How Well Do Patients—and Clinicians—Know Their Lipids?
The prevention of symptomatic coronary heart disease and other vascular disorders represents a significant health care priority, especially in a population that is growing older and more obese. However, a recent survey has shown that many laypersons—and even some physicians—do not know all the target lipid levels that are associated with optimal reduction of cardiovascular risk.
An Internet survey by the National Lipid Association (NLA) examined the knowledge and attitudes of more than 500 physicians and 2000 laypersons regarding lipids—and in particular, triglycerides.1 The results were both surprising and informative.
LIMITS OF PATIENTS' KNOWLEDGE
Fewer than 40% of the laypersons surveyed knew that a lipid profile included a measurement of triglyceride levels. Although 46% believed they knew what normal lipid levels were, only 3% could actually identify the correct levels. A modest 37% of those surveyed were aware that diabetes is associated with elevated lipid levels.
Not surprisingly, those who were at increased risk for future cardiac events (such as those with diabetes) demonstrated greater knowledge than other laypersons. Nonetheless, the majority of survey participants who were at increased risk for cardiovascular disease were unaware of normal triglyceride levels. Among those with diabetes, only 15% knew that normal triglyceride levels were less than 150 mg/dL; only 3% knew the normal levels for total cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides. Although elevated triglyceride levels pose a greater cardiovascular risk for women than they do for men, a mere 13% of women could identify the normal triglyceride level. While a triglyceride level of 150 mg/dL is considered normal, when the level exceeds 200 mg/dL—and is accompanied by an HDL cholesterol level of less than 40 mg/dL—the risk of coronary artery disease is increased 4-fold.2
EXTENT OF PHYSICIANS' KNOWLEDGE
Most of the physicians surveyed (89%) knew that elevated triglyceride levels are an independent cardiovascular risk factor. Sixty-seven percent of those surveyed had discussed optimal triglyceride levels with their patients. Still, fewer than half of the patients surveyed recalled such discussions; these exchanges typically lasted less than 5 minutes.
Although the physicians reported familiarity with all National Cholesterol Education Program (NCEP ATP III) guidelines, only 50% could identify each of the guidelines correctly.
The physicians surveyed included 205 general practitioners, 155 cardiologists, and 150 endocrinologists. The endocrinologists were most likely to know the normal triglyceride levels and were most likely to discuss triglycerides with their patients.
NEED FOR MORE INTENSIVE EDUCATION
The evidence of nonadherence and poor control of lipid levels is well documented. Of the 35% of adults in the United States with dyslipidemia (total cholesterol level greater than 200 mg/dL), only 5% have achieved good control (ie, lowered their total cholesterol level to under 200 mg/dL).3 This suboptimal control of lipid levels has 2 aspects:
- Physician nonadherence to published therapeutic goals.
- Patient nonadherence to prescribed regimens.4
For example, in one study of 130,000 patients with coronary heart disease and dyslipidemia, only slightly more than 30% of participants were receiving lipid-modifying therapy5—even though such therapy has been shown to reduce cardiovascular morbidity and mortality.6 In another study, fewer than 50% of patients for whom a lipid-lowering drug had been prescribed were still taking it 12 months later.7
The results of the NLA survey underscore the need for more intensive efforts to educate both patients and physicians about the role of lipid levels— and in particular, levels of triglycerides—in the prevention of coronary heart disease.
1. National Lipid Association. Moving beyond cholesterol to total lipid control: survey at a glance. Availableat: lipid.org/press/survey_glance.pdf. Accessed February 23, 2007.
2. Krone W, Gouni-Berthole I. Hypertriglyceridemia—why, when and how should it be treated? Zeitschriftfür Kardiologie. 2005;94:11.
3. Ford ES, Mokdad AH, Giles WH, Mensah GA. Serum total cholesterol concentrations and awareness,treatment, and control of hypercholesterolemia among US adults: findings from the National Health andNutrition Examination Survey, 1999-2000. Circulation. 2003;107:2185-2189.
4. National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatmentof High Blood Cholesterol in Adults (Adult Treatment Panel III). Third report of the National CholesterolEducation Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterolin Adults (Adult Treatment Panel III) final report. Circulation. 2002;106:3143-3421.
5. Fonarow GC, French WJ, Parsons LS, et al. Use of lipid-lowering medications at discharge in patients withacute myocardial infarction: data from the National Registry of Myocardial Infarction 3. Circulation.2001;103:38-44.
6. Libby P. The forgotten majority: unfinished business in cardiovascular risk reduction. J Am Coll Cardiol.2005;46:1225-1228.
7. Huser MA, Evans TS, Berger V. Medication adherence trends with statins. Adv Ther. 2005;22:163-171.