I promised you in July that I would tell you about research results that we would be presenting in November 2011 at the American College of Rheumatology annual meeting. These results suggested that some arthritis-related treatments might reduce the risk of heart attacks. Physicians call heart attacks “Myocardial Infarctions” or MIs.

Last spring we got a call from researchers at the University of North Carolina and Duke University. They had been studying treatments for osteoporosis called bisphosphonates. You may know bisphosphonates by their brand names, which include Actonel, Aredia, Boniva, Didronel, Fosamax, Reclast, Skelid, and Zometa. During 2010, about 17% of people in the NDB reported using bisphosphonates.

We all lose some calcium from the bones as we get older. But people who lose significant amounts of calcium have the disease called osteoporosis. For such people, bisphosphonates are prescribed. Osteoporosis is pretty much an illness that doesn’t cause symptoms, but it is a major cause of fractures as we get older. Bisphosphonates are prescribed, and they can be very helpful in preventing or reducing fractures.

Drug companies compete with each other to develop better and more effective treatments, and many bisphosphonate drugs have been developed by different companies, as you may have guessed by the many different drugs names above. In analyzing the result of the clinical trials of bisphosphonates, researchers discovered, around 2007, that people who had received such treatment had reduced mortality; that is, they lived longer. The reduction in mortality couldn’t be explained just by having fewer fractures. Studies suggested that people who received bisphosphonates might be having fewer deaths from heart disease. In particular, perhaps people who took bisphosphonates had fewer heart attacks (MIs).

The NDB was able to help UNC and Duke because we have been collecting information on bisphosphonate use and MIs for a very long time. We set out to understand whether we could show that MIs were reduced in bisphosphonate users. The first thing we did was to review hospital records to be certain that what we were calling MIs were really MIs. Frederick Wolfe, MD

Here are some of the problems we encountered: First, people who had MIs were usually older men, but women were more likely to get osteoporosis. Second, people who weighed more were less likely to have osteoporosis, but they were more likely to have heart attacks and diabetes. So if we compared people taking bisphosphonates directly with those not taking them, the difference in the risk of heart attacks might not be related to bisphosphonates. It could be related to something else: age, sex, weight, other medications, and so on.

In the research we did, we adjusted the analyses so that we compared people at the same age and weight, women with women and men with men. That way everything was the same except the use of bisphosphonates. Here is what we found— Bisphosphonates reduced the risk of MI by about 30% to 50%. This confirmed the results of the previous studies, possibly identifying an extra benefit to taking bisphosphonates.

 

In the graph, the top line shows how many people who took bisphosphonates had heart attacks during 9 years of follow-up (about 1%), while the bottom line shows the rate in those who did not take bisphosphonates (about 2%), a difference of about 1% at 9 years of follow-up.

 

Proven? Well, maybe. But suppose those who took bisphospho- nates were healthier in other ways, say by exercising more. Could it be that exercise, and not bisphosphonates, was the cause of what we observed? It’s possible. So we can’t be really sure, but it does seem likely the bisphosphonates reduce MIs. We’ll submit this research for publication soon. If other studies confirm our results, then we can be sure.

To all of you who allowed us to use your data, thanks. I think we are on to something here.