Early Use of Insulin in Type 2 Diabetes Mellitus
Stoneking, Kent; Farr, Glen E, Drug Topics
Diabetes mellitus is reaching epidemic proportions in the United States, affecting almost 8% of the U.S. population between the ages of 20 and 74 years. The prevalence rate is expected to increase by more than 165% by 2050. Of the estimated 16 million Americans with diabetes, approximately 90% have Type 2. This dramatic increase is due primarily to the increased obesity and sedentary lifestyle of Americans.
A recent issue of the Journal of the American Medical Association reports that obesity and diabetes have increased in the nation over the past decade. JAMA reported that in 2000 in the United States: *The prevalence of obesity (BMI >= 30 kg/ m^sup 2^) was 19.8%.
*The prevalence of diabetes was 7.3%.
* Mississippi had the highest rates of obesity (24.3%) and diabetes (8.8%).
*Colorado had the lowest rate of obesity (13.8%).
* Alaska had the lowest rate of diabetes (4.4%).
*Twenty-seven percent of U.S. adults did not engage in any physical activity, and another 28.2% were not regularly active.
*Only 24.4% of U.S. adults consumed fruits and vegetables five or more times daily.
Diabetes and its complica
tions cause substantial loss in quality of life and account for more than $100 billion annually in U.S. healthcare expenditures. According to the American Diabetes Association, Type 2 diabetes has been the leading cause of new blindness cases for the past several years and is the seventh-leading cause of death. Three out of four patients who die of diabetesrelated causes are known to have cardiovascular disease as well, with Type 2 diabetes now considered a primary risk factor for heart disease.
Most patients are now assessed and treated for comorbid hypertension and hyperlipidemia at the time of their Type 2 diagnosis. The recognition of several adverse metabolic risk factors has gained broader recognition with the postulation of "Syndrome X" in the past two decades. G. M. Reaven proposed that obesity, dyslipidemia, hypertension, and hyperglycemia are at least partially caused by insulin resistance and are recognizable as a syndrome precursor to Type 2 diabetes and cardiovascular disease. Additional evidence of a discrete syndrome has led to recent substantial support for a discrete syndrome called metabolic syndrome.
In spite of all we have learned in recent years, many popular myths still prevail in the general public about Type 2 diabetes. Patients often say, "I just have a touch of sugar," suggesting that they do not really have diabetes. There also is the common notion that Type 2 diabetes is less severe than Type 1, since insulin is not often used as first-line therapy in Type 2. The American Diabetes Association, however, reports that patients with poorly controlled Type 2 diabetes are far more likely to suffer from diabetic neuropathies and cardiovascular disease than are Type 1 patients.
To optimize normalization of glycemic control, the practitioner must understand the pathophysiology of Type 2 diabetes. Simply, hyperglycemia is due to one or all of the following:
* insulin resistance
* hepatic glucose production
* Beta-cell deficiency
According to data from the International Diabetes Center (IDC) in Minneapolis, Type 2 diabetes is a slowly progressing disease that takes years to manifest as shown in Figure 1. For example, B-cell deficiency is a slowly progressive decline that begins years before the diagnosis of Type 2 diabetes is made, as demonstrated in data collected in the United Kingdom Prospective Diabetes Study (UKPDS) and shown in Figure 2.
Optimizing therapy: Earlier use of insulin
The standard initial therapy for Type 2 diabetes is diet and exercise. The important role of diet and exercise was again reported in a study published in the Sept. 13, 2001, issue of the New England Journal of Medicine, which demonstrated that moderate exercise and a healthy diet could head off more than 90% of Type 2 diabetes. …