Cholesterol

Cholesterol is a waxy, fat-like substance found in every body cell. Cholesterol is essential for life. However, after infancy, your body makes all the cholesterol you need to survive. Any cholesterol you consume in your diet is extra. By blocking or narrowing the arteries, extra cholesterol contributes to the development of vascular disease, including heart attack, stroke and peripheral vascular disease.


General information
To provide a more accurate picture of your risk of heart disease, cholesterol readings are often broken down into different categories, including total cholesterol, low-density lipoproteins (LDL), high-density lipoproteins (HDL) and triglycerides.
Total cholesterol
Total cholesterol levels should be less than 200 milligrams/deciliter of blood. Readings between 200 and 239 mg/dL are considered borderline high. Anything 240 mg/dL or higher is considered high. For children older than age 2 who are at high risk for heart disease, total cholesterol should be less than 170mg/dL.

Low-density lipoproteins
Lipoproteins are the proteins that carry cholesterol through your bloodstream. Low-density lipoproteins are sometimes called "bad" cholesterol. LDLs take cholesterol from the liver and bring it to the cells to do its job, but any extra LDL is deposited on your artery walls. Over time, these deposits can lead to heart disease. Elevated levels of Lp(a), an inherited variation of LDL, may increase the risk of early development of fatty deposits in the arteries. There's currently no evidence to support general screening for Lp(a) levels, however. Reducing your LDL levels will also lower Lp(a) levels.

According to recently updated guidelines from the National Cholesterol Education Program (NCEP), the desirable LDL level is less than 100 mg/dL. Readings between 100 and 129 are considered near optimal/above optimal. Readings between 130 and 159 mg/dL are considered borderline high. Anything 160 mg/dL or higher is considered high.

It's important to note that recent trial results support new recommendations for when to treat elevated LDL levels in people who have a moderately high to high risk for having a heart attack. Your doctor will use a formula to calculate your risk of having a heart attack or dying from heart disease within 10 years. The result is used along with other factors to determine your risk level for heart disease. For example, you're at high risk if you:

have heart disease or blood vessel disease
have diabetes
have two or more risk factors (such as smoking and high blood pressure) AND your 10-year risk of having a heart attack or dying from heart disease is more than 20 percent
You're considered moderately high risk if you:

have two or more risk factors (such as smoking and high blood pressure) AND your 10-year risk of having a heart attack or dying from heart disease is 10 to 20 percent
When your doctor determines your risk level for heart disease, he or she may recommend lifestyle changes and medication based on your LDL level. For example, if you're at high risk, current guidelines suggest an LDL level less than 100 mg/dL. However, your doctor may recommend lowering your LDL level to less than 70 mg/dL based on the new trial results. If you're at moderately high risk, a desirable LDL level would be less than 130 mg/dL, but your doctor may recommend treatment with medication to lower your LDL to less than 100 mg/dL. The new recommendations are meant to reduce LDL levels in people at moderately high to high risk for having a heart attack by 30 to 40 percent.

High-density lipoproteins
High-density lipoproteins are sometimes called "good" cholesterol. They help remove "bad" cholesterol from the blood. HDL readings of 40 mg/dL or less are considered low and put you at risk for developing heart disease. Readings 60 mg/dL or higher are considered desirable because they help lower your risk for heart disease.

Triglycerides
Triglycerides are another form of fat in the blood. They're produced from the carbohydrates and fats in the foods you eat. Triglyceride and HDL levels seem to be related -- high triglyceride levels are usually accompanied by low HDL levels and vice-versa. Triglyceride levels less than 150 mg/dL (recently lowered from 200 mg/dL) are considered healthy. Readings between 150 and 199 mg/dL are considered borderline high, and readings higher than 200 mg/dL are considered high


Causes/associated factors
High cholesterol is often related to diet, lifestyle and genetics. Elevated cholesterol can also be a result of certain thyroid, kidney or liver disease.
Diet
What you eat helps determine your blood cholesterol levels. From birth to about age 2, it's not necessary to limit fat intake because fats help fuel a rapidly growing brain and nervous system. After age 2, however, excessive fat intake can cause deposits of plaque along the artery walls.

Lifestyle
A sedentary lifestyle can lead to high cholesterol and excess weight gain.

Genetics
Genetics also play a role in determining your cholesterol level. Genetic risk factors include having one parent with a blood cholesterol level of 240 mg/dl or higher or having a parent, grandparent or sibling who developed heart disease before age 55. If you're at risk for developing high cholesterol, ask your doctor for a cholesterol test.


