Insulin resistance-associated cardiovascular disease: potential benefits of conjugated linoleic acid

Type 2 diabetes and associated cardiovascular disease have reached global epidemic proportions. Recent data from the World Health Organization Multinational Study of Vascular Disease in Diabetes indicate that cardiovascular disease is the leading cause of mortality (52% of deaths) in individuals with type 2 diabetes. Although insulin resistance plays a critical role in the pathogenesis of type 2 diabetes-related cardiovascular disease, other related risk factors often cluster in a single patient; the combination of insulin resistance and these risk factors is known as the metabolic syndrome. According to the World Health Organization definition, this constellation of risk factors includes hypertension, elevated plasma triacylglycerol, reduced HDL cholesterol, central obesity, and microalbuminuria. The Multiple Risk Factor Intervention Trial showed that, although diabetes or insulin resistance is an independent risk factor for cardiovascular disease mortality, these other components of the metabolic syndrome confer additive risk. Thus, to effectively address cardiovascular disease in persons with diabetes, intervention would ideally target all these factors. Conjugated linoleic acid could represent a candidate agent. The therapeutic potential of conjugated linoleic acid against insulin resistance-associated cardiovascular disease is discussed on the basis of the reported effects of conjugated linoleic acid on individual components of the metabolic syndrome.