Like most physicians, I follow recommended guidelines for my patients and obtain liver tests about six weeks after prescribing statin treatment and then roughly annually thereafter. Even so, a frequently asked question by patients who are treated with a statin is, "How about my liver, doc?" Why such concern?
My colleagues and I take precautions despite the fact that there has never been a documented instance of permanent liver damage from taking a statin. While some people do experience elevated liver enzymes levels, this has not been connected to liver failure. The huge Heart Protection Study, which followed more than 20,000 patients taking either a placebo or 40 mg of the statin simvastatin for five years, found no detectable risk of liver disease in those taking simvastatin. The authors of the report concluded that liver enzymes should be measured before patients are placed on a statin, but that these tests need never be repeated if the baseline values are normal. It is possible that undesirable liver enzyme changes might occur with the use of other statins, but the results of several smaller studies with other statins make this unlikely.
Testing lipid levels
It does make sense to obtain a lipid panel blood test soon after starting a statin (or any other lipid-lowering drug) to see if treatment goals have been achieved. If not, the statin dose might be increased or another medication added. When lipid panels show that total and LDL cholesterol levels reach target goals, it is unnecessary to repeat these measurements more often than annually unless there has been some major change in your eating habits or health status.
It is, of course, important to make sure that you continue to take your lipid-lowering medication. Some people have the mistaken notion that they can stop the medication once cholesterol levels are lowered sufficiently. If medications are stopped, however, blood cholesterol will rapidly return to the previously high levels.
In addition, lipid tests must be obtained more often if you've been treated for elevated triglyceride levels because levels of these fats in the blood are more variable than LDL cholesterol.
Tests for muscle pain
Another test your doctor might run after you're taking statins is a blood test to check for creatine kinase; this test is only needed to evaluate the cause of muscle pain or weakness.
Ask your doctor what lab tests are necessary
When reviewing patient records, I am always surprised and dismayed to find how frequently doctors order a new set of laboratory tests at each patient visit. This excessive number of tests contributes to the high costs of medical care for individual patients, insurance companies, and the health care system.
If you are sent off to a laboratory for blood tests, ask your doctor what tests have been ordered and why.