Lipid profile or lipid panel, is a panel of blood tests that serves as an initial broad
medical screening tool for abnormalities in lipids, such as cholesterol and triglycerides.
The results of this test can identify certain genetic diseases and can determine approximate
risks for cardiovascular disease, certain forms of pancreatitis, and other diseases.
Lipid panels are commonly ordered as part of a physical exam, along with other panels
such as the complete blood count and basic metabolic panel.
Components The lipid profile typically includes:
Low-density lipoprotein High-density lipoprotein
Triglycerides Total cholesterol
Using these values, a laboratory may also calculate:
Very low-density lipoprotein Cholesterol:HDL ratio
Procedure and Indication Current recommendations for cholesterol testing
come from the Adult Treatment Panel III guidelines, and are based on many large clinical studies,
such as the Framingham Heart Study. For healthy adults with no cardiovascular
risk factors, the ATP III guidelines recommend screening once every five years. A lipid profile
may also be ordered at regular intervals to evaluate the success of lipid-lowering drugs
such as statins. In the pediatric and adolescent population,
lipid testing is not routinely performed. However, the American Academy of Pediatrics
and NHLBI now recommend that children aged 9–11 be screened once for severe cholesterol
abnormalities. This screening can be valuable to detect genetic diseases such as familial
hypercholesterolemia that can be lethal if not treated early.
Traditionally, most laboratories have required patients to fast for 9–12 hours before screening.
However, recent studies have questioned the utility of fasting before lipid panels, and
some diagnostic labs now routinely accept non-fasting samples.
VLDL may be calculated using the Friedewald's equation:
VLDL = Triglycerides/5 VLDL = Total cholesterol –
Implications
This test is used to identify hyperlipidemia, many forms of which are recognized risk factors
for cardiovascular disease and rarely pancreatitis. A total cholesterol reading can be used to
assess an individual's risk for heart disease, however, it should not be relied upon as the
only indicator. The individual components that make up total cholesterol reading—LDL,
HDL, and—are also important in measuring risk.
For instance, someone's total cholesterol may be high, but this may be due to very high
HDL cholesterol levels,—which can actually help prevent heart disease. So, while a high
total cholesterol level may help give an indication that there is a problem with cholesterol levels,
the components that make up total cholesterol should also be measured.
References ^ National Cholesterol Education Program Expert
Panel On Detection, E.. "Third Report of the National Cholesterol Education Program Expert
Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults final
report". Circulation 106: 3143–3421. PMID 12485966. ^ "Pediatric Cardiovascular Risk Reduction
Guidelines - NHLBI, NIH". ^ Sidhu, D.; Naugler, C.. "Fasting Time and
Lipid Levels in a Community-Based PopulationA Cross-sectional StudyFasting
Time and Lipid Levels". Archives of Internal Medicine 172: 1–4. doi:10.1001/archinternmed.2012.3708.
PMID 23147400. ^ Friedewald WT, Levy RI, Fredrickson DS.
Estimation of the concentration of low-density lipoprotein cholesterol in plasma, without
use of the preparative ultracentrifuge. Clin Chem. 1972;18:499-502..
External links Lipid Profile: At a glance at Labtestsonline.org
Total Cholesterol - What Are Total Cholesterol Levels? at About.com
Friedewald’s equation for calculating VLDL and LDL at Cardiophile.org