Syndrome X – it sounds like a scary disease associated with aliens and science-fiction movies however, this disorder is affecting more and more Europeans. Syndrome X, also known as the metabolic syndrome or insulin resistance syndrome, has been linked to rising levels of obesity and declines in the levels of physical activity.

Syndrome X is diagnosed when a person has three or more of the following conditions: abdominal obesity, high triglyceride levels, low HDL (high-density lipoprotein) cholesterol levels, high blood pressure, and high fasting blood sugar levels. People who have syndrome X are at greater risk of developing Type 2 diabetes and heart disease. Sufferers are also more likely to die prematurely from heart disease and other causes.

Insulin Resistance: The Key to Syndrome X

Under normal conditions, a hormone known as insulin allows blood sugar to move into the cells of the body, where it is used to produce energy. However, when normal amounts of insulin are not able to transport glucose into the cells, insulin resistance occurs. In other words, the cells resist the action of insulin and the glucose cannot pass into the cells. When this happens, the pancreas must produce more insulin to maintain normal blood glucose levels. Although people with syndrome X have higher levels of glucose in their blood, it is still within the normal range, and they are not diabetic.
What causes insulin resistance? The answer is still unclear, but it is estimated that about half of all cases of insulin resistance are due to genetic factors. However, insulin resistance is also affected by factors that we can influence: body weight (in particular, abdominal fat) and fitness levels.

Insulin Resistance, Obesity, and Fitness Levels

Obesity greatly increases the likelihood of insulin resistance. Dietary approaches to treating and preventing syndrome X vary depending on an individual’s symptoms, but nearly all experts agree that symptoms are greatly improved by reducing body weight, even by as little as 10 percent, and increasing the level of physical activity.
Exercise is essential because muscle is the biggest tissue in the body—30 to 40 percent of body mass is muscle – and it is the major site of glucose disposal. Inactive muscle is not as sensitive to insulin.

Many experts recommend that people work towards being moderately physically active for at least 30 minutes per day, most days of the week. Simply being less sedentary can also help. For example, taking the stairs instead of the lift; losing the remote control to the television or standing for 30 minutes per day rather than sitting all the time while watching television.

Long Term Solutions

Like other chronic diseases, syndrome X is a complex, lifestyle-induced illness. Its solutions are not difficult to understand: eat less whilst maintaining a wide variety of foods, exercise more. These solutions must become part of everyday life and integrated into society to be effective.

Clinical parameters of syndrome X

Syndrome X is defined as having three or more of these risk factors listed in the table.

Risk Factor	Defining Level
Abdominal obesity	Waist circumference Men: > 102cm or 40in Women: > 88cm or 35in
High triglyceride levels	> = 150 mg/dl
Low high density lipoprotein	Men: = < 40mg/dl Women: = < 50mg/dl
High blood pressure	> = 140/ > = 90mmHg
High fasting glucose levels	> = 110mg/dl

For Further Information:

• Hill J and Horton E, eds (2000). Contributing factors to insulin resistance. An ILSI North America Workshop. Nutrition Reviews, 58; S1-S26.
• Astrup A and Finer N (2000) Redefining type 2 diabetes: 'Diabesity' or 'Obesity Dependent Diabetes Mellitus'. Obesity Reviews, 1; 57-59.
• The Metabolic Syndrome: Where Are We and Where Do We Go? A brief critical Review, Nutrition Reviews, vol. 60, p335.

FOOD TODAY 04/2003