What is cholesterol?
Cholesterol is a waxy, fatty substance, known as a lipid, that is made in the liver. Your body uses cholesterol to make hormones, vitamin D, and the bile acids that help to digest food. It takes only a small amount of cholesterol to meet these needs, and your liver makes all the cholesterol you need. Cholesterol is also found in some foods that contain animal fats (such as meat, eggs, and dairy).
What is high cholesterol and how does it increase my risk for heart disease?
High cholesterol (also called hypercholesterolemia or hyperlipidemia) means that there is too much cholesterol in your blood. Having high cholesterol does not mean that you have heart disease; however, it increases your risk for getting heart disease or having a heart attack. This is because the excess cholesterol can stick to the walls of the arteries. Over time, this fatty plaque buildup will narrow the arteries causing atherosclerosis. If the arteries that carry blood to your heart (the coronary arteries) are affected, less blood and oxygen can get to your heart. This can cause chest pain(angina). Eventually the fatty plaque may rupture and block the arteries causing a heart attack. High cholesterol alone does not have any symptoms, which is why it is important to have a cholesterol test.
What are the different types of cholesterol and lipids?
Total cholesterol refers to all of the cholesterol in the blood. Because cholesterol is fatty and blood is watery, the two don’t mix. Cholesterol is carried in the blood by lipoproteins, a ball-shaped shell that cholesterol can slip into. The are two main types of lipoproteins that carry cholesterol:
High-density lipoprotein, or HDL cholesterol, is the good kind. It moves easily through the blood and does not stick to the artery walls. HDL helps prevent heart disease by carrying cholesterol away from the arteries to the liver where it can be removed from the body. Think “H” for healthy – with HDL cholesterol, a high level is good.
Low-density lipoprotein, or LDL cholesterol is the bad kind. It tends to stick to the lining of the artery walls, leading to fatty plaque buildup. With LDL cholesterol, a high level is bad because it increases your risk for heart disease.
In addition to cholesterol, triglycerides are another type of fat or lipid found in the blood that can increase your risk of heart disease when present in high amounts.
Your Cholesterol Numbers :
What do my cholesterol numbers mean?
The results of your cholesterol test will be compared with guidelines from the National Cholesterol Education Program of the National Heart, Lung, and Blood Institute, National Institutes of Health. Cholesterol and triglycerides are measured in milligrams per deciliter of blood (mg/dL). A deciliter is one-tenth of a liter.
What do my total cholesterol numbers mean?
|Total Cholesterol Numbers|
|Desireable||Less than 200|
|Borderline High||200 to 239|
|High||240 or higher|
Your total cholesterol level should be below 200 mg/dL. Younger women tend to have lower cholesterol than younger men; cholesterol levels increase in men and women as they get older. After menopause, cholesterol levels rise an additional 10 to 20 mg/dL in women; beginning at age 45, a higher percentage of women than men have high cholesterol. Having high total cholesterol increases your risk of heart disease. A 40-year-old women with high total cholesterol is twice as likely to develop heart disease than a woman of the same age with a level below 200 mg/dL.
What do my LDL (bad) cholesterol numbers mean?
|LDL Cholesterol Numbers|
|Optimal||Less than 100|
|Near Optimal||100 to 129|
|Borderline High||130 to 159|
|High||160 to 189|
|Very High||190 or higher|
A level of LDL (bad) cholesterol below 130 mg/dL is a good target for most women. However, research suggests that for bad cholesterol the lower the better, particularly for people who have heart disease or are at high risk (see: How low should my LDL (bad) cholesterol be?).
In women, LDL cholesterol increases an average of 2 mg/dL a year between the ages of 40 and 60. This increase is partly due to the decline in the hormone estrogen that occurs with the menopause. In a study of mostly postmenopausal women, those with the highest levels of bad cholesterol were 3 times more likely to suffer a heart attack or die from heart disease than women with the lowest levels.
How low should my LDL (bad) cholesterol be?
Research suggests that for bad cholesterol, the lower the number the better, particularly for people who have heart disease or are at high risk. The higher your risk, the lower your LDL cholesterol goal. The risk factors listed below affect your LDL cholesterol goal—how many do you have?
