Cholesterol and Women's Cardiovascular Health

Cholesterol is a fatty, wax-like substance. Your body uses cholesterol to make the outer coverings of cells. Cholesterol is a part of certain hormones, including estrogen and testosterone. It also helps your body make vitamin D and produces the bile that helps you digest food.

The liver makes most of the cholesterol in your body. A small amount comes from foods, such as meat and dairy products. The fat in these foods is turned into triglycerides. Triglycerides travel through the bloodstream and are stored in fat cells as a source of energy. The body also converts sugars in fruits and sugary foods into triglycerides.

In the liver, cholesterol, triglycerides, and a protein are packaged into substances called lipoproteins. There are two main types of lipoproteins:

1. LDL (low-density lipoprotein)—This type of lipoprotein carries cholesterol to where it is needed in the body. If there is too much of it, it tends to collect in the walls of blood vessels. LDL sometimes is called “bad cholesterol.”

2. HDL (high-density lipoprotein)—This type of lipoprotein picks up cholesterol in the bloodstream and takes it back to the liver. The liver breaks down cholesterol so that it can pass out of the body. HDL sometimes is called “good cholesterol.”

An easy way to remember the two types of cholesterol is that you want a high level of “happy” HDL and a low level of “lousy” LDL.

Having abnormal levels of cholesterol or triglycerides is called dyslipidemia. A common dyslipidemia in the United States is having an LDL cholesterol level that is too high, an HDL cholesterol level that is too low, and elevated levels of triglycerides. This type of dyslipidemia increases the risk of cardiovascular disease.

When the level of LDL is high, it can collect inside the walls of blood vessels. When the level of HDL is low, there may not be enough available to remove the “bad cholesterol” from the blood vessels.

LDL within the walls of blood vessels triggers a response by the body’s immune system. Eventually, this immune response can lead to a buildup of a substance called plaque in the blood vessels. Plaque can narrow and harden the arteries, a condition called atherosclerosis.

Atherosclerosis makes it harder for blood to move through the arteries. Coronary artery disease is a condition caused by the narrowing of the arteries in the heart.

Over time, plaque can develop into a blood clot that narrows or blocks the flow of blood in an artery. If this occurs in an artery in the heart, it can cause a heart attack. If this occurs in an artery in the brain, it can cause a stroke.

Other risk factors include

• advancing age

• male sex

• family history of cardiovascular disease

• smoking

• physical inactivity

• obesity

• a poor diet

• and medical conditions such as diabetes mellitus and high blood pressure.

Some of these risk factors cannot be changed. Others can be modified by making lifestyle changes and getting regular health care.

Many people have multiple risk factors for cardiovascular disease. Metabolic syndrome is the name given to a group of risk factors that occur together and that increase the risk of cardiovascular disease. Metabolic syndrome may be diagnosed if you have three or more of the following factors:

• Waist circumference equal to or greater than 35 inches for women and equal to or greater than 40 inches for men

• Triglyceride level 150 mg/dL or higher

• HDL cholesterol less than 50 mg/dL

• Blood pressure 130/85 mm Hg or higher

• Fasting glucose level 100 mg/dL or higher

Metabolic syndrome has become more common in the United States as the rates of obesity have increased.

Some conditions increase the risk of cardiovascular disease, including

• polycystic ovary syndrome (PCOS)

• high blood pressure disorders that occur during pregnancy

• gestational diabetes

Women have a higher level of HDL than men. It is thought that estrogen, the female hormone, natu­rally increases the HDL level.

Women have less risk of cardiovascular disease than men until about the time they reach menopause (usually around age 50), when LDL levels start to rise. By 55, women have higher LDL levels than men. By about 75, cardiovascular disease risk for men and women is the same.

Cardiovascular disease is the number one killer of women in the United States.

A simple blood test can show if your cholesterol levels are healthy. A complete lipoprotein analysis measures the levels of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.

Women without risk factors should have their cholesterol levels measured every 4 to 6 years beginning at age 21. Women who have risk factors for cardiovascular disease may need to start cholesterol screening earlier.

The following changes may reduce your risk of cardiovascular disease:

• Eat a heart-healthy diet. A heart-healthy diet is one that includes vegetables, fruits, beans, low-fat dairy products, fish, and poultry. Limit red meat, sugary foods and drinks, and sodium. Visit Healthy Eating to learn more.

• Exercise. Exercise strengthens your heart and promotes the health of your blood vessels. It helps boost your HDL levels and lower blood pressure levels. Visit Staying Active: Physical Activity and Exercise to learn more.

• Lose weight. Weight loss is recommended if you are overweight or obese. Talk with a health care professional about a diet and exercise program that can help you lose weight safely and effectively. Visit Weight Control: Eating Right and Keeping Fit to learn more.

• Stop smoking. Smoking is one of the biggest risk factors for heart disease. It decreases HDL levels and may increase the level of triglycerides in your blood. Visit It’s Time to Quit Smoking to learn more.

The most common type of LDL-lowering medications are called statins. These medications cause the liver to make less cholesterol. In addition to lowering LDL levels, they also may help decrease the levels of triglycerides and increase levels of HDL.

Atherosclerosis: Narrowing and clogging of the arteries caused by a buildup of plaque. Also called hardening of the arteries.

Bile: A substance made in the liver that helps digest fats.

Cardiovascular Disease: Disease of the heart and blood vessels.

Cells: The smallest units of a structure in the body. Cells are the building blocks for all parts of the body.

Cholesterol: A natural substance that is a building block for cells and hormones. This substance helps carry fat through the blood vessels for use or storage in other parts of the body.

Coronary Artery Disease: A buildup of cholesterol in the walls of the arteries. This buildup can narrow arteries and lead to a heart attack.

Diabetes Mellitus: A condition in which the levels of sugar in the blood are too high.

Estrogen: A female hormone produced in the ovaries.

Gestational Diabetes: Diabetes that starts during pregnancy.

Heart Attack: Damage to an area of heart muscle that occurs when its blood supply is interrupted. A heart attack almost always is caused by narrowing or blockage of the blood vessels in the heart.

Hormones: Substances made in the body that control the function of cells or organs.

Immune System: The body’s natural defense system against viruses and bacteria that cause disease.

Lipoproteins: Substances that transport cholesterol to and from the liver throughout the blood.

Menopause: The time when a woman’s menstrual periods stop permanently. Menopause is confirmed after 1 year of no periods.

Metabolic Syndrome: A combination of problems that can lead to diabetes and heart disease. These problems include high blood pressure, waist size of 35 inches or more (in women), higher-than-normal blood sugar level, lower-than-normal levels of “good” cholesterol, and high levels of fats in the blood (triglycerides).

Polycystic Ovary Syndrome (PCOS): A condition that leads to a hormone imbalance that affects a woman’s monthly menstrual periods, ovulation, ability to get pregnant, and metabolism.

Stroke: A sudden interruption of blood flow to all or part of the brain, caused by blockage or bursting of a blood vessel in the brain. A stroke often results in loss of consciousness and temporary or permanent paralysis.

Testosterone: A hormone made by the testes in men and in smaller amounts by the ovaries in women. This hormone is responsible for male sex characteristics such as hair growth, muscle development, and a lower voice.

Triglycerides: A form of body fat found in the blood and tissues. High levels can cause heart disease.