By: Zeenat Farooq
Hyperlipidemia is an elevation of one or more fat proteins in the blood. It is commonly referred to as high cholesterol. One-third of American adults have it, only 1 in 3 has it under control and having hyperlipidemia doubles the risk of developing heart disease. Genetic predisposition, cigarette smoking, obesity, poor diet, and a sedentary lifestyle can all lead to hyperlipidemia. Although hyperlipidemia has no symptoms, it can be detected by a simple blood test.
Hyperlipidemia in the general sense of the term means “too much cholesterol in the blood”. Cholesterol is a waxy, fat protein manufactured by the liver and is essential for healthy cell membranes, hormone production, and vitamin storage. Even the brain depends on cholesterol for proper functioning. Cholesterol becomes a problem only when too much of the bad kind is produced or ingested through regular eating of unhealthy foods. Cholesterol is carried through the blood to cells by lipoproteins that are either low density (LDL) or high density (HDL). The lipoproteins are protein conjugates of various lipids such as cholesterol and it is in the form of lipoproteins that cholesterol and other lipids are transported through the blood to the organs of action or deposition. We may think of lipoproteins as the vehicle and cholesterol as the passenger. HDL is the good lipoprotein because it carries extra cholesterol back to the liver where it can be eliminated. LDL is bad, as it will build up excess cholesterol in the blood. Triglycerides, a type of fat in the blood, are different from cholesterol, but these have a very strong association with heart disease. Often it is both the LDL and triglycerides that are elevated in hyperlipidemia.
What causes hyperlipidemia?
The causes of hyperlipidemia are either genetic (familial or primary hyperlipidemia) or from a poor diet and other specific factors (secondary hyperlipidemia). When the body cannot utilise or remove excess fat, it accumulates in the blood. Over time, the buildup damages the arteries and internal organs. This process contributes to the development of heart disease. In familial hyperlipidemia, the high cholesterol has nothing to do with poor habits but is caused by a genetic disorder. A mutated gene passed down from either the mother or father and causes a missing or malfunctioning LDL receptor. This LDL accumulates to dangerous amounts in the blood. Certain ethnic groups such as French Canadians, Christian Lebanese and Ashkenazi Jews are at a higher risk of hereditary hyperlipidemia. Other causes of hyperlipidemia may include excessive drinking of alcohol, obesity, side effects of medications such as hormones or steroids, diabetes, kidney disease, underactive thyroid gland and pregnancy.
A common gene variant that affects cholesterol may raise heart problem risk. People who carry a common mutation in a gene called SCARB1 that regulates cholesterol may have a higher risk of developing heart disease, say the researchers behind a new study published in the journal PLOS ONE. Another new study published in JAMA claims to have found evidence to support a causal association between “high levels of bad cholesterol and aortic valve stenosis” a form of aortic valve disease in which the valve is narrowed, restricting blood flow from the heart.
Signs and symptoms of hyperlipidemia
With familial hyperlipidemia, a person could show signs of high cholesterol with yellowish fatty growths (xanthomas) around the eyes or the joints. Otherwise, hyperlipidemia has no signs or symptoms, and unless picked up with the fasting lipid profile, the high cholesterol would remain undetected. An individual could have a heart attack or stroke, and later learn it was precipitated by hyperlipidemia.
Excessive fat in the blood accumulates over time, forming plaques on the walls of the arteries and blood vessels. This will narrow the openings, producing turbulent blood flow through the vessels, and cause the heart to use more force to get the blood through the constricted areas.
Tests and diagnosis of hyperlipidemia
Screening for hyperlipidemia is done with a blood test called a lipid profile. It is important that a person has nothing to eat or drink for 9-12 hours prior to having the sample drawn. Screening should start at age 20, and if normal, it should be repeated at least every five years. Normal levels for a lipid profile are listed below
Total cholesterol: less than 200
LDL: less than 100
HDL: greater than 40 for men, greater than 50 for women (higher is even better)
Triglycerides: less than 140.
Treatment and prevention of hyperlipidemia
Lifestyle modification remains the best strategy for both preventing and treating hyperlipidemia. This involves adhering to a “heart healthy” diet, regular exercise habits, no smoking, and maintenance of a healthy weight. Additionally, medications known as statins might be prescribed to some individuals.
Rather than having a grossly low-fat diet, it is recommended to reduce the intake of saturated fat, trans fats, and cholesterol. The diet should consist of a colorful array of whole fruits and vegetables, be high in fibre, and whole grains. Fast foods, high carbohydrate foods, and any foods that do not offer good nutritional value should be restricted. Regular servings of fish, nuts, and legumes are recommended. When oil is used, it should be olive or monounsaturated oil.
Being overweight is a risk factor for hyperlipidemia and heart disease. Losing weight can help lower your
LDL, total cholesterol, and lower your triglyceride levels. It can also raise your HDL, which helps to remove the bad cholesterol out of the blood.
Not being physically active is a risk factor for heart disease. Regular exercise and activity can help lower LDL (bad) cholesterol and raise HDL (good) cholesterol levels. It also helps you lose weight. One should try to be physically active for 30 minutes at least 5 days a week. Brisk walking is an excellent and easy choice for exercise.
Smoking activates many problems that contribute to heart disease. It promotes plaque buildup on the walls of arteries, increases the bad cholesterol, and encourages blood clot formations and inflammatory responses. Quitting smoking will result in increases in HDL, which may be part of the reduced cardiovascular disease risk seen after smoking cessation.
The medical practitioner will use established guidelines to evaluate the lipid profile of the patient, along with other risk factors to determine if and when medications may be necessary. The most commonly prescribed high cholesterol medicines are statins (simvastatin, lovastatin, atorvastatin, and rosuvastatin). Occasionally statins are not tolerated due to side effects of muscle pain.
Hyperlipidemia is a common health problem that can lead to serious cardiovascular (heart) disease. There are no signs or symptoms of high cholesterol making it vital that individuals be aware of the need to be screened. Hyperlipidemia and subsequent heart disease can be prevented and treated through an appropriate use of medication and maintenance of a heart healthy lifestyle.
The author is a Research Scholar at Department of Biotechnology, University of Kashmir.