Metabolic Syndrome

What is metabolic syndrome?
An association between certain metabolic disorders and cardiovascular disease has been known since the 1940s. In the 1980s this association became more clearly defined and the term metabolic syndrome (also known as syndrome X or the dysmetabolic syndrome) was coined to designate a cluster of metabolic risk factors that come together in a single individual. In more current times, the term metabolic syndrome is found throughout medical literature and in the lay press as well. There are slight differences in the criteria of diagnosis - depending on which authority is quoted. Regardless, the concept of a clustering of risks factors leading to cardiovascular disease is well accepted.

The main features of metabolic syndrome include:

1. insulin resistance,
2. hypertension (high blood pressure),
3. cholesterol abnormalities, and an increased risk for clotting.
4. Patients are most often overweight or obese.

Insulin resistance refers to the diminished ability of cells to respond to the action of insulin in promoting the transport of the sugar glucose, from blood into muscles and other tissues. Because of the central role that insulin resistance plays in the metabolic syndrome, a separate article is devoted to insulin resistance.

How is metabolic syndrome defined?
The definition of metabolic syndrome depends on which group of experts is doing the defining. Based on the guidelines from the 2001 National Cholesterol Education Program Adult Treatment Panel (ATP III), any three of the following traits in the same individual meet the criteria for the metabolic syndrome:
Abdominal obesity: a waist circumference over 102 cm (40 in) in men and over 88 cm (35 inches) in women.
Serum triglycerides 150 mg/dl or above.
HDL cholesterol 40mg/dl or lower in men and 50mg/dl or lower in women.
Blood pressure of 130/85 or more.
Fasting blood glucose of 110 mg/dl or above. (Some groups say 100mg/dl)

The World Health Organization (WHO) has slightly different criteria for the metabolic syndrome:
High insulin levels, an elevated fasting blood glucose or an elevated post meal glucose alone with at least 2 of the following criteria:
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.
Cholesterol panel showing a triglyceride level of at least 150 mg/dl or an HDL cholesterol lower than 35 mg/dl.
Blood pressure of 140/90 or above (or on treatment for high blood pressure).

How common is metabolic syndrome?
Metabolic syndrome is quite common. Approximately 20%-30% of the population in industrialized countries have metabolic syndrome. By the year 2010, the metabolic syndrome is expected to affect 50-75 million people in the US alone.

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

1. Genetic factors influence each individual 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 the metabolic syndrome.
   
2. Environmental issues such as low activity level, sedentary lifestyle, and progressive weight gain also contribute significantly to the risk of developing the 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 five or more pounds per year raise their risk of developing metabolic syndrome by up to 45%.
   
3. While obesity itself is likely the greatest risk factor,

Others factors of concern include:

1. women who are post-menopausal,
2. smoking,
3. eating an excessively high carbohydrate diet,
4. lack of activity (even without weight change),
5. and consuming an alcohol-free diet.