Type 2 Diabetes
Insulin is a hormone needed to convert sugars and starches into glucose for energy. In patients with type 2 diabetes, the body doesn't make enough insulin or isn't able to effectively use insulin. Despite high levels of glucose circulating in the blood, the cells of the body are starved for energy.
According to the American Diabetes Association, about 17 million Americans have diabetes. Nearly 90 to 95 percent of cases are type 2. (Type 1 diabetes, the other main kind, occurs when the body doesn't produce any insulin, and patients need regular injections of insulin to stay alive.) Some risk factors for type 2 diabetes include being over 45, family history of the disease, obesity, sedentary lifestyle, and low HDL cholesterol or high triglycerides. It's also more common in certain ethnic groups (African Americans, Latinos, Native Americans, and Asian and Pacific Islanders) and women who develop gestational diabetes during pregnancy.
Over time, high levels of glucose can damage blood vessels and organs, causing life-threatening complications. Diabetics are two to four times more likely to develop heart disease or stroke. Nearly three-quarters of patients have high blood pressure. Among adults, diabetes is the leading cause of blindness and end-stage kidney disease. About 60 to 70 percent of patients have some degree of nerve damage and are at greater risk of needing an amputation.
Researchers have noted that people who develop type 2 diabetes often have higher than normal glucose levels for some time, but the levels aren't high enough to classify as diabetes. Doctors have termed this condition, "pre-diabetes" because patients are at high risk of eventually developing diabetes. Studies suggest most people with pre-diabetes develop overt diabetes within 10 years. In addition, even before diabetes sets in, moderately elevated blood glucose levels can adversely affect health. The American Diabetes Association estimates patients with pre-diabetes are 1.5 times more likely than those with normal glucose levels to develop cardiovascular disease. (By the time diabetes occurs, patients have a two to four-fold increased risk for cardiovascular disease.)
Most people with pre-diabetes don't know they have elevated glucose levels. Screening is done through one of two tests. In the fasting blood glucose test, blood sugar levels are measured after an overnight fast. Normal levels are under 110 mg/dL. Patients with pre-diabetes have fasting glucose levels of 110 to 125 mg/dL. Diabetes occurs at levels of 126 mg/dL or higher. Screening may also be done with an oral glucose tolerance test. Blood is drawn after an overnight fast. In addition, a second measurement is taken two hours after swallowing a high-glucose drink. After the drink, normal blood glucose levels are below 140 mg/dL. Pre-diabetes levels are 140-199 mg/dL, and levels of 200 mg/dL and higher are considered diabetes.
The key to the new findings is that through lifestyle changes (weight loss and exercise) many pre-diabetic patients can prevent or delay the onset of diabetes. Weight loss of five to ten pounds and 30 minutes of physical activity a day may prevent or delay diabetes development by up to 58 percent. The American Diabetes Association and the National Institute of Diabetes and Digestive and Kidney Disease have issued a statement asking physicians to consider screening all patients over 45 for pre-diabetes. Screening is strongly recommended for patients over 45 and overweight. Testing is also recommended for adults under 45 who are overweight and have at least one other risk factor for diabetes. Patients whose blood glucose levels are within normal ranges should be retested every three years.
Type 2 Diabetes