Coronary artery disease is a narrowing and hardening of the blood vessels leading to the heart muscle. Narrow vessels restrict the flow of oxygen-rich blood to the heart, which can lead to a heart attack and initiate major changes in the cardiovascular system. Several factors determine a person's risk for developing coronary artery disease. Each risk factor can be considered as one point, or strike, with the objective being to have as few points as possible.
Non-Modifiable Risk Factors
Age, gender, family history and ethnicity are considered non-modifiable risk factors for heart disease because they are not within a person's control. Age becomes a risk factor for males at 55 and females at 65. Women tend to develop heart disease a decade later in life than men. Family history is considered a risk factor if an immediate family member has died prematurely from heart disease. Research on ethnicity by the American Heart Association found black and Hispanic individuals to be at a higher risk of developing high blood pressure, high cholesterol and diabetes, all of which increase the overall risk of heart disease.
High Blood Pressure
High blood pressure, also referred to as hypertension, occurs when a person's systolic blood pressure is greater than 140mmHg or when the diastolic pressure is higher than 90mmHg. Taking medication that controls hypertension does not remove the risk factor point because the underlying disease is still present when the medication is removed.
High Cholesterol
Cholesterol is a combination of elements including total blood cholesterol and triglycerides, as well as levels of HDL and LDL, or "good" and "bad" cholesterol, respectively. The National Institutes of Health define high cholesterol as total cholesterol levels above 200mg/dL, LDL-cholesterol above 130mg/dL, HDL-cholesterol below 40mg/dL and triglycerides above 150mg/dL.
Diabetes
The presence of diabetes is determined through blood testing conducted after at least eight hours of fasting. According to the Mayo Clinic, fasting blood glucose levels higher than 126mg/dL measured on two occasions is a positive indicator of diabetes.
Obesity
Body mass index, or BMI, is a ratio of weight to height and is commonly used to determine the presence of obesity. A BMI of 30 or higher indicates the presence of obesity and is considered a risk factor for heart disease because of its contribution to high blood pressure, high cholesterol and the formation of diabetes.
Smoking
The National Heart, Lung and Blood Institute states that smoking contributes to the development of other risk factors, such as high blood pressure and high cholesterol and can also alter the structure of blood vessels that leads to a reduction in blood flow to the heart muscle. Smoking remains a risk factor until a person has been a nonsmoker for at least six months.
Sedentary Lifestyle
Sedentary lifestyle contributes to the development of other modifiable risk factors by removing the protective effects of physical activity. Physical activity reduces blood pressure in hypertensive individuals, decreases total cholesterol and LDL-cholesterol levels and raises HDL cholesterol. Additionally, physical activity protects against obesity and diabetes. For those who are already obese or diabetic, physical activity can reverse the presence of these risk factors. In essence, regular physical activity can reduce the risk of heart disease by altering the effects of modifiable risk factors, strengthening the heart muscle and improving blood flow.
References
- "Circulation"; Heart Disease and Stroke Statistics 2010 Update; Donald Lloyd-Jones, M.D.; 2010
- National Institutes of Health: National Cholesterol Education Program
- Mayo Clinic: Prediabetes
- National Heart, Lung and Blood Institute: Coronary Artery Disease
