Overlooked ugly cholesterol causes heart disease

The risk of ischaemic heart disease – a disease affecting some 150,000 Danes – is three times higher in persons with high levels of the so-called ‘ugly’ cholesterol. This is the finding of a new study of 73,000 Danes, which is shedding light on a long debate on this topic. The results have just been published in the Journal of the American College of Cardiology.

Most Danes are aware that High cholesterol is life-threatening. But very few know which type of cholesterol is the most frequent killer. Cholesterol is divided into ‘the good’ HDL cholesterol, ‘the bad’ LDL cholesterol and ‘the ugly’ cholesterol. It is the so-called ‘ugly cholesterol’ – also called ‘remnant-like particle cholesterol’ – that is the really bad guy.

“LDL cholesterol or ‘the bad’ cholesterol’ is of course bad, but our new study reveals that the ugly cholesterol is the direct cause of arteriosclerosis (hardening of the arteries) resulting in ischaemic heart disease and early death. By examining 73,000 persons, we found that an increase in the ugly cholesterol triples the risk of ischaemic heart disease, which is caused by lack of oxygen to the heart muscle due to narrowing or blocking of the coronary arteries,” says Professor Børge Nordestgaard, chief physician at Herlev Hospital and Clinical Professor at the Faculty of Health Sciences at the University of Copenhagen.

“I hope that this new knowledge will lead to better preventive treatment, as more than one in five Danes suffers from high ugly cholesterol. We also hope that the pharmaceutical industry will develop new drugs targeted specifically at raised ugly cholesterol levels,” he emphasises.

Widespread disease worldwide

In Denmark alone, 20,000 persons are diagnosed with ischaemic heart disease every year, and some 150,000 Danes are currently affected by the disease. According to World Health Organization estimates, 17 million people fall victim to cardiovascular disease – the most frequent cause of death in the world.

“High ugly cholesterol is the result of high blood levels of normal fat (triglycerides). The most important cause of high ugly cholesterol is overweight and obesity. Persons with high ugly cholesterol should therefore be advised to lose weight, but drugs such as statins and fibrates may also lower levels of ugly cholesterol in the blood,” says Børge Nordestgaard.

Cholesterol - the good and the bad

Cholesterol is carried in the blood stream in particles called lipoproteins.

These are named according to how big they are:

  the very large particles are called Very Low Density Lipoproteins (VLDL)
  the intermediate size ones are called Low Density Lipoprotein (LDL) and these particles cause heart disease
  the smallest particles are called High Density Lipoproteins (HDL) and these particles actually protect against heart disease.

What to do if your cholesterol level is high

The most effective way to lower your cholesterol is to reduce the amount of animal fat in your diet by various means.

You could:

  reduce cheese intake and/or substitute low fat varieties
  choose reduced fat milks
  use polyunsaturated or monounsaturated margarine or oils instead of butter
  choose lean cuts of meat and remove all visible fat
  eat skinless chicken, fish or beans
  beware of pies, pasties, fish and chips and commercial cakes (hidden fat)
  make cakes at home with polyunsaturated fat, cook chips with polyunsaturated or monounsaturated oil
  lose weight if overweight.

If you make a number of changes to your diet you can expect your cholesterol to fall by 10 per cent.

About 15 per cent of people will see no change and another 15 per cent will see changes of 20-30 per cent.

Samples from 73,000 Danes with genetic defect

Anette Varbo, physician and PhD student at Herlev Hospital, has been part of the research team behind the new findings. She says that the findings shed light on a long-standing debate among researchers on the so-called triglyceride, arteriosclerosis and cholesterol.

What about triglycerides?

Triglycerides are a stored energy source.

Most of the triglyceride is found in the very large particles, the VLDL.

Under some circumstances high blood triglyceride can be a risk factor.

If your cholesterol is high (greater than 6.5) and your HDL cholesterol is low (less than 0.9) then triglycerides can increase the risk of heart disease if they are greater than 1.7.

Triglyceride levels greater than 10 can cause inflammation of the pancreas which is a very serious condition.

How can I lower my triglyceride?

Reduce your intake of animal or hard vegetable fats, lose weight and reduce alcohol intake.

Alcohol is very powerful at elevating triglyceride.

See your family doctor if it remains elevated as you may require medication.

“To be able to examine the correlation between ugly cholesterol and heart disease, we have used blood samples from persons having a genetic defect which means that they suffer from high ugly cholesterol their entire life. The research findings do therefore not depend on their lifestyle patterns in general. Unhealthy lifestyle factors such as smoking, fatty foods and overweight all increase the risk of heart disease, and the blood samples from persons having this genetic defect thus give the most accurate results,” says Anette Varbo.

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The scientific article is based on the following three population studies: the Herlev-Østerbro study, the Østerbro study and the Copenhagen heart study.

Facts about cholesterol:

  Cholesterol is divided into ‘the good’ HDL (High Density Lipoprotein) cholesterol, ‘the bad’ LDL (Low Density Lipoprotein) cholesterol and ‘the ugly’ cholesterol (or ‘remnant-like particle cholesterol’).

  If the levels of normal fat, triglyceride, in the blood are high, then the levels of ugly cholesterol are also high. This can be determined by a blood sample.

  More than 50% of all Danes have high blood cholesterol levels.

  You can lower your blood cholesterol level by eating a low-fat diet and avoiding overweight. Should this not lower the cholesterol level sufficiently, it may be lowered with drugs.

  Ischaemic heart disease is caused by arteriosclerosis of the coronary arteries and often manifests itself as chest pain (angina pectoris) and/or a heart attack (myocardial infarction).

(Fact Sources: The Danish Heart Foundation and the medical compendium Medicinsk Kompendium)

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