Genetics may play a part in all types of diabetes mellitus. Other causes and risks vary depending on the type of diabetes involved.
Type 1 diabetes might be caused by autoimmune disorders, in which the body makes antibodies that destroy pancreatic cells. The rate of cell destruction is usually higher in children than in adults. Type 1 also has an idiopathic form, which has no known cause. Type 1 diabetes is more common in whites than in other groups.
Type 2 diabetes involves cell resistance to insulin. Glucose transport can be ineffective. Risk factors for type 2 diabetes include:ˇ obesity, which is the main cause of type 2 diabetes in both adults and children. A recent study showed a 33% increase in the number of
Americans with type 2 DM over the past 8 years. The increase was 70% in people aged 30 to 39 years old and was attributed by researchers to a sharp rise in obesity in this population. ˇ race. Type 2 diabetes is more common in African Americans, Hispanic Americans, Asian Americans, Native Americans, and Pacific Islanders. ˇ lack of physical exercise. A recent study showed that walking briskly for 3 hours a week, or exercising vigorously for an hour and a half each week, reduces a woman's risk of type 2 diabetes by 40%. ˇ high blood pressure, which is defined as a blood pressure equal to or greater than 140/90 ˇ an HDL ("good cholesterol") level equal to or less than 35 mg/dL, and/or a triglyceride level greater than or equal to 250 mg/dL ˇ an age of 45 or older ˇ a history of gestational diabetes, or delivery of babies whose birth weight is more than 9 pounds ˇ possibly hormonal changes linked to menopause. A recent study of 16,000 American women between the ages of 40 and 65 years of age showed that diabetes was one of the top 6 diseases diagnosed. A long-term study is underway to see if menopause and changes in hormone level are factors in the development of type 2 diabetes.
Gestational diabetes is considered when a woman has any abnormal glucose test result during pregnancy. It may be the result of increased hormone levels during pregnancy, which work against insulin. Weight gain during pregnancy might also be a factor in causing gestational diabetes.
The "other specific types" category of diabetes includes: ˇ diabetes caused by hormonal imbalances. One example is Cushing's syndrome, which involves high levels of adrenal hormones. ˇ diabetes caused by medications, such as prednisone, thiazide diuretics, or oral contraceptives. ˇ diabetes caused by chronic inflammation, infection, or other damage to the pancreas.
How is the disease diagnosed?
A healthcare provider may suspect diabetes mellitus after taking a person's health history and doing a physical exam. Diabetes is diagnosed based on a high glucose level in the blood. There are several types of blood tests used to diagnose diabetes, including: ˇ a test for blood sugar known as the fasting plasma glucose test, which is the preferred method to diagnose most cases of diabetes. In this test, a person is asked to fast overnight, at least 8 hours, and the level of glucose in the blood is then checked. Normal fasting plasma glucose levels are less than 110 milligrams per deciliter or mg/dL. A fasting plasma glucose level of more than 126 mg/dL usually indicates diabetes. ˇ a random test for blood sugar, or plasma glucose test, which can be done without fasting. A level of 200 mg/dL or higher generally indicates diabetes. Usually, if there is a level above 200 mg/dL, a fasting glucose test or oral glucose tolerance testis done to confirm the diagnosis of diabetes. ˇ an oral glucose tolerance test which is the preferred way to diagnose gestational diabetes. In this test, a person is asked to drink a sweet liquid. Blood samples are then drawn at timed intervals. If a person does not have diabetes, the glucose levels will rise and then fall quickly after drinking the sweet liquid. When a person has diabetes, glucose levels will rise higher than normal and fail to come down as fast as those in a person without diabetes.
