Apolipoprotein A1: what it is, what it tells you and when it’s tested

Apolipoprotein A1, or ApoA1, is the main protein in HDL, the cholesterol called good. Every HDL particle carries it. It helps collect extra cholesterol from your arteries and take it back to the liver.

When it’s tested

Doctors mostly order it to look into a very low HDL, or to work out the ratio between ApoB and ApoA1 when they assess heart risk. Sometimes a lipid specialist orders it when an inherited form is suspected.

It is not a routine test for people who feel well. It says roughly the same as HDL, which every cholesterol test measures. And raising it has not been shown to protect the heart.

That is why Rosa does not test it. Instead it measures HDL and ApoB, the protein on the particles that do the damage, which says more about risk.

What it tells you, and what it does not

If it is low, HDL is usually low too. People with low ApoA1 have more heart attacks on average, especially when ApoB is high.

The ratio between ApoB and ApoA1 puts the two together: the particles that carry cholesterol into your arteries and the ones that take it away. The lower it is, the better.

If it is high, that is usually a good sign, but on its own it does not protect your heart. How many ApoB particles you have matters more.

That is why it is read together with other tests:

Normal apolipoprotein A1 levels

The lab decides what is normal. A typical report gives 105 to 175 mg/dL for men and 105 to 205 mg/dL for women. Other labs use different limits, or only print a desirable value above a certain level.

It is usually higher in women than in men.

You usually do not need to fast, because a meal changes it very little. Follow your lab’s instructions all the same.

What your result means

Find the row for your result, in mg/dL. Which values need a doctor? Below the limit on your report, especially with a low HDL or a high ApoB.

If your apolipoprotein A1 is low or high

What lowers apolipoprotein A1

The causes are almost the same as for a low HDL. There is often more than one.

What can change the result

A few things raise or lower it without saying much about your heart.

When to worry

Talk to your doctor if:

Frequently asked questions

What are normal apolipoprotein A1 levels? It depends on the lab. A typical report gives 105 to 175 mg/dL for men and 105 to 205 mg/dL for women. The range on your own report is what counts.

What does low apolipoprotein A1 mean? Usually that your HDL is low too. Smoking, extra weight, little exercise or high triglycerides are often behind it. Your doctor looks at your heart risk as a whole.

What is the ApoB/ApoA1 ratio? It compares the particles that carry cholesterol into your arteries, with ApoB, and the ones that take it away, with ApoA1. The lower it is, the lower the risk of a heart attack. The limits depend on the lab.

How do you raise apolipoprotein A1? The same things that raise HDL: stopping smoking, regular exercise and losing extra weight. But raising it with medicines or infusions did not reduce heart attacks: lowering ApoB matters more.

Does Rosa test apolipoprotein A1? No. Rosa measures HDL, ApoB, triglycerides and lipoprotein(a), which say more about your heart risk. If your doctor wants ApoA1, they order it separately.

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