Metabolic syndrome

A cluster of common abnormalities, including insulin resistance, impaired glucose tolerance, abdominal obesity, reduced high-density lipoprotein (HDL)-cholesterol levels, elevated triglycerides, and hypertension.

Incidence is increasing in line with the number of people who are overweight or obese, with one quarter of the Western population estimated to have the condition.

Multiple criteria exist to define metabolic syndrome.

Increases risk of cardiovascular disease and diabetes, although there are ethnic variations in the incidence of comorbidities associated with metabolic syndrome defined by the same criteria.

The precise pathogenetic mechanisms unifying all of its components are as yet unknown, although insulin resistance certainly plays a key role.

Obesity, an atherogenic diet, and physical inactivity are the strongest risk factors for the development of metabolic syndrome.

Lifestyle interventions, including a diet low in saturated fats and moderate to intense physical activity, are the mainstay of treatment.

A multifactorial approach targeting low-density lipoprotein (LDL)-cholesterol and non-HDL-cholesterol levels, blood pressure control, and glucose reduction is recommended.

Statins are considered first-line treatment when lifestyle measures do not achieve the desired non-HDL-cholesterol levels. Fibrates also play a significant role in the modification of lipid levels.

Metabolic syndrome, originally described by Reaven in 1988 as "syndrome X" or "insulin resistance syndrome", is a cluster of common abnormalities, including insulin resistance, impaired glucose tolerance, abdominal obesity, reduced high-density lipoprotein (HDL)-cholesterol levels, elevated triglycerides, and hypertension.[1]Obunai K, Jani S, Dangas GD. Cardiovascular morbidity and mortality of the metabolic syndrome. Med Clin North Am. 2007;91:1169-1184. http://www.ncbi.nlm.nih.gov/pubmed/17964915?tool=bestpractice.com [2]National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). Third report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) final report. Circulation. 2002;106:3143-3421. http://circ.ahajournals.org/cgi/reprint/106/25/3143 http://www.ncbi.nlm.nih.gov/pubmed/12485966?tool=bestpractice.com [3]Reaven GM. Banting lecture 1988: role of insulin resistance in human disease. Diabetes. 1988;37:1595-1607. http://www.ncbi.nlm.nih.gov/pubmed/3056758?tool=bestpractice.com No known common cause unifies its components. The condition reflects the sedentary lifestyle, overnutrition, and resultant excess adiposity of the modern world. Metabolic syndrome is associated with endothelial dysfunction and atherosclerosis resulting in an increased risk of cardiovascular disease (CVD) and type 2 diabetes mellitus.[1]Obunai K, Jani S, Dangas GD. Cardiovascular morbidity and mortality of the metabolic syndrome. Med Clin North Am. 2007;91:1169-1184. http://www.ncbi.nlm.nih.gov/pubmed/17964915?tool=bestpractice.com [2]National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). Third report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) final report. Circulation. 2002;106:3143-3421. http://circ.ahajournals.org/cgi/reprint/106/25/3143 http://www.ncbi.nlm.nih.gov/pubmed/12485966?tool=bestpractice.com The main utility of diagnosing metabolic syndrome is the identification of people at high risk of CVD beyond low-density lipoprotein (LDL)-cholesterol levels. However, whether a diagnosis of metabolic syndrome provides more useful information than its individual components regarding cardiovascular risk is greatly controversial.