Understanding Your Lipid Profile: Cholesterol Explained

A lipid profile is a blood test that measures different fats in your blood, including cholesterol and triglycerides. It shows how these fats circulate in your bloodstream [NLA, 2014].

What does each marker in a lipid profile measure?

Total cholesterol measures the overall amount of cholesterol in your blood [NLA, 2014]. Low-density lipoprotein, or LDL, carries cholesterol from your liver to your cells [AHA, 2018].

High-density lipoprotein, or HDL, absorbs cholesterol and brings it back to the liver [AHA, 2018]. Triglycerides are a type of fat that stores unused calories from the foods you eat [NLA, 2014].

Why are LDL and HDL called bad and good cholesterol?

LDL is called "bad" because excess amounts can build up inside artery walls [AHA, 2018]. Higher levels of circulating LDL are associated with plaque accumulation in blood vessels [ESC/EAS, 2019].

HDL is called "good" because it helps clear excess cholesterol from the circulation [AHA, 2018].

Why are South Asians screened at an earlier age?

South Asians tend to develop coronary heart disease at younger ages than other populations [RSSDI, 2022]. Clinical guidelines advise starting lipid checks earlier for individuals of South Asian origin [NICE, 2023].

This population often presents with lower HDL and higher triglyceride levels at lower body weights [RSSDI, 2022].

How should you read your numbers against the lab range?

Labs print a reference range next to your result to show expected healthy levels [CLSI, EP28-A3c]. Standard targets often list total cholesterol under 200 mg/dL and fasting triglycerides under 150 mg/dL [NLA, 2014].

An optimal LDL level is commonly listed below 100 mg/dL [NLA, 2014]. Different laboratories may use slightly different reference intervals based on their testing equipment [CLSI, EP28-A3c].

Do you need to fast before a lipid profile?

Some lipid tests require fasting for 9 to 12 hours, while others do not [EAS/EFLM, 2016]. Food intake primarily alters triglyceride levels rather than total cholesterol or HDL [EAS/EFLM, 2016].

Your ordering clinician or laboratory specifies whether fasting is necessary for your specific panel [EAS/EFLM, 2016].

Frequently asked questions

What is considered a normal total cholesterol level?

Most guidelines define a total cholesterol level under 200 mg/dL as desirable [NLA, 2014].

What is the optimal level for HDL cholesterol?

An HDL level of 40 mg/dL or higher for men and 50 mg/dL or higher for women is typical [NLA, 2014].

Can you check lipid levels without fasting?

Non-fasting lipid testing is acceptable for routine risk screening in many clinical guidelines [EAS/EFLM, 2016].

What causes triglyceride numbers to change rapidly?

Triglyceride concentrations rise significantly within a few hours following a meal [EAS/EFLM, 2016].

At what age should South Asian adults begin lipid screening?

Guidelines recommend that South Asian adults begin regular screening starting by age 25 to 30 [RSSDI, 2022].

Sources

• National Lipid Association (NLA). NLA Recommendations for Patient-Centered Management, 2014.
• American Heart Association (AHA). Guideline on the Management of Blood Cholesterol, 2018.
• Research Society for the Study of Diabetes in India (RSSDI). Clinical Practice Recommendations, 2022.
• European Atherosclerosis Society and European Federation of Clinical Chemistry and Laboratory Medicine (EAS/EFLM). Fasting is not routinely required for determination of a lipid profile, 2016.
• Clinical and Laboratory Standards Institute (CLSI). Defining, Establishing, and Verifying Reference Intervals in the Clinical Laboratory, Approved Guideline, EP28-A3c, 2010.