Lipoprotein(a): A big genetic risk for heart disease
It is often tempting to think that people who exercise, are thin, and look healthy are at a low risk for heart disease. But beneath all the healthiness can lurk a genetically driven risk factor for a heart attack: elevated lipoprotein a.
Heart disease is the number one cause of death in the US and in most countries around the world. Statistics show that one in four people in the US will die of heart disease.
We often have a picture in our heads of someone at risk for a heart attack: obese, older man who looks unhealthy, perhaps with a stressful job. Looking at the statistics, being overweight increases the risk of heart disease by 35% and being obese (BMI >35) can double the risk.[ref] Compare this to the healthy looking person who has no signs or symptoms but yet has a 3x risk of heart attack due to a genetically elevated lipoprotein(a) — Lp(a) — level.
The Biggest Loser host and fitness trainer, Bob Harper, has been open about his recovery from a very serious heart attack that he had in 2017. He was the epitome of healthiness — fitness trainer, nutritional guru, athlete, and only in his early fifties. But he also had genetically elevated levels of Lp(a). Here is a Today show interview where he explains some of his recovery and what he is doing to prevent a second heart attack.
Family history is always mentioned by the doctor as an important indicator of your risk of heart disease, especially if you have a close family member who had a heart attack fairly young. One big way that researchers have found that family history plays a role is through the inheritance of a genetic variant that increases lipoprotein(a).
Lipoprotein(a) or LP(a) — called L P little a — is a blood particle that carries LDL cholesterol and proteins. Elevated levels of Lp(a) are a strong risk factor for having a heart attack due to atherosclerosis. Read more about Lp(a) on the Lipoprotein(a) Foundation website.
There are questions and controversy on the role that cholesterol plays in heart disease, and that may lead people to dismiss Lp(a) as just the latest number to talk about. (Lots of people on a low carb or keto diet like to point out the flaws in the studies on cholesterol.) I think it would be a big mistake to dismiss the research on Lp(a). There is abundant and really good research on the increased risk for heart attack, narrowing of the arteries, and stroke (i.e. cardiovascular disease) being caused by elevated lipoprotein (a).[ref][ref]
LPA gene variants:
The LPA gene controls the formation of the lipoprotein(a) molecule. Variants in the gene, specifically variable number tandem repeats (VNTR), cause the body to create more Lp(a). About 25% of the population carries one or more risk alleles (listed below) that correlate to the VNTR.
Check your 23andMe results for rs3798220 (v4, v5):
- CC: risk of elevated Lp(a), increased risk for heart disease — 3.7x risk of aortic stenosis [ref]
- CT: risk of elevated Lp(A), increased risk for heart disease, increased risk of aortic stenosis
- TT: normal
Check your 23andMe results for rs10455872 (v4, v5):
- GG: likely elevated Lp(a), increased risk for heart disease — 2x risk of aortic stenosis [ref][ref]
- AG: likely elevated Lp(A), increased risk for heart disease
- AA: normal
Studies also showed that carrying one risk allele for both of the above — compound heterozygous — also doubled the risk of aortic stenosis.[ref]
So what do you do if you carry the risk alleles? Knowledge is power here.
Keep in mind that this is a fairly common genetic risk factor, so it isn’t a reason to stress out or be anxious. It is an excellent reason to do what you can from a lifestyle perspective to lower your risk of a heart attack: stop smoking, don’t drink too much, be active, eat healthily, reduce stress. You know all of these things, and now you know that they apply to you.
Talk to your doctor about getting an Lp(a) blood test done.
If you are one of those people who always ignores the “talk to your doctor” advice, you can also order a lipoprotein (a) test done through Walkinlab.com for about $45. There are other online companies that you can order lab work through as well, and they all offer specials and coupons, so shop around.
How high is high?
One study shows a 3x risk of aortic valve stenosis for those with Lp(a) levels greater than 90 mg/dl.[ref] Another source says normal Lp(a) levels are less than 30 mg/dl (or 75 nmol/L)[ref] while others put it at less than 50 mg/dl.[ref] Again — this is something to talk to a doctor about and keep up with the research as it comes out.
There are a couple of therapies for high Lp(a) that have been well studied as well as new drugs coming out to target it.[ref]
- Apheresis, where they run your blood through a machine to remove the LDL particles, is considered effective, but expensive and inconvenient.[ref]
- Niacin (vitamin B3) has been used for decades to lower the risk of heart disease. Studies show that 1 -3 g/day lowers Lp(a) levels by an average of 30–40%.[ref][ref][ref] Most studies use the type of niacin that causes flushing.
- Overall, lowering your LDL cholesterol numbers can help lower Lp(a) some since Lp(a) is the carrier for LDL. Here is a good article on it from the Cleveland Clinic. How do you lower your cholesterol with diet? That seems to be the million dollar question. A more whole food, plant-based diet, in comparison with a higher meat and fat based diet, works to lower cholesterol for some people. It may be that you need to try out several diets — Mediterranean, DASH, etc — and test to see what works for your body.
- One study showed Gingko Biloba reduced Lp(a) levels. The study used 120mg, twice a day and showed a 23% decrease in Lp(a). [ref]
More to read/watch: