Metabolic Syndrome
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Metabolic Syndrome

(Syndrome X; Insulin Resistance Syndrome; Deadly Quartet)

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Animation Movie AvailableWhat is Metabolic Syndrome?


Metabolic syndrome is a group of risk factors of a metabolic origin that increase the risk of diabetes , coronary heart disease , stroke , and peripheral vascular disease . In general, it is characterized by:

Coronary Heart Disease

Stereostatic Biopsy

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Metabolic syndrome may be caused by:

  • Genetic factors
  • Insulin resistance
  • Dietary factors
  • Chronic low-grade inflammation
  • Aging
  • Lifestyle factors, such as:
    • Obesity
    • Lack of physical activity

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

Risk factors for metabolic syndrome include the following:


In general, metabolic syndrome causes no noticeable symptoms, except perhaps those related to obesity. Although, the diseases that may result from metabolic syndrome have symptoms, for example, those related to diabetes, heart disease, stroke, and poor leg circulation.


The doctor will ask about your medical history, perform a physical exam, and order laboratory tests.

Tests may include:

  • Blood tests to measure:
    • Fasting blood sugar levels (glucose) or a two-hour post-glucose challenge blood sugar level
    • Fasting insulin
    • Triglyceride level
    • HDL cholesterol level
  • Blood pressure
  • Calculation of body mass index (BMI) from weight and height
  • Calculation of the 10 year risk of cardiovascular disease

There are several criteria for diagnosing metabolic syndrome. You may be diagnosed with metabolic syndrome if you have at least three of the following measures:

  • Waist measurement—greater than 40 inches in Caucasian men (35 inches in Asian men) or 35 inches in Caucasian women (31 inches in Asian women)
  • Fasting blood sugar (glucose)—greater than or equal to 100 mg/dL* (5.55 mmol/L)
  • Serum triglycerides—greater than or equal to 150 mg/dL (1.7 mmol/L)
  • Serum HDL (“good”) cholesterol—less than 40 mg/dL (1.0 mmol/L) in men and less than 50 mg/dL (1.3 mmol/L) in women
  • Blood pressure—greater than or equal to 130/85 millimeters of mercury (mm Hg)
*mg/dL = milligrams per deciliter blood, mmol/L = millimoles per liter blood.


The treatment of metabolic syndrome involves two parts: treatment of underlying causes and treatment of specific metabolic abnormality.

Treatment of Underlying Causes

  • Reducing excess weight by at least 10% in the next 6 to 12 months
  • Increasing physical activity to 30-60 minutes of moderate aerobic exercise four or more days per week
  • Lowering blood pressure to below 130/85 mmHg with diet, exercise, and possibly medication
  • Improving triglyceride and HDL cholesterol levels through diet, exercise, and possibly medication

Treatment of Specific Metabolic Abnormality

  • High blood pressure—treated with medications (eg, angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists)
  • Insulin resistance—treated with medications (eg, metformin, thiazolidinediones)
  • High blood lipids—treated medications (eg, statins, ezetimibe, fibrates, nicotinic acid)
  • Clotting tendency—treated with low dose aspirin, especially in those with moderate to high cardiovascular risk


To help prevent metabolic syndrome:

  • Achieve and maintain a healthful weight.
  • Do 30 minutes of moderate aerobic exercise at least four days per week.
  • See your healthcare provider regularly.

In addition, other unhealthy lifestyle factors also contribute to heart disease, stroke, and peripheral vascular disease. To lower your risk of these diseases:

  • Eat a healthful diet , one that is low in saturated fat and rich in whole grains, fruits, and vegetables
  • If you smoke, quit
  • Drink alcohol in moderation only


American Heart Association

National Institute of Diabetes & Digestive & Kidney Diseases


Canadian Cardiovascular Society

Canadian Diabetes Association


Deen D. Metabolic syndrome: time for action. Am Fam Physician . 2004;69:2875-2882.

Eckel RH, Grundy SM, Zimmet PA. The metabolic syndrome. Lancet . 2005;365:1415-1428.

Findings and recommendations from the American College of Endocrinology on the insulin resistance syndrome. American Association of Clinical Endocrinologists website. Available at: . Accessed January 17, 2003.

Gami AS, Witt BJ, Howard DE, et al. Metabolic syndrome and risk of incident cardiovascular events and death. J Am Coll Cardiol . 2007;49:403-414.

Grundy SM, Brewer HB, Cleeman JI, et al. American Heart Association, NHLBI. Definition of metabolic syndrome: report of the NHLBI/AHA conference on scientific issues related to definition. Circulation . 2004;109:433-438.

Grundy SM, Cleeman JI, Diniels SR, et al. AHA/NHLBI Diagnosis and management of the metabolic syndrome: an AHA/NHLBI Scientific Statement. Circulation . 2005;112:2735-2752.

National Heart, Lung, and Blood Institute. Available at: .

National Institute of Diabetes & Digestive & Kidney Diseases. Available at: .

Reaven GM. The metabolic syndrome or the insulin resistance syndrome? Different names, different concepts, and different goals. Endocrinol Metab Clin North Am . 2004; 33: 283-304.

Syndrome x or metabolic syndrome. American Heart Association website. Available at: . Accessed January 17, 2003.

Wright Jr JT, Harris-Haywood S, Pressel S, et al. Clinical outcomes by race in hypertensive patients with and without the metabolic syndrome (ALLHAT). Arch Int Med. 2008;168:207-217.

Last reviewed March 2008 by David Juan, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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