Q: I recently saw my doctor and was told that my triglycerides were 300 mg/dL (milligrams per deciliter), but was not given any treatment. At home I saw on the lab report that the normal level is 165 mg/dL. I'm worried about what to do.
A: I can easily understand why you and many other people are confused about lipids and what to do about them when they're too high. Even many health professionals have forgotten their training in biochemistry, and there is professional debate about the best approach to treating someone with high triglycerides.
I will attempt to explain the chemistry underlying one of the most deadly diseases we have to face -- atherosclerosis. It's complex enough that you may have to read this more than once to understand fully. You may want to set it aside and read it again later as well.
Two main types of fats, or lipids, are in the body (and the bloodstream): cholesterol and triglycerides. Although you commonly hear about them in a negative vein, they are critical to life.
Cholesterol is the basic building block for bile for digestion and steroids. And it's essential for the structural strength of cell membranes. Triglycerides, on the other hand, are very important in transferring energy from our food into our cells.
Lipids are transported in the bloodstream in packets attached to proteins. The more protein in each packet, the denser it is. These packets come in three forms: high density lipoprotein (HDL), low density (LDL) and very low (VLDL).
The HDL form has a lot of protein and mostly cholesterol as the remainder. The LDL is primarily cholesterol with less protein. And although triglycerides are found in all three forms, they predominate in the VLDL.
You may have heard about HDL and LDL. And you may recall that having too much LDL is bad and having higher HDL is good (the so-called bad and good cholesterols).
The easiest explanation for this is that the HDL packets don't have much cholesterol, so when they travel through the bloodstream, they pick up cholesterol, taking it away from the blood vessels and returning it to the liver.
Although it appears that there are many other factors involved in atherosclerosis -- most recently a bacterial infection has been implicated -- having too much cholesterol at the site of an inflamed blood vessel greatly increases the risk of plaque formation that leads to blood clots and heart attacks.
It's very clear that if your cholesterol is too high and you have less HDL in proportion to your LDL, lowering the LDL and raising the HDL will decrease your heart attack risk.
But the situation is very different with the other lipids (triglycerides) that are carried around in the VLDL packets. Except when they're at very high levels, it has not been shown that treatment provides much benefit.
The normal value for triglycerides is 165 mg/dL, as long as the blood test is done after you've fasted for 12 hours. That's because the level can go up significantly following a meal.
It's clear that, for values greater than 1,000 mg/dL, a person has a much greater risk of getting inflammation of the pancreas (pancreatitis). And because of the wild fluctuations in blood levels following meals, many recommend treatment if it is over 400.
Although there appears to be a relationship between a high triglyceride level and heart disease, many think that this is secondary to the lower levels of HDL that go along with it. In any case, some physicians recommend treating someone with values over 250 if they already have heart disease.
I hope this column has helped you understand better the rather complex issue of lipids. But whenever you feel worried after a visit with a doctor, I suggest you call back and say so -- both for your sake and for the doctor's.
Dr. Allen Douma welcomes questions from readers. Although he cannot respond to each one individually, he will answer those of general interest in his column. Write to Dr. Douma in care of Tribune Media Services, 435 N. Michigan Ave., Suite 1400, Chicago, Ill. 60611. His e-mail address is DRFamily@aol.com.