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What makes cholesterol “good” or “bad”? This is a question many ponder when reviewing their lipid panel results. Understanding the key components of cholesterol and their influence on cardiovascular health is crucial for managing one’s health.
Cholesterol plays several vital roles in our body. Produced primarily by the liver and released into the bloodstream, it is essential for forming cell membranes, aiding digestion, converting vitamin D in the skin, and producing hormones. But how does cholesterol travel through our bodies? The answer lies in lipoproteins, tiny particles made up of fats and proteins.
High cholesterol (hyperlipidaemia) is a silent condition that often presents no symptoms, making detection possible only through a blood test. This test reveals important information about an individual’s lipid profile, including levels of low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglyceride (a type of fat in the blood).
LDL, often referred to as "bad cholesterol," transports cholesterol to tissues, including arteries, where buildup can occur. Higher LDL levels increase the risk of atherosclerosis, a condition where cholesterol deposits form plaques in the artery walls, potentially leading to blockages. Conversely, HDL, known as "good cholesterol," removes excess cholesterol from the bloodstream and artery walls, carrying it to the liver for elimination. Higher HDL levels are generally associated with better cardiovascular health.
Triglycerides, while not a type of cholesterol, also play a crucial role in the lipid panel. These fats are stored in cells and used as an energy source. High triglyceride levels are often found in people with high cholesterol, heart problems, or diabetes, further contributing to cardiovascular risk.
When calculating the total cholesterol score, doctors consider all these components. Specifically, they add up the HDL, LDL, and 20% of the triglyceride value. A combination of high LDL and triglycerides, along with low HDL, can significantly increase the risk of atherosclerosis and related cardiovascular issues.
Effective cholesterol management is about striking a balance. The goal is to lower LDL (bad cholesterol) while raising HDL (good cholesterol). This balance is crucial as excessive LDL can lead to atherosclerosis, where plaques in arteries may thicken and become unstable, increasing the risk of ruptures that can cause heart attacks.
LDL-mediated heart disease often first appears as angina - chest pain during physical exertion that subsides with rest. In more severe cases, plaque rupture can lead to sudden, potentially fatal heart attack.
Plaque rupture in blood vessel
Cholesterol levels are influenced by a complex variety of factors, some controllable through lifestyle changes and others not. These include:
Exercise: Physical activity can significantly alter cholesterol composition. It helps lower LDL while boosting HDL. At least 150 minutes of moderate-intensity exercise weekly is recommended to raise HDL and maintain a healthy weight.
Diet: Food choices directly influence lipid profiles. A hearthealthy diet includes reducing saturated and trans fats found in red meat, palm oil derivatives like margarine, and processed foods. Incorporating omega-3 fatty acids and fibre-rich foods, like salmon and oatmeal, can positively impact cholesterol levels.
Weight: Excess body weight often leads to imbalanced cholesterol levels. Obesity is strongly associated with higher LDL, lower HDL, and elevated triglycerides. Achieving a healthy weight can improve the lipid profile. For Asian populations, the optimal body mass index (BMI) range is between 18.5 to 22.9kg/m².
Lifestyle choices: Certain habits can disrupt cholesterol balance. Alcohol consumption and smoking contribute to unfavourable lipid profiles and should be limited or eliminated. For individuals with diabetes, proper blood sugar management is essential, as uncontrolled diabetes can raise LDL and triglycerides while lowering HDL.
Genetics and age: While lifestyle modifications can significantly impact cholesterol levels, some factors are beyond control. Genetic predisposition, family history and age all influence cholesterol. As people age, cholesterol levels naturally tend to rise.
Recent studies suggest that fasting is not always required for cholesterol testing. In a study involving type 2 diabetes patients, fasting and non-fasting cholesterol levels showed minimal differences. However, if triglyceride levels remain consistently high, a fasting sample may still be necessary for accurate assessment. Cholesterol management targets vary based on individual risk profiles. For those without a history of heart attack or stroke, the targets are more flexible, while high-risk individuals require stricter control. General guidelines include:
LDL level above 4.9 mmol/L is considered very high and may necessitate medication.
HDL level below 1 mmol/L could indicate the need for lifestyle changes.
Triglyceride levels should remain under 1.7 mmol/L for optimal heart health.
Regular screenings are essential, especially for those over 40, as high cholesterol often presents no symptoms. By managing cholesterol through lifestyle changes and medications, when necessary, individuals can greatly lower their risk of heart attack, stroke, and other cardiovascular issues.
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