ESSENTIALS OF DIAGNOSIS
Random plasma glucose ≥200 mg/dL with polydipsia, polyuria, polyphagia, and/or weight loss.
Fasting plasma glucose ≥126 mg/dL (require confirmatory test).
Two-hour oral glucose tolerance test ≥200 mg/dL after a 75-g glucose load (require confirmatory test).
A1C ≥ 6.5% [by labwork using a method that is certified by the National Glycohemoglobin Standardization Program (NGSP) and standardized to the DCCT assay] (require confirmatory test).
The age-adjusted prevalence of diabetes has doubled in the United States since the late 1990s. The adoption of a Western diet and the resulting worldwide explosion of obesity have led to an epidemic of diabetes with >347 million people worldwide afflicted. It is a major cause of blindness, renal failure, lower extremity amputations, cardiovascular disease, and congenital malformations. Rates are disproportionately high in African Americans, Native Americans, Pacific Islanders, Hispanics, and Asians. With 90% of patients receiving their care from primary care physicians, diabetes is the epitome of a chronic disease requiring a multidisciplinary management approach.
Type 1 diabetes is the result of an autoimmune destruction of the pancreatic β cells with an inability of the body to produce insulin. Type 2 diabetes develops from an increasing cellular resistance to insulin; a process accelerated by obesity and inactivity, and is becoming increasingly common in adolescents and children. A small percentage of patients will develop a more insidious onset of autoimmune diabetes, latent autoimmune diabetes of adulthood (LADA), that may respond for a short period of time to oral medications.
Patients with metabolic syndrome or a hemoglobin A1c (HbA1c) of 5.7–6.4% should be targeted for intensive lifestyle intervention. Conversion to a Mediterranean style diet, a reduction in screen time, and at least 150 minutes of moderate intensity exercise weekly, leading to weight loss as well as smoking cessation, have been shown to delay the onset of diabetes more effectively than medications. In women, exercise (of at least moderate intensity) decreases the risk of developing type 2 diabetes, and more exercise creates a greater risk reduction. Motivation for lifestyle change is difficult, but more cost-effective and safer medications, and these changes will also improve blood pressure and lipids, leading to greater reductions in cardiovascular risk.
Medications that may also slow progression to diabetes include metformin (cheapest and fewest side effects), acarbose, and a thiazolidinedione. Tight control of hyperglycemia and blood pressure reduce the complications of diabetes, and a sustained reduction in A1c is associated with significant cost savings within 1–2 years.
et al.. Can diabetes prevention programs be translated effectively into Section of General Internal Medicine, Department of Medicine. Diabetes Research and Training Center, The University of Chicago, Chicago, IL, ...