Lipoprotein (a), or Lp(a), is a little-known genetic cholesterol that raises heart attack risk and isn’t routinely tested for. Photo / 123RF
There is a kind of cholesterol doctors know little about and which isn’t routinely tested for but can have severe impacts on health.
In 2012 Emma Print, then 33, got the phone call that changed the course of her life. Her slim, healthy mother had died after aheart attack, at the age of just 66.
Print had been on a sabbatical in the United States and Canada with her now-husband, a career break after years spent working on yachts together across the world. Receiving the news was “traumatic,” she says. “It was a sudden heart attack, with limited warning. I was utterly devastated and shocked to my core.”
Along with her grief, she also felt fear. “My mum’s sudden death really scared me,” she says. “I’ve been a gymnast since I was 2 and a half years old, and I used to run marathons. It took me eight months to go running again because I was so afraid of what might happen. The first few times I did go out, I insisted that my husband or friends come with me.”
Her father had been diagnosed with high cholesterol when she was 11, and the whole family had since eaten a low-fat diet with little red meat. Her mother had normal cholesterol levels, and none of her relatives had heart disease. So how could she have died in this way?
After flying home to take care of her father, Print visited the family doctor for a check-up and was immediately prescribed statins. Her overall cholesterol levels were measured as being at 8.4mmol/L, considered to be extremely high for anyone but especially for a woman of her age, weight and health – Print was a slim seven and a half stone, at 5′6″ tall.
“I was offered genetic testing to see whether I had a hereditary condition, but at the time I didn’t want to know,” she recalls. Then three years later, in 2016, “I lost my dad to a suspected heart attack, which was crushing.”
As Print prepared to return to her job sailing around the world, “another doctor told me that it would be great if I could travel the world without having to dock every three months to pick up statins,” she says. “The only way I could do that was if I knew my high cholesterol could be modified through my diet and lifestyle after all, and wasn’t caused by a genetic problem.”
A doctor at Royal United Hospitals in Bath tested her for familial hypercholesterolemia (FH), a genetic condition that causes high levels of “bad” LDL cholesterol. She was also tested for abnormally high levels of lipoprotein Lp(a), another kind of fatty protein that carries cholesterol through your bloodstream. High levels of Lp(a) raise the risk that someone might suffer a heart attack.
Print was diagnosed with FH, explaining her high cholesterol despite her super-fit lifestyle. She was also found to have “really really high” levels of Lp(a), independently of her FH diagnosis. While she had been told what FH was before, “I had never heard of Lp(a) in my life,” she says. As doctors don’t routinely test for it, Print and her family will never know whether her mother may also have had high levels of Lp(a).
Most of the British public have never heard of lipoprotein A, or Lp(a), yet one in five of us is deemed to have dangerously high levels of it in our systems. “While cardiologists are becoming more and more aware of Lp(a), most general practice doctors have never heard of it,” says Dr Jaimini Cegla, a consultant in metabolic medicine at Imperial College hospitals.
Print has to explain the issue to most GPs that she sees even though, as she says, “it’s incredibly common” to have dangerously high levels of Lp(a). With at-home gene tests now on the market, and more people opting to pay for private healthcare, many are discovering their own Lp(a) levels and finding information hard to come by.
“I get emails from people who’ve done an Lp(a) test and presented it to their GP, who has had no idea what to do with the result,” Dr Cegla says. “They inevitably turn to Google, find people like me and say, please help.
Unlike other kinds of lipoproteins that carry cholesterol around your bloodstream, like “good” HDL cholesterol and “bad” LDL cholesterol, Lp(a) isn’t routinely measured, even though “it can be an important risk factor in why some people might develop heart disease or have a heart attack despite having lived a healthy life,” Dr Cegla says.
The amount of Lp(a) you have in your body is determined by your genetics and “will pretty much stay the same throughout your life,” Dr Cegla explains. For this reason “a lot of international guidelines say that Lp(a) should be measured just once in a lifetime”.
While no country in the world yet mandates it, testing is on the rise in some European countries. In Poland, some people at high risk from cardiovascular disease have been offered tests since 2021, when a number of scientific bodies began to urge that more people should know their own Lp(a) status.
While 20% of people are believed to have Lp(a) levels that heighten their heart attack risk, those with the most extreme levels, about 5% of the population, “could have as much as a two to three times greater risk of a heart attack or stroke,” Dr Cegla says.
As Print learnt, there is nothing that you can do to lower the amount of Lp(a) you have. “Being diagnosed definitely had an impact on how I felt about the future,” she says – especially as women sometimes see a bump in Lp(a) levels during menopause, the only circumstance in which they can increase throughout a person’s lifetime.
“It can take some time to sink in that you have this condition for life, and that you’ll always have to think about it. I worry for family members, too. Some of them have chosen not to have a genetic test as they’d rather not know their level of risk.
“Others did go for cholesterol tests with their GP and were told that they had nothing to worry about. But GPs know very little about Lp(a) and generally assume that if your LDL cholesterol is fine, then there is no issue. We have to self-advocate and push for tests, which isn’t easy.”
For Print, it has been an extra reminder to exercise and eat well. Today she is a personal trainer and still competes in adult gymnastics competitions. “Strictly speaking there’s nothing you can do to lower your risk from a heart attack if you have high Lp(a) levels, but it’s wise to keep your LDL cholesterol as low as possible because you can have high Lp(a) and low LDL,” she says.
“Currently there aren’t any commercial therapies specifically targeting high Lp(a), but a healthy, low-fat diet, exercising regularly, not smoking, and drinking minimal alcohol is the best option to keep your LDL cholesterol as low as possible, along with taking LDL medicines like statins or ezetimibe,” says Print.
“I follow a low-fat diet, and I opt for low-sugar options elsewhere. I buy whole foods and read the back of packets before I eat things. But I am human, and at the end of the day it can be difficult to manage this sort of risk through diet and lifestyle alone.”
Fortunately, the fact that Lp(a) levels can’t be modulated may soon change. “There are some potentially, quite exciting clinical trials around the corner, with some new medicines potentially able to lower a person’s Lp(a) levels by as much as 90%,” Dr Cegla says.
The impact on patients could be huge. “One woman that I work with, who had a heart attack at 40 and her only risk factor was high Lp(a), is very concerned for her children that they could suffer the same when they grow up. Having a treatment to give to her and her children would be amazing.”
For now, both Print and Dr Cegla would be keen to see tests given to patients on the NHS [UK’s National Health Service] automatically, at least once in their lives.
“If everyone was offered tests we would be able to stratify the population by risk more effectively,” Dr Cegla says. “If you knew at 18 that you had this risk, then you’d almost certainly never smoke, you’d have a healthy diet, and you would avoid drinking to excess – you’d monitor and control your blood pressure and LDL much more tightly. That’s a change that would save a lot of lives.”