Inherited Cholesterol Disorder

The food link to high blood cholesterol is well known. The higher the intake of fatty food, the higher the cholesterol levels in our body. Less known is the exercise connection. Regular exercise helps bring down the cholesterol levels.


Perhaps what is not known is the genetic connection to high blood cholesterol can be inherited from your parents. And when it does occur its management often requires more than just lifestyle modifications. Treatment with drugs is required.


This page is about helping you understanding and manage
Familial Hypercholesterolemia or
inherited cholesterol disorder (ICD).

 

What is Familial Hypercholesterolemia (Inherited Cholesterol Disorder)?

Familiar Hypercholesterolemia or FH in short is a genetic disorder that is passed from one generation to another. It is a condition where the boy is unable to remove the bad cholesterol (low density lipoprotein or LDL) from the blood.

The problem stems from an abnormal gene that maybe present in one or both parents. When a child inherits an abnormal gene from one parent the condition is called Heterozygous FH. It usually affects 1 in 400 people and if left untreated, can cause coronary artery disease at the age of 40 to 45.

When 2 heterozygotes marry and when one of their children inherit the FH gene from each of them, the child will then have an extreme form of the disorder, known as homozygous FH. This is an extremely rare case and occurs in about 1 in 1 million people. In such cases cholesterol levels maybe as much as 4 times their normal value and if left untreated people with this condition often develop atherosclerosis by their early teens and die from heart attack or sudden death before the age of 20.

 

How can FH be Detected?

Detecting FH in its early stages is extremely beneficial as it can prevent the atherosclerotic process, which begins in childhood.

In children, FH can be detected while the children is still in the mother's womb by testing the child's blood from umbilical cord. The other option is to test a child's cholesterol level by the age of 2 especially in families with a history of high cholesterol and heart attacks.

In adults, clues to the presence of FH include white rings around the iris, lumps in the tendon on the backs of the hands and ancles and also lump on the knees.

Screening of first-degree relatives (brothers, sisters, uncles, aunts and cousins) of FH patients is an extremely effective method in identifying FH at an early stage. When one FH patient is identified many other silence FH sufferers can be detected and this will help diffuse the silently ticking time bombs in families where premature heart attacts are the norm.

DNA testing is the latest diagnostic test that is said to be the most sensitive in identifying FH patients. It can help increase the identification of FH sufferers by another 16.6%.

What are the Risks Associated with FH?

The main risk is death or disability from atherosclerosis, especially of the coronary arteries. This risk is greater than for other types of hyperlipidemia because hypercholesterolemia is more severe and is present throughout life. Apart from this increased risk of coronary disease, individuals with FH are normally in all other aspects.

 

How is FH Treated? 

  1. In Children

    Statins are usually the preferred drugs as they have been very extensively studied and have been proven to be very safe for children according to studies conducted in Belgium. Statins are not only effective in reducing cholesterol levels but are also found to be very safe in children as young as 6 years old

    Drug treatment has to go hand-in-hand with lifestyle modifications like diet and ecercise. It is not possible to be too strict with a child's diet, as they need a wide variety of nutrients. A healthy combination of foods from the various food groups is important to them for their continued growth and development. It is important to avoid fast foods, snacks like chips and chocolate bars and to avoid soft drinks with lots of sugar. Consult a dietician for advice on healthy food choices for your child. 
  2. In Adult

    Drug therapy is always prescribed for FH patients, as the blood cholesterol values in these patients are very high. Again statins are the drugs of choice in the treatment of FH as they are highly effective and well tolerated with minimal side effects. Usually a combination of statin-resin drug therapy is used to treat FH patients in order to reach target blood cholesterol values. Sometimes nicotinic acid and fibrates are also prescribed as an addition in resistant cases

    In homozygotes, additional measures maybe required like Plasmapheresis. This consists of removing the blood and returning it after LDL is filtered out. This will help lower the blood cholesterol level. The only drawback to this method of therapy is that it is rather expensive and time cosuming.

    Ileal bypass is a surgical intervention that lowers blood cholesterol and bile acid uptake from the gut. Although the effectiveness of this procedure in lowering the risk of heart attacks is well proven, complications of this procedure such as diarrhea are difficult to live with.

    Liver transplant is another option.