- Cigarette smoking
- High blood pressure (140/90 mm Hg or higher, or you are taking blood pressure medicine)
- Low HDL cholesterol (40 mg/dL)*
- Family history of early heart disease (father or brother before age 55; mother or sister before age 65)
- Age (55 years or older for women)
* if your HDL cholesterol is 60 mg/dL or higher, subtract 1 risk factor from your count. If your final tally is 2 or more risk factors, use this calculator to measure your risk of having a heart attack in the next 10 years (your risk score). The table below shows your LDL (bad) cholesterol goal.
|Risk Level||LDL Goal (mg/dL)|
|Risk score 20% or more
OR heart disease or diabetes
|Less than 100|
|Risk score 10% to 20%
AND 2 or more risk factors
|Less than 130|
|Risk score less than 10%
AND 2 or more risk factors
|Less than 130|
|Zero or 1 risk factor||Less than 160|
If you are at very high risk, your doctor may suggest lowering your LDL (bad) cholesterol even further to less than 70 mg/dL. The very high risk category includes women who had a heart attack or anyone diagnosed with cardiovascular disease (e.g., stroke or chest pain) and one of these:
- 2 or more heart disease risk factors (count those listed above and diabetes)
- severe or poorly controlled risk factors (e.g., you smoke more than a pack a day)
- the metabolic syndrome, a clustering of risk factors including higher than normal triglycerides and a large waistline (more than 35 inches in women)
What do my HDL (good) cholesterol numbers mean?
|HDL Cholesterol Numbers|
|Low (Bad)||Less than 40*|
|High (Good)||60 or higher|
|*Less than 50 mg/dL is considered relatively low for women.|
A HDL (good) cholesterol level of 60 mg/dL or more is considered protective against heart disease. Remember that for HDL cholesterol, higher numbers are better. The official definition of a low level of good cholesterol is 40 mg/dL or lower, but because women’s HDL cholesterol levels are about 10 mg/dL higher than men’s, a level less than 50 mg/dL is considered relatively low for women.
If your good cholesterol is between 40 to 50 mg/dL, you may be advised to make changes to your diet or to exercise more, but it is unlikely that you will be put on medication to raise your HDL cholesterol. The Framingham Heart study followed nearly 2,500 men and women for 12 years. Women with the lowest levels of HDL cholesterol had a 6-fold higher risk of suffering a heart attack than women with the highest levels.
HDL cholesterol may be more important for women than men. It is estimated that a 1 mg/dL increase in HDL cholesterol cuts the risk of heart disease by 3% in women compared with 2% in men.
What do my triglyceride numbers mean?
|Normal||Less than 150|
|Borderline High||150 to 199|
|High||200 to 499|
|Very High||500 or higher|
Women should aim for a triglyceride level at or below 150 mg/dL.1 High triglycerides may increase a woman’s risk of heart disease more so than a man’s. In a combined analysis of 17 studies on triglycerides, an increase of nearly 90 mg/dL raised the risk of heart disease by 37% in women compared with 14% in men.
How many women are affected by high cholesterol?
|Prevalence of High Cholesterol|
|Borderline or High Total Cholesterol||High LDL (bad)||High HDL (good)|
|Women by Race|
|Figures include adults 20 years or older|
More than half of American women have borderline to high total cholesterol levels, about 40% have high LDL (bad) cholesterol, and 13% have low HDL (good) cholesterol. Between 1988-1994 and 1999-2002, levels of total and LDL (bad) cholesterol declined in US adults. This decline was most noticeable in men aged 60 years or older and women aged 50 years or more. It is probably due to the increased use of cholesterol-lowering medications.
High Cholesterol – Causes & Treatment
What causes high cholesterol?
The main causes of high cholesterol relate to your lifestyle and include:
- Diet: A diet high in saturated and trans fats causes your bad cholesterol level to rise
- Physical inactivity: Regular exercise helps you lose weight, lowers triglycerides, and raises HDL (good ) cholesterol
- Smoking: Cigarette smoking raises LDL (bad) cholesterol and triglycerides and lowers HDL (good) cholesterol
- Overweight and obesity: Being overweight or obese tends to increase your LDL cholesterol and lower your HDL cholesterol. Having fat in the belly area (a waistline above 35 inches) is also linked to high cholesterol and triglycerides.
