Recent study reinforces science of new statin guidelines

DEAR READERS: You’ve sent me lots of correspondence about the new statin guidelines. Most have come from people whose doctors put them on statins because of the new guidelines. In October 2015, I discussed the new guidelines in two columns and said I’d keep you up-to-date about any important new information.

To refresh your memory, statins are medicines that were developed to lower blood levels of low-density lipoprotein cholesterol (LDL, or “bad,” cholesterol). Studies showed that statins greatly lowered LDL cholesterol and reduced the risk of heart disease. Most of us assumed that this was because they lowered cholesterol. So guidelines were developed that said that people with LDL cholesterol above a certain level should take statins.

However, additional research revealed that statins do more than just lower cholesterol. They also reduce inflammation inside plaques of atherosclerosis, which, like lowering cholesterol, also reduces the risk of a heart attack or a stroke.

Then, a large study based at Harvard Medical School showed that statins reduced the risk of heart disease even in people with normal levels of LDL cholesterol. So there were two different ways (anti-cholesterol and anti-inflammation) in which statins could lower the risk of heart disease.

Based on this new information, updated guidelines published in 2013 moved away from recommending statins just for people who had high blood levels of LDL cholesterol. Instead, the new guidelines recommended a statin for anyone between 40 and 75 years of age who had a 7.5 percent or higher risk of having a heart attack or stroke over the next 10 years.

How do you calculate your risk? There are different internet-based risk calculators. Here’s one I recommend: www.reynoldsriskscore.org. Risk calculators take into account things like your age, your gender, close relatives with heart disease, high blood pressure, diabetes (including pre-diabetes), obesity, amount of exercise, whether you are or have been a smoker, and whether you eat lots of refined carbohydrates with a high glycemic load.

Doctors have been divided about the new guidelines. Some think we should still prescribe statins based on the level of a person’s LDL and HDL cholesterol. Others agree with the new guidelines: Even if your cholesterol is normal, if your risk of heart disease is high enough, you should be taking statins. In my previous columns, I’ve said I agreed with the new guidelines.

A new study published in the New England Journal of Medicine in May 2016 supports that position. Nearly 13,000 people were assigned at random to take either a statin or a placebo (sugar pill) — regardless of their cholesterol level. Like other studies before it, this study found that those taking the statin had a substantial (24 percent) reduction in “cardiovascular events,” including heart attacks, strokes and sudden death. This benefit was seen even in those with relatively low or normal cholesterol levels.

So I’m sticking with my previous conclusion: The new guidelines make sense. If my cardiac risk were high, and my cholesterol was normal, I would still take a statin.

Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.