    It is absolutely essential that diet modification and exercise to reduce weight go hand-in-hand with drug treatement. Cut down on animal foods and fatty or oily foods. Eat more wholegrain foods, cereals, legumes, fruits and vegetables. And exercise at least 3 to 4 times a week for a minimum of 30 minutes.

 

Drug Therapy

There are 4 types of drugs used to treat high cholesterol. They include

Statins (HMG-CoA reductase inhibitors)
Bile acid sequestrants (bile acid resins)
Niacin (nicotinic acid)
Fibric acid derivates
Among them statins are the most commonly prescribed drugs for lowering cholesterol. This is because they have been very extensively studied and have been proven to be very effective in patients with minimal side effects.

  1. Statins

    Statins work quickly by lowering cholesterol within one to two weeks. Cholesterol levels keep dropping until about four to six weeks of treatment. After this point, the levels usually hold steady as long as you stay on the medication. You may need to take statins for a long time to keep your cholesterol levels in check.

    Statins work by interfering directly with the manufacture of cholesterol in the body, specifically by blocking an enzyme called HMG-CoA reductase, which the body needs to make cholesterol. With less cholesterol in the body the liver is encouraged to remove more LDL from the bloodstream. As cholesterol in the bloodstream goes down, so too does the risk of clogged blood vessels and heart disease.
  2. Bile Acid Sequesrants / Resins

    Your liver secretes bile acids, which aid digestion by breaking down dietary fats in the intestines. These drugs binds to the bile acids, causing them to be passed with the stool. With fewer bile acids in circulation, the liver is prompted to convert more cholesterol into bile acids(80% of the cholesterol made by the liver is used to make bile) encouraging the removal of LDL from the blood.
  3. Niacin

    Niacin can lower LDL levels in as little as five to seven days. How much cholesterol is reduced depends on the dosage. When combined with bile acid sequestrants, the result can be even lower LDL levels - a reduction of as much as 40% to 60%.
  4. Fibrates

    Lowering triglycerides fats and may also help in raising HDL levels.

 

What is Cholesterol?

Cholesterol is a soft waxy substance found in all your body's cell. Despite all the nasty things that you've heard about cholesterol, you need a certain amount of it to live:- Cholesterol is essential to your body's cell membranes, to the insulation of your nerves, and for the production of certain hormones. It is also used by your liver to make bile acids, which helps in the digestion of food.

Interestingly, the majority of cholesterol in your blood is manufactured by your own body - mainly by your liver - and only 20% comes from the food you consume, especially animal based foods like milk products and meat as well as some cooking oil.

 

Good and Bad Cholesterol

As cholesterol can't be transported in blood special carries called lipoproteins transport it to and from cells. There are 2 kinds of lipoproteins that you need to be concern about.

  1. LDL (low-density lipoprotein)

    When too much LDL circulates in the blood, it can slowly build up in the walls of the arteries and can form plaque (thick hard deposits) that can clog up arteries. If a clot forms where the plaque is, oxygen-rich blood flow can be blocked to the heart muscles leading to a heart attack. If the clot blocks the blood flow to part of the brain a strok can manifest. This is why a high level of LDL is reffered to as the bad cholesterol. Lowering LDL levels will help reduce the plaque buildup in your arteries leading to healthier arteries.
  2. HDL (high-density lipoprotein)

    HDL cholesterol is called the good cholesterol because it contains a relatively small amount of cholesterol itself and carries away harmful fatty deposits from cells and tissues to the liver for excretion from the body. This helps prevent the buildup of cholesterol in the walls of your arteries.

 

Your Cholesterol Reading

Cholesterol readings generally include total cholesterol, LDL cholesterol, HDL cholesterol and triglyceride levels. It is important to take note of all 3 readings and not just total cholesterol.

Total Cholesterol [mmol/L (mg/dl)]
Desirable: <5.2 (<200)
Borderline High: 5.2 - 6.2 (200 - 239)
High: >=6.2 (>=240)

LDL Cholesterol [mmol/L (mg/dl)]
Desirable: <3.3 (<130)
Borderline High: 3.3 - 4.1 (130 - 159)
High: >=4.1 (>=160)

HDL Cholesterol [mmol/L (mg/dl)]
Acceptable: >=0.9 (>=35)
Risky: <0.9 (<35)

Triglyceride [mmol/L (mg/dl)]
Desirable: <2.3 (<200)