Cholesterol is an important component in the blood used by the body for several essential functions. The level of cholesterol is contributed by the person’s diet and increased production by the liver. Excessive intake of cholesterol rich food, such as animal fats and egg yolks, may result in an increased level of cholesterol, leading to a condition known as atherosclerosis. When atherosclerosis occurs, fats are deposited on the inner walls of blood vessels causing the narrowing of the blood vessels. These deposits may cause a blood clot and block blood supply to vital organs resulting in a stroke or heart attack.
High cholesterol is seen in hypercholesterolemia, kidney disease, hypothyroidism, primary biliary cirrhosis and diabetes. Very low levels of cholesterol may not be beneficial, suggesting other medical conditions. There are two other important fractions of cholesterol known as HDL and LDL cholesterol described below.
HDL (High Density Lipoprotein) Cholesterol
HDL Cholesterol is known to be the ‘good’ cholesterol as it helps remove cholesterol from the tissue and transport it to the liver for harmless excretion. A high level of HDL cholesterol lowers the risk of atherosclerosis and a low level increases the risk of atherosclerosis and coronary artery disease.
LDL (Low Density Lipoprotein) Cholesterol
This is the ‘bad’ cholesterol as it transports cholesterol to be deposited as fat on the walls of blood vessels. An increase in LDL cholesterol is associated with increased risk of coronary artery disease.
Cholesterol/ HDL Ratio
This ratio is derived from the Total Cholesterol value divided by the HDL Cholesterol value. It is a useful indicator to assess the risk factor of a heart attack. Higher ratio (above normal range) indicates a higher risk of a heart attack while lower ratio means lower risk.
Triglycerides are a type of fat found in the fat tissue of the body. They are converted from excess calories and stored in fat tissue providing a major source of energy for the body. Consumption of foods rich in animal fats and alcohol are known to elevate the triglyceride level. Very high levels are associated with obesity and coronary risk whereas moderately elevated triglyceride levels are found in some women taking certain hormones and contraceptives as well as during pregnancy.