New Pharmacologic, Diagnostic Options Advance Diabetes Care

Article excerpt

Diabetes mellitus is the most common endocrine disorder in the United States, affecting nearly 16 million people. Over the past decade, prevalence of the disease among adults has increased by 33%. Among Americans in their 30s, it has jumped by 70%. Each year, approximately 798,000 people are diagnosed with the condition; unfortunately, one-third of the people afflicted are currently undiagnosed.

Diabetes is the seventh-leading cause of death in the United States. Each year, at least 190,000 people die as a result of diabetes and its complications. It is the leading cause of new cases of blindness, kidney failure, and nontraumatic lower-limb amputations. In addition, diabetic patients are two to four times more likely to have heart disease or to suffer a stroke. The important thing to remember is that these complications can be prevented or delayed with appropriate care and self-management skills and education.

The economic implication of this disease is also an important consideration. While people with diabetes account for only 6% of the population, their direct medical costs account for 12% of all health-care expenditures. In 1997, the total direct and indirect cost associated with diabetes was estimated to be $98 billion.

The two major types of diabetes are Type 1, also known as autoimmune diabetes, and Type 2, also known as insulin-resistant diabetes. Chronic hyperglycemia leads to both microvascular (retinopathy, nephropathy, and neuropathy) and macrovascular (myocardial infarction, stroke, peripheral vascular disease) complications. The Diabetes Control and Complications Trial (DCCT) and the United Kingdom Prospective Diabetes Study (UKPDS) demonstrated that intensive glycemic control can delay or prevent the development of these long-term complications. Patients who maintain fasting blood glucose concentrations between 70 and 120 mg/dl and a glycosylated hemoglobin (HbA^sub 1c^) that is lower than 7% are at lower risk for complications. The HbA^sub 1c^ is a laboratory test that indicates a patient's average blood glucose level over the past two to three months. HbA^sub 1c^ is an important tool in the management of diabetes because it reflects both fasting and postprandial (after a meal) glucose levels.

Current treatment strategies for blood glucose control include dietary modification, exercise, and pharmacologic therapy. In addition, patients are becoming more involved in their own medical care. The practice of self-monitoring of blood glucose is essential in the treatment and management of diabetes.

Recently, significant attention has been placed on the role of postprandial hyperglycemia in diabetes. The postprandial state is defined as the four-hour period that immediately follows ingestion of a meal. In any individual, blood glucose concentrations rise following the breakdown of dietary carbohydrates. However, persons with diabetes either do not produce enough insulin in response to glucose intake or are unable to effectively use the insulin produced; consequently, blood glucose concentrations following a meal are higher and last longer than normal. Postprandial hyperglycemia is the earliest abnormality noted in diabetes. It has been identified as a risk factor for heart attack and is associated with an increased risk of death.

The thiazolidinediones

The thiazolidinediones, or "insulin sensitizers," enhance the action of insulin in the muscle, fat, and other tissues and reduce insulin resistance. Direct stimulation of the peroxisome proliferator activated receptor gamma (PPAR-y) leads to a reduction in hepatic glucose production and increases glucose use in skeletal muscle. These drugs require the presence of insulin in order to work and so are used only in Type 2 diabetes. The thiazolidinediones have the potential to decrease both fasting and postprandial glucose. These drugs, if used alone, are not associated with hypoglycemia. This is due to their slow onset of action (maximal treatment benefit is not seen for approximately three months) and their lack of stimulation of insulin secretion. …