A lipid panel generally includes total cholesterol, HDL-cholesterol (HDL-C), LDL-C, and triglycerides. Rather than measuring each particle specifically, we measure the 'cargo' of each class of particle. That is, we don't routinely measure the number of LDL particles, for example, instead we isolate the LDL particles (using specific detergents) and measure the total cholesterol of those particles. This is often abbreviates as LDL-C (LDL-cholesterol).
Likewise, HDL-C is measurement of the cholesterol in the lipoprotein HDL.
Cardiovascular disease (CVD) is associated with elevations in LDL-C; increased LDL-C in individuals puts them at risk for CVD. The opposite is true for HDL-C. One of the functions of this lipoprotein is to remove excess cholesterol, transporting it to the liver for reprocessing or excretion. To prevent cardiac disease, HDL-C levels should remain high, within a healthy reference range (see below for healthy ranges). If HDL is below this recommended range, steps are taken to try and raise the HDL-C concentration. LDL-C should be low, and there are multiple, effective drugs that can be used to lower LDL-C in patients.
The recommended ranges for lipids below have been in use since 2001. These were originally recommendations from the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP-III). In 2013 the American College of Cardiology and the American Heart Association revised the treatment guidelines slightly, with regard to the goals for lipid-lowering treatment (see table).
| NCEP ATP III vs ACC/AHA |
| NCEP ATP III | ACC/AHA - ATP IV |
| Risk categories | 3 main risk categories: - CHD/CHD risk equivalent (DM, Clinical CHD, symptomatic CAD, PAD)
- 2+ risk factors & 10-yr risk ≤ 20%
- 0-1 risk factors & 10-yr risk <10%
| 4 statin benefit groups: - Clinical ASCVD
- Primary LDL-C elevations ≥190 mg/dL
- DM without clinical ASCVD
- No DM/CVD with 10-yr ASCVD ≥7.5%
|
| Rx targets | LDL-C primary target - <100 mg/dL
- <130 mg/dL (<100 ml/dL if risk 10-20%)
- <160 mg/dL
(in the order of categories mentioned above) | Intensity of statin therapy - High intensity statin therapy (LDL-C reduction ≥50%) recommended for most patients in 4 statin benefit groups
|
| Rx recommendations | Statin (or bile acid sequestrants or nicotinic acid) to achieve LDL-C goal | Maximally tolerated statin first-line to reduce risk of ASCVD events |
These new goals for therapy, which are based on a patient's risk factors, are sometimes termed ATP-IV. Most laboratories still use the ATP-III numbers as 'reference ranges' for lipids. But unlike other analytes, lipid and cholesterol ranges are not based on a 'normal' population reference range. Rather, they are based on what patients should have, not what is normal. These are healthy targets rather than the mean ranges in a US population.
- Cholesterol <200 mg/dL
- Triglyceride <150 mg/dL
- LDL-C <100 mg/dL
- HDL-C >59 mg/dL
