Happy cholesterol, lousy cholesterol, and something called Lp(a)

David BovaDavid Bova

Dr Keith Baranowski, CPS Research

While back home in the States a few years ago, I was talking to a couple about their health. Whenever you meet new people and they find out you are a doctor, if often follows that they will start to open up to you about their personal medical experiences and problems. As much as I might try to switch off on holiday, at the same time, there is always part of you that appreciates the relationship that you can develop with others on the basis of your profession and the little things you can learn through conversation.

We chatted about local Napa Valley wineries, their passion for food and cooking, and the results of recent blood tests that one of them had following a visit to the doctor. With an otherwise clean bill of health, it turned out that his ‘lousy’ cholesterol was too high, and this needed to be addressed. I thought to myself, “‘lousy’ cholesterol, that’s a new one!” While I fully understood what he was getting at, I had a laugh after asking him more about this. His doctor had told him about his two cholesterols, HDL and LDL, also known as ‘happy cholesterol’ and ‘lousy cholesterol.’ Wonderful, I was definitely stealing these terms for use in general practice back home.

While I may have had a chance to use these terms in discussion with other patients over time, much of my focus as a doctor now is on drug development and clinical research. Whether happy or lousy, too high or too low, why do we care about these cholesterols and what do they really mean to us? Eggs are good. Eggs are bad. Eat less meat. Eat more porridge. Cholesterol is a normal part of our diet but has also long been recognised as an important factor in determining what is called our cardiovascular risk. Along with other factors like gender, smoking status, weight, or even a post code, cholesterol levels in the blood can be used in calculations that are made to tell us how likely it is that someone might have a heart attack or stroke over say, the next 10 years. The reason we can calculate this risk is because there is an enormous amount of health data out there that can all be put together to help determine the odds. 

What matters is that there is only so much that any one of us can do to help reduce the risk of having a given health issue. This comes down to modifiable and non-modifiable risk factors. You can change your diet or quit smoking, for example, but you can’t change your genes (generally speaking). The more we know about what contributes to risk and how it affects risk, the more that can be done to intervene where possible. 

Current guidelines issued by the National Institute for Health and Care Excellence tell doctors that if someone’s odds of having a heart attack or stroke are over 1 in 10 they should consider the use of a statin medication to help that person keep their cholesterol under control, ‘if lifestyle modification is ineffective or inappropriate’. I know that there has been considerable discussion in the press about statins, their potential benefits and their potential side effects. More recently there has even been talk about now making statins directly available from pharmacists. Whether in need of a statin or not, I fully encourage everyone to be actively involved in their healthcare decisions and to get whatever advice they need from healthcare professionals to make informed choices through an understanding of the contributing risk factors for disease.

LDL and HDL stand for low-density and high-density lipoprotein, respectively. They are essentially little particles of protein that travel around in the blood, carrying fat and cholesterol throughout the body. They are part of a family of lipoprotein particles, and LDL has long been the black sheep as it has historically been implicated in the process of hardening of the arteries. Statins prevent your body from making as much cholesterol and this causes the body to get rid of more of this LDL from the blood. HDL, on the other hand is seen as good, because it also helps the body remove extra cholesterol.

In recent years there has been considerable focus on another cholesterol-related protein particle called lipoprotein(a) or Lp(a). It is thought that this particle itself could be another independent risk factor for cardiovascular disease and a potential target for future therapies. Current research is being done to help find out how higher levels of Lp(a) in the blood might also be related to risk. The reason for higher levels is likely genetic, so not everyone will be affected, but being able to identify those people who do have high Lp(a) could prove advantageous in further reducing their risk of heart attack and stroke.

Getting back to that initial conversation, it is all food for thought. Cholesterol is not all bad after all, our bodies would not function without it. It’s yet another one of those things in life with an elusive happy medium achieved through striking the right balance. And while there are many sides to that equation, part of this risk comes down to our genetics. Hopefully the more we understand about this the better, and the more that can be done.

Maybe one day the conversation won’t just be about ‘happy’ and ‘lousy’, but also about Lp(a). We might just have to think of another adjective to describe it.