What is cholesterol?

And what are its types?

What is its role in the body?

What are normal cholesterol levels?

What are the causes of high cholesterol, are nutritional factors, genetics, or other factors?

What are the consequences of high cholesterol on health?

The answers are in this report...

We asked these questions to Dr. George Nimr, interim dean of the College of Health and Life Sciences at Hamad Bin Khalifa University in Qatar, who answered them in an exclusive interview with Al Jazeera Net.

Dr. George Nemer is the interim dean of the College of Health and Life Sciences at Hamad Bin Khalifa University and Professor of Genomics and Precision Medicine at the college.

Dr. Nimr received his Ph.D. in pharmacology from the University of Montreal in 2002. His thesis, which discussed “the first use of the mouse as a model for congenital malformation in the human heart,” is one of the most cited papers in the field.

What is cholesterol?

Cholesterol is a type of fat that is made endogenously in most mammalian and animal kingdom organisms in general. It is composed of carbon and hydrogen atoms linked by covalent bonds and is classified as an unsaturated type because it contains double bonds.

Cholesterol is formed when you eat foods of animal origin such as egg yolk, meat, liver and brain.

What is the role of cholesterol in the body?

Cholesterol is essential for the normal functioning of all animal cells and is an essential component of cell membranes.

It also plays a role in the formation of many important substances such as adrenal and gonadotropin steroid hormones, bile acid, and vitamin D.

What are normal cholesterol levels?

Free cholesterol travels in the blood through lipoproteins and is always measured as bound to these lipoproteins, as follows:

  • The proteins that carry cholesterol from the liver to the tissues are referred to as low-density lipoprotein (LDL) and known as bad cholesterol (normal levels of these proteins should be less than 100 mg/dL).

  • The proteins that carry cholesterol toward the liver are referred to as low-density lipoprotein (LDL) or good cholesterol (normal levels should be above 45 mg/dL).

  • For total cholesterol, its level in the blood should be less than 170 mg/dL.

What are the causes of high cholesterol?

Is it nutritional, genetic or other factors?

Hypercholesterolemia is characterized by elevated levels of cholesterol in the blood (more than 170 mg/dL).

There are 3 main causes of hypercholesterolemia:

  • High cholesterol associated with obesity in general.

  • Cholesterol-rich diet.

  • genetic predisposition.

What are the consequences of high cholesterol on health?

A high level of cholesterol in the blood directly leads to the formation of plaques that clog blood vessels, thus impeding blood flow to various organs.

Among the consequences of occlusion of blood vessels is the rupture of these vessels or their complete occlusion, which leads to injury of the heart or cerebral blood vessels, the occurrence of ischemia and complete organ damage.

When does the doctor resort to drugs to lower cholesterol?

Reducing total cholesterol by controlling diet is the first recommendation that doctors give to their patients. Diet, if strictly followed in the case of non-hereditary hypercholesterolemia, can restore blood cholesterol levels to normal.

However, if individuals cannot strictly follow the diet and if they are at risk for other medical problems such as obesity, diabetes and impaired kidney function, doctors prescribe cholesterol-lowering medications.

What are the main types of cholesterol-lowering drugs?

The most prominent drugs used to combat hypercholesterolemia are statins, which have generic names such as Lipitor and Crestor, among others, as they prevent the formation of endogenous cholesterol.

Other drugs, such as ezetimibe, block the absorption of cholesterol from the intestine, while newer classes such as evolocumab block the degradation of LDL receptors.

What are the main findings of the study that you participated in about family patterns of high cholesterol?

I have been studying Lebanese patients with familial hypercholesterolemia since 2012, and I have major publications showing that new drugs - such as evolocumab - have not been shown to be effective in treating Lebanese patients who carry a mutation in the high-density lipoprotein receptor, which is known as the Lebanese allele. .

The group of Lebanese patients we recently studied was part of an international study that I co-authored and published in The Lancet.

The study showed the existence of disparity and inequality in the services of diagnosis, treatment and follow-up among patients all over the world, and stressed the need for early genetic testing because familial hypercholesterolemia is the most prominent genetic disease affecting the cardiovascular system with a prevalence rate of one case out of every 250 people.

In Qatar, this spread is slightly more severe due to kinship, and Hamad Bin Khalifa University is making strenuous efforts in collaboration between Sidra Medicine, the Qatar Genome Program, and Qatar Biobank to document the genetic basis of the disease and improve response to treatment.

With the blessed month of Ramadan approaching, what are the most prominent nutritional advice for people in general, and for patients with high cholesterol in particular?

The most important message I offer to those who are fasting during the holy month of Ramadan is to refrain from eating excessively foods rich in cholesterol or fat in general.

But the most important thing is not to spoil their daily routine diet and not to wait until the end of the holy month to start following a strict diet to reduce cholesterol intake, especially for those who suffer from high cholesterol levels.