THE CONVERSATION: What is lipoprotein(a) cholesterol, or Lp(a)? And can you lower yours?

Most people know about “good” and “bad” cholesterol. But few realise there is another type called lipoprotein(a). It can raise the risk of heart attacks and strokes, even in people who do everything right.

This lesser-known cholesterol particle, often written as Lp(a), is gaining increasing attention from researchers and drug companies.

Lp(a) isn’t included in routine cholesterol tests and there’s currently little we can do about it. That may now be changing.

Lipoprotein(a) is a cholesterol that carries lipoprotein – particles made of fats and proteins – in your blood. It’s structurally similar to LDL (low-density lipoprotein, or “bad” cholesterol), but with an additional protein attached called apolipoprotein(a).

This extra protein component seems to make Lp(a) more likely to contribute to the build-up of fatty deposits in arteries. It may also promote blood clotting. Together, these processes increase the likelihood of cardiovascular disease (heart disease and stroke).

Large-scale studies and international guidelines now recognise Lp(a) as a risk factor for heart disease and stroke.

Unlike most other cholesterol measures, Lp(a) is largely determined by genetics. Around 70-90% of variation in Lp(a) levels is inherited. This is driven mainly by differences in the LPA gene, which controls the structure of apolipoprotein(a).

Because of this strong genetic control, Lp(a) levels are usually set early in life and remain relatively stable over time, with little influence from diet, exercise or body weight.

There are some smaller influences. Levels can vary by sex, ethnicity and hormonal changes, and may be slightly affected by factors such as menopause or kidney disease.

A growing body of research shows higher Lp(a) levels are associated with an increased risk of heart attacks, strokes and aortic valve disease. Importantly, the relationship appears continuous. In long-term studies, cardiovascular risk rises step by step as Lp(a) levels increase.

Lp(a) also adds to overall risk. For example, someone with high LDL cholesterol and high Lp(a) is likely to be at higher risk than someone with elevated LDL cholesterol alone.

For people with higher Lp(a) levels, cardiovascular risk rises mainly when inflammation is elevated. This helps explain why some people develop cardiovascular disease despite otherwise favourable risk profiles.

Lifestyle changes that improve heart health, such as eating well, being physically active and not smoking, remain essential. But they have minimal effect on Lp(a) itself.

Most commonly used cholesterol-lowering medications, in