Pathophysiologic, diagnostic, and therapeutic aspects of the metabolic syndrome.

The metabolic syndrome, characterized by increases in waist circumference, blood pressure, and triglyceride concentrations combined with reduced high-density lipoprotein and evidence of glucose intolerance, results from the interaction of visceral or central obesity with insulin resistance. This syndrome presents a clinical situation of systemic inflammation and increased cardiovascular risk. Blood pressure, even if only in the "prehypertensive" range, plays an important role in increasing the risk of cardiovascular disease. Recognition and treatment of each individual component of the metabolic syndrome is critical in reducing cardiovascular risk. Treatment should begin with lifestyle changes, including diet, exercise, and weight reduction. Antihypertensive therapy should be directed toward reduction of blood pressure to levels as close to optimal (<120/80 mm Hg) as feasible, and treatment protocols that do not cause worsening of glucose intolerance should be selected. Therapy for dyslipidemia should be directed at reducing triglycerides and increasing high-density lipoprotein. Glucose-lowering agents may be indicated, and drugs such as metformin and thiazolidinediones, which reduce insulin resistance, should form the basis of therapy. Carefully chosen therapy will effectively improve cardiovascular outcomes.