Heart Disease - Risk Factors for Coronary Artery Disease (CAD)
The lifetime risk of developing coronary artery disease (CAD) after age 40 is 49% for males, 32% for women. Efforts to reduce controllable risk factors, including diet and physical activity, should be taken to decrease CAD risk.
Controllable risk factors for CAD:
- Low-density lipoproteins (LDL cholesterol): an overabundance of LDL cholesterol causes atherosclerosis, a narrowing of coronary arteries due to plaque build up on artery walls. Blood clots can form on plaque surfaces, further blocking the blood supply to the myocardium (heart muscle) and resulting in myocardial infarction (heart attack).
- High-density lipoproteins (HDL cholesterol): HDL carries cholesterol away from the heart back to the liver where it is eventually removed from the body. High HDL cholesterol removes excess LDL cholesterol from artery walls, reducing atherosclerosis (a narrowing of the arteries).
|Total cholesterol (mg/dL)||LDL cholesterol (mg/dL)||HDL cholesterol (mg/dL)|
|Ideal: Less than 200
Borderline high risk: 200-239
High risk: 240 and over
|Ideal: less than 130
Borderline high risk: 130-159
High risk: 160 or higher
|Ideal: 60 or higher|
High risk: lower than 40
LDL cholesterol levels can be reduced by limiting consumption of saturated fats (whole-fat dairy products, cheeses, red meats), increasing physical activity, and weight reduction when appropriate. Increased consumption of monounsaturated fats (olive oil, nuts, fatty fish) has been shown to reduce LDL cholesterol and increase HDL cholesterol, lowering CAD risk. Drug therapy for cholesterol reduction includes statins, bile acid resins, nicotinic acid and fibrates.
The U.S. government recently recommended treating high cholesterol more aggressively in people with diabetes. Click here to read more.
|Blood Pressure Category||Systolic(mm Hg)||Diastolic(mm Hg)|
|Normal||less than 120||and||less than 80|
|Stage 2||160 or higher||or||100 or higher|
* Source: American Heart Association
Smoking: Smoking significantly increases heart disease and stroke risk. Specifically, smoking causes atherosclerosis (narrowing of arteries), thrombosis (blood clots), coronary artery spasm (abnormal constriction of the muscle fibers of the coronary artery) cardiac arrhythmia (abnormal heartbeat) and other disorders which increase the risk of myocardial infarction (heart attack). Further, research shows smoking to reduce HDL ("good") cholesterol levels.
Diabetes: Diabetes increases the risk of heart disease, stroke, blindness, hypertension, kidney disease, and amputations. Type II diabetes, formerly called adult onset diabetes, can often be prevented by increasing physical activity and reducing weight. For patients who already have diabetes, the focus should be placed on reducing controllable CAD risk factors such as cholesterol levels, blood pressures levels, not smoking, etc. Diabetics with high cholesterol should be treated aggressively to decrease the risk of heart disease.
Obesity: Obesity increases CAD and stroke risk. Obesity increases strain on the heart, raises blood pressure and cholesterol, and increases diabetes risk. Weight reduction can be achieved with modifications to diet and increased physical activity.
Body mass index (BMI) measures a person’s total body fat based on weight and height. BMI is derived by multiplying a person's weight in pounds by 703 and then dividing it twice by the person’s height in inches. According to federal guidelines:
- BMI of 24 or under = not overweight
- BMI of 25 to 29.9 = overweight
- BMI of 30 or greater = obese
The following chart provides calculations for BMI based on weight and height:
Height (feet and inches)
Lack of physical activity: Regular exercise reduces CAD risk by controlling blood cholesterol levels, decreasing the risk of obesity or diabetes, and lowering blood pressure levels in some patients.
Stress: Research indicates a possible relationship between stress and CAD. Hypertension and high cholesterol are associated with stress, as are an increased tendency to smoke, gain weight, and/or decrease physical activity.
Uncontrollable risk factors for CAD:
Gender: Males are at higher risk of CAD than females, and males are also more likely to suffer myocardial infarction (heart attack) earlier in life. However, heart disease kills more females each year than any other disease, including breast cancer. An alarming survey reported by the American Heart Association found that only 8% of women perceive heart disease as the greatest threat to their health despite the fact that heart disease is the leading cause of death among both women and men. Over 500,000 American women die from cardiovascular disease each year--twice the number of deaths from all cancers combined. Also, women are more likely to die within the first year of a heart attack than men.
Advancing Age: Four out of five patients who suffer myocardial infarction (heart attack) are 65 years of age or older. For example, post-menopausal women are much more likely to have a heart attack than pre-menopausal women.
Family History: A family history of heart disease increases the risk for CAD and other heart problems.
Race: In the United States, African Americans tend to have more severe high blood pressure (hypertension) than Caucasians, increasing CAD risk. The incidence of heart disease is also higher among certain population groups such as Mexican Americans, American Indians, native Hawaiians and some Asian Americans. This may be due to the fact that obesity and/or diabetes may be higher among some of these population groups.
Genetics: Patients may have congenital heart defects or other diseases that increase CAD risk.
Updated: March 16, 2008