Syndrome X – The Insulin Resistance Syndrome

The Insulin Resistance Syndrome
A diagnosis of the Insulin Resistance Syndrome is established when 3 or more of these risk factors are present.
Risk Factor Defining Level
Abdominal obesity*

Waist circumference



Blood Pressure
Fasting Glucose


> 102 cm (> 40 in)
> 88 cm (> 35 in)

≥ 150 mg/dl

< 40 mg/dl
< 50 mg/dl

≥ 130 mm Hg or
≥ 85 mm Hg or
current use of BP med

≥ 110 mg/dl or
current use of diab. med.

*Abdominal obesity is more highly correlated with IRS than weight or BMI
Expert Panel on Detection Evaluation and Treatment of High Blood Cholesterol in Adults, JAMA: 285: 2486-2497, 2001

Adapted from Using Insulin © 2003


Syndrome X, which is also known as the “metabolic syndrome” or “Insulin Resistance Syndrome”, is a condition that is linked to an increased risk of diabetes and heart disease. It was first recognized in the 1960s and information about it was first published in 1990.

It is marked by abdominal obesity, elevated levels of triglycerides, low levels of HDL (“good”) cholesterol, high blood pressure, and high blood sugar levels. Recent research shows that 22% of adults between the ages of 20 and 79 have at least three of these symptoms. Other symptoms include smoking, high fat and calorie diet