Cholesterol is a lipid substance that is vital for our bodies to function properly. It plays a key role in the formation of cell membranes, the synthesis of steroid hormones, bile, and vitamin D. However, when present in excess, it can lead to serious health complications, primarily cardiovascular diseases.
Cholesterol, being insoluble in water, is transported in the bloodstream by lipoproteins. These molecules consist of a lipid core, rich in cholesterol and other fat-soluble substances, surrounded by a protein and phospholipid shell. They are classified based on their density, which varies inversely with their lipid content. The key types include Very Low-Density Lipoproteins (VLDL), Low-Density Lipoproteins (LDL), Intermediate Density Lipoproteins (IDL), and High-Density Lipoproteins (HDL).
LDL, often referred to as 'bad cholesterol,' transports cholesterol from the liver to the body's periphery, promoting its deposition on arterial vessel walls. On the other hand, HDL, or 'good cholesterol,' carries cholesterol from the body's periphery to the liver, acting like a street cleaner, clearing arteries from cholesterol deposits. It's no surprise that high LDL cholesterol levels are associated with increased cardiovascular risk, while high HDL cholesterol levels correlate with lower cardiovascular risk.
Hypercholesterolemia is a medical term used to denote high levels of cholesterol in the blood, it can lead to severe health complications, predominantly cardiovascular diseases.
As previously mentioned the most concerning situation arises when there is a rise in low-density lipoprotein cholesterol (LDL also called "bad cholesterol"). Excessive LDL cholesterol tends to accumulate on the blood vessel walls, forming plaques that obstruct blood flow and harden the arteries. This condition can lead to vascular ischemia, vessel ruptures, and hypertension.
On the other hand, high-density lipoprotein cholesterol (HDL or "good cholesterol"), lowers cardiovascular risk. HDL particles help rid the body of cholesterol by capturing it and transporting it to the liver for elimination.
Numerous factors can influence blood cholesterol levels. Here's a detailed look at some of them:
When high cholesterol levels persist despite a balanced diet and regular physical activity, it may be a condition known as familial hypercholesterolemia or primary hypercholesterolemia. This condition, often rooted in genetics, prompts the body to produce excessive amounts of cholesterol from a young age.
There are three primary forms of hereditary hypercholesterolemia:
Hypercholesterolemia is largely asymptomatic, meaning it usually does not present with noticeable symptoms. However, severe forms of the condition can lead to the development of xanthomas and xanthelasmas, which are cholesterol deposits in the skin and tendons.
Xanthomas are yellow-orange plaques or nodules with a waxy appearance that occur due to lipid accumulation under the skin. These are often seen in individuals with high cholesterol and triglyceride levels. Xanthelasmas, on the other hand, are yellowish-white papular or nodular lesions that occur on the upper and lower eyelids.
High cholesterol is a major risk factor for cardiovascular diseases, which are the leading cause of death in industrialized countries. This is primarily due to the role of cholesterol in the development of atherosclerosis, a degenerative disease that affects large and medium-sized arteries, reducing their elasticity and blood flow.
In atherosclerosis, inflammatory and scarring lesions form on the inner walls of the arteries. These lesions accumulate deposits of lipids and immune cells, making the artery more prone to rupture and obstructing normal blood circulation. This reduces the amount of oxygen and nutrients available to the tissues downstream of the obstruction. The higher the cholesterol levels, the greater the risk of atherosclerosis.
Complications of atherosclerosis include angina pectoris, ischemic heart disease, myocardial infarction, intermittent claudication, erectile dysfunction, and stroke. Symptoms of these conditions can include chest pain, cramps during walking, mental confusion, and headaches.
Cholesterol levels can be easily measured with a simple blood test and should be monitored regularly.
In addition to blood tests, doctors may recommend other checks to evaluate the state of heart health and the cardiovascular system. These could include blood pressure measurement, blood sugar control, kidney function evaluation, electrocardiogram (ECG), angiography, and Doppler ultrasound.
It's critical to note that total cholesterolemia alone is a poor predictor of cardiovascular risk. A situation where total cholesterol is within the norm but the HDL fraction is particularly low is much more dangerous than another where total cholesterolemia exceeds the limit value of 200 mg/dL but the HDL fraction is higher in percentage.
Cholesterol levels in the blood, or cholesterolemia, are commonly measured to evaluate a person's circulatory system health. The total cholesterol value, which should ideally be less than 200 mg/dl of blood, represents the overall quantity of cholesterol contained in various lipoproteins (LDL, VLDL, HDL). Alongside total cholesterol, it's crucial to measure LDL and HDL quantities.
Adults should measure their cholesterol levels every five years or more frequently if they have one or more risk factors for cardiovascular disease. Children and teenagers should be tested between the ages of 9-11 and 17-21.
Despite the fact that this condition can be genetically inherited, lifestyle modifications play a crucial role in managing the condition. A well-planned diet, combined with regular physical exercise, can help maintain a healthier lipid balance.
Dietary recommendations typically include:
If dietary and lifestyle changes are insufficient, lipid-lowering medications may be necessary. These include statins and fibrates, which work synergistically with dietary changes to manage cholesterol levels. Other commonly used medications include ezetimibe, niacin, and bile acid sequestrants.
Prevention is the key strategy to maintain healthy cholesterol levels. This primarily involves maintaining a healthy diet, regular physical activity, weight management, and avoiding smoking. By understanding the factors that influence cholesterol levels and taking proactive steps to manage them, it's possible to reduce the risk of hypercholesterolemia and its associated health complications.