A question from a reader:
Two years ago, my doctor recommended a comprehensive lipid screening because both of my parents had heart disease. My only blood component way out of line was LP (a) [lipoprotein(a)]. It was 130. According to the lab that conducted the screening, Berkeley Heart Lab, a level above 30 should be cause for concern. I was stunned that mine was more than quadruple the danger level.
I began taking two grams [2000 mg] of niacin a day in addition to the Lipitor I was already taking. The next reading, a few months later, was 87. Over a period of about 18 months, I had a total of four readings from Berkley Heart Lab. My LP (a) fluctuated in the 80-130 range – still way above normal. My doctor said there was little else I could do to control it.
That doctor has since retired. I now see another doctor who uses a different lab. My first LP (a) reading with him a few months ago was 17, which is normal. I am still taking the same amount of niacin and Lipitor and I can’t think of anything that would account for the huge discrepancy. I’m going to have another test again soon.
Is one of the labs giving erroneous readings? If so, how can I tell which? If Berkeley Heart Lab is correct, is there anything I can do about my increased coronary risk due to high LP (a)?
Tom D.
Tom's frustration on the variation of Lp(a) is due to the fact that laboratories run the Lp(a) test by several different techniques and will generate tremendous variation in values. The key is to stick to the same measure over and over from the same lab, else you'll be terribly confused and frustrated. Tom essentially should ignore the value obtained that was unexpectedly low.
Another issue: Lp(a) is a turtle. It responds very slowly. In fact, we rarely check it more than once or twice a year. Check it too soon after a treatment change and it won't fully reflect the effect. You've got to wait at least several months before re-checking.
How about treatment alternatives? They are:
--More niacin. Not my favorite choice, since niacin >2000 mg per day begins to generate more side-effects, but it is a choice. You can go to 4000-5000 per day, but only with your doctor's supervision due to liver effects.
--Testosterone for males. We use topical testosterone from Women's International Pharmacy in Madison, Wisconson. Prescription patches like Testim are also effective.
--Estrogen for females. This is less "clean" than testosterone, introducing questions about endometrial and breast cancer risk, but it is a choice.
--DHEA--A small effect but every little bit can help. We use 25-50 mg per day, depending on blood levels and only if you're 45 years old or older.
--l-carnitine--In my experience, a small effect. It requires 2000 mg per day, which is expensive. Sometimes, an expected large effect develops, so it's worth a try if it fits in your budget.
--Fibrates--These are the drugs Tricor and Lopid. I don't like these agents very much because I think they're weak, including the effect on Lp(a) reduction. But they are choices for you and your doctor.
Lastly, you can simply be guided by your heart scan score. For example, if Tom's initial heart scan score is 200, and he continues his current program and one year later his score is 300, then alternative treatments are worth considering. But what if Tom's score is 189--he's regressed his coronary plaque. Then, who cares what his Lp(a) is?
Another issue to keep in mind is that, in the presence of Lp(a), keeping LDL to very low numbers (e.g., 60 mg/dl) may added value in preventing coronary plaque growth.