As well as HDL and LDL cholesterol measurements, research has shown that other components of lipoproteins, including VLDL, chylomicron remnants, IDL (intermediate density lipoprotein) and lipoprotein A, are significant, and their measurement helps calculate the risks of developing cardiovascular disease (CVD).[4] For example, lipoprotein A is a carrier of oxidised phospholipids. These are inflammatory and significantly increase the risk of developing atherosclerosis.[5] Atherosclerotic plaques cause arteries to narrow, thus limiting blood supply to vital organs. If a piece of plaque breaks off, it can cause a blood clot to form, completely blocking the blood supply to organs such as the heart or brain, leading to heart attack and/or stroke.[3]

Lifestyle and diet play a huge role in managing the risk of dyslipiaemia.[1] Other risk factors include:[6]

• Age

• Gender- (being male increases the risk of high cholesterol)

• Menopause

• Family history

• Kidney disease

• Liver disease

• Diabetes

• Hypothyroidism

• Growth hormone deficiency

Dyslipidaemia can occur secondary to other conditions such as diabetes and kidney disease, which is why cholesterol levels should be monitored for people with these conditions and treatment offered to reduce CVD risk if appropriate.[1]

High cholesterol is known as a silent killer, as there are usually no symptoms, so those affected have no way of knowing without a blood test. Those with familial hypercholesterolaemia (FH) may have some visible signs such as:[6]

• Tendon xanthoma: swellings on the knuckles or Achilles tendon from cholesterol deposits

• Xanthelasma: small yellow lumps in the corners of the eyes

• Corneal arcus: a white ring around the iris

It is thought that those with FH have an enhanced cholesterol absorption caused by certain gene variants in sterol transporters like ABCG5/G8 (estimated 30% of the population.)[7]

The NHS offers free cholesterol screening for those over 40 or for individuals with risk factors, i.e. family history of heart disease or hypercholesterolaemia, high blood pressure, diabetes and kidney disease.[8] The blood test checks levels of HDL, non-HDL, total cholesterol, the ratio of HDL to LDL and triglycerides.[9]  Total cholesterol should be <5mmol/L, non-HDL <4mmol/L, HDL >1mmol/L and fasting triglycerides <1.7mmol/L.18. The primary targets for treatment are the total cholesterol and LDL levels, which have the greatest risk for developing CVD.[9]

One of the most important CVD research trials took place in 2002 on over 20,000 people (known as the Heart Protection study) and it successfully showed that reducing levels of LDL cholesterol led to a reduced risk of heart attack and stroke and that statins were beneficial in the prevention of CVD.[3,13] This then underpinned the routine use of statins in primary care, to help lower people’s CVD risk.

The British Heart Foundation continues to help fund a lot of CVD research, and, on reviewing their website, I found there are many new areas currently being researched:

Gender reassignment and CVD risk
The risk of CVD may be higher in those who have undergone gender reassignment. Research from the University of Glasgow found trans women had an increased risk of heart attack and stroke compared with the rest of the population, and trans men were found to have higher blood pressure and cholesterol levels.[16] It is thought that there is a possible link between gender-affirming hormone therapy and the risk of blood clots and dyslipidaemia. However, research is still ongoing as the evidence base is not definitive.[16]

Tribbles-1
There is a protein known as Tribbles-1, which can reduce cholesterol levels, and with manipulation of microRNAs, the liver will produce more Tribbles-1, which will theoretically lower cholesterol. [17-19]

PET scans for diagnosis
Cambridge University is carrying out a study to look at improving the identification of atherosclerosis using positron emission tomography (PET) scans. It is hoped this method will help identify those who have large plaques in danger of rupturing, so preventative treatment can be given.[3]

Atherosclerosis
Cambridge University is also researching how blood vessels are affected by atherosclerosis and if it is possible to prevent this.[3]

Immune modulation
Genetic studies are being carried out focusing on the way T-lymphocytes react aggressively towards atherosclerosis, increasing damage to blood vessels. This may lead to an immune-modulating treatment that can reduce atherosclerotic damage.[3]