Statins have been in the news lately, so I thought I might write a few words about them. Statins chemically mimic an enzyme in the liver (HMG-Co-A) that is used in the first step of making cholesterol, and when the liver tries to use the statin, then overall less cholesterol is produced, and your serum levels fall. The body makes most of its cholesterol between midnight and dawn, which is why the earliest statins, which had a short half-life, were prescribed to be taken at bedtime. But the later statins such as Lipitor and Crestor have a much longer half-life, so they may be taken at any time during the day, and food does not significantly affect their absorption.
There is absolutely no question, based on numerous clinical studies, that statins definitely provide secondary protection against a heart attack or a stroke. That is, if you have had a heart attack or a (non-hemorrhagic) stroke, taking a statin will lower your risk of having a second one. Whether or not you should also take aspirin should be decided by you and your doctor, and adding a regime of exercise provides an additional benefit above and beyond the benefit from taking the statin. All statins appear to give equivalent results.
The question of primary prevention is a little more complicated. There is no satisfactory study showing that a person with no risks for heart disease other than elevated cholesterol benefits from taking a statin. Many doctors will prescribe a statin for a patient with a risk factor for coronary artery disease or a stroke: smokers, diabetics, patients with ASCVD, and patients with significant narrowing of a carotid artery. There is evidence for decreased mortality when a patient with documented ASCVD takes a statin, even in the absence of a heart attack.
I have found the most troublesome side-effect to be leg cramps, which are sometimes severe enough to awaken patients at night. Often the leg pains can be helped by reducing the dose of the statin or switching to another brand. The statins can also raise liver enzymes, and some patients report difficulty with mental concentration. There is some weak data that statin use can slightly increase your risk of developing adult-onset diabetes, but it may also reduce your risk of getting cancer (see my earlier blog about this). The muscle cramps and occasional myositis may be related to the fact that all statins lower the level of Coenzyme Q-10.
Statins are one of the few drugs where the ingestion of grapefruit juice should probably be avoided. A chemical in grapefruit inhibits the P450 enzyme that degrades statins, so the use of grapefruits can raise the level of the statin in your blood and your liver.
Let me close by summarizing the results of the JUPITER study. This study showed that in patients who had an elevated CRP (a marker of inflammation) who also took a statin had a lower incidence of heart attacks, coronary artery surgery, and strokes. Strangely enough, there was no decrease in the indicence of deaths from coronary artery disease, but there were 20% fewer deaths from all causes, mainly cancer.
There are many, many clinical trials of statins in various medical conditions being conducted, and you can expect to see future stories about their benefits, side effects, or, occasionally, a null result. There was also a recent retrospective study showing that patients that lowered their LDL cholesterol through diet had an increased rate of cardiac events and deaths, so it may well be that the beneficial effect of statins is due more
to their anti-inflammatory effect than to their lowering cholesterol.