Early detection of undiagnosed diabetes mellitus: a US perspective.

Undiagnosed Type 2 diabetes has become a common condition in the US, comprising one-third of all cases of the disease. We believe that screening for and detection of undiagnosed Type 2 diabetes is an important endeavor. In this review we provide evidence that diabetes is a condition that is appropriate for population screening and detection. This includes evidence that: 1. Type 2 diabetes is a significant health problem. It affects more than 16 million adults in the US and places these individuals at high risk for serious complications of the eyes, nerves, kidneys, and cardiovascular system. 2. There is a latent phase before diagnosis of Type 2 diabetes. During this period of undiagnosed disease, risk factors for diabetic micro- and macrovascular complications are markedly elevated and diabetic complications are developing. 3. Diagnostic criteria for diabetes have been established and are based on plasma glucose values. These criteria define a group of individuals with significant hyperglycemia who also have a high frequency of risk factors for micro- and macrovascular disease. 4. The natural history of Type 2 diabetes is understood. In most patients, diabetes proceeds inexorably from genetic predisposition, through the stage of insulin resistance and hyperinsulinemia, to beta cell failure and overt clinical disease. 5. There are effective and acceptable therapies available for Type 2 diabetes and its complications. Treating hyperglycemia to prevent complications is more effective than treating these complications after they have developed. Furthermore, guidelines for treatment to prevent cardiovascular disease in people known to have diabetes are more stringent than in those individuals who are not known to have diabetes. 6. There is a suitable test for screening for undiagnosed Type 2 diabetes that has high sensitivity and specificity - measurement of fasting plasma glucose. Guidelines for identifying persons at high risk for diabetes have been established.