Gettysburg Medical News
The Clinical View
 by P.E. Hoffsten, MD
25 July 2007

WHAT ARE TRIGLYCERIDES?

            Beginning in the 1950’s, it was recognized that high blood cholesterol was a factor predisposing to heart attacks and strokes.  In the last 50 years, many studies have shown that a cholesterol component in the blood called LDL-C (low density lipoprotein-cholesterol) is one of the best markers for future heart attacks.  In the late 1980’s, a group of medications called statin drugs came on the market and have been almost miraculous in their ability to lower LDL-C.  These drugs include:  Zocor (simvastatin), Lipitor (atorvastatin), Pravachol (pravastatin), Crestor (rosuvastatin), Lescol (fluvastatin) and Mevacor (lovastatin).  A combination product called Vytorin using simvastatin and ezetimibe (Zetia) is clearly the most effective product on the market today.  All of these drugs have a remarkably low side effect profile with a demonstrated benefit to prevent heart attack and stroke.

            But there is a second component in blood called triglycerides.  While cholesterol is an essential component of every cell in the body, triglycerides are purely for storing energy as fat.  Basically, triglycerides can be thought of as sugar and carbohydrates that were eaten but not immediately burned that day.  The liver takes the unused carbohydrates and turns them into triglycerides that are then stored as fat. Very overweight individuals can surprisingly have very low cholesterol values but have very high levels of triglycerides in the blood.  A normal value for triglycerides is around 150 mg%.  Generally, the more a person eats and the more overweight they are the higher the triglyceride levels in their blood.  Since being overweight especially with central obesity (apple type) was highly associated with heart attacks, it was thought triglyceride measurements would provide an index of a person’s risk for heart attack.  That did not turn out to be the case.  Over years of observation, it was seen that a person would come to a laboratory, have their blood drawn, and the triglyceride level measured.  Values up to 500 or 600 mg % were relatively common in overweight individuals.  But when other factors such as high blood pressure, diabetes, and low good cholesterol values were factored in, it didn’t seem that high triglyceride level by itself was a bad thing.  Thus, over the years triglycerides have not been listed as a major factor in developing heart attacks and strokes.

            In the July 18^th issue of the Journal of the American Medical Association, that all changed.  The change was a simple one.  It turns out that all this time, we have been measuring fasting triglyceride levels.  The patient would be instructed to come to clinic and have their blood drawn in the morning before they had had anything to eat.  That would be the lowest and best triglyceride level that they had all day and measuring that didn’t seem to be a good indicator of anything.

            But then some smart scientists looked at the big picture.  They recognized in the United States today, very few people spend their time not eating.  Today, America eats from dawn to bedtime.  We have meals larger than we need, snacks every place we turn, and reward ourselves with food when we perform well.  From the time we are 4 years old, we are trained just like dogs.  If you hit a good ball in t-ball, your 4-year old or 5-year old child is taken to the Zesto for an ice cream cone or there is dessert which is always a reward at the end of a meal. So these scientists recognized that, in fact, we should be measuring triglyceride levels in the non- fasting state.  When that was done, it was seen that high triglyceride levels were probably as good a predictor of a heart attack as was the bad cholesterol. 

            It is now recognized that there are two major patterns marking an individual for a heart attack.  Pattern A is the type with high LDL-C cholesterol.  Pattern B is the type with high triglycerides and low good cholesterols (HDL-C).  Statin drugs work very well to control the Pattern A individuals with high cholesterols but they do very poorly to control the Pattern B. 

            So how is Pattern B high triglyceride-induced heart attack and stroke prevented?  I just hate to say it because it is just such a worn out piece of advice. But the best way to treat high triglyceride levels is to eat less and exercise more.  Most specifically, the low carbohydrate diet is the most effective to lower triglyceride levels.  This is because carbohydrates that are eaten each day but not used that day are taken to the liver and turned into triglycerides that are then sent to fat deposits around the body.  Thus, by eating less carbohydrate, liver production of triglycerides is decreased and blood levels go down.

            If one wants to use medication to lower triglycerides, there are several that will be helpful.  Perhaps one of most effective and cheapest is fish oil.  Using 4 of the gel caps per day will result in a very significant drop in the triglycerides in most people.  Alternatively, the other medication which is helpful is gemfibrozil.  This is somewhat more expensive and is the drug that often causes muscle problems when prescribed with a statin drug.  It is a poor third choice but may be all that works in some patients.

            In summary, that triglyceride levels were not a marker for heart problems is probably not true but the best way to find the high triglyceride level is the non-fasting state.  Drawing a fasting panel won’t find this dangerous marker.  The best way to treat high triglycerides is to eat less and exercise more.  If you can’t do that, fish oil is cheap, easy, with no side effects (you won’t grow fins and you won’t smell like a fish). 

This and other columns available at www.macpierre.com.