The metabolic syndrome and the liver.

Together with the worldwide epidemic proportions of obesity the incidence of 'the metabolic syndrome' is rising across countries. The metabolic syndrome is described as a complex condition that is linked to (intra-abdominal) obesity and is characterized by insulin resistance, dyslipidaemia and hypertension. Several definitions for the metabolic syndrome have been suggested, all trying to identify individuals at high risk for both type 2 diabetes and cardiovascular disease. The primary hepatic complication of obesity and insulin resistance is nonalcoholic fatty liver disease (NAFLD). NAFLD is not included as a component of the metabolic syndrome as it is currently defined; however, data suggest an association. Although the data are mainly epidemiological, the pathogenesis of NAFLD and the metabolic syndrome show common components, with the focus on insulin resistance as a key factor. Even so the treatment of patients with the metabolic syndrome and NAFLD shows a certain degree of similarity, and should focus on the management of associated conditions including obesity, glucose and lipid abnormalities. Lifestyle modifications comprising healthy eating habits and regular exercise are the primary interventions recommended to patients with the metabolic syndrome and those with NAFLD. A pharmacological approach like insulin-sensitizing agents, lipid lowering drugs, antihypertensive drugs and antiobesity agents can be successful in the treatment of certain risk factors that are currently clustering with both the metabolic syndrome and NAFLD. In some cases bariatric surgery may be necessary.