High blood cholesterol

[David Baxter PhD]

High blood cholesterol
By Mayo Clinic Staff
June 24, 2008

Cholesterol is found in every cell in your body. Cholesterol is used by your body to build healthy cells, as well as some vital hormones.

When you have high cholesterol, you may develop fatty deposits in your blood vessels. Eventually, these deposits make it difficult for enough blood to flow through your arteries. Your heart may not get as much oxygen-rich blood as it needs, which increases the risk of a heart attack. Decreased blood flow to your brain can cause a stroke.

High cholesterol (hypercholesterolemia) is largely preventable and treatable. A healthy diet, regular exercise and sometimes medication can go a long way toward reducing high cholesterol.

Symptoms
High cholesterol has no symptoms. A blood test is the only way to detect high cholesterol.

When to see a doctor
Ask your doctor for a baseline cholesterol test at age 20 and then have your cholesterol retested at least every five years. If your test results aren't within desirable ranges, your doctor may recommend more frequent measurements. Your doctor may also suggest you have more frequent tests if you have a family history of high cholesterol or other risk factors, like smoking or diabetes.

Causes
Cholesterol is carried through your blood, attached to proteins. This combination of proteins and cholesterol is called a lipoprotein. You may have heard of three different types of cholesterol, based on what type of cholesterol the lipoprotein carries. They are:

• Low-density lipoprotein (LDL). LDL, or "bad," cholesterol transports cholesterol particles throughout your body. LDL cholesterol builds up in the walls of your arteries, making them hard and narrow.
• Very-low-density lipoprotein (VLDL). This type of lipoprotein contains the most triglycerides, a type of fat, attached to the proteins in your blood. Like LDL cholesterol, VLDL cholesterol makes LDL cholesterol particles larger, causing your blood vessels to narrow. If you're taking cholesterol-lowering medication but have a high VLDL level, you may need additional medication to lower it because VLDL is high in triglycerides.
• High-density lipoprotein (HDL). HDL, or "good," cholesterol picks up excess cholesterol and takes it back to your liver.

Various factors within your control ? such as inactivity, obesity and an unhealthy diet ? contribute to high LDL cholesterol and low HDL cholesterol. Factors beyond your control may play a role, too. For example, your genetic makeup may keep cells from removing LDL cholesterol from your blood efficiently or cause your liver to produce too much cholesterol.

Risk factors
You're more likely to have high cholesterol that can lead to heart disease if you have any of these risk factors:

• Smoking. Cigarette smoking damages the walls of your blood vessels, making them likely to accumulate fatty deposits. Smoking may also lower your level of HDL, or "good," cholesterol.
• Obesity. Having a body mass index (BMI) of 30 or greater puts you at risk of high cholesterol.
• Poor diet. Foods that are high in cholesterol, such as red meat and full-fat dairy products, will increase your total cholesterol. Eating saturated fat, found in animal products, and trans fats, found in some commercially baked cookies and crackers, also can raise your numbers.
• Lack of exercise. Exercise helps boost your body's HDL "good" cholesterol while lowering your LDL "bad"cholesterol. Not getting enough exercise puts you at risk of high cholesterol.
• High blood pressure. Increased pressure on your artery walls damages your arteries, which can speed the accumulation of fatty deposits.
• Diabetes. High blood sugar contributes to higher LDL cholesterol and lower HDL cholesterol. High blood sugar also damages the lining of your arteries.
• Family history of heart disease. If a parent or sibling developed heart disease before age 55, high cholesterol levels place you at a greater than average risk of developing heart disease.

Complications
High cholesterol can cause atherosclerosis, a dangerous accumulation of cholesterol and other deposits on the walls of your arteries. These deposits ? called plaques ? can reduce blood flow through your arteries. If the arteries that supply your heart with blood (coronary arteries) are affected, you may have chest pain (angina) and other symptoms of coronary artery disease.

If plaques tear or rupture, a blood clot may form at the plaque-rupture site ? blocking the flow of blood or breaking free and plugging an artery downstream. If blood flow to part of your heart stops, you'll have a heart attack. If blood flow to part of your brain stops, a stroke occurs.

