Lipoprotein(a), is usually written as Lp(a) and pronounced “L-P little a”. It is an important inherited risk factor for cardiovascular disease. It is worth knowing about because it can increase your risk of a heart attack or stroke even if your ordinary cholesterol levels are normal.
The good news is that measuring it can help you and your doctor make better decisions about heart disease prevention.
So, what exactly is Lp(a)?
Lp(a) is a cholesterol-carrying particle similar to Low density lipoprotein (LDL) or “bad cholesterol”, with an additional protein called apolipoprotein(a).
High levels can contribute to:
Coronary artery disease — plaque build-up in the arteries supplying the heart.
Heart attack and stroke.
Aortic valve stenosis — narrowing of the heart's aortic valve or main valve.
It is an independent cardiovascular risk factor, meaning having high Lp(a) is a risk for heart disease regardless of other risk factors such as smoking, diet, exercise and body habitus.
Would someone like me have high Lp(a)?
The most important thing to understand is that Lp(a) is largely determined by your genes.
Levels are inherited from your parents.
Diet, exercise and weight loss have very little effect on the level itself.
Levels are generally relatively stable throughout adult life.
Approximately one in five people worldwide has a level considered elevated.
Interestingly, it is possible for Lp(a) to increase around perimenopause.
This means that someone can eat very well, exercise regularly, have a healthy weight and have excellent LDL or “bad” cholesterol, and still have high Lp(a). Annoyingly, Lp(a) is not a reflection of how fit or well or how good someone’s lifestyle is.
What is actually considered a high level to have?
< 75 nmol/L is generally desirable.
75 – 124 nmol/L is considered intermediate risk
>125 nmol/L is considered high risk and
>250 nmol/L is considered extremely high risks
These levels need to be interpreted in the context of the patient meaning that whilst the level of Lp(a) is important, it is also influenced by a persons other cardiovascular risk factors such as their diet, LDL cholesterol levels, family history of heart disease, whether they smoke, their exercise levels etc.
So, who should have their Lp(a) level tested?
Australian Douglas Hanly Moir Laboratories recommends testing for the following patients:
Those with a parent or sibling who had a heart attack or stroke at a relatively young age.
Those with a family history of very high cholesterol or familial hypercholesterolaemia.
Those with known cardiovascular disease or unexpectedly high cardiovascular risk despite apparently normal cholesterol. E.g. high coronary artery calcium score or rapidly progressive cardiovascular disease despite good control of LDL cholesterol ith appropriate treatment.
Those who have had cardiovascular events at a young age (< 60 years in women, < 55 years in men), especially if they were not smokers.
Those with a family history of elevated Lp(a).
Those with high-risk considerations such as diabetes, kidney disease of familial hypercholesterolemia.
Lp(a) levels do not need to be checked at multiple times in a person’s life, usually just once to see if they are elevated. It is not recommended that all Australians are tested. It is an out-of-pocket cost ~ $40 -75 and fasting is not required.
My Lp(a) is high! What now?
1. Reduce your overall cardiovascular risk
- Lower LDL/bad cholesterol: sometimes your doctor might recommend a medication to help you do this such as a statin, or ezetimibe. There is also a new injectable medication in Australia, which is a PCSK9 inhibitor. You need to meet certain criteria to quality for treatment with this medication. It has been found to reduce LDL cholesterol substantially and have a moderate effect on lowering Lp(a).
- Maintain a healthy blood pressure around 120 – 130 / 80 – 90. Lower if you are a diabetic
- Maintain tight control of sugar levels if you are a diabetic.
- Seek help to quit smoking if you smoke
- Look at ways to increase your exercise and fitness levels
- Keep your weight in the healthy weight range
- Increase the fibre in your diet
- Increase the “good” fat in your diet through increasing the intake of fatty fish such as salmon and tuna, olive oil and avocado.
2. Encourage family members to have their Lp(a) levels tested to assess their risk.
3. There is also a lot of research into further medications for LDL and Lp(a) currently being undertaken, so this is a space to keep watching.
Take Home Messages in Heart Disease Prevention and Lp(a)
It is reasonable to discuss with your GP whether it would be appropriate for you to have your Lp(a) level measured.
Lp(a) needs to be interpreted alongside your LDL cholesterol level, blood pressure, smoking status, diabetes status and family history.
If Lp(a) is high, discuss whether more intensive LDL lowering is warranted rather than focusing on trying to change the Lp(a) number itself.
If Lp(a) is high, it is reasonable to advise your first degree family members.