Using insulin as a drug rather than as a replacement hormone during acute illness: a new paradigm

The direct correlation between glucose levels and cardiovascular disease in individuals with type 2 diabetes can now be applied to individuals that share an abnormal metabolic milieu similar to that found in central obesity, the metabolic syndrome, and type 2 diabetes. Premature macrovascular complications with a very high morbidity and mortality rate can be found in these nondiabetic populations. The typical phenotype has visceral or central obesity, excess of free fatty acids, insulin resistance, increased insulin secretion, and hypertension. A more complex metabolic-cardiovascular syndrome develops that includes dyslipidemia, abnormal production of cytokines, chronic inflammatory state, and abnormal coagulation. The interplay of all these cardiovascular risk factors is responsible for the accelerated atherosclerotic process. The different terminologies used for populations sharing this common ground for premature cardiovascular disease now generally accepted as the metabolic syndrome, are also discussed. Aggressive insulin treatment during acute illness in individuals with the abnormal metabolic milieu is beneficial. Insulin treatment is changing from using insulin as a hormone to treat only severe hyperglycemia, to a new paradigm using insulin in high doses as a drug. Aggressive insulin regimens should be used to treat only minimal elevations of blood glucose or to prevent hyperglycemia. The newly observed properties of insulin are reviewed which include suppression of inflammatory cytokines and adhesion molecules, improved hemostasis, and other cardiac beneficial effects. The concomitant administration of intravenous glucose and insulin permits the administration of higher insulin doses that can result in improved outcome due to its nonglycemic-related benefits. The use of aggressive insulin therapy requires both better and more cost-effective algorithms to successfully treat this high-risk population during acute illness.