Risk relationship between insulin resistance, diabetes, and atherosclerotic cardiovascular disease

In recent years, there has been great interest in the concept of a clustering of risk factors for cardiovascular disease (CVD) occurring in a given individual to a greater degree than expected by chance. This clustering, commonly referred to as the “metabolic syndrome,” has clinical manifestations frequently observed in obesity and is believed to be associated with underlying insulin resistance (IR) in the majority, of individuals. In its original conception, “syndrome X” [1] or the “insulin resistance syndrome” [2] provided a framework to understand the relationship or association between IR, multiple metabolic abnormalities, and the development of type 2 diabetes mellitus (T2DM). This “metabolic” clustering of risk factors (obesity, elevated triglycerides [TG] and low high-density lipoprotein [HDL] cholesterol, hypertension, IR, abnormal fasting or 2-h plasma glucose levels, and others) is used primarily to CVD risk profiling in an individual subject.