Other factors outside of your control that affect cholesterol levels are:
- Older age: As you get older, your levels of total and LDL (bad) cholesterol rise
- Heredity: High cholesterol can run in families. About 1 in 500 Americans have a type of inherited high cholesterol called familial hypercholesterolemia. This leads to very high levels of LDL (bad) cholesterol and a very high risk of having a heart attack at a young age.
How does my diet affect my cholesterol and triglyceride levels?
Eating too much saturated fat and trans fats increases your bad cholesterol levels. Saturated fats are found mainly in meat and dairy products. Trans fats are made through a chemical process called hydrogenation, which essentially turns healthier fats into unhealthy ones. Trans fats are found in fried foods, some margarines, baked goods (e.g., cookies and doughnuts), and snack foods. Since January 2006, trans fats are listed on food labels; foods that list “partially hydrogenated vegetable oils” contain trans fats.
Your triglycerides rise when you overeat or drink too much alcohol; the excess calories are converted into triglycerides to be stored as fat in the body. Some research suggests that a very high carbohydrate diet (more than 60% of total daily calories) may cause your triglyceride level to go up and your HDL (good) cholesterol to fall. This does not seem to happen if the high-carb diet is also rich in fiber and monounsaturated fat (e.g., olive and sunflower oils) or part of a healthy lifestyle that includes regular exercise.
How is high cholesterol treated?
High cholesterol is always first treated with diet and exercise. If you are concerned about developing high cholesterol, you should follow a heart healthy diet that limits saturated fat, sodium, and cholesterol intake. If you already have heart disease or high cholesterol, you should try the Therapeutic Lifestyle Changes (TLC) diet, which cuts saturated fat and cholesterol even more. The American Heart Association recommends that if you have a high level of bad cholesterol, you should get less than 7% of your daily calorie intake from saturated fats and consume less than 200 milligrams of cholesterol per day. It is also important to exercise at least 30 minutes on most, preferably all, days of the week. Exercise aids weight loss, helps lower your triglycerides, and boosts your HDL (good) cholesterol. Losing weight lowers levels of total and bad cholesterol and triglycerides. If you smoke, you should stop.
What if I need medicine for high cholesterol levels?
Diet and exercise are not always enough to lower cholesterol. If you need additional help, your healthcare provider may prescribe a cholesterol-lowering medication. If you are prescribed medication, it is still important to follow a diet low in saturated fat and cholesterol, exercise, and manage your weight. The main goal of cholesterol-lowering medications is to lower your LDL (bad) cholesterol level enough to reduce your risk of getting heart disease or having a heart attack.
There are several types of drugs available for cholesterol-lowering and you may have to take more than one. These include statins (e.g., Lipitor), bile acid resins (e.g., Welchol), and cholesterol absorption inhibitors (e.g., Zetia). Statins are the best medications for lowering LDL (bad) cholesterol in men and women. Nicotinic acid or niacin, and fibrates (e.g., Tricor) are used to raise HDL (good) cholesterol.
Does lowering my cholesterol reduce my risk for heart disease?
Yes. Studies show that lowering high levels of total and bad cholesterol reduces a woman’s risk of having a heart attack or dying from heart disease. Lowering triglycerides and raising levels of good cholesterol also seems to reduce your risk. It is difficult to tease out whether changes in triglycerides and good cholesterol alone are beneficial or if other improvements in risk factors that tend to occur at the same time, including weight loss and reductions in total and bad cholesterol, are really responsible.
High Cholesterol – Testing
How often should I have my cholesterol levels checked?
The National Cholesterol Education Program of the National Heart, Lung, and Blood Institute, National Institutes of Health recommend that everyone above the age of 20 should have their cholesterol measured at least once every 5 years. If your levels are high or you have risk factors for heart disease, you will be retested more often. The best test to have is the fasting lipid (or lipoprotein) profile. There is evidence that women are less likely than men to be tested and treated for high cholesterol.
What does a cholesterol test measure?
There are two types of cholesterol test. The preferred test is a lipid (or lipoprotein) profile. This is a fasting blood test, meaning you do not eat for 9 to 12 hours before the test. It measures:
- total blood cholesterol
- LDL (bad) cholesterol
- HDL (good) cholesterol
If you can’t have a lipid profile done, you can have your total cholesterol measured without having to fast.
How do I prepare for a cholesterol test?
