Blood draw
Apolipoprotein A2 (ApoA2)
ApoA2; component of the HDL profile.
€ 35,00
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Heart and vessels · Blood
Apolipoprotein A2
The second protein of HDL cholesterol; its significance for the risk of cardiovascular disease is unclear.
At a glance
- Measured in blood
- In 1 test panel
- No special preparation
Explanation
Apolipoprotein A2: what is measured?
Cholesterol and other fats travel through the blood in small spheres called lipoproteins. The proteins on these spheres are called apolipoproteins. HDL, the particle that brings cholesterol from the blood vessel wall back to the liver, mainly carries apolipoprotein A1 and, in addition, apolipoprotein A2. Apolipoprotein A2 is therefore the second most important protein of HDL. Exactly what role it plays in removing cholesterol and in inflammation is not yet well known.
What can it detect?
- An indication of the amount and composition of HDL particles
- Rarely: a rare inherited disorder of HDL metabolism
Result
What does the result mean?
Apolipoprotein A2 too high
A high value usually goes together with a high HDL cholesterol. Alcohol use and some medicines, such as estrogens and anti-epileptic drugs, can also raise the value. Whether a high value is favorable or unfavorable for the risk of cardiovascular disease is not clear; studies contradict each other. A high value causes no symptoms.
Apolipoprotein A2 too low
A low value usually goes together with a low HDL cholesterol, as with smoking, overweight, little exercise, diabetes or a high triglyceride level. Rarely, a very low value fits an inherited disorder of HDL metabolism. A low value causes no symptoms itself; what counts for the risk of cardiovascular disease is mainly LDL or non-HDL cholesterol and the other risk factors.
After an abnormal result
An abnormal value on its own usually does not lead to follow-up. The GP looks at the full cholesterol test and the other risk factors and, with an increased risk, follows the Dutch GP guideline (NHG) on cardiovascular risk management. With a very low HDL cholesterol without explanation, referral to an internist (specialist in internal medicine) may follow.
Reliability
How reliable is the test?
What an abnormal apolipoprotein A2 means for the risk of cardiovascular disease has been little studied, and the findings are contradictory. There are no agreed cut-off values. According to the Dutch Society for Clinical Chemistry (NVKC), even apolipoproteins A1 and B add something to HDL and LDL cholesterol at most in complex cases; even less is known about A2. For the risk estimate according to the Dutch GP guideline (NHG) on cardiovascular risk management, age, blood pressure, smoking and non-HDL cholesterol say much more.
What can affect the result?
- Alcohol, estrogens (including the contraceptive pill) and some anti-epileptic drugs raise the value.
- The value largely follows HDL cholesterol and adds little information to it.
- Measurement methods and reference values differ per laboratory and are not well standardized.
Who it is for
Who is the test useful for?
Useful for
The result says little in people without symptoms, and in estimating the risk of cardiovascular disease it also adds little to standard cholesterol testing. It can be meaningful when a rare inherited disorder of HDL metabolism is suspected, for example with a very low HDL cholesterol in the family.
How common is it?
There are no Dutch figures on how often an abnormal apolipoprotein A2 occurs, because the test has no agreed cut-off values. Cardiovascular disease itself is common in the Netherlands and is one of the main causes of death.
NVKC, allesovertesten.nl; no Dutch registration figure available
Drawbacks and risks
- An abnormal value without a fixed meaning can cause unnecessary worry or lead to unnecessary follow-up testing.
Get tested
Apolipoprotein A2: test panels
Apolipoprotein A2 is part of these test panels. You order online and have your blood drawn at a collection point or collect the sample at home.
Evidence
Sources
This explanation is based on Dutch guidelines and independent information. It is general information, not a diagnosis. Discuss an abnormal result with your GP.
More about risks and resultsMore explanations
Other tests: Heart and vessels
- Apo B/A1 ratio
- Apolipoprotein A1
- Apolipoprotein B
- Cholesterol, total
- Cholesterol/HDL ratio
- DHA
- EPA
- HDL cholesterol
- HDL-LDL risk index
- Homocysteine
- LDL cholesterol
- Lipoprotein(a)