On call: Measuring triglycerides
Q. My wife's doctor always tells her to fast before he checks her cholesterol so he can measure her triglycerides, but my doctor says triglycerides don't matter. Who is right?
A. There is no short answer to your question. Your wife's doctor is certainly right when he says you must avoid eating for 12–14 hours to get an accurate triglyceride reading — but your own doctor may be right in putting less emphasis on triglycerides than on LDL ("bad") and HDL ("good") cholesterol levels, which can be determined without a strict fast.
Doctors have been divided about triglycerides for years. That's because high triglyceride levels are often associated with other risk factors, such as high cholesterol, obesity, and diabetes. Do triglycerides tell doctors any more than they could learn from measuring the other factors? Some studies say yes, others, no. A helpful report from the University of California re-analyzed three major investigations, the Multiple Risk Factor Intervention Trial (MRFIT), the Lipid Research Clinics Coronary Primary Prevention Trial, and the Lipid Research Clinics Prevalence and Mortality Follow-up Study. With few exceptions, they found that triglyceride measurements did not add to the information gained from simple cholesterol determinations — and most of those exceptions were in women.