Signs/symptoms
High cholesterol is difficult to detect through symptoms. Some people only learn their cholesterol level is elevated through routine screening or after experiencing some type of heart trouble, such as a heart attack. Rarely, a person who has congenital high cholesterol problems may have small fatty deposits on the skin, abdominal pain, or an enlarged spleen or liver.

Diagnosis
A simple blood test can measure your blood levels of cholesterol and other fats. Testing is most accurate when the sample is taken from a vein, rather than a finger prick. If you'll be tested for triglycerides, you'll need to fast for 12 hours before the test. Home cholesterol testing isn't recommended because the results aren't considered reliable.

Treatment
Lifestyle modifications
Depending on your risk factors, the first steps your doctor may recommend are changing your eating habits, maintaining an optimal weight, exercising regularly, and quitting smoking. Your doctor may also recommend that you limit your alcohol consumption to no more than 2 to 3 ounces of alcohol per day.

Diet: If you have high cholesterol, your doctor will recommend limiting your cholesterol and fat intake. Your doctor may refer you to a registered dietitian as well. Three months after beginning your new diet, your cholesterol will probably be checked again. Then, periodic testing will be done to monitor your progress. Unless your doctor has recommended a more restrictive diet, here are some tips:

When you're shopping for groceries, take time to read nutritional labels and make wise choices. For help understanding nutritional labels, consult your doctor or a registered dietitian.

Eat no more than 300 milligrams of cholesterol a day. Cholesterol is found in foods from animal sources, such as meat, egg yolks, fish, poultry and dairy products. Cholesterol isn't found in any foods derived from plants.

Minimize your fat intake. As a general rule, get no more than 30 percent of your calories from fat each day, and no more than 10 percent from saturated fat. The National Academies' Institute of Medicine recommends adults limit fat intake to 20 to 35 percent of their daily calories. (If you have heart disease or are at high risk for heart disease, your doctor may limit your saturated fat intake even more.) Saturated fats are usually solid at room temperature, and unsaturated fats are usually liquid at room temperature. All fat that's not used by your body in its daily metabolism will be converted into body fat and can lead to increased buildup of plaque in your arteries.
Keep in mind that fats play a bigger role in elevating blood cholesterol levels than dietary cholesterol. If you eat 2,000 calories a day, limit your total fat intake to about 67 grams a day. Limit your saturated fat intake to no more than 22 grams. Saturated fat is found in foods such as meat (especially red meat), whole milk, cheese and regular ice cream. Unlike cholesterol, fat can be found in plant foods in addition to animal foods.


Eat at least 20 to 35 grams of fiber each day. It may help lower your cholesterol.
Exercise: You can often lower high blood cholesterol levels by increasing physical activity and, if necessary, losing any excess weight. Moderate physical activity every day -- currently defined as 30 to 60 minutes per day -- can help raise "good" cholesterol levels, and even 5 to 10 pounds of weight loss can help lower total cholesterol levels.

Benefits: Low-fat, low-cholesterol diets have been shown to lower blood pressure, lower blood cholesterol, and slow the progression of atherosclerosis. Regular exercise has many benefits, including raising HDL levels and lowering LDL levels. If you quit smoking, you may also improve your overall cholesterol level. Consult your doctor if you're having trouble quitting. Many products and programs are available to help.

Risks: Changing long-term habits such as eating unhealthfully or smoking can be difficult to do and maintain. It takes education in nutrition, as well as commitment and willpower. Sometimes, even these changes aren't enough to lower your blood cholesterol and reduce the risks of high cholesterol.

Medication
Medication is usually reserved for those who are unable to adequately reduce cholesterol levels through lifestyle and dietary changes, or for people who have high risk factors or heart disease. While medication is usually effective, you must also make significant lifestyle changes, such as staying on a fat- and calorie-restricted diet and following your doctor's recommendations concerning exercise and weight control. Always talk with your doctor before making any changes to your medications.

Types of medications to reduce cholesterol levels include statins, bile-acid binding resins and fibrates. Other medications, such as niacin and ezetimibe, may also be prescribed

Statins: Statins block the enzyme that triggers the liver to make cholesterol. They include Lovastatin (Mevacor, for example), pravastatin (Pravachol, for example), rosuvastatin (Crestor, for example) and simvastatin (Zocor, for example). Examples of newer statins include fluvastatin (Lescol, for example) and atorvastatin (Lipitor, for example). Statins are often the first medication of choice to lower cholesterol levels, particularly for people who have heart disease or diabetes.

Benefits: Statins lower levels of bad (LDL) cholesterol and triglycerides, and raise good (HDL) cholesterol levels. If you have heart disease, they can reduce your risk of having a heart attack.

