The biggest indicator for your risk of type 2 diabetes is the diagnosed presence of prediabetes. But since the vast majority of people with prediabetes remain undiagnosed, assessing the presence of the other common risk factors for type 2 diabetes is important.
Age and Ethnicity
According to the American Diabetes Association, over half of all cases of type 2 diabetes occur in people over age 50, and over 12 million Americans age 60 and older suffer from the disease. Individuals over age 45 should be tested for diabetes, and retested every three years thereafter if the initial test is normal. If you have additional risk factors for type 2 diabetes, you may require more frequent screening — talk to your doctor about your particular screening needs.
Certain ethnic groups and minorities have an increased risk of developing type 2 diabetes, including the following:
While everyone with type 2 diabetes has some degree of insulin resistance, not everyone with insulin resistance has type 2 diabetes. Metabolic syndrome is a constellation of features — insulin resistance, low HDL and high LDL and triglycerides, excess abdominal fat, and high blood pressure — that put you at risk for heart disease.
Heredity plays a large part in the development of type 2 diabetes. If you have a first-degree relative with type 2 diabetes, your chances of developing the disease double. And there is a concordance rate of up to 90 percent among identical twins with type 2, meaning that in up to 90 percent of cases where one twin has the disease, the other one develops it as well.
The good news for those with diabetes in their family is that environmental factors such as your activity levels, health habits, and diet do play a large role in whether or not you will develop type 2 diabetes. Large-scale studies such as the Diabetes Prevention Program (DPP) have proven that prevention is often possible through diet, exercise, and other moderate lifestyle changes.
Hypertension and Cholesterol Levels
Hypertension, or blood pressure of 140/90 mmHg or higher, is a known risk factor for the development of type 2 diabetes, and is also a frequent comorbid (i.e., coexisting) condition of the disease. A large-scale study of over 12,000 patients published in the New England Journal of Medicine in 2000 found that people with diagnosed hypertension were 2.5 times more likely to develop type 2 diabetes than those with normal blood pressure levels.
In addition, that study and others have shown a correlation between beta-blockers, a medication used to treat high blood pressure, and an increased risk of type 2.
Triglyceride levels over 250 mg/dl and/or levels of HDL (or “good cholesterol”) under 35 mg/dl put you at an increased risk for type 2 diabetes. HDL acts as a lubricant for the circulatory system, moving the other lipids (triglycerides and LDL cholesterol) through the blood vessels and into the liver for metabolism. It helps to prevent the buildup of fatty plaque that can otherwise clog the arteries, resulting in atherosclerosis and consequently high blood pressure. Elevated triglycerides are also associated with an increased risk of heart disease.
Women who have a history of gestational diabetes should be vigilant about regular testing for diabetes (once every three years if their glucose levels are normal postpartum, annually if they are not).
Gestational Diabetes and Perinatal Risk Factors
Women who had gestational diabetes mellitus (GDM) during their pregnancy are at an increased risk of developing type 2 diabetes. Five to ten percent of women with GDM will have type 2 diabetes after labor and delivery. And women with a history of GDM have a 40 to 60 percent chance of developing type 2 diabetes within five to ten years after giving birth.
Giving birth to a baby weighing over nine pounds is also considered a risk factor for later development of type 2. Several studies have linked high birth weights (over 4,000 grams, or 8.8 pounds) to type 2 diabetes.
A number of studies have also associated a low birth weight (under 2,500 grams, or 5.5 pounds) with an increased risk for type 2 diabetes later in life, possibly due to poor fetal nutrition.