Metabolic Syndrome

Medically Reviewed by James Beckerman, MD, FACC on June 04, 2022
5 min read

Metabolic syndrome, also known as syndrome X or dysmetabolic syndrome, refers to a cluster of metabolic conditions that can lead to heart disease.

The main features of metabolic syndrome include insulin resistance, hypertension (high blood pressure), abnormal cholesterol, and an increased risk for clotting. People diagnosed with this syndrome are usually overweight or obese.

Insulin resistance is a condition in which the body produces insulin but does not use it properly. Insulin, a hormone made by the pancreas, helps the body use glucose, a form of sugar, for energy. If a person has insulin resistance, their body is not converting glucose for use by muscles and other tissues.


According to American Heart Association guidelines, any three of the following traits in the same person meet the criteria for the metabolic syndrome:

  1. Abdominal obesity: a waist circumference over 102 cm (40 in) in men and over 88 cm (35 inches) in women
  2. Serum triglycerides: 150 mg/dl or above, or taking medication for elevated triglycerides
  3. HDL (''good'') cholesterol: 40mg/dl or lower in men and 50mg/dl or lower in women
  4. Blood pressureof 130/85 or above (or taking medication for high blood pressure)
  5. Fasting blood glucoseof 100 mg/dl or above

The World Health Organization (WHO) has slightly different criteria for defining the metabolic syndrome:

  1. High insulin levels, an elevated fasting blood glucose or an elevated post-meal glucose alone with at least two of the following criteria:
  2. Abdominal obesity as defined by a waist-to-hip ratio of greater than 0.9, a body mass index of at least 30 kg/m2 or a waist measurement over 37 inches
  3. Cholesterolpanel showing a triglyceride level of at least 150 mg/dl or an HDL cholesterol lower than 35 mg/dl
  4. Blood pressure of 130/80 or higher (or on treatment for high blood pressure)


Approximately 20%-30% of the population in industrialized countries has metabolic syndrome.

As is true with many medical conditions, genetics and the environment both play important roles in the development of metabolic syndrome.

Genetic factors influence each component of the syndrome, and the syndrome itself. A family history that includes type 2 diabetes, hypertension, and early heart disease greatly increases the chance that an individual will develop metabolic syndrome.

Environmental issues such as low activity level, sedentary lifestyle, and progressive weight gain also contribute significantly to the risk of developing metabolic syndrome.

Metabolic syndrome is present in about 5% of people with normal body weight, 22% of those who are overweight and 60% of those considered obese. Adults who continue to gain 5 or more pounds per year raise their risk of developing metabolic syndrome by up to 45%.

While obesity itself is likely the greatest risk factor, others include:

  • Being in postmenopause
  • Smoking
  • Eating a diet that is excessively high in carbohydrates
  • Not getting enough physical activity



Metabolic syndrome is a condition that can lead to both diabetes and heart disease, two of the most common chronic diseases today.

Metabolic syndrome increases the risk of type 2 diabetes (the common type of diabetes) anywhere from 9 to 30 times over the normal population. As to the risk of heart disease, studies vary, but metabolic syndrome appears to increase the risk 2 to 4 times that of the normal population.

Other health risks from metabolic syndrome include fat accumulation in the liver (fatty liver), resulting in inflammation and the potential for cirrhosis. The kidneys can also be affected, as metabolic syndrome is associated with microalbuminuria, the leaking of protein into the urine, a subtle but clear indication of kidney damage. The syndrome can also cause obstructive sleep apnea, polycystic ovary syndrome, increased risk of dementia with aging, and cognitive decline in older adults.

The major goals are to treat both the underlying cause of metabolic syndrome and to reduce factors that may lead to heart problems.

Lifestyle modification is the preferred treatment of metabolic syndrome. Weight reduction usually requires a specifically tailored, multifaceted program that includes diet and exercise. Medications also may be useful.

Diets come and go, but experts generally recommend the Mediterranean diet -- one that is rich in "good" fats (olive oil) and contains a reasonable amount of carbohydrates and proteins (such as from fish and chicken).

The Mediterranean diet is palatable and easy to maintain. In addition, recent studies have shown that when compared to a low-fat diet, people on the Mediterranean diet have a greater decrease in body weight and greater improvements in blood pressure, cholesterol levels, and other markers of heart disease, all of which are important in evaluating and treating metabolic syndrome.

A sustainable exercise program -- for example, 30 minutes a day 5 days a week -- is reasonable as a starting point, providing there is no medical reason you can't. If you have any special concerns in this regard, check with your doctor first. Exercise has a beneficial effect on blood pressure, cholesterol levels, and insulin sensitivity, regardless of whether you lose weight. In itself, exercise is helpful in treating metabolic syndrome.


So, if a large waistline is the problem, why not just have liposuction to remove the fat? It's not so simple. Studies show no benefit in liposuction on insulin sensitivity, blood pressure, or cholesterol. Diet and exercise are still the recommended first-line treatment of metabolic syndrome.

What if changes in diet and activity levels do not do the trick? Drugs to control cholesterol and high blood pressure may be considered.

Blood pressure goals are generally set lower than 130/80, and recommendations may change depending on your age. Some blood pressure medications -- ACE inhibitors -- have also been found to reduce levels of insulin resistance and to defer the complications of type 2 diabetes. This is an important consideration when discussing the choice of blood pressure drugs in the metabolic syndrome.

Metformin (Glucophage), usually used to treat type 2 diabetes, also has been found to help prevent the onset of diabetes in people with metabolic syndrome. However, there are currently no established guidelines on treating metabolic syndrome patients with metformin if they do not have a diabetes diagnosis.

Statins are a class of drugs often prescribed by doctors to help lower cholesterol levels in the blood. They work by blocking the action of the liver enzyme that is responsible for producing cholesterol.