From the Guidelines
Total cholesterol can be elevated if High-Density Lipoprotein (HDL) is high, but this does not necessarily indicate increased cardiovascular risk. The most recent and highest quality study 1 suggests that total cholesterol is a measure that includes LDL cholesterol and HDL cholesterol, but it can be a misleading metric due to the different effects of LDL cholesterol and HDL cholesterol on health.
Components of Total Cholesterol
The components of total cholesterol include:
- High-density lipoprotein (HDL)
- Low-density lipoprotein (LDL)
- Very low-density lipoprotein (VLDL, which is estimated by measuring triglycerides) As stated in the study 1, HDL cholesterol transports lipids back to the liver for recycling and disposal, and high levels of HDL cholesterol are an indicator of a healthy cardiovascular system.
Evaluating Cholesterol Levels
When evaluating cholesterol levels, doctors look at the complete lipid profile rather than just total cholesterol. A high total cholesterol reading with elevated HDL (above 60 mg/dL) may actually be protective against heart disease, while the same total cholesterol with high LDL (above 100 mg/dL) would be concerning. This is why the ratio of total cholesterol to HDL or the specific values of LDL and HDL are more informative than total cholesterol alone, as reported in the study 1.
Optimal Cholesterol Levels
For optimal cardiovascular health, aim for:
- HDL levels above 40 mg/dL for men and above 50 mg/dL for women
- LDL below 100 mg/dL
- Triglycerides below 150 mg/dL As noted in the study 1, reductions in LDL cholesterol can decrease the incidence of heart attacks and ischaemic strokes, and individuals with elevated total cholesterol levels have approximately twice the coronary heart disease (CHD) risk of those with optimal levels.
Importance of HDL
HDL is often called "good cholesterol" because it helps remove other forms of cholesterol from your bloodstream and carries them back to the liver for processing and elimination. The study 1 highlights the importance of interventions aimed at reducing serum cholesterol levels, and notes that a reduction in total cholesterol is still considered the gold standard in preventative cardiovascular medicine.
From the Research
Total Cholesterol Composition
- Total cholesterol is composed of several lipid components, including high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, and triglycerides (TGs) 2, 3
- The lipid profile, which includes total cholesterol, HDL-cholesterol, TGs, and LDL-cholesterol, is important in the risk assessment for cardiovascular disease 2
Relationship Between HDL and Total Cholesterol
- High levels of HDL-cholesterol are considered "good" cholesterol, while high levels of LDL-cholesterol are considered "bad" cholesterol 4
- Total cholesterol can be elevated even if HDL is high, as it is a composite measure that includes both HDL and LDL cholesterol, as well as triglycerides 3, 5
- Elevated total cholesterol, LDL-cholesterol, and non-HDL-cholesterol concentrations are associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD) and mortality 5
Factors Affecting Total Cholesterol
- Male sex, greater body mass index, and smoking are correlated with higher total cholesterol, LDL-cholesterol, and triglyceride concentrations, and lower HDL-cholesterol concentrations 5
- Certain therapeutic targets, such as endothelial lipase and lecithin cholesterol acyl transferase, can help raise HDL-cholesterol levels, while others, such as proprotein convertase subtilisin-like kexin type 9 (PCSK9), can help lower LDL-cholesterol levels 4