Familial hypertriglyceridaemia
Familial hypertriglyceridaemia (also known as Type IV) is a common condition that causes raised triglyceride levels. It’s passed down through families, and may raise your risk of Type 2 diabetes and diseases of the heart and blood vessels.
Triglycerides are a type of blood fat that are important for giving us energy, but when triglyceride levels in the blood are too high, this can lead to conditions such as heart disease and Type 2 diabetes.
Triglycerides are transported around the body in little parcels called VLDL – a type of cholesterol, or lipoprotein. In people with familial hypertriglyceridaemia, the liver makes too much VLDL and too little is removed from the blood, so VLDL and triglyceride levels become raised.
Familial hypertriglyceridaemia does not usually cause a rise in other blood fats such as cholesterol unless the condition gets worse, which can cause a delay in removing all blood fats.
What causes familial hypertriglyceridaemia?
Familial hypertriglyceridaemia is caused by a genetic defect passed down through families. It is ‘autosomally dominant’ which means that if you inherit one faulty copy of the gene involved – from one parent – you will have the condition. However, it is thought to have a polygenic inheritance meaning a number of genes may be responsible, not a single gene.
It is usually accompanied by other conditions such as obesity, high blood pressure and high blood glucose. It can also be accompanied by a lower level of HDL cholesterol.
Triglycerides don’t usually rise until puberty or early adulthood, and usually in people who have other risk factors such as:
- obesity
- high blood sugar and insulin.
These conditions can make familial hypertriglyceridemia worse because they cause the liver to make more VLDL, raising triglycerides in the blood.
Other lifestyle factors can also have an effect:
- diet high in saturated fat and added sugars
- drinking a large amount of alcohol
- progression of raised blood sugar and insulin to type 2 diabetes.
What are the symptoms of familial hypertriglyceridemia?
Familial hypertriglyceridemia doesn’t usually cause any symptoms but may put you at higher risk of Type 2 diabetes and diseases of the heart and blood vessels.
How is familial hypertriglyceridaemia diagnosed?
If other people in your family have had hypertriglyceridaemia (high triglycerides) then you should have blood tests to check your triglyceride levels. This should be done at the same time as a cholesterol test.
Healthy triglyceride levels are usually below 1.7mmol/L after fasting or below 2.3mmol/L without fasting (sometimes blood tests are done after fasting for 12-14 hours so that they are not affected by any meals).
You might have familial hypertriglyceridaemia if blood tests show your triglycerides are mildly to moderately raised even after fasting for 12 to 14 hours, with relatively normal cholesterol.
How is familial hypertriglyceridemia treated?
Treatment focuses on reducing triglyceride levels. Triglycerides can often be lowered by making healthy changes to your lifestyle and reaching a healthy weight. For those with higher levels of triglycerides, medications such as statins and fibrates will need to be considered.