Key for What is Cholesterol?

  • What are LDL and HDL?
  • LDL and HDL represent the two structures of cholesterol we have in our bodies. Both LDL and HDL are lipoproteins. LDL stands for “low-density lipoprotein.” HDL stands for “high-density lipoprotein.” HDL absorbs LDL and carries it to the liver, which then removes it from the body. LDL is more prevalent than HDL, and although essential in appropriate amounts, when the LDL level is too high it leads to plaque buildup in blood vessels, such as arteries, which could lead to heart disease or stroke.
  • How do LDL and HDL differ structurally and functionally?

LDL Cholesterol / HDL Cholesterol
~ Twice as big as HDL
~ Large amount of fat surrounded by proteins
~ High lipid to protein ratio
~ Lower Density
~ Essential (ex. Need as part of cell membranes), but accumulates in arteries causing health issues when present in too high of concentrations
~ Carries cholesterol from the liver to the body / ~ Half the size of LDL
~ Small amount of fat surrounded by proteins
~ Low lipid to protein ratio
~ Higher Density
~ Essential for carrying LDL to the liver when it can be removed from the body
~ Carries cholesterol from the body to the liver
  • Why do doctors monitor the concentrations of LDL and HDL in patients’ blood?
  • HDL and LDL are monitored to assess risk of atherosclerosis, which is hardening of the arteries, which may lead to heart disease and stroke.
  • How are the concentrations of LDL and HDL associated with the risk for heart disease and associated disorders?
  • Low levels of LDL indicate the person is in good cardiovascular shape, indicating a low chance of cardiovascular related issues. Also, levels of HDL must be high enough to remove excess LDL and promote good heart health. High levels of LDL indicate the person has too much cholesterol that may begin accumulating in their arteries, increasing their chances of cardiovascular problems.
  • Additionally, the ratio of HDL to LDL is important. A high HDL to LDL ratio is healthier than a low HDL to LDL ratio, even if both patients have high cholesterol overall.
  • What other molecules in a patient’s blood are monitored along with LDL and HDL?
  • Triglycerides are often monitored along with cholesterol levels. Triglycerides are a type of fat in the blood. High levels of triglycerides often result from a diet high in animal fats and contribute to heart disease. High levels of both cholesterol and triglycerides would be very concerning.

Triglyceride Level (mg/dL) / Interpretation
> 500 / Very High
200-499 / High
150-199 / Borderline High
< 150 / Optimal
  • What do the results of a cholesterol test mean? How do patients interpret each value?

LDL Level (mg/dL) / Interpretation / HDL Level (mg/dL) / Interpretation / Total Cholesterol (mg/dL) / Interpretation
≥ 190 / Very High / < 40 / Low / > 240 / High
160-189 / High / ≥ 40 / Optimal / 200 - 239 / Borderline High
130-159 / Borderline High / < 200 / Optimal
100-129 / Above Optimal
< 100 / Optimal
  • What can patients do to change the levels of LDL and HDL in their blood?
  • A patient can change their diet to one low in cholesterol and saturated, animal fat. The patient can also exercise more to promote good cardiovascular health. In the case that these changes do not lower cholesterol it may be due to genetics, in which case medications, such as statins, may be taken to reduce the concentration of cholesterol.
  • How does intake of unsaturated, saturated, and trans fats affect cholesterol levels and overall health?
  • LDL is essential, but is also naturally made by the body. When saturated and trans fats are consumed cholesterol levels increase, increasing the chances of cardiovascular disease. Unsaturated fats (fats that are liquid at room temperature) will lower LDL levels because it helps remove the LDL from the body, promoting a healthy cardiovascular system.
  • Anna’s laboratory Test Result Interpretation:

Anna’s CBC Results (mg/dL) / Interpretation
Total Cholesterol – 389 / Very High
LDL – 243 / Very High
HDL – 60 / Normal
Triglycerides - 145 / Normal
  • Recommendations for Anna Garcia:
  • Diet Change
  • Eat smaller portions and few calories
  • Eat as few “empty” calories as possible
  • Eat as little trans-fats as possible, but eat as many unsaturated fats as possible
  • Exercise (walk) daily; attempt to lose weight
  • Medical Care
  • Take cholesterol lowering medication, such as a statin
  • Follow up with blood work to track improvement