Lipid Disorders/High Cholesterol

	Figure 1: Ruptured cholesterol plaque with thrombus

What is cholesterol and why is it important in heart disease?

Cholesterol is an essential nutrient used for various functions in the body including: 1) building and repairing healthy cells, 2) hormone production, and 3) boosting cell connections in the brain helpful in learning and memory. Cholesterol comes from both one’s diet as well as from production in our bodies.  Surprising to most is that approximately 2/3rds of one’s total cholesterol is produced by the liver.  People are born with a certain number of cholesterol receptors used for transport; however the danger to coronary artery health occurs when the cholesterol levels in the blood stream outnumber the number of available receptors.  Overabundance of lipoproteins results in deposition of cholesterol into the arterial wall.  The body recognizes this cholesterol as “foreign” and sends macrophages (white blood cells) to the area.  This process can make this vessel area “unstable”, which may then rupture and cause clot formation.  Once an obstruction results in a significant decrease in blood supply to the heart muscle, angina or chest pain may result.  If the artery becomes completely obstructed, one may suffer a heart attack and even death. Figure 1 demonstrates a ruptured plaque with occlusion of the artery by a thrombus. 

What are the different types of cholesterol?

When you are given your lab slip to obtain a “lipid profile” the following things are usually included:

1. Triglycerides
2. LDL
3. HDL
4. VLDL
5. Total cholesterol
6. Cholesterol ratio

All of the items listed above are categories of lipoproteins in the body.  They can be easily measured in the blood, and therefore, are used as the main cholesterol measurement system.

Triglycerides are a type of fat found in your blood. When you eat, your body converts any calories it doesn't need to use right away into triglycerides. The triglycerides are stored in your fat cells.  Low-density lipoprotein otherwise known as “LDL” or “bad cholesterol” is thought to be the protein that deposits in the arteries resulting in blockages.  LDL is not usually a direct measurement, but instead a calculated lab value. High-density lipoproteins otherwise known as “HDL” or “good cholesterol” are naturally formed in the liver and act as cholesterol scavengers, picking up excess cholesterol in your blood and taking it back to your liver for disposal.  LDL contains the highest amount of cholesterol. HDL contains the highest amount of protein. VLDL “Very low-density lipoproteins” is the third major form of cholesterol.  VLDL contains the highest amount of triglyceride, a blood fat. Like LDL cholesterol, VLDL cholesterol is considered a type of "bad" cholesterol because elevated levels are associated with an increased risk of coronary artery disease.  There is no simple, direct way to measure VLDL cholesterol. Instead VLDL cholesterol is usually estimated as a percentage of your triglyceride value.  The total cholesterol is a combination of the HDL, LDL, and VLDL.  The total cholesterol is correlated to an increased risk in coronary artery. Cholesterol goals often focus on increasing the HDL and decreasing the LDL thereby improving the cholesterol ratio (Total cholesterol to HDL ratio).  Specific goals are different for each patient and are based on assessment of individual risk factors.  These target goals may change over time as well as the ability to reach these goals may require significant medical expertise, and therefore, regular follow up with your cardiologist is recommended.

How do I determine my risk for heart disease and my cholesterol goals?

Risk factors for heart disease include many factors, some of which can be modified through lifestyle change and medication.

• Modifiable risk factors include: smoking, high blood pressure, diabetes, insulin resistance, PCOS (polycystic ovary syndrome), high cholesterol, physical inactivity, obesity, increased abdominal adiposity, alcohol abuse, chronic inflammation, and stress.
• Non-modifiable risk factors include: gender, family history, increasing age, post menopausal state, and heredity including race.

Risk of coronary artery disease is higher among African Americans, Mexican Americans, American Indians, Asian Americans, and native Hawaiians due to a higher incidence of obesity and diabetes as well as genetic factors. Cholesterol goals are determined based on your risk factors.  As can be seen, there are many factors that need to be considered by your physician before establishing your individual cholesterol goals.

Additional testing is available that may help to determine risk of developing coronary artery disease.  A few of the lab tests available include:

1. Lipoprotein a or Lp(a)
2. Apolipoprotein E or ApoE
3. C-reactive protein (C-RP)
4. Homocysteine levels
5. Elevated white blood cell count and fibrinogen-prothrombotic state
6. IDL (Intermediate-Density Lipoprotein)
7. Lp-Pla2
8. Adiponectin- Cardiometabolic risk

What medications are commonly used to treat my cholesterol? 