Preparing for your appointment
To check your cholesterol levels, you'll need to have blood drawn after you've been fasting. Usually, you'll need to go without eating or drinking anything but water for nine to 12 hours before your blood draw. Because of this, it's likely your doctor will recommend you have your blood drawn early in the morning.

At your appointment, your doctor may ask if you have a family history of high cholesterol or heart disease, since high cholesterol levels can be hereditary. Have this information ready, along with any other questions you might have.

Tests and diagnosis
A blood test to check cholesterol levels ? called a lipid panel or lipid profile ? typically reports:

• Total cholesterol
• LDL cholesterol
• HDL cholesterol
• Triglycerides ? a type of fat in the blood

For the most accurate measurements, don't eat or drink anything (other than water) for nine to 12 hours before the blood sample is taken.

Interpreting the numbers
Cholesterol levels are measured in milligrams (mg) of cholesterol per deciliter (dL) of blood in the United States and some other countries. Canada and most European countries measure cholesterol in millimoles (mmol) per liter (L) of blood. Consider these general guidelines when you get your lipid panel (cholesterol test) results back to see if your cholesterol falls in optimal levels (see attachment for table).

LDL targets differ
Because LDL cholesterol is associated with heart disease, it's the main focus of cholesterol-lowering treatment. But it's not as simple as the chart may appear. Your target LDL number can vary, depending on your underlying risk of heart disease.

Most people should aim for an LDL level below 130 mg/dL (3.4 mmol/L). If you have other risk factors for heart disease, your target LDL may be below 100 mg/dL (2.6 mmol/L). If you're at very high risk of heart disease, you may need to aim for an LDL level below 70 mg/dL (Below 1.8 mmol/L).

So who's considered very high risk? You might be if you've had a heart attack or if you have diabetes. In addition, two or more of the following risk factors also might place you in the very high risk group:

• Smoking
• High blood pressure
• Low HDL cholesterol
• Family history of early heart disease
• Age older than 45 if you're a man, or older than 55 if you're a woman

Treatments and drugs
Lifestyle changes such as exercising and eating a healthy diet are the first line of defense against high cholesterol. But, if you've made these important lifestyle changes and your total cholesterol ? and particularly your LDL cholesterol ? remains high, your doctor may recommend medication.

The specific choice of medication or combination of medications depends on various factors, including your individual risk factors, your age, your current health and possible side effects. Common choices include:

• Statins. Statins ? among the most commonly prescribed medications for lowering cholesterol ? block a substance your liver needs to make cholesterol. This depletes cholesterol in your liver cells, which causes your liver to remove cholesterol from your blood. Statins may also help your body reabsorb cholesterol from accumulated deposits on your artery walls, potentially reversing coronary artery disease. Choices include atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Altoprev, Mevacor), pravastatin (Pravachol), rosuvastatin (Crestor) and simvastatin (Zocor).
• Bile-acid-binding resins. Your liver uses cholesterol to make bile acids, a substance needed for digestion. The medications cholestyramine (Prevalite, Questran), colesevelam (Welchol) and colestipol (Colestid) lower cholesterol indirectly by binding to bile acids. This prompts your liver to use excess cholesterol to make more bile acids, which reduces the level of cholesterol in your blood.
• Cholesterol absorption inhibitors. Your small intestine absorbs the cholesterol from your diet and releases it into your bloodstream. The drug ezetimibe (Zetia) helps reduce blood cholesterol by limiting the absorption of dietary cholesterol. Zetia can be used in combination with any of the statin drugs.
• Combination cholesterol absorption inhibitor and statin. The combination drug ezetimibe-simvastatin (Vytorin) decreases both absorption of dietary cholesterol in your small intestine and production of cholesterol in your liver. You may have heard reports that this combination medication is no more effective than taking simvastatin by itself. But, this small study didn't find any differences in death, hospitalization or heart attacks between the two medications. If you are on this combination medication, you should continue to take it unless your doctor tells you otherwise.

