Hypercholesterolemia
Hypercholesterolemia is a medical condition characterized by elevated levels of cholesterol in the bloodstream, which significantly increases the risk of heart attacks and strokes. Cholesterol, a fatty substance found in the body, is carried in the blood as low-density lipoproteins (LDLs) and high-density lipoproteins (HDLs). While LDLs are often referred to as "bad" cholesterol due to their role in transporting cholesterol to various body parts, HDLs are known as "good" cholesterol because they help transport excess cholesterol back to the liver for excretion.
The condition can go unnoticed, as individuals typically do not experience symptoms until serious complications arise, such as the buildup of plaque in arteries that can lead to blockages. Chronic hypercholesterolemia is often influenced by dietary choices, with higher intakes of fruits, vegetables, and grains recommended while reducing red meat and high-fat dairy products.
Treatment approaches include lifestyle changes like increased physical activity and prescribed medications such as statins and newer agents like PCSK9 inhibitors, which help to lower LDL levels. Regular monitoring by healthcare professionals is essential to manage the condition and prevent potential cardiovascular events. Understanding hypercholesterolemia is crucial for individuals looking to maintain cardiovascular health and mitigate associated risks.
Hypercholesterolemia
ANATOMY OR SYSTEM AFFECTED: Blood, blood vessels, circulatory system, heart, liver
DEFINITION: A high level of cholesterol in the bloodstream, which is considered a major risk factor for heart attack or stroke
CAUSES: Diet, high levels of low-density lipoproteins (LDLs) and low levels of high-density lipoproteins (HDLs)
SYMPTOMS: Plaque buildup on artery walls and possible blockage, causing stroke or heart attack
DURATION: Chronic
TREATMENTS: Dietary changes (increase in vegetables, fruits, and grains and decrease in red meat, egg yolks, and high-fat dairy products); increased physical exercise; medications (statins, niacin, bile-acid resins, fibric acid derivatives, cholesterol absorption inhibitors)
Causes and Symptoms
In the recent past, it has been difficult for medical professionals to establish a clear, causal connection between high cholesterol in the blood and heart disease. After numerous studies involving large numbers of patients over extended periods of time was it possible to establish the now widely accepted statistical between high and problems. Cholesterol is a fatty material similar to animal fats, which are called lipids. In the bloodstream, cholesterol combine with proteins to form either a low-density lipoprotein (LDL) or high-density lipoprotein (HDL). LDL transports cholesterol from the liver and to other parts of the body where it is needed. HDL transports excess cholesterol back to the liver where it is metabolized and excreted. HDL prevents excess fat from being deposited on the walls of and therefore is commonly called the “good” cholesterol. Research has established that LDL in blood should be less than 200 milligrams per deciliter, whereas HDL should be greater than 50 milligrams per deciliter, with a ratio of LDL to HDL of preferably four or less. A person is not aware of having high cholesterol. If the condition is not treated, however, then the likelihood of buildup on artery walls and a possible blockage, which could then cause a or heart attack, is increased.
Treatment and Therapy
The first step to reduce excess cholesterol in the bloodstream is a change in diet. As a general guideline, the consumption of vegetables, fruits, and grains should be increased, while red meat, egg yolks, and high-fat dairy products should be decreased. Vegetable oils made from corn, olives, or soybeans, which are low in saturated fats, are preferable to butter and animal fats. The next step is to increase physical exercise, which generally raises HDL, the good cholesterol. Several prescription medications, such as the statins Zocor or Lipitor and nicotinic acid medication such as nicolar and niaspan have been shown to be effective in lowering LDL. A physician needs to monitor a patient’s liver function to verify that no harmful side effects are occurring.
Perspective and Prospects
The 1985 Nobel Prize in Physiology or Medicine was awarded to Michael S. Brown and Joseph L. Goldstein for their study of cell-surface receptors that control the entry of LDL into cells. They showed that some people have a deficiency of these receptors. As a result, LDL does not enter cells at the normal rate but continues to circulate in the bloodstream, where it then can adhere to artery walls. In 2015, the US Food and Drug Administration approved the first proprotein convertase subtilisin/kexin type 9 inhibitor to limit the amount of LDL cholesterol in the bloodstream. Known as PCSK9 inhibitors, the drugs block the PCSK9 protein from breaking down LDL receptors on the liver. This allows the liver to remove more of the bad cholesterol from the blood. As of 2024, there were two PCSK9 inhibitors approved for use in the United States: alirocumab and evolocumab.
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