If you are just having a total cholesterol test, then there is no special preparation. For a fasting lipid profile (the better test) you will not be allowed to eat anything for 9 to 12 hours before the test. You should follow your healthcare provider’s restrictions on diet, exercise, and medication use prior to the test.
You should also tell your healthcare provider about all prescription and over-the-counter medications you are taking, because some of these may affect the accuracy of the test. If you have diabetes, you should discuss dietary concerns for the day of the test with your healthcare provider in order to moderate your blood sugar levels.
What does a cholesterol test entail?
For a fasting lipid profile and most cholesterol tests, a blood sample is taken from a vein in your arm. Some total cholesterol tests use only a finger prick of blood. The test takes less than a minute and the results should be available in a day or two.
Does a cholesterol test have any limitations?
Yes. Cholesterol should not be measured when you are sick or if you just had an accident or surgery, because these events can temporarily lower your blood cholesterol. Cholesterol levels are higher during pregnancy; pregnant women should wait until 6 weeks after the baby is born before having a cholesterol test. Certain medications including anabolic steroids, some high blood pressure medicines, hormones, and birth control pills can affect cholesterol levels.
If your test results are high, your healthcare provider should check if the high cholesterol is caused by medications you are taking, liver problems, or an underactive thyroid gland.
Other Types of Blood Fat (Lipids)
What is non-HDL cholesterol?
Non-HDL cholesterol is calculated by subtracting the HDL (good) cholesterol from the total cholesterol. You don’t need a separate test for it. Measuring non-HDL cholesterol is particularly helpful in people with high triglycerides. Non-HDL cholesterol is better at predicting who will develop heart disease or have a heart attack than LDL (bad) cholesterol because it includes all of the bad types of cholesterol and lipids. There are no official cutoffs for non-HDL cholesterol; the American Heart Association suggests that women aim for a level below 130 mg/dL.
What is Lp(a) and should I be tested for it?
Another type of lipid or fat that seems to increase a woman’s risk for heart disease is Lp(a), pronounced “lipoprotein little a” or “Lp little a.” Lp(a) is made up of LDL linked to a protein called apolipoprotein (a). Women with high levels of Lp(a) are more likely to develop fatty plaque blockages in their arteries and have a higher risk of having a heart attack compared with women with lower levels.
There is no standard test for Lp(a) and no established definition of a high or low level. Research studies suggest that less than 30 mg/dL is ideal. Women with levels above 30 mg/dL had twice the risk of suffering a heart attack or other heart problems than women with lower levels in one study. Cutoffs may vary by race because levels of Lp(a) are naturally higher in African Americans than in whites.
Your healthcare provider may order an Lp(a) test if you have heart disease but none of the traditional risk factors (such as smoking, diabetes, or high total cholesterol), or if you have a family history of heart disease. Your Lp(a) level is largely set by genetics. There are no medications specifically for lowering Lp(a) and diet and exercise don’t seem to affect it. Nicotinic acid or niacin, a medication mostly used for raising HDL (good) cholesterol, lowers Lp(a). It has yet to be shown that lowering Lp(a) will lower your risk for heart disease.
What is apo-B and should I be tested for it?
Apo-B stands for apolipoprotein B, the protein part of LDL. High levels of apo-B may be a stronger risk factor for heart disease than previously thought. Apo-B is not routinely tested for because calculating non-HDL (which doesn’t require a separate test) gives you similar information. If your LDL (bad) cholesterol is high, then your apo-B level will be high too, so there is no point in testing for it. If you have very high triglycerides, it is difficult to accurately measure your bad cholesterol level and an apo-B test may be helpful in this case. Your healthcare provider may put you on a stricter diet or a different dose of medication depending on your apo-B test results. Your healthcare provider may test for apo-B if you have a personal or family history of heart disease, especially if you have high triglyceride levels.
There is no official definition of a high or low level of apo-B. Studies suggest that under 130 mg/dL is a good target for men and women with 1 or no risk factors; those with 2 or more risk factors should aim for a level below 110 mg/dL, and people already diagnosed with heart disease or diabetes should aim even lower (under 90 mg/dL). Most cholesterol drugs that lower LDL (bad) cholesterol, such as statins(e.g., Lipitor) also lower apo-B. A heart-healthy diet and exercise can also lower apo-B levels. It has yet to be shown that lowering apo-B will lower your risk for heart disease.