METABOLIC SYNDROME: What is it? What is the Role of Nutrition?

What is it?

The metabolic syndrome is a constellation of risk factors of metabolic origin that raises the risk of coronary heart disease (CHD).  Aggregation of these risk factors raises the risk for CHD at any given level of LDL cholesterol. 

The underlying causes of the metabolic syndrome are:

• Excess weight
• Physical inactivity

The general features of the metabolic syndrome are:

• Abdominal obesity
• Atherogenic dyslipidemia (high triglycerides, low HDL choleserol)
• Raised blood pressure
• Insulin resistance
• Prothrombotic state
• Proinflammatory state

In addition to the term “metabolic syndrome” other terms that are used that generally refer to the same syndrome include:

• Syndrome X
• Insulin Resistance Syndrome
• Deadly Quartet

Diagnosis

According to the National Cholesterol Education Program’s 2001 Guidelines (ATPIII), the diagnosis of the metabolic syndrome is made when 3 or more of the following risk factors are present:

Prevalence of the Metabolic Syndrome

The significance of the metabolic syndrome was recently highlighted in a report from the Centers for Disease Control (CDC), which determined that the prevalence of the metabolic syndrome among Americans is quite high.  The prevalence increases with age and approaches 40-50% in men and women >50years.

This bar graph summarizes the data from the CDC report (JAMA 2002; 287:356-9).

Management of the Metabolic Syndrome 

The objectives of management of the metabolic syndrome are summarized below.  Diet modification that results in weight reduction is key to successful management of the metabolic syndrome.

• Reduce underlying causes:
  • Excess weight: Weight reduction will reduce all components of the metabolic syndrome.
  • Physical inactivity: Physical inactivity may not only augment the risk factors of the metabolic syndrome but may also enhance risk by compromising coronary blood flow and cardiovascular fitness.
    • Regular physical activity reduces VLDL and LDL cholesterol, while raising HDL cholesterol, lowering blood pressure, and reducing insulin resistance.
  • Treat associated lipid and nonlipid risk factors

The diagnosis and treatment of the metabolic syndrome are illustrated in the following illustration. 

Before Treatment	After Treatment