Most readers of these columns, I assume, are aware of the relation between elevated cholesterol and coronary heart disease, and of the benefit of reducing high cholesterol with diet and medication. The statins have saved many lives, and newer agents have come to market for those who cannot take statins.
I do hope you are not among the third of Americans who do not know their cholesterol.
What I would like to discuss here is another heart risk factor, which has been prominently discussed recently in the cardiology community but has not received much attention more widely. This is lipoprotein(a), commonly referred to as Lp(a) and verbalized as “L p little a.”
Lp(a) is an LDL (low density lipoprotein) molecule with an apo(a) protein attached. It can be trapped in the arterial wall, causing atherosclerosis (“hardening of the arteries”) and it increases clotting.
We know a lot about Lp(a.) It is genetically determined; there is very little effect of diet on levels. This means that you don’t need to measure it on a regular basis – if it is high, it will stay high, and if it is low, it will stay low.
It is a major factor in causing coronary disease, independent of standard cholesterol values.
As of now, there are no medications available to lower it, but new medicines are on the horizon.
If we cannot treat it, you may ask, why measure it?
First, if it is elevated, your doctor can put you on cholesterol-lowering medication even if your standard cholesterol levels are normal and would not be treated. No one risk factor works alone, and even if we cannot yet lower a high Lp(a), we can still reduce your risk of heart attack by treating other risk factors.
Second, there is recent evidence that low-dose daily aspirin, which is now considered not appropriate for the general population, will cut in half the heart-attack and stroke risk in people with Lp(a) over 50.
So, at your next visit, ask your doctor if they have ever measured your Lp(a), and request they do so if it has never been done.
Knowledge is power.
Dr. Ed Hoffer is the chairman of the Marion Board of Health, a graduate of MIT and Harvard Medical School. He is Associate Professor of Medicine, part-time, at Harvard and a Senior Scientist at the Massachusetts General Hospital.
By Dr. Ed Hoffer