Metabolic syndrome and cardiovascular disease

The clustering of metabolic and pathophysiological cardiovascular risk factors has long been recognized but it was Reaven who popularized the syndrome in the Banting lecture of 1988. Since 1999, several major international or national organizations proposed their own definitions for the syndrome, named the metabolic syndrome. The prevalence of the metabolic syndrome varies according to definition, ethnicity and gender. The prevalence is under 20% among Chinese and Korean people but over 50% among Maori and Pacific Islanders in New Zealand. People with the metabolic syndrome have 50-60% higher cardiovascular risk than those without. The absolute cardiovascular risk of the metabolic syndrome, however, is not necessarily higher than those of its individual components. The pathogenesis underlying the clustering of cardiovascular risk factors remains unclear. Factors including genetic disposition, obesity, insulin resistance and inflammation have been suggested as being involved. Since the metabolic syndrome is multifactorial in origin, strategies for reducing cardiovascular risk in individuals with the metabolic syndrome involve the management of multiple risks. Lifestyle changes are an effective first-line management; pharmacological interventions for hypertension, diabetes and dyslipidaemia are in accordance with established guidelines. Pharmacological and surgical therapies for obesity are effective in selected patients. In this article we discuss the definitions, prevalence, pathogenesis and management of the metabolic syndrome in relation to cardiovascular risk.