Abstract  The clustering of cardiovascular risk factors associated with abdominal obesity is well established. Although currently lacking a universal definition, the metabolic syndrome describes a constellation of metabolic abnormalities, including abdominal obesity, and was originally introduced to characterize a population at high cardiovascular risk. Adipose tissue is a dynamic endocrine organ that secretes several inflammatory and immune mediators known as adipokines. Dysregulation of adipokine secretion, free fatty acid toxicity, and the site-specific differences in abdominal (visceral) versus subcutaneous fat support abdominal obesity as a causal factor mediating the insulin resistance, increased risk of diabetes, and cardiovascular disease in the metabolic syndrome.