As you get into a certain age range, it is quite common for your general practitioner to request routine blood tests measuring your lipids.
Depending on your levels, they may give you a pat on your back, lifestyle advice regarding exercise and diet, or start you on a cholesterol medication.
But what are lipid profiles and how do you interpret them?
Lipid Profiles
New Zealand lipid profiles contain 4 measurements: triglycerides, LDL, HDL and LDL:HDL ratio.
Triglycerides
Triglycerides are a type of fat (lipid) found in your blood. When you eat, your body converts any calories it doesn’t need to use right away into triglycerides, which are stored in fat cells. Later, hormones release triglycerides for energy between meals. High levels of triglycerides can increase the risk of coronary artery disease, especially in women.
VLDL (Very-Low-Density Lipoprotein)
VLDL, although not routinely measured, is one of the three main types of lipoproteins. VLDL carries triglycerides from the liver to tissues in the body. It is considered a type of “bad” cholesterol because it helps cholesterol build up on the walls of arteries, leading to increased risk of heart disease.
LDL (Low-Density Lipoprotein)
Often referred to as “bad” cholesterol, LDL transports cholesterol particles throughout your body. LDL cholesterol builds up in the walls of your arteries, making them hard and narrow, which can lead to atherosclerosis, a form of heart disease.
HDL (High-Density Lipoprotein)
HDL is a type of cholesterol often referred to as “good” cholesterol. It is considered beneficial because it helps transport cholesterol from other parts of the body back to the liver, where it can be broken down and removed from the body. This process is vital as it helps reduce the likelihood of cholesterol building up in the arteries, which can lead to blockages and increase the risk of heart diseases like heart attacks and strokes. HDL is measured as part of a lipid profile, and higher levels of HDL are generally associated with a lower risk of cardiovascular disease. Therefore, maintaining healthy HDL levels is an important aspect of cardiovascular health.
LDL:HDL Ratio
The LDL:HDL ratio is a comparison of the amounts of LDL (bad) cholesterol to HDL (good) cholesterol in your blood. It is used to assess the risk of heart disease. A higher ratio indicates a higher risk of heart disease, as it suggests there is more LDL cholesterol relative to HDL cholesterol. HDL cholesterol is beneficial because it carries cholesterol away from the arteries and back to the liver, where it’s processed and removed from the body.
Interpretation and Management
The recent cardiology guidelines primarily focus on LDL (low-density lipoprotein) cholesterol levels rather than the cholesterol ratio (LDL:HDL).
There’s a strong emphasis on achieving specific LDL targets, particularly in patients at high risk of cardiovascular disease. The guidelines recommend lower LDL levels for both primary and secondary prevention, indicating that lower LDL levels are associated with a reduced risk of cardiovascular events.
For the LDL targets in the new guidelines:
- High-risk secondary prevention: <1.29 mmol/L
- Primary prevention: <1.81 mmol/L
- High polygenic risk score (for statin therapy consideration): >4.14 mmol/L
There’s growing evidence that lower LDL levels are better.
As for the cholesterol ratio (LDL:HDL), the recent guidelines do not appear to provide specific updates or recommendations. However, it’s worth noting that many doctors now consider determining non-HDL cholesterol levels to be more useful than calculating the cholesterol ratio for predicting heart disease risk. Non-HDL cholesterol includes all the “bad” cholesterol components (LDL, IDL, VLDL, and lipoprotein(a)) and is considered a better predictor of heart disease risk than the total cholesterol level or even the LDL cholesterol level alone.
It’s important to note that these guidelines are subject to change as new evidence and research become available.
Bibliography
- American College of Cardiology. (2023). There Is an Urgent Need to Re-Establish LDL-C Measurement and Control as Quality Metrics in the US Health Care System. [Online] Available at: https://www.acc.org [Accessed 29 Nov. 2023].
- Early Career Voice. (2023). The 2023 Cholesterol Guidelines. [Online] Available at: https://earlycareervoice.professional.heart.org [Accessed 29 Nov. 2023].
- Mayo Clinic. (2023). Cholesterol ratio or non-HDL cholesterol: Which is most important? [Online] Available at: https://www.mayoclinic.org [Accessed 29 Nov. 2023].
- British Heart Foundation. (2023). Understanding the new cholesterol guidelines. [Online] Available at: https://www.bhf.org.uk [Accessed 29 Nov. 2023].
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