with ARB’s as well.

One downside to this success story is the most common side-effect of ACE inhibitors: a dry cough, which may occur in as many as 10 to 20 percent of recipients. This type of cough should not be confused with the rare but potentially dangerous reaction called “angioedema,” characterized by shortness of breath and swelling. Both the ACE inhibitor cough and angioedema appear to be caused by different amounts of another small protein called bradykinin. As it turns out, the enzyme blocked by ACE inhibitors is the same one responsible for breaking down bradykinin. The more bradykinin present, the more capillary leakage and fluid buildup which occurs in the skin and many other parts of the body. For some persons, an ACE inhibitor cough is simply a “nuisance symptom,” something noticed and occasionally annoying, but not life-changing or dangerous. For others, it is bothersome enough to stop the offending agent. Due to their different mechanism of action, ARBs do not increase bradykinin levels, and thus do not raise the risk of cough. Whether or not you should switch from an ACE inhibitor to an ARB depends solely on how much the cough bothers you. The cardiovascular and renal benefits of both types of medication are fairly similar.

Is red meat an absolute no-no if you’re a heart patient? I heard recently that lean red meat might actually be healthier than we used to think.

There is little doubt that high levels of red meat consumption increase risk of heart disease, namely, CAD and heart attack. Our general recommendations are that patients with symptomatic CAD—defined as a previous previous heart attack, angina, stenting or coronary artery bypass grafting (CABG)—generally should not consume more than two servings of red meat per week. And the cuts of meat should be as lean as possible, such as filet mignon or pork tenderloin rather than ribeye steak. So, in answer to your question, eating less red meat is clearly better for you, but you do not need to completely abstain from it, either. A recent analysis of multiple dietary studies performed around the world suggested that eating more processed meats, such as hot dogs, cold cuts, bacon, and sausage was associated with a significantly increased risk of CAD and diabetes, as well as a trend towards increased risk of stroke. While increased red meat consumption was not significantly associated with increased risk of CAD, it did predict more strokes, and there was a trend towards more diabetes.  Far from exonerating red meat, this study simply suggested that processed meats are worse for you.