If you also have high triglycerides, your doctor may prescribe:

• Fibrates. The medications fenofibrate (Lofibra, TriCor) and gemfibrozil (Lopid) decrease triglycerides by reducing your liver's production of very-low-density lipoprotein (VLDL) cholesterol and by speeding up the removal of triglycerides from your blood. VLDL cholesterol contains mostly triglycerides.
• Niacin. Niacin (Niaspan) decreases triglycerides by limiting your liver's ability to produce LDL and VLDL cholesterol. Various prescription and over-the-counter preparations are available, but prescription niacin is preferred as it has the least side effects. Dietary supplements containing niacin that are available over-the-counter are not effective for lowering triglycerides, and may damage your liver.
• Combination niacin and statin. If your doctor recommends niacin in addition to a statin, you might want to discuss taking a medication that combines both niacin and a statin, such as Simcor or Advicor. These medications can reduce the number of pills you have to take, although no research studies have yet shown that the combination drugs lower cholesterol more than taking niacin and a statin separately.

Most of these medications are well tolerated, but effectiveness varies from person to person. The common side effects are muscle pains, stomach pain, constipation, nausea and diarrhea. If you decide to take cholesterol medication, your doctor may recommend periodic liver function tests to monitor the medication's effect on your liver.

Lifestyle and home remedies
Lifestyle changes are essential to improve your cholesterol level. To bring your numbers down, lose excess weight, eat healthy foods and increase your physical activity. If you smoke, quit.

Lose excess pounds
Excess weight contributes to high cholesterol. Losing even 5 to 10 pounds of excess weight can help lower total cholesterol levels. Start by taking an honest look at your eating habits and daily routine. Consider your challenges to weight loss - and ways to overcome them.

Eat heart-healthy foods
What you eat has a direct impact on your cholesterol level. In fact, researchers say a diet rich in fiber and other cholesterol-lowering foods may help lower cholesterol as much as statin medication for some people.

• Choose healthier fats. Saturated fat and trans fat raise your total cholesterol and LDL cholesterol. Get no more than 10 percent of your daily calories from saturated fat. Monounsaturated fat ? found in olive, peanut and canola oils ? is a healthier option. Almonds and walnuts are other sources of healthy fat.
• Eliminate trans fats. Trans fats, which are often found in margarines and commercially baked cookies, crackers and snack cakes, are particularly bad for your cholesterol levels. Not only do trans fats increase your total LDL "bad" cholesterol, but they also lower your HDL "good" cholesterol.
  
  You may have noticed more food labels now market their products as "trans fat-free." But don't rely only on this label. In the United States, if a food contains less than 0.5 grams of trans fat a serving, it can be marked trans fat-free. It may not seem like much, but if you eat a lot of foods with a small amount of trans fat, it can add up quickly. Instead, read the ingredients list. If a food contains a partially hydrogenated oil, that's a trans fat, and you should look for an alternative.
  
• Limit your dietary cholesterol. Aim for no more than 300 milligrams (mg) of cholesterol a day ? or less than 200 mg if you have heart disease. The most concentrated sources of cholesterol include organ meats, egg yolks and whole milk products. Use lean cuts of meat, egg substitutes and skim milk instead.
• Select whole grains. Various nutrients found in whole grains promote heart health. Choose whole-grain breads, whole-wheat pasta, whole-wheat flour and brown rice. Oatmeal and oat bran are other good choices.
• Stock up on fruits and vegetables. Fruits and vegetables are rich in dietary fiber, which can help lower cholesterol. Snack on seasonal fruits. Experiment with veggie-based casseroles, soups and stir-fries.
• Eat heart-healthy fish. Some types of fish ? such as cod, tuna and halibut ? have less total fat, saturated fat and cholesterol than do meat and poultry. Salmon, mackerel and herring are rich in omega-3 fatty acids, which help promote heart health.
• Drink alcohol only in moderation. In some studies, moderate use of alcohol has been linked with higher levels of HDL cholesterol ? but the benefits aren't strong enough to recommend alcohol for anyone who doesn't drink already. If you choose to drink, do so in moderation. This means no more than one drink a day for women, and one to two drinks a day for men.

