Once a problem mainly in select populations, diabetes mellitus in the 21st century is being described as an international epidemic.
The World Health Organization estimates that by the year 2025, 300 million adults worldwide will have diabetes.
Currently, 20.8 million people in the United States have diabetes, and at least 90% of them have type 2 diabetes.
An additional 41 million Americans have prediabetes, defined by the American Diabetes Association (ADA) as a fasting plasma glucose level of 100 to 125 mg/dL or 140 to 199 mg/dL on a 2-hour oral glucose tolerance test.
Prediabetes and risk factors such as hyperinsulinemia and high body mass index, formerly found primarily in adults, are increasingly common among US children.
Unsurprisingly, type 2 diabetes imposes a huge and rising healthcare cost burden. Intensive treatment for tight glycemic control can lower costs by reducing the number of emergency department visits and hospitalizations. Unfortunately, the ADA estimates that more than 6 million Americans with diabetes remain undiagnosed and therefore untreated.
This supplement provides an overview of the natural history and pathophysiology of type 2 diabetes, from the onset of insulin resistance and beta cell dysfunction to eventual microvascular and macrovascular complications. The relationships among insulin resistance, hyperglycemia, metabolic syndrome, diabetes, and cardiovascular disease are reviewed. ADA recommendations for diabetes screening and treatment goals are summarized, and current evidence-based monotherapy and combination therapy with the most commonly used oral antidiabetic agents–the sulfonylureas, metformin, and thiazolidinediones (TZDs)–are discussed, with attention to long-term glycemic outcomes and the rationale for early intervention and early introduction of TZDs. Clinical management issues specific to the use of TZDs are also explained.
One of the more exciting developments in recent diabetes research is the recognition that TZDs prescribed for diabetes can also have beneficial cardiovascular effects. Because of the relationships among diabetes, insulin resistance, and cardiovascular disease, these effects may have lasting positive impact on the health of many patients with both glycemic and cardiovascular problems. The supplement describes cardiovascular effects and outcomes with TZDs and combination oral therapies. Ongoing multicenter studies are assessing long-term outcomes after early aggressive intervention in diabetes, with encouraging results. As clinicians adopt a more proactive approach to diabetes screening and treatment, we can look forward to better glycemic control and prevention of long-term complications associated with diabetes.
Global burden of diabetes, 1995-2025: prevalence, numerical estimates, and projections.
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