Approximately 5 million of the 18 million people with diabetes in the U.S. do not know they have it.56 Early detection and treatment of diabetes is an important step toward keeping people with diabetes healthy. It can help to reduce the risk of serious complications such as premature heart disease and stroke, blindness, limb amputations, and kidney failure.57
Some of the important signs and symptoms of diabetes are shown in Table 2. Many people with type 2 diabetes have no signs or symptoms, but do have risk factors (see Table 1). For persons at increased risk or those experiencing these signs and symptoms, several tests are used to diagnose diabetes:
- A fasting plasma glucose test measures blood glucose after not eating for at least 8 hours. This test is used to detect diabetes (126 mg/dl and above) or pre-diabetes (between 100 mg/dl and 125 mg/dl).58
- An oral glucose tolerance test measures blood glucose after not eating for at least 8 hours and 2 hours after drinking a glucose-containing beverage. This test is used to diagnose diabetes (200 mg/dl and above) or pre-diabetes (between 140 mg/dl and 199 mg/dl).59
- In a random plasma glucose test, blood glucose is checked without regard to when food is consumed. Values of 200 mg/dl or greater in the presence of specific symptoms, such as increased urination or thirst and unexplained weight loss, indicate a diagnosis of diabetes.60
Positive test results should be confirmed by repeating the fasting plasma glucose test or the oral glucose tolerance test on a different day.
Type 1 diabetes is typically detected much sooner after onset than type 2 disease because the symptoms are dramatic and the need for medical care is immediate and obvious. In contrast, the signs and symptoms of type 2 diabetes can be absent or so mild that the disease may not be diagnosed for 7 to 10 years after the onset resulting in increased risk for complications, such as nerve, eye, and kidney disease, when the disease is finally detected.61
In the past, type 2 diabetes was a disease seen primarily in adults over age 45 with the highest percentage occurring in adults 60 years and older.62 It is now being seen at increasingly younger ages, including children and adolescents.63 As with adults, identifying type 2 diabetes in children is challenging because children may not have any symptoms or show only very mild symptoms. Diagnosis of type 2 diabetes in young people means that they may have the disease for a longer period time than if they developed diabetes as adults. The longer duration of the disease increases the rate of severe complications such as blindness, renal failure, and amputations.64
Early diagnosis of diabetes and pre-diabetes is important so that patients can begin to manage the disease early and potentially prevent or delay the serious disease complications that can decrease quality of life. Recognizing the importance of identifying the more than 5 million Americans with undiagnosed diabetes, Secretary Tommy G. Thompson launched the Diabetes Detection Initiative (DDI) in November 2003. The DDI is a new community-based effort to identify persons with undiagnosed type 2 diabetes and refer them for follow-up blood testing and treatment, if appropriate. The pilot program was evaluated in 10 locations throughout the U.S. (see Appendix C for more information on the DDI).
Table 2. Signs and Symptoms of Diabetes
SOURCES: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). (2004). Am I at risk for type 2 diabetes? NIH Publication No. 04-4805. Available at http://diabetes.niddk.nih.gov/dm/pubs/riskfortype2/. Accessed May 28, 2004.
Juvenile Diabetes Research Foundation. Knowing the warning signs for type 1 diabetes could save a child’s life. Available at
http://www.jdrf.org/index.cfm?fuseaction=home.viewPageandpage_id=117E31F.... Accessed May 28, 2004.
56 Williamson DF, Vinicor F, Bowman BA. (2004). Centers For Disease Control and Prevention Primary Prevention Working Group: Primary prevention of type 2 diabetes mellitus by lifestyle intervention: implications for health policy. Ann Int Med, 140(11), 951-957.
57 U.S. Department of Health and Human Services (DHHS). Diabetes detection initiative: Finding the undiagnosed. Available at: http://www.ndep.nih.gov/ddi/about/index.htm.
58 National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). (2003). Diagnosis of diabetes. NIH Pub No. 04-4642. Available at: http://diabetes.niddk.nih.gov/dm/pubs/diagnosis/index.htm.
61 DHHS, op.cit.
63 Centers for Disease Control and Prevention (CDC). (2000). CDC funds registries for childhood diabetes. Press release, November 21. Available at http://www.cdc.gov/od/oc/media/pressrel/r2k1226.htm.