What are lipid disorders?

Lipid disorders are a range of conditions that result in abnormal elevations of different types of particles that carry fats in the blood. There are two main types of fats carried in the blood and we only need them in small amounts: high levels cause harm the longer they remain elevated. Professor Kausik Ray tells us a little bit more about lipid disorders and where they come from.

The two main types of fats that can be found in the blood are cholesterol, which is needed for hormone metabolism and making cell membranes and triglycerides which provide energy. Typically lipid disorders result in either elevated LDL cholesterol, triglycerides, both or elevated lipoprotein.

What are the different types of lipid disorders

Broadly lipid disorders fall into 3 main groups.

• Elevated low-density lipoprotein (LDL) cholesterol which increases your risk of heart attacks, strokes and vascular diseases.
• Elevated triglycerides which increase your risk of a condition called pancreatitis, resulting in inflammation of the pancreas and severe abdominal pain.
• Elevated lipoprotein which increases your risk of heart attacks and strokes.

Importantly low, high and medium levels of lipid disorders are predominantly asymptomatic until problems arise.

What causes lipid disorders

Some types of lipid disorders are secondary to other causes, such as:

• An underactive thyroid, poor control of diabetes or obesity, which makes the body less sensitive to insulin (a hormone which controls triglycerides as well as blood sugar).
• High alcohol intake.

However, the vast majority of lipid disorders will have a genetic basis, inherited as a single gene abnormality from one parent. These are present from birth, so by the time detection occurs later in life, the disorder may have been causing harm for over 40 years. For instance, a condition called familial hypercholerolaemia occurs in about 1 in 250 people and increases the likelihood of heart disease in midlife if untreated.

More commonly, elevated cholesterol comes from multiple inherited genes (polygenic), each of which has a small effect on cholesterol, but together increase cholesterol levels significantly. Usually, these genetic effects manifest themselves later in life, so by the time they are detected the body has been exposed to them for a much shorter period of time.

Both inherited lipid disorders and those caused by secondary factors respond well to cholesterol-lowering treatments called statins. For elevated triglycerides, there is an important genetic basis, but lifestyle factors also play a major role. A combination of marked dietary control (carbohydrates) and medications (fibrates or fish oils) can reduce triglycerides and reduce the consequences of high triglycerides.

What does screening for Lipid Disorders involve?

Screening involves taking a fasting blood sample (1.5 tablespoons of blood or 7.5ml) to measure a range of fats in the blood and potential causes of elevated cholesterol. If the findings of the blood test are sufficiently abnormal, then about twice the volume of blood as the basic test is needed to extract DNA and uncover the causes of the abnormal lipids.

For more information on lipid disorders and cholesterol visit Professor Kausik Ray’s Top Doctors profile.