Metabolic Syndrome
(Syndrome X; Insulin Resistance Syndrome; Deadly Quartet)
Definition
Metabolic syndrome is a group of risk factors. The factors are related to the breakdown and use of food. These conditions are risk factors for health issues such as:
In general, it is characterized by:- Abdominal obesity—high amount of fat in trunk area
- Dyslipidemia —high triglycerides and low high-density lipoprotein (HDL, or “good”) cholesterol
- High blood pressure
- Insulin resistance (glucose intolerance or prediabetes)—insulin helps move glucose out of the blood into cells; if a resistance develops it will increase the amounts of blood glucose
Coronary Heart Disease
Causes
The exact cause of metabolic syndrome is not known. It believed to be due to a combination of factors, such as:
- Genetic factors
- Insulin resistance
- Obesity —especially central obesity, in core of body
- Lack of physical activity
- Poor diet
- Fatty tissue abnormalities linked to insulin resistance and obesity
- Psychological stress
- Chronic low-grade inflammation
- Aging
Risk Factors
Risk factors for metabolic syndrome include the following:
- Overweight (especially excessive fat in the abdominal region)
- Poor diet
- Sedentary lifestyle
-
Gender
- No difference in Caucasians
- African Americans: females more than males by 57%
- Mexican Americans: females more than males by 26%
- Genetics: family history of diabetes, lipid disorders, high blood pressure , or heart disease
- Socioeconomic factor with high incidence in low household income families
- Age: over 60 years old
- Ethnicity: Latino/Hispanic American, African American, Native American, Asian American, Pacific Islander
- History of glucose intolerance or gestational diabetes
-
A diagnosis of any of the following conditions:
- High blood pressure
- Elevated triglycerides/low HDL-cholesterol
- Cardiovascular disease
- Polycystic ovary syndrome
- Acute pancreatitis
- Chronic kidney disease
Symptoms
Except for obesity, there are no obvious symptoms. Those who are obese may have the following symptoms and signs:
- Sleep apnea
- Back or knee pain
- Shortness of breath
- Reduced exercise tolerance
- Fatigue
- Central obesity
- Elevated blood pressure
Diagnosis
The doctor will ask about your medical history. A physical exam will be done.
Your doctor may order lab tests such as:
-
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
- C Reactive Protein, especially highly sensitive CRP
- Blood pressure
- Calculation of body mass index (BMI) from weight and height
- Calculation of the 10 year risk of cardiovascular disease
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 (30 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)
Treatment
The treatment of metabolic syndrome involves two parts:
- Treatment of underlying causes
- 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)
- Exercise may also help to reduce insulin resistance. *²
- 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
Prevention
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 doctor 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 . It should be low in saturated and trans fats. Also keep it low in cholesterol. Aim for a diet that is rich in whole grains, fruits, and vegetables. Avoid soda. Ask your doctor if the Mediterranean diet is right for you. *¹
- If you smoke, quit .
- Drink alcohol in moderation only.
RESOURCES:
American Heart Association
http://www.americanheart.org
National Institute of Diabetes & Digestive & Kidney Diseases
http://www.niddk.nih.gov
CANADIAN RESOURCES:
Canadian Cardiovascular Society
http://www.ccs.ca/home/index_e.aspx
Canadian Diabetes Association
http://www.diabetes.ca/
References:
Cornier MA, Dabelea D, Hernandez TL et al: the metabolic syndrome. Endocr Rev. 2008;29:777-822.
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: http://www.aace.com . 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.
Metabolic syndrome. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php . Updated May 2009. Accessed May 18, 2009.
National Heart, Lung, and Blood Institute. Available at: http://www.nhlbi.nih.gov .
National Institute of Diabetes & Digestive & Kidney Diseases. Available at: http://www.niddk.nih.gov .
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.
Steinberger J, Daniels SR, Eckel RH et al: AHA scientifc statement: progress and challenges in metabolic syndrome in children and adolescents. Circulation. 2009;119:628-647.
Syndrome x or metabolic syndrome. American Heart Association website. Available at: http://www.americanheart.org . 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.
*¹1/13/2009 DynaMed's Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : Salas-Salvadó J, Fernández-Ballart J, Ros E, et al. Effect of a Mediterranean diet supplemented with nuts on metabolic syndrome status: one-year results of the PREDIMED randomized trial. Arch Intern Med. 2008;168:2449-2458.
*²2/17/2009 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php : Davidson LE, Hudson R, Kilpatrick K, et al. Effects of exercise modality on insulin resistance and functional limitation in older adults: a randomized controlled trial. Arch Intern Med. 2009;169:122-131.
*³5/11/2009 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php : Nettleton JA, Lutsey PL, Wang Y, Lima JA, Michos ED, Jacobs DR. Diet soda intake and risk of incident metabolic syndrome and type 2 diabetes in the Multi-Ethnic Study of Atherosclerosis (MESA). Diabetes Care. 2009;32:688-694.
Last reviewed February 2009 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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