Heart and Vascular Center

Diabetes

Diabetes is a disease in which the body doesn't produce or properly use insulin. Insulin is a hormone produced in the pancreas, an organ near the stomach. Insulin is needed to turn sugar and other food into energy. When you have diabetes, your body either doesn't make enough insulin or can’t use its own insulin as well as it should, or both. This causes sugars to build up too high in your blood.

Diabetes mellitus is defined as a fasting blood glucose of 126 milligrams per deciliter (mg/dL) or more. “Pre-diabetes” is a condition in which blood glucose levels are higher than normal but not yet diabetic. People with pre-diabetes are at increased risk for developing type 2 diabetes, heart disease and stroke, and have one of these conditions:

  • Impaired fasting glucose (100 to 125 mg/dL)
  • Impaired glucose tolerance (fasting glucose less than 126 mg/dL and a glucose level between 140 and 199 mg/dL two hours after taking an oral glucose tolerance test)

What are type 1 and type 2 diabetes?

Type 2 diabetes is the most common form. It appears most often in middle-aged adults; however, adolescents and young adults are developing type 2 diabetes at an alarming rate. It develops when the body doesn’t make enough insulin and doesn’t efficiently use the insulin it makes (insulin resistance).

Type 1 diabetes usually occurs in children and young adults. In type 1, the pancreas makes little or no insulin. Without daily injections of insulin, people with type 1 diabetes won’t survive.

Both forms of diabetes may be inherited in genes. A family history of diabetes can significantly increase the risk of developing diabetes. Untreated diabetes can lead to many serious medical problems. These include blindness, kidney disease, nerve disease, limb amputations and cardiovascular disease (CVD).

How are insulin resistance, diabetes and CVD related?

Diabetes is treatable, but even when glucose levels are under control, it greatly increases the risk of heart disease and stroke. In fact, most people with diabetes die of some form of heart or blood vessel disease.

Pre-diabetes and subsequent type 2 diabetes usually result from insulin resistance. When insulin resistance or diabetes occur with other CVD risk factors (such as obesity, high blood pressure, abnormal cholesterol and high triglycerides), the risk of heart disease and stroke rises even more.

Insulin resistance is associated with atherosclerosis (fatty buildups in arteries) and blood vessel disease, even before diabetes is diagnosed. That’s why it’s important to prevent and control insulin resistance and diabetes. Obesity and physical inactivity are important risk factors for insulin resistance, diabetes and cardiovascular disease.

How is diabetes treated?

When diabetes is detected, a doctor may prescribe changes in eating habits, weight control and exercise programs, and even drugs to keep it in check. It's critical for people with diabetes to have regular checkups. Work closely with your healthcare provider to manage diabetes and control any other risk factors. For example, blood pressure for people with diabetes and high blood pressure should be lower than 130/80 mm Hg.

AHA Recommendation

Diabetes is a major risk factor for stroke and coronary heart disease, which includes heart attack. People with diabetes may avoid or delay heart and blood vessel disease by controlling the other risk factors. It's especially important to control weight and blood cholesterol with a low-saturated-fat, low-cholesterol diet and regular aerobic physical activity. It's also important to lower high blood pressure and not to smoke.