By the dLife Editors
Type 2 diabetes—previously referred to as adult-onset or non-insulin dependent diabetes—accounts for 90 to 95 percent of all diabetes cases in the United States. It’s characterized by the body’s inability to use insulin effectively. Insulin is a hormone produced by the pancreas that helps the body turn glucose into energy. Unlike people with type 1 diabetes, who do not produce insulin at all, people with type 2 diabetes do make insulin. They may not, however, produce enough to handle the concentration of glucose in their blood. Or, they may have insulin resistance, which means the body produces enough but it can’t use the insulin anymore to break down all the glucose.
Type 2 Causes
The exact causes of type 2 diabetes aren’t completely understood, but it’s widely accepted that a combination of inherited genetic risk factors and environmental triggers is involved. Risk factors include: obesity, physical inactivity, poor diet, smoking, chronic stress, low birth weight, high blood pressure, a history of gestational diabetes and high fasting blood glucose levels.
Individuals with a parent or sibling with type 2 diabetes have a higher chance of developing the disease than those with no family history. African Americans, Hispanics/Latinos, Native Americans, some Asians, and Pacific Islanders are at greater risk for type 2 diabetes. Risk increases with age, but it is important to note that rates of type 2 diabetes in children and adolescents have been on the rise recently.
Type 2 Symptoms
Not everyone with type 2 diabetes has symptoms, particularly in the early stages of the disease. In fact, 8.1 million of the 29.1 million people with diabetes in America are unaware that they even have the disease. 8.9 percent of Americans have type 2 diabetes.
Type 2 diabetes symptoms may include one or more of the following:
- Excessive thirst
- Frequent urination
- Extreme hunger
- Unexplained weight loss
- Fatigue, or a feeling of being “run down” and tired
- Rapid breathing
- Blurred vision
- Dry, itchy skin
- Tingling or burning pain in the feet, legs, hands, or other parts of the body
- High blood pressure
- Mood swings
- Irritability, depression
- Frequent or recurring infections, such as urinary tract infections, yeast infections, and skin infections
- Slow healing of cuts and bruises
Unlike type 1 diabetes, which frequently has a sudden onset of symptoms and reaches a crisis point before diagnosis is made, the signs of type 2 diabetes may be gradual and more insidious. Often, the first symptoms that people with undiagnosed type 2 diabetes experience result from complications of the disease, such as blurry vision (retinopathy) or foot pain (neuropathy).
If you’re experiencing any type 2 diabetes symptoms, please contact your healthcare provider immediately for medical evaluation.
Type 2 Diagnosis
The National Institutes of Health (NIH) and the American Diabetes Association (ADA) recommend screening for all people beginning at the age of 45, at baseline intervals of every three years. It is also recommended that testing be considered in adults of any age if they are overweight and have one or more additional risk factors for type 2 diabetes. Those with additional diabetes risk factors may require more frequent testing.
Diabetes may be diagnosed using various combinations of the following tests. Please note that many of the blood tests described below require specific preparation for optimum performance. To get the most accurate results, be sure to closely follow the instructions of your healthcare provider. This list is not all-inclusive, and other blood tests may be prescribed based upon your specific medical history.
- Fasting Plasma Glucose Test: Measures blood glucose levels after a fast (no food for at least eight hours). Levels of 126 mg/dL (7 mmol/L) or higher indicate a need for a subsequent retest on a different day to confirm a diagnosis of diabetes.
- Oral Glucose Tolerance Test (OGTT): The patient is given an oral dose of glucose solution (75 grams of an extremely sweet drink), and glucose levels are checked multiple times over three hours. Glucose levels that quickly rise above normal levels (i.e., 200 mg/dL (11.11 mmol/L) or higher) and take longer to normalize usually indicate diabetes.
- Two-Hour Postprandial Glucose Test: Measures ability to metabolize carbohydrates and produce insulin. Postprandial means after a meal, and this test is administered following an oral glucose tolerance test (OGTT). Two-hour postprandial glucose values of 200 mg/dL (11.1 mmol/L) or higher indicate diabetes.
- HbA1C (A1C): Measures the amount of glycated hemoglobin in the bloodstream over a 120-day period. A high percentage of glycated hemoglobin indicates problems with long-term blood sugar control. A1C results of 6.5 percent (48 mmol/mol) or greater indicate diabetes.
- Random Plasma Glucose: Measures blood glucose levels with a small blood draw taken at any time of the day (hence the name “random”). Levels of 200 mg/dL (11.1 mmol/L) or higher, along with the presence of symptoms of diabetes, indicate a diagnosis of diabetes.
Type 2 Treatment
A long-term commitment to good nutrition, careful monitoring of carbohydrate intake, and regular physical activity are critical to successful type 2 diabetes treatment. Medications for type 2 diabetes, including oral medications and injectables, are prescribed when diet and exercise alone aren’t enough to keep blood sugars within a safe range. Some people with type 2 diabetes may eventually require regular insulin injections to keep their blood glucose levels under control.
The information provided by regular blood sugar testing helps your healthcare team assess the efficacy of your type 2 diabetes treatment plan, and provides data for making the necessary adjustments.
American Diabetes Association. “Standards of Medical Care in Diabetes—2016.” Diabetes Care. January 2016. Volume 39, Supplement 1: S1-S112. http://care.diabetesjournals.org/content/suppl/2015/12/21/39.Supplement_1.DC2/2016-Standards-of-Care.pdf.
Lyssenko, V., and M. Laakso. 2013. “Genetic Screening for the Risk of Type 2 Diabetes.” Diabetes Care. American Diabetes Association. August 2013. http://dx.doi.org/10.2337/dcS13-2009.
S. National Library of Medicine. “Health Screening—Men—Ages 40 to 64.” Medline Plus. May 22, 2015. https://medlineplus.gov/ency/article/007465.htm.
S. National Library of Medicine. “Health Screening—Women—Ages 40 to 64.” Medline Plus. May 22, 2015. https://medlineplus.gov/ency/article/007467.htm.
United States Centers for Disease Control and Prevention. “Diabetes.” CDC.gov. July 25, 2016. https://www.cdc.gov/chronicdisease/resources/publications/aag/diabetes.htm.
Updated by Julia Telfer, MPH, 9/16.