What is Metabolic Syndrome?

Metabolic syndrome (also called metabolic syndrome X, syndrome X, and insulin resistance syndrome) is a combination of medical conditions that places one at increased risk for cardiovascular disease and type 2 diabetes mellitus. The clustering of risk factors that comprise metabolic syndrome has become increasingly more prevalent in the United States. In fact, an estimated 34% of US adults over the age of 20 years have metabolic syndrome (1). Individuals with metabolic syndrome are twice as likely to develop cardiovascular disease and five times more likely to develop type 2 diabetes compared to individuals without metabolic syndrome (2). In addition to a heightened risk for these diseases, metabolic syndrome has recently been shown to impair health-related quality of life (3).

Although the prevalence of metabolic syndrome increases with age, the syndrome is becoming increasingly more common in children and adolescents. However, applying adult diagnostic criteria (see below) to children is controversial because there are multiple definitions for pediatric metabolic syndrome (4). In fact, 40 different definitions for pediatric metabolic syndrome have been used in various studies, and a standardized definition is needed (5). Using different diagnostic definitions, the prevalence of metabolic syndrome in US adolescents varied from 2% to 9% overall and 12% to 44% in obese adolescents (6).

What are the Components of Metabolic Syndrome?

In 2001, the Adult Treatment Panel III of the National Cholesterol Education Program (NCEP) outlined metabolic syndrome as a clinical condition with specific criteria for diagnosis (7). These criteria have since been revised (see below) (8). For instance, the threshold for impaired fasting glucose was lowered to 100 mg/dL; this level may better predict type 2 diabetes (9). The syndrome consists of several different components, including abdominal obesity, atherogenic dyslipidemia, hypertension, insulin resistance with or without impaired glucose tolerance, and evidence of prothrombotic and inflammatory states (7). All of these conditions are risk factors for cardiovascular disease. Moreover, insulin resistance can lead to type 2 diabetes (8).

What are the Diagnostic Criteria for Metabolic Syndrome?

Diagnostic criteria include the presence of three or more of the following conditions (8):

  • Abdominal obesity (waist circumference: ≥40 inches [102 cm] for men and ≥35 inches [88 cm] for women)
  • Elevated triglycerides (≥150 mg/dL or on drug treatment for elevated triglycerides)
  • High blood pressure (≥130 mm Hg for systolic blood pressure or ≥85 mm Hg for diastolic blood pressure or taking anti-hypertensive drugs)
  • Elevated fasting glucose (≥100 mg/dL or on drug treatment for elevated glucose)
  • Decreased HDL cholesterol (<40 mg/dL for men and <50 mg/dL for women, or on drug treatment for low HDL cholesterol)

How is Metabolic Syndrome Prevented?

  • Eat a healthy diet. Consume a diet rich in fruit, vegetables, fish, and whole grains. Reduce your intake of foods high in saturated fats or trans fats, such as butter, cheese, animal fat, stick margarine, and vegetable shortening. Reduce your intake of potatoes, white flour, and white rice by substituting whole grain products. Avoid foods and drinks that are high in sugar and low in nutrients, such as soft drinks, sugar-coated breakfast cereals, and candy — keep sugar intake low (less than 10% of calories). More information on Healthy Eating can be found in the Linus Pauling Institute's "Rx for Health."
  • Get regular physical activity. See Healthy Lifestyle in the Linus Pauling Institute Prescription for Health.
  • Maintain a healthy body weight. Becoming overweight (BMI of 25-29.5) or obese (BMI of 30 or more) increases the risk of many chronic diseases. Calculate your BMI. Having too much abdominal fat (waist circumference greater than 40 inches for men and greater than 35 inches for women) also increases risk for various diseases and metabolic syndrome. Even a relatively small weight loss (10% of your current weight) can help lower your risk of metabolic syndrome.
  • Do not smoke. If you smoke, make every effort to quit. Even if you have smoked many years, quitting will result in dramatically decreased risk of chronic diseases. Smoking cessation resources
  • Schedule regular medical checkups.

How is Metabolic Syndrome Treated?

People with metabolic syndrome should schedule regular check-ups with their medical provider. In addition to prescribed medications, several lifestyle modifications can help treat metabolic syndrome:

  • Eat a healthy diet; see above and Healthy Eating in the Linus Pauling Institute Prescription for Health. Adherence to the DASH (Dietary Approaches to Stop Hypertension) diet has been shown to reduce systolic and diastolic blood pressure. The DASH diet emphasizes fruit, vegetables, whole grains, poultry, fish, nuts, and low-fat dairy products. More information on the DASH diet is available from the National Institutes of Health (NIH) website.
  • Exercise regularly. See Healthy Lifestyle in the Linus Pauling Institute Prescription for Health.
  • Losing weight can lower blood pressure and increase insulin sensitivity; even a 10% reduction in excess body weight would benefit these conditions.
  • Do not smoke. If you smoke, make every effort to quit. Even if you have smoked many years, quitting will result in dramatically decreased risk of chronic diseases. Smoking cessation resources

Micronutrients, Phytochemicals, Food, and Beverages Related to the Medical Conditions of Metabolic Syndrome

High Blood Pressure

Cholesterol Levels

High Triglycerides

Type 2 Diabetes (Non-Insulin Dependent Diabetes)

Informational Resources

National Heart, Lung, and Blood Institute

American Diabetes Association

American Heart Association

Weight-control Information Network

Dietary Guidelines for Americans 2015

Last updated 4/19/17   Copyright 2008-2020  Linus Pauling Institute

References

1.  Ervin RB. Prevalence of metabolic syndrome among adults 20 years of age and over, by sex, age, race and ethnicity, and body mass index: United States 2003-2006. National Health Statistics Reports. 2009;13:1-8.  Available at: http://www.cdc.gov/nchs/nhanes/new_nhanes.htm.

2.  Grundy SM. Metabolic syndrome pandemic. Arterioscler Thromb Vasc Biol. 2008;28(4):629-636.  (PubMed)

3.  Ford ES, Li C. Metabolic syndrome and health-related quality of life among U.S. adults. Ann Epidemiol. 2008;18(3):165-171.  (PubMed)

4.  Pietrobelli A, Malavolti M, Battistini NC, Fuiano N. Metabolic syndrome: a child is not a small adult. Int J Pediatr Obes. 2008;3 Suppl 1:67-71.  (PubMed)

5.  Ford ES, Li C. Defining the metabolic syndrome in children and adolescents: will the real definition please stand up? J Pediatr. 2008;152(2):160-164.  (PubMed)

6.  Cook S, Auinger P, Li C, Ford ES. Metabolic syndrome rates in United States adolescents, from the National Health and Nutrition Examination Survey, 1999-2002. J Pediatr. 2008;152(2):165-170.  (PubMed)

7.  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(19):2486-2497.  (PubMed)

8.  Grundy SM, Cleeman JI, Daniels SR, et al. Diagnosis and management of the metabolic syndrome: an American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Circulation. 2005;112(17):2735-2752.  (PubMed)

9.  Genuth S, Alberti KG, Bennett P, et al. Follow-up report on the diagnosis of diabetes mellitus. Diabetes Care. 2003;26(11):3160-3167.  (PubMed)