Metabolic syndrome

Metabolic 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.

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

Increases risk of cardiovascular disease and diabetes, although there are ethnic variations in the incidence of metabolic syndrome components 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 weight loss, low-density lipoprotein (LDL)-cholesterol and non-HDL-cholesterol levels, blood pressure control, and glucose reduction is recommended.

Comorbidities commonly associated with metabolic syndrome include polycystic ovarian syndrome, hypogonadism, and metabolic dysfunction-associated steatotic liver disease.

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]Alberti KG, Eckel RH, Grundy SM, et al. Harmonizing the metabolic syndrome: a joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and International Association for the Study of Obesity. Circulation. 2009 Oct 20;120(16):1640-5. https://circ.ahajournals.org/content/120/16/1640.full http://www.ncbi.nlm.nih.gov/pubmed/19805654?tool=bestpractice.com ​ Multiple criteria, all with slight differences, exist to define metabolic syndrome; no single definition is accepted as the international standard. See Diagnostic criteria.

The precise pathogenetic mechanisms unifying all of its components are as yet unknown, although insulin resistance certainly plays a key role. 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.[2]Obunai K, Jani S, Dangas GD. Cardiovascular morbidity and mortality of the metabolic syndrome. Med Clin North Am. 2007 Nov;91(6):1169-84. http://www.ncbi.nlm.nih.gov/pubmed/17964915?tool=bestpractice.com [3]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 Dec 17;106(25):3143-421. https://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.