Metabolic syndrome

Metabolic syndrome is a combination of medicaldisorders that affect a large number of people in a clustered fashion. In some studies, the prevalencein the USA is calculated as being up to 15% of the population.

Nomenclature

Other names for this syndrome are:

• Syndrome X;
• Metabolic syndrome X;
• Insulin resistancesyndrome;
• Reaven's Syndrome, after Dr Gerald M. Reaven (who put the syndrome on the map in 1988in the Banting lecture, named after Sir Frederick Banting);
• CHAOS (Australia);
• Wohlstandssyndrom (German).

It is not related to:

• Fragile X syndrome(a chromosomalabnormality);
• Cardiac syndrome X- this term is now mainly used for a type of angina pectoriswhere there is cardiac ischemia on exercise testing but no causative atherosclerosis on a coronary angiogram.

Signs and symptoms

Symptoms and features are:

• Diabetes mellitustype II (or impaired glucose tolerance or insulin resistance);
• High blood pressure;
• Central obesityand difficulty losing weight;
• High cholesterol(combined hyperlipidemia):
  • Elevated LDL;
  • Decreased HDL;
  • Elevated triglycerides;
• Fatty liver(especially in concurrent obesity).

Associated diseases are:

• Polycystic ovarian syndrome;
• Hemochromatosis(iron overload);
• Acanthosis nigricans(a skin condition featuring dark patches);
• Non-alcoholic steatohepatitis(extreme form of fatty liver).

Diagnosis

The above diseases are all diagnosed separately; please see the relevant articles. The Adult Treatment PanelIII of the National Cholesterol Education Program(2001) defined the diagnosis as three or more of the following five:

• Increased waist circumference (>=102 cm in men and >=88 cm in women), indicating centralobesity
• Elevated triglycerides(>=150 mg/dL or 1.7 mmol/l)
• Decreased HDLcholesterol (<40 mg/dL for men, <50 mg/dL for women)
• Blood pressureabove 130/85 or active treatment for hypertension
• Glucoselevels above 100 mg/dL

Pathophysiology

The causes of metabolic syndrome are extremely complex and have only been partially elucidated. Most patients have a degree of insulin resistance, but there is debate whether this is the cause of the metabolic syndrome or a byproduct of a more far-reaching metabolic derangement. There is a role for systemic inflammation, as a number of inflammatory markers (including C-reactive protein) is often increased, as are fibrinogen, IL-6, TNFαand others.

Therapy

Generally, the individual diseases that comprise Syndrome X are treated separately (e.g. diureticsand ACE inhibitorsfor hypertension). A remarkable finding is, however, that drugs that decrease insulin resistance(metforminand thiazolidinediones) not only reduce hyperglycemiabut generally lead to an improvement in blood pressureand cholesterol(lipid profile) as well. Exerciseand weight lossmay be helpful, particularly in preventing progression to diabetes mellitus.

External links

• ApolloLipids - resource for medical professionals providing articles and slides on metabolic syndrome concerning cardiovascular disease, lipids and obesity.

History

The Marseillesphysician Dr Jean Vague appears to have been one of the first to link abdominal obesity with metabolic abnormalities in 1947.

The concept that risk factors for myocardial infarction concur to form a "constellation of abnormalities" associated with heart disease, aging, obesity and other clinical states -- what is now commonly referred to as the "metabolic syndrome" -- was first reported in 1978 by Dr. Gerald B. Phillips, who suggested there was an underlying factor linking the abnormalities. He hypothesized that this factor was sex hormones. In 1988, in his Banting lecture, Dr. Gerald M. Reaven proposed insulin resistance as the underlying factor and named the constellation of abnormalities Syndrome X. Abdominal obesity has also been hypothesized as the underlying factor, but none of these three hypotheses has been confirmed.

See also

• Hyperinsulinemia

References

• Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Executive Summary of The 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). JAMA 2001;285:2486-97. PMID 11368702.
• Grundy SM. Obesity, Metabolic Syndrome and Cardiovascular Disease. J Clin Endocrinol Metab 2004;89:2595-600. PMID 15181029.
• Phillips GB, Jing TJ, Heymsfield SB: Relationships in men of sex hormones, insulin, adiposity, and risk factors for myocardial infarction. Metabolism 52:784-790, 2003
• Reaven GM. Banting lecture 1988. Role of insulin resistance in human disease. Diabetes 1988;37:1595-607. PMID 3056758.
• Zavaroni I, Dall?aglio E, Bonora E, Alpi O, Passeri M, Reaven GM: Evidence that multiple risk factors for coronary artery disease exist in persons with abnormal glucose tolerance. Am J Med 83:609-612, 1987
• Phillips GB: Sex hormones, risk factors and cardiovascular disease. Am J Med 65:7-11, 1978
• Phillips GB: Relationship between serum sex hormones and glucose, insulin, and lipid abnormalities in men with myocardial infarction. Proc Natl Acad Sci USA 74:1729-1733, 1977
• Vague J. Sexual differentiation. A factor affecting the forms of obesity. Presse Med 1947; 30: 339-340.de:Metabolisches Syndrom

es:Síndrome Metabólico sv:Metabolt syndrom zh:?????

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It uses material from the http://en.wikipedia.org/wiki/Metabolic+syndrome Wikipedia article Metabolic syndrome.