The medications used to treat cholesterol are determined based on cholesterol goals, current medications, and individual medical history.  We approach lifestyle modification first, using medication when necessary to achieve cholesterol goals.  The most common group of medications used to treat abnormal cholesterol is the statins.  This group of medications works by inhibiting HMG-CoA reductase, which is an enzyme, used in cholesterol formation.  Not only can they effectively reduce cholesterol levels, but more importantly, have been demonstrated to reduce death risk and major morbidity caused by heart attack or stroke.  Statins will reduce LDL, total cholesterol, and triglycerides while some may additionally raise HDL.  Frequently discussed side effects are muscle aches and fatigue in the large muscle groups and this you should bring to your doctor’s attention if you believe is present.  Liver function and muscle enzyme blood tests may periodically be sent while taking this medication. 

Nicotinic Acid (Niacin), Niaspan, Slo-Niacin is also frequently used for treatment of dyslipidemia.  Nicotinic Acid can lower triglycerides and LDL, and increase HDL.  Niaspan is often used in combination with other cholesterol medications for an additive effect.  To reduce possible side effects, this medication is most commonly taken ½ hour after consuming an aspirin.  Additionally avoiding hot drinks, and eating a small snack may help reduce side effects that can include hot flushing, headache, and dizziness.  After about 1 week, these symptoms most often subside, though skipping a dose of the medication can heighten the side effects, so compliance is strongly recommended.  Possible GI effects may also occur. 

Fibrates (Tricor, Antara, or fenofibrate)  This group of medications helps with decreasing triglycerides, total cholesterol, VLDL, and LDL.  Side effects can include liver abnormalities, muscle aches and pains, GI discomfort, rash, and sensitivity to sunlight.  The fibrates may also interact with certain foods and medications.

Bile Acid Resins (Welchol) bind to the bile acid responsible for cholesterol excretion.  This group of medications is used to decrease LDL cholesterol when a patient is intolerant to other medications or when additional cholesterol lowering is required.  Common side effects include GI discomfort with constipation, heartburn, and flatulence. If dissolved in water, these symptoms tend to be less. 

Zetia (ezetimibe) affects dietary cholesterol absorption in the intestinal tract.  It should be used in coordination with other medications to reach one’s cholesterol goals and only as a monotherapy if you cannot tolerate a statin.  Zetia is available in a combination medication with simvastatin (Zocor) named Vytorin.

Fish Oil (Omega Three Fatty Acids) and Lovaza lower triglycerides and LDL and increase HDL.  Omega three fatty acids or fish oils are available in food such as fish, walnuts, and eggs.  Fish oil is sold over the counter though may have variable concentrations of active ingredients. 

What are some lifestyle changes that I can make to benefit my cholesterol?

When treatment focuses on lifestyle changes, this means diet and exercise.  In terms of diet, we consider the recommendation as a “way of life” change and not a temporary “diet.”  The diet that we recommend focuses on a Mediterranean-style approach that is high in alpha-linolenic acid (polyunsaturated omega-3 fatty acid) and uses whole wheat or multigrain bread, increased intake of fruits and vegetables, walnuts, legumes, beans, fish, chicken, and turkey.  This recommendation is based on the reported effectiveness of this diet when compared to others.  Additionally beef, lamb, pork, butter, cream, and preparation of foods with breading and frying should be limited or avoided completely.  Focus on avoiding hydrogenated, processed, or fortified foods, and increasing the use of olive oil and garlic seasoning.  Wine is consumed in low to moderate amounts.  Consult with your health care provider before following any diet.

Exercise is beneficial to maintenance of a healthy weight, decreasing abdominal adiposity, improving mood and sleep habits, and promoting cardiovascular health among other benefits.  Depending on your medical history, age, medications, and possible disabilities, intensity of exercise can vary and each patient should receive an exercise prescription plan based on these parameters.   A broad generalization recommends moderate intensity exercise (50-70% of HR maximum) for 40-60 minutes; most days of the week in order to achieve weight stability and most effectively benefit cardiovascular health. 

Your cardiologist should be consulted prior to initiating these lifestyle changes so that your time, effort, and health are not compromised and proper screening tests and monitoring can occur.

Patients are encouraged to call the office with questions regarding the above topics and come in to be seen and evaluated. Good luck with your risk factor management for coronary artery disease.  This is the most expensive disease and number one killer in the United States and lifestyle changes and proper medical treatment will benefit not only you, but your family, and society as a whole.