Obesity and the Metabolic Syndrome

In recent years, scientists have found that some of the complications of obesity, which include diabetes, hypertension, insulin resistance, and heart disease, were more clearly related to the central distribution of fat (excessive fat tissue in the abdominal region), than to overall level of obesity.

This central location of fat and the release of fatty acids and cytokines (powerful chemical substances secreted by cells) from the enlarged fat cells in this area, provide the major agents that define the Metabolic Syndrome.

What is the Metabolic Syndrome?

Metabolic Syndrome, also called the dysmetabolic syndrome or Syndrome X, is a collection of factors that individually are risks for cardiovascular disease, the number one cause of death in the United States. Some of these factors that can be included in the syndrome are:

• hyperinsulinemia (high levels of insulin in the blood)
• hypertension (high blood pressure)
• abnormal blood lipids (cholesterol, triglycerides, HDL, LDL)
• increased coagulant state (abnormal blood clotting)
• and other clinical features

What causes Metabolic Syndrome?

Metabolic Syndrome is caused from a genetic predisposition that involves insulin resistance and environmental factors, such as obesity and a sedentary lifestyle. The National Cholesterol Education Program (NCEP) through the Adult Treatment Panel III (ATP III), has provided criteria for diagnosing the presence of the Metabolic Syndrome. At least 3 of the criteria listed below must be present for a diagnosis:

Clinical Features of the Metabolic Syndrome:

Abdominal obesity (waist circumference):
Men: > 102 cm (40 in)
Women: > 88 cm (35 in)

HDL cholesterol: Men: < 50 mg/dL Women: < 60 mg/dL

Triglycerides: ≥ 150 mg/dL

Fasting glucose: ≥ 110 mg/dL

Blood Pressure: ≥130 / 85 mmHg

What are the Risk Factors for the Metabolic Syndrome?

The most likely risk factors observed are abdominal obesity, elevated triglycerides, decreased HDL cholesterol, and elevated blood pressure. Once elevated fasting blood glucose is observed, then the likelihood of having diabetes is greatly increased, therefore, intervention prior to the observance of elevated fasting blood glucose is desired.

As mentioned above, Metabolic Syndrome is closely linked to insulin resistance. According to the American Heart Association, one group of such people are those with diabetes who have a defect in insulin action and can’t maintain a proper level of glucose in their blood. Another group are those mainly with high blood pressure, who do not have diabetes and insulin-resistance, but who compensate by secreting large amounts of insulin. This condition is known as hyperinsulinemia. A third group is heart attack survivors who, unlike hypertensives, have hyperinsulinemia without having abnormal glucose levels.

How Prevalent is Metabolic Syndrome?

The prevalence of Metabolic Syndrome is 25% in United States adults, and this increases with advancing age, increasing BMI (body mass index) and certain ethnicities, but overall, the individuals with Metabolic Syndrome are more alike than dissimilar across these groups. Metabolic Syndrome is a high cardiovascular risk state that is probably higher than the sum of its components.

How is Metabolic Syndrome Treated and/or Prevented?

Therapies aimed at reducing insulin resistance, is the main treatment for the Metabolic Syndrome. Weight loss of approximately 10% has been shown to significantly decrease insulin resistance, and it should be the primary target of intervention due to its ripple effect in other areas, including hypertension, increased triglycerides, decreased LDL, and decreased insulin resistance. The secondary target of intervention is exercise, due to its ripple effects of decreased weight (improved insulin resistance), decreased blood glucose, decreased triglycerides, increased HDL and decreased blood pressure.

Other steps of treatment of the Metabolic Syndrome

• Monitor blood glucose, lipoproteins and blood pressure
• Treat diabetes and hyperlipidemia
• Choose drug therapy for hypertensive people with care—different agents have different effects on insulin sensitivity

With the rate of obesity increasing at such an alarming rate, metabolic syndrome will be one of our nation’s greatest challenges of the 21st century. It’s imperative that we prevent or defer the progression of this disease, and reduce the associated risk factors, as described above.