Risks: These medications may cause myositis (inflammation of the muscle tissue) and the development of higher levels of certain enzymes in the liver. Side effects may also include aching joints and muscle pain.
Bile-acid binding resins: Resins work by attaching to bile, which is made from cholesterol. Cholestyramine (Questran, for example) and colestipol hydrochloride (Colestid, for example) are often used to prevent high cholesterol or reduce mildly elevated LDL levels.

Benefits: Resins can reduce cholesterol levels and may reduce your risk of having a heart attack.

Risks: Resins are not as effective as statins and are no longer first-line agents. Resins can also interact with other medications. Side effects include gastrointestinal symptoms such as heartburn and constipation. Bile-acid binding resins are often prescribed along with other medications.
Fibrates: Fibrates are often prescribed to lower triglyceride levels. Gemfibrozil (Lopid, for example) and fenofibrate (Tricor, for example) are medications in this category.

Benefits: Fibrates lower triglyceride levels. If you have heart disease, they may reduce your risk of having a heart attack.

Risks: Fibrates have varied effects on LDL levels. Side effects of fibrates include muscle pain and, rarely, muscle and kidney damage.
Niacin: Niacin (Nicobid or Nicolar, for example) is a B vitamin (B3) that's found in foods such as fortified cereals, bread, liver and lean meat. It's available as a capsule, tablet or powder that must be mixed with liquid.

Benefits: Niacin raises HDL levels and lowers total cholesterol and triglyceride levels when taken in doses that exceed recommended vitamin requirements.

Risks: This medication can have many side effects, including flushing skin, itching and gastrointestinal distress. It may also make it difficult for people who have diabetes to control their blood sugar. As an alternative, the U.S. Food and Drug Administration (FDA) has approved a sustained-release preparation called Niaspan that's often better tolerated.
Ezetimibe (Zetia, for example) is a new cholesterol-lowering medication that prevents the intestine from absorbing cholesterol. Research is currently underway on another new medication to raise HDL levels, torcetrapib. This medication blocks the protein known to lower HDL.

Combination medications that can treat more than one condition or the same condition in various ways are becoming more widely available. For example, the medication Caduet combines Lipitor for high cholesterol and Norvasc for high blood pressure. Vytorin combines Zetia, a cholesterol blocker, and Zocor, a statin.


Complications
Heart disease is a serious complication of sustained high cholesterol. Risk factors for heart disease include:
advanced age
being male
family history of high cholesterol
family history of heart disease before age 55
diabetes
high cholesterol
smoking
obesity
high blood pressure
sedentary lifestyle
The U.S. Preventive Services Task Force recommends that adults who have high cholesterol be screened for diabetes to help reduce the risk of heart disease.


Pregnancy-specific information
During pregnancy, it's important to eat a healthful, balanced diet. Specific guidelines for cholesterol aren't typically needed. Consult your doctor or a registered dietitian about your specific dietary needs.

Senior-specific information
The risk of developing heart disease and diabetes increases with age, so monitoring your dietary cholesterol may become more important as you grow older. Consult your doctor or a registered dietitian about your specific dietary needs.

Prevention
The National Cholesterol Education Program currently recommends a fasting lipoprotein profile (to measure total cholesterol, HDL, LDL and triglycerides) for all adults age 20 and older every five years. Depending on your risk factors for heart disease, your doctor may recommend more frequent testing.
To maintain healthy cholesterol levels, eat a low-fat, low-cholesterol diet, maintain a healthy weight, exercise and quit smoking. Consider these simple steps toward a healthful diet:

Choose foods with the lowest level of saturated fats.

Use olive or canola oil. Avoid palm and coconut oils. When possible, use olive oil instead of butter.

Avoid hydrogenated fats, which are commonly found in commercially prepared pastries, shortening and margarine.

Choose lean meat and trim visible fat. Limit meat portions to 3 ounces per serving.

Instead of bacon, use lean ham or Canadian bacon.

Consider cooked or canned dried beans, veggie burgers and tofu for meat substitutes. Try meatless main courses.

Choose poultry without skin.

If you eat eggs, limit to two per week -- one egg has 213 milligrams of cholesterol. For baked goods, use two egg whites instead of one egg.

Request salad dressing on the side and use sparingly.

Instead of butter, flavor vegetables with lemon, orange, herbs, flavored vinegar or spices.

Switch to low-fat or nonfat dairy products.

Avoid hot dogs, fatty processed meats, coconut, fried foods, regular mayonnaise and full-fat ice cream.

Eat more fiber. Eat whole-grain breads, cereals, brown rice, pasta and other grains to take the place of some of the animal foods in your diet.