Exercise regularly
Regular exercise can help improve your cholesterol levels. With your doctor's OK, work up to 30 to 60 minutes of exercise a day. Take a brisk daily walk. Ride your bike. Swim laps. To maintain your motivation, keep it fun. Find an exercise buddy or join an exercise group. And, you don't need to get all 30 to 60 minutes in one exercise session. If you can squeeze in three to six 10-minute intervals of exercise, you'll still get some cholesterol-lowering benefits.

Don't smoke
If you smoke, stop. Quitting can improve your HDL cholesterol level. And the benefits don't end there. Just 20 minutes after quitting, your blood pressure decreases. Within 24 hours, your risk of a heart attack decreases. Within one year, your risk of heart disease is half that of a smoker's. Within 15 years, your risk of heart disease is similar to that of someone who's never smoked.

Alternative medicine
Few natural products have been proved to reduce cholesterol, but some might be helpful. With your doctor's OK, consider these cholesterol-lowering supplements and products:

• Artichoke
• Barley
• Beta-sitosterol (found in oral supplements and some margarines, such as Promise Activ)
• Blond psyllium (found in seed husk and products such as Metamucil)
• Garlic
• Oat bran (found in oatmeal and whole oats)
• Sitostanol (found in oral supplements and some margarines, such as Benecol)

You may have also heard of another supplement to reduce cholesterol, red yeast rice. The Food and Drug Administration released a warning regarding three brands of red yeast rice because they were found to contain lovastatin, the active ingredient in the drug Mevacor. This can be unsafe, since there's no way to determine the quantity or quality of the lovastatin in the supplement.

If you choose to take cholesterol-lowering supplements, remember the importance of a healthy lifestyle. If your doctor prescribes medication to reduce your cholesterol, take it as directed. Make sure your doctor knows which supplements you're taking as well.

 

[Retired]

What is total cholesterol to HDL cholesterol ratio?
What is a desirable ratio?​

Dr. Gregory Thomas:
The total cholesterol to HDL cholesterol ratio is a number that is helpful in predicting an individual's risk of developing atherosclerosis.

The number is obtained by dividing the total cholesterol value by the value of the HDL cholesterol. (High ratios indicate higher risks of heart attacks, low ratios indicate lower risk).

High total cholesterol and low HDL cholesterol increases the ratio, and is undesirable. Conversely, high HDL cholesterol and low total cholesterol lowers the ratio, and is desirable.

An average ratio would be about 4.5. Ideally we want to be better than average if we can. Thus the best ratio would be 2 or 3, or less than 4.


Another ratio is LDL/HDL. The LDL/HDL ratio is actually a purer ratio than total cholesterol/HDL, because LDL is a measure of "bad' cholesterol and HDL is a measure of "good" cholesterol, whereas the total cholesterol is the sum of HDL, LDL, and the VLDL. Adding up the values for the HDL, LDL and VLDL makes up the total cholesterol measurement.

Even though the total cholesterol/HDL ratio is not as accurate or pure as the LDL/HDL ratio, the former is more commonly obtained because the total cholesterol is easier and cheaper to obtain than the LDL cholesterol level.

It is important to remember that even with a favorable ratio; we have learned that it is still important to try to obtain an LDL of less than 80-100, regardless of the HDL value, especially in the presence of multiple other risk factors for coronary artery disease (genetic predisposition, tobacco use, hypertension, and diabetes). In patients with known coronary artery disease (history of bypass surgery, stents, or PTCA), an LDL of less than 80 is extremely desirable.

About the Author:
Dr. Gregory Thomas is a cardiologist in private practice in Mission Viejo, California. Dr. Thomas began his cardiology fellowship at Cedars Sinai Medical Center in Los Angeles, and then completed his fellowship at Massachusetts General Hospital. He is currently assistant clinical professor at UC Irvine, California. His special interest is in the treatment of cholesterol abnormalities and in the prevention and treatment of coronary heart disease.
Source: medicinenet.com