Cholesterol and cardiovascular disease
Cardiovascular disease encompasses all heart and blood vessel diseases. The arteries, which transport oxygen-rich blood to the cells, are the blood vessels primarily affected.
Cholesterol is a fatty substance necessary for hormone production, vitamin D synthesis, and bile acid formation to aid in digestion. It is also crucial for building and maintaining cell membranes. While the body produces some cholesterol, mainly in the liver, it also comes from the food we consume. In essence, cholesterol is vital for sustaining life.
Triglycerides, another type of fat in the blood, are used for energy and excess is stored as fat. Elevated triglyceride levels are linked to a higher risk of cardiovascular disease.
How does cholesterol transport around our human body?
Cholesterol, being insoluble in blood, is transported by proteins in the form of lipoproteins.
There are two main types: LDL (Low Density Lipoprotein) and HDL (High Density Lipoprotein). LDL, known as 'bad' cholesterol, carries cholesterol to cells, while HDL, known as 'good' cholesterol, transports cholesterol from cells to the liver for removal.
LDL (low density lipoprotein) = “bad” cholesterol
LDL transports cholesterol to the cells. The body’s cells take up the LDL cholesterol via an LDL receptor (this is the process which is faulty in FH). This controls the amount of cholesterol in the blood. The protein component of LDL is called apolipoprotein B (Apo B). High levels of Apo B indicate an increased risk of cardiovascular disease. New research suggests Apo B may be a better overall marker of cardiovascular risk than LDL cholesterol.
HDL (high density lipoprotein) = “good” cholesterol
HDL transports cholesterol from the cells to the liver for removal. HDL can also act as an antioxidant. The major protein component of HDL is called apolipoprotein A1 (Apo A1). Low levels of Apo A1 indicate an increased risk of cardiovascular disease.
If an excess of LDL cholesterol is present in the bloodstream, it may accumulate in the arterial walls, leading to the development of cardiovascular disease.
These accumulations are referred to as plaque or atheroma, and the process is known as atherosclerosis.
Atherosclerosis
The plaque gradually narrows the arteries over time, eventually causing blockages. This obstruction results in a decrease in oxygen supply to the affected organ, leading to tissue damage, as depicted in Figure b. Additionally, plaques have the potential to rupture, forming blood clots that can swiftly obstruct the artery. Depending on where the cardiovascular disease is located and how severe it is it can cause:
angina or heart attacks if it occurs in the heart (known as heart disease, coronary heart disease (CHD) or coronary artery disease (CAD)) strokes if it occurs in the brain other circulation problems (peripheral artery disease) if it occurs in other parts of the body e.g. leg pain when walking (intermittent claudication) and erectile dysfunction in men.
In 2011/13, a survey revealed that one out of three Australian adults had high total cholesterol, totaling to 5.6 million individuals. This alarming statistic highlights high cholesterol as a prevalent health issue in Australia.
Poor lifestyle choices, including an unhealthy diet, lack of physical activity, obesity, and smoking, are all contributing factors to the increased risk of high cholesterol and cardiovascular disease.
As individuals age, cholesterol levels tend to rise, and with Australia's aging population, this demographic shift is significantly impacting the prevalence of high cholesterol.
Furthermore, high cholesterol can also be attributed to a genetic condition known as Familial Hypercholesterolaemia (FH), which is not influenced by lifestyle choices or aging.
While there are other medical reasons for high cholesterol, it is essential to consult with your doctor for a thorough evaluation and diagnosis.
Please note that the information provided on this website is not a substitute for professional advice from your GP or healthcare provider.