Biomarkers

Cholesterol

Cholesterol is a key biomarker for cardiovascular health. High levels can lead to serious illnesses, making it essential to manage cholesterol through a balanced diet, exercise, and regular testing.

What is cholesterol?

Cholesterol is a waxy, fatty substance found in every cell in the body. It is essential for a variety of body functions, including:

  • Building cell membranes.
  • Produce hormones.
  • Making vitamin D.

Cholesterol circulates in the blood in the form of lipoproteins, a combination of fats (lipids) and proteins.

There are two main sources of cholesterol:

  1. Endogenous cholesterol : Produced by the liver, which makes all the cholesterol the body needs.
  2. Exogenous cholesterol : From food, especially animal products such as meat, poultry and dairy products.

Understanding these sources allows you to better manage your cholesterol levels and maintain good heart health.

Prevalence

  • Approximately 7% of American children and adolescents (ages 6-19) have high total cholesterol.
  • Nearly 86 million American adults (20 years and older) have total cholesterol above 200 mg/dL.
  • Around 25 million adults have total cholesterol in excess of 240 mg/dL.
  • Cholesterol Types

    Cholesterol is carried by lipoproteins in the blood, including:

    1. Low density lipoproteins (LDL)
      • Nicknamed “bad” cholesterol, it contributes to the accumulation of plaques in the arteries.
      • These plaques thicken arterial walls, increasing the risk of cardiovascular disease.
    2. Very low density lipoproteins (VLDL)
      • They mainly transport triglycerides.
      • Like LDL, high levels can increase the risk of atherosclerosis.
    3. High density lipoproteins (HDL)
      • Known as “good” cholesterol, they eliminate excess cholesterol from the blood by bringing it back to the liver.
      • High levels of HDL help lower the risk of heart disease.

    Why Cholesterol Levels Matter

    Relationship between Cholesterol and Heart Disease

    High levels of LDL and triglycerides, combined with low levels of HDL, can cause atherosclerosis (a buildup of plaques in the arteries), resulting in:

    • Narrowing of arteries and reduced blood flow.
    • Clot formation that can cause heart attacks or strokes.

    Potential Consequences of High Cholesterol

    1. Coronary heart disease : Reduces blood supply to the heart, causing chest pain (angina) or heart attacks.
    2. Peripheral artery disease : Reduces the blood supply to the legs, causing pain and mobility problems.
    3. Carotid artery disease : Reduces blood supply to the brain, increasing the risk of stroke.

    How to Measure Cholesterol

    Lipid Test (Lipid Panel)

    A blood test measures:

    • Total cholesterol : Overall quantity of cholesterol in the blood.
    • LDL : “Bad” cholesterol.
    • HDL : “Good” cholesterol.
    • Triglycerides : A type of fat in the blood.

    Preparing for the test

    • Fasting : Avoid eating or drinking (except water) for 9 to 12 hours prior to the test.
    • Medications : Tell your doctor what medications or supplements you are taking.
    • Hydration : Drink plenty of water before the test.
    • Avoid alcohol : Refrain from alcohol for at least 24 hours prior to the test.

    Cholesterol Levels by Age and Gender

    Adults (20 years and older)

    • Total cholesterol : Less than 200 mg/dL.
    • LDL : Less than 100 mg/dL.
    • HDL : 40 mg/dL or more (men); 50 mg/dL or more (women).
    • Triglycerides : Less than 150 mg/dL.

    Children and Teens (under 19)

    • Total cholesterol : Less than 170 mg/dL.
    • LDL : Less than 110 mg/dL.

    Cholesterol Levels by Age and Gender

    Adults (20 years and older)

    • Total cholesterol : Less than 200 mg/dL.
    • LDL : Less than 100 mg/dL.
    • HDL : 40 mg/dL or more (men); 50 mg/dL or more (women).
    • Triglycerides : Less than 150 mg/dL.

    Children and Teens (under 19)

    • Total cholesterol : Less than 170 mg/dL.
    • LDL : Less than 110 mg/dL.

    High Cholesterol Risk Factors

    Feeding

    • Foods that increase LDL :
      • Saturated fats: Fatty meats, whole milk products.
      • Trans fats: Processed products, fried foods.
    • Cholesterol-lowering foods :
      • Soluble fibers: Oats, fruits, vegetables.
      • Omega-3 fatty acids: Fatty fish (salmon, sardines).
      • Healthy fats: avocados, nuts, olive oil.

    Lifestyle

    • Exercise : Increases HDL, reduces LDL and triglycerides.
    • Tobacco : Reduces HDL and damages arteries.
    • Alcohol : Consuming it in moderation can increase HDL, but excess increases triglycerides.

    Genetic Factors

    Family history plays an important role. Familial hypercholesterolemia can cause high LDL levels at a young age.

    Medical conditions

    Some diseases contribute to high cholesterol:

    • Diabetes : Increases LDL and reduces HDL.
    • Hypothyroidism : Increases total cholesterol and LDL.
    • Kidney or liver disease : Imbalances cholesterol levels.

    When to Get Your Cholesterol Checked?

    1. Kids : Between 9 and 11 years old for a first test.
    2. Adults (20 years and older) : Every 4 to 6 years if the risks are low.
    3. From the age of 40 : More frequent checks according to cardiovascular risk.
    4. High Risk Individuals : More regular tests according to medical recommendations.

    Cholesterol Management

    • Diet : Choose foods that are high in fiber and low in saturated fats.
    • Regular exercise : Aim for at least 30 minutes of moderate activity per day.
    • Quitting smoking : Improves HDL levels.
    • Medical treatments : Follow the prescriptions in case of high cholesterol.

    Proactive cholesterol management is essential for maintaining good cardiovascular health.