Type 2 diabetes care: the role of insulin-sensitizing agents and practical implications for cardiovascular disease prevention

  • Robert R. Henry
    Requests for reprints should be addressed to Robert R. Henry, MD, Veterans Administration Hospital, 3350 La Jolla Village Drive, La Jolla, California 92161
    Department of Medicine, School of Medicine, University of California, San Diego, San Diego, California, USA
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      Millions of Americans are at risk for cardiovascular morbidity and mortality related to disorders of glucose intolerance—particularly type 2 diabetes and prediabetic conditions, including the insulin resistance, or “cardiovascular dysmetabolic,” syndrome. The latter is apparently more intricately associated with macrovascular disease—myocardial infarction, stroke, and peripheral vascular disease. In some situations the risk of cardiovascular disease might be reduced by the prevention of diabetes and also by prevention or treatment of the cardiovascular dysmetabolic syndrome. Studies have shown that intensive glycemic control can delay the development of microvascular complications in type 1, and possibly type 2, diabetes. Several longitudinal observational studies have demonstrated a relationship between glycemic control and the development of cardiovascular disease. Prospective clinical intervention trials to address this issue are underway. Insulin may have a role in atherogenesis, both directly and by promoting development of such risk factors as hypertension and dyslipidemia. Genetic factors and mechanisms promoting or discouraging development of glucose intolerance are also under investigation. Lifestyle changes—dietary and exercise modification, weight loss, and smoking cessation—have been shown to have a positive effect on cardiovascular disease risk. Clinical trials suggest that oral antidiabetic agents—particularly the new noninsulin secretagogues (including troglitazone and metformin, which act on the liver and on skeletal muscle)—may be useful in delaying or preventing development of type 2 diabetes and the cardiovascular dysmetabolic syndrome, as well as in their treatment, when present. Both agents, acting primarily by different mechanisms of action, have also demonstrated potential beneficial effects on serum lipid profiles and other cardiovascular risk factors and may be useful in patients with cardiovascular dysmetabolic syndrome who do not yet meet the criteria for diabetes.
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