WHAT IS CHOLESTEROL?
Cholesterol is a waxy, fat-like substance made in the liver and other cells. It is also found in certain foods, like dairy products, eggs and meat.
We often undeniably, hear about cholesterol with all its negative connotations especially in regards to heart disease and strokes.
What we fail to hear though, is that cholesterol is not all bad and it has earned its rightful place in the human body as well.
The body needs cholesterol in order to function properly. It is a precursor of hormones such asprogesterone, cortisol, aldosterone, testosterone, oestrogens and vitamin D. All these are very essential to a healthy functioning body.
This essential biological function of cholesterol has been forgotten by the medical world at large, instead, cholesterol has managed earn a bad reputation in the field of medicine due to its ability to form plaques on blood vessel walls, particularly in the heart and brain.
These plaques are commonly the triggers for heart attacks and strokes.
Cholesterol traverses the blood attached to a protein – called a lipoprotein molecule.Lipoproteins have different classes. The amount of protein a cholesterol molecule contains, determines its class.
A high ratio of protein makes the molecule more dense and this is usually known as the HDL (high density lipoprotein), due to its density, it is unable to carry too much fat.
A lower ratio of protein will be less dense and carry more triglycerides (fat). This is called the LDL (Low density lipoprotein).
These classes can be further differentiated into:
- Very low density lipoprotein (VLDL),
- Intermediary density lipoprotein (IDL) and
- Low density lipoprotein (LDL)
- High density lipoprotein (HDL)
This article intends to bring forward some very important markers of cholesterol testing with special attention to LDL or ‘bad’ Cholesterol and your underlying genes.
The specialised testing that is available, informs the individual in more detail, about their LDL cholesterol types and particle numbers in relation to their risk in developing heart disease or stroke.
WHAT IS LDL CHOLESTEROL?
Low Density Lipoprotein Cholesterol (LDL- C)particles are the main ones involved in carrying cholesterol and fat in the blood.
LDL delivers its cholesterol to the cells in the body by binding to a receptor on the surface of cells called the “LDL receptor”. Too much LDL cholesterol floating around in the blood stream is not desirable as it can slowly build up within the inner walls of the arteries if the endothelium is inflamed and unhealthy. Most arteries will be affected but the ones supplying blood to the heart and brain are most vulnerable.
When LDL-C levels are high especially in high risk individuals, like in smokers, hypertensive or diabetic individuals, the build-up of plaques happen quicker in the arteries because they have an unhealthy endothelium. This condition is called ATHEROSCLEROSIS. If the plaque is deemed unstable and there is a tear on the surface of the plaque, then a thrombus or clot may form, which further obstructs the flow of blood to the heart or brain, causing the dreaded heart attack or stroke.
As important as cholesterol is in causing plaque formation, they are all not the same. Instead, the focus should be on the LDL-C particle size, number, and the dangers of oxidised LDL-C rather than the total cholesterol level.
A quick way to remember LDL as the BAD Cholesterol is L for LDL, L for “Lousy Cholesterol”.
WHAT IS HDL CHOLESTEROL?
High Density Lipoprotein Cholesterol (HDL-C) is responsible for transporting cholesterol from all the different parts of the body to the liver.
HDL is also responsible for removing excess cholesterol from atherosclerotic plaques in the arterial walls. This in turn slows down the growth of plaques. Here, elevated levels of HDL-C is known to be protective against heart attacks whereas low HDL-C levels confer the opposite affect and is undesirable.
HDL-C molecules also have preferential particle sizes and numbers but their impact in terms of atherosclerosis is not so critical as LDL-C.
As a rule, it is good to make sure HDL-C is never low.
A quick way to remember HDL as the GOOD cholesterol is H for HDL, H for “Healthy cholesterol”
WHAT IS VLDL AND IDL CHOLESTEROL?
Very Low Density Lipoprotein (VLDL-C) contains the highest amount of triglycerides and lowest amount of protein. Therefore it is the most dangerous form of LDL-C. VLDL-C eventually gets converted to LDL-C after it releases most of the triglycerides present in the molecule.
Triglycerides themselves are independent risk indicators of heart disease. Their description and role needs special attention, as excess carbohydrates in the diet play a prominent role. This is why diabetics with poor diet control are at very high risk for atherosclerosis.
High levels of VLDL cholesterol have been associated with the development of plaque deposits on artery walls, which narrow the passage and restrict blood flow.
There is no simple direct way to measure VLDL cholesterol, which is why it is normally not mentioned during a routine cholesterol screening.
Intermediate Density Lipoprotein Cholesterol (IDL – C) is formed from the degradation of Very Low Density Lipoproteins (VLDL). IDL enables fats and cholesterol to move within the water-based solution of the bloodstream.
As a rule, IDL-C falls in between VLDL-C and LDL-C. Hence it is equally atherogenic and contributes to the formation of plaques.
Collectively, LDL, IDL and VLDL are all known as non HDL-C molecules and and on your lipid profile results will just be counted as LDL-C.
The best way to lower your VLDL cholesterol is to lower your triglycerides.
I DO MY CHOLESTEROL TEST EVERY YEAR. WHAT DOES THAT TELL ME?
