People who have type 1 or type 2 diabetes are at risk for diabetic heart disease (DHD). Diabetes affects heart disease risk in three major ways.
                
First, diabetes alone is a very serious risk factor for heart disease. Second, when combined with other risk factors, diabetes further raises the risk of heart disease. Third, compared with people who don't have diabetes, people who have the disease are more likely to:
                
Have heart attacks and other heart and blood vessel diseases. In men, the risk is double; in women, the risk is triple.
                
Have more complications after a heart attack, such as angina (chest pain or discomfort) and heart failure.
                
Die from heart disease.
                
The higher your blood sugar level is, the higher your risk of DHD. (A higher than normal blood sugar level is a risk factor for heart disease even in people who don't have diabetes.)
                
Type 2 diabetes raises your risk of having silent heart diseasethat is, heart disease with no signs or symptoms. You can even have a heart attack without feeling symptoms. Diabetes-related nerve damage that blunts heart pain may explain why symptoms aren't noticed.
                
Other Risk Factors
                
Other factors also can raise the risk of coronary heart disease (CHD) in people who have diabetes and in those who don't. You can control most of these risk factors, but some you can't.
                
For a more detailed discussion of these risk factors, go to the Health Topics Coronary Heart Disease Risk Factors article.
                
Risk Factors You Can Control
                
Unhealthy blood cholesterol levels. This includes high LDL cholesterol (sometimes called "bad" cholesterol) and low HDL cholesterol (sometimes called "good" cholesterol).
                
High blood pressure. Blood pressure is considered high if it stays at or above 140/90 mmHg over time. If you have diabetes or chronic kidney disease, high blood pressure is defined as 130/80 mmHg or higher. (The mmHg is millimeters of mercurythe units used to measure blood pressure.)
                
Smoking. Smoking can damage and tighten blood vessels, lead to unhealthy cholesterol levels, and raise blood pressure. Smoking also can limit how much oxygen reaches the body's tissues.
                
Prediabetes. This is a condition in which your blood sugar level is higher than normal, but not as high as it is in diabetes. If you have prediabetes and don't take steps to manage it, you'll likely develop type 2 diabetes within 10 years.
                
Overweight or obesity. Being overweight or obese raises your risk of heart disease and heart attack. Overweight and obesity also are linked to other heart disease risk factors, such as high blood cholesterol, high blood pressure, and diabetes. Most people who have type 2 diabetes are overweight.
                
Metabolic syndrome. Metabolic syndrome is the name for a group of risk factors that raises your risk of heart disease and type 2 diabetes. Metabolic syndrome also raises your risk of other health problems, such as stroke.
                
Lack of physical activity. Lack of physical activity can worsen other risk factors for heart disease, such as unhealthy blood cholesterol levels, high blood pressure, diabetes, and overweight or obesity.
                
Unhealthy diet. An unhealthy diet can raise your risk of heart disease. Foods that are high in saturated and trans fats, cholesterol, sodium (salt), and sugar can worsen other heart disease risk factors.
                
Stress. Stress and anxiety can trigger your arteries to tighten. This can raise your blood pressure and your risk of having a heart attack. Stress also may indirectly raise your risk of heart disease if it makes you more likely to smoke or overeat foods high in fat and sugar.
                
Risk Factors You Can't Control
                
Age. As you get older, your risk of heart disease and heart attack rises. In men, the risk of heart disease increases after age 45. In women, the risk increases after age 55. In people who have diabetes, the risk of heart disease increases after age 40.
                
Gender. Before age 55, women seem to have a lower risk of heart disease than men. After age 55, however, the risk of heart disease increases similarly in both women and men.
                
Family history of early heart disease. Your risk increases if your father or a brother was diagnosed with heart disease before 55 years of age, or if your mother or a sister was diagnosed with heart disease before 65 years of age.
                
Preeclampsia (pre-e-KLAMP-se-ah). This condition can develop during pregnancy. The two main signs of preeclampsia are a rise in blood pressure and excess protein in the urine. Preeclampsia is linked to an increased lifetime risk of CHD, heart attack, heart failure, and high blood pressure.