By Drs. David Niesel and Norbert Herzog, Medical Discovery News
Cholesterol-lowering drugs called statins are the most prescribed drug ever. About 30 percent of Americans are currently taking statins such as Crestor, Lipitor, Mevacor and Zocor. Overall, statins can be good thing, but as with all drugs, there are some negative effects.
Statins lower cholesterol by inhibiting a protein called HMG-CoA reductase. Since high cholesterol levels are linked to heart disease, statins can reduce the risks of heart attack and stroke, two of the leading causes of death in the United States. Recent reports from the American Heart Association and the American College of Cardiology even argue that more people should be taking statins. They want everyone with a 7.5 percent or higher risk of developing heart disease in the next decade to start taking them. This would be about half of all eligible adults ages 40-75.
However, some are concerned about this many people taking statins because of serious risks associated with their use. People have reported having issues with memory loss, muscle weakness that may lead to permanent damage and elevation of blood sugar levels that can lead to Type II diabetes. Other experts argue that the benefits of statins far exceed their risks, which seem to disproportionately affect women and older individuals.
Precision medicine, also called personalized medicine, may have found a solution to this debate by studying a specific gene called SLCo1B. This gene produces a key protein that metabolizes statins in our bodies, and it causes the myopathy or muscle weakness that some people experience when they take statins. We are all unique as humans, and as such there are changes in our DNA that result in different variations of the same gene. Although small, such variants can alter the proteins the gene encodes, leading to slightly different activities. Scientists have identified variants of the SLCo1B gene. About 25 percent of people have the one variant, which makes them almost five times more likely to develop muscle weakness when taking a statin. About 2 percent of people have another variant, which makes them 17 times more likely to do so. Wouldn't it be useful to know which variant of the gene you possess before you begin a cholesterol-lowering regimen? Thanks to molecular genetics, you can.
There is a simple DNA test that can identify each SLCo1B1variant. This involves isolating a small amount of your DNA to analyze the type of SLCo1B1gene present. This costs $100-200, is relatively easy and based on established technology. Unfortunately, like plenty of genetic tests, many insurance companies do not yet cover these charges, but if more insured people request these tests, the insurance companies are likely to change their view on paying for them. After all, it would be cheaper to pay for a genetic test than for the care required to treat a heart attack or stroke.
While we may know how statins impact our muscles and blood sugar, we do not know the full extent of the effects they have on humans. It's possible there are other side effects that we will not be aware of until large groups of people have been taking them for a decade or longer. This remains the subject of many studies.
Medical Discovery News is hosted by professors Norbert Herzog at Quinnipiac University, and David Niesel of the University of Texas Medical Branch. Learn more at www.medicaldiscoverynews.com.