Apolipoprotein A1
What this test measures
Apolipoprotein A1 is the main protein on the surface of HDL, the 'good' cholesterol particle. Measuring it gives a count of the protective particles themselves rather than the cholesterol they happen to be carrying. It is usually reported alongside apolipoprotein B.
Why doctors request it
Doctors and private lipid clinics request it, often with apolipoprotein B, for a more detailed look at lipid particles than the standard profile gives, particularly where there is a family pattern of heart disease.
What commonly pushes it up
- Regular exercise
- Moderate alcohol intake
- Oestrogen, including some hormone treatments
- Being female, in the general population
What commonly pushes it down
- Smoking
- Being overweight and type 2 diabetes
- High triglycerides
- Some medicines, including anabolic steroids and some beta blockers
- Rare inherited conditions of HDL
Everyday reasons for a value outside the range
- A recent illness lowers it for a few weeks
- Methods differ between laboratories, so figures from two labs are not directly comparable
About the sample
No fasting needed. Read alongside apolipoprotein B and the standard lipid profile; the trend matters more than a single value.
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Read my report freeThis is an educational summary of results you uploaded. It is not medical advice, a diagnosis or a treatment plan, and it does not replace the doctor who requested the test. If you are worried, or a result is marked outside range, discuss it with your doctor. Written and reviewed by a UK consultant physician. Reference ranges vary between laboratories.