The screening test that is usually performed is a blood test called a Lipid profile. Anyone in the adult age group can check their levels.
It is recommended that every individual with risk of cardio-vascular illnesses and other chronic lifestyle diseases like diabetes and hypertension should frequently assess their lipid levels as often as twice a year.
You can test your LDL-C and HDL-C levels at annual check- ups at hospitals or clinics by doing a routine Lipid Profile Test. From this test you can calculate two ratios that are useful. Commonly reported is the Tot CHOL: HDL ratio, which should be less than 5:1.
Functional medicine doctors also calculate the Triglycerides : HDL which are ideal at levels of 2:1.
It is a good first-level test to determine where you stand.
However, the actual detailed testing of particle size and numbers of LDL-C is not routinely tested.
WHAT IS THE IMPORTANCE OF THE PARTICLE SIZE OF LDL-C?
‘Small’ LDL-C molecules that are dense and gritty will hurt the vessel walls if the endothelium /lining of the walls are already unhealthy. This embedding of cholesterol to heal the cracks on the walls is the beginning of plaque formation.
‘Large’ LDL-C molecules are big and fluffy enough to bounce off the vessels walls, and contribute less to damage and atherosclerosis. The health risk is lower for those who have large LDL-C.
Small, dense and therefore dangerous LDL-C particles may be concealed behind normal cholesterol levels. This means that although your LDL-C may be normal, there still may be some risk of coronary disease because of a predominance of small, dense, LDL-C.
Conversely, elevated LDL-C levels need not always be associated with a higher risk of plaque formation if you have the large fluffy particles of LDL-C.
This partially explains why some individuals with high LDL-C do not succumb to coronary plaques while some others with normal levels do.
WHEN SHOULD I TEST FOR THE LDL SUB-FRACTIONS?
It is increasingly useful to do additional tests when assessing risk in people who have the following high risk factors:
- Cigarette smoking
- Hypertension (BP > 140/90 mmHg or on antihypertensive medication)
- High LDL cholesterol (>2.58mmol)
- Low HDL cholesterol (< 1mmol)
- Family history of premature chronic heart disease (CHD). Specifically: CHD in first-degree male relative < 55 years; or CHD in first-degree female relative < 65 years.
- men > 44 years; or women > 54 years
- Clinical coronary heart disease, symptomatic carotid artery disease, peripheral arterial disease, or abdominal aortic aneurysm.
The LDL-C Sub-Fraction Test also known as the LDL Particle Test (LDL-P), can determine more accurately the cardiovascular risk presented by your LDL-C levels, than a regular lipid profile.
Traditional lipid profiles do not identify and determine the presence of small dense type LDL-C that causes blockage of the blood vessels.
The LDL-C Sub-fraction test actually looks in detail into the types of LDL-C molecules that are prominent in an individual and quantifies it.
This test is not routinely ordered, but its use is important as it has the potential to predict the development of coronary vessel disease, so that preventive steps can be put in place much earlier than they otherwise may have.
HOW WILL GENETIC TESTING GIVE ME MORE INFORMATION?
Genetic testing can be done to identify your genetic susceptibility to cardiac related diseases and conditions.
Familial hypercholesterolemia is an inherited condition characterised by higher than normal levels of LDL blood cholesterol. Individuals with this inherited condition usually have very high cholesterol levels and fall prey to the disease at a much younger age, usually before 50 years.
These people can benefit from specialised testing as aggressive strategies may be needed to control the dangerous LDL-C sub-fractions.
There are also other genes involved in cholesterol regulation, found in Asian and Western populations. The presence of these genetic mutations can say a lot about their heart health risk. These gene mutations also give more insight into why some of us are at risk to have the more dense and dangerous LDL-C. Some of these genes are:
- APOE (Apolipoprotein E),
- CETP (Cholesteryl Ester Transfer Protein)
- SELE (selectin E)
Understanding the above genes explains why certain individuals will benefit from dietary strategies, whilst others do better on exercise. They also tell us why some of us respond to statins (cholesterol lowering agents) in a negative way while some of us respond well.
If you have a family history of heart disease, you most probably would have inherited at least some high risk genes. Therefore it is crucial to know exactly where your weaknesses are, so that personalised targeted interventions can be put in place.
HOW CAN FUNCTIONAL MEDICINE HELP ME?
Everyone is biochemically unique – this is the very essence of Functional Medicine. Because of that, the same treatment strategies cannot be successfully used be everyone, rather strategies need to be tailored to the individual.
Elements Medical Fitness uses the Functional Medicine model of healthcare in approaching all chronic health problems. If you have a strong family history of heart disease or if you feel that you are at risk for heart disease because of your current state of health and lifestyle, then Functional Medicine can help you understand your personal risk.
Come in for a discussion with our practitioners and Functional Medicine doctors. Our practitioner team will ensure that the ‘RIGHT’ Cholesterol tests are done, so that you get the answers that you need.
Remember: It is not just about having lower cholesterol; it is about having the right type of cholesterol.
“The INTERHEART study, published in the Lancet in 2004, followed 30, 000 people and found that changing lifestyle could prevent at least 90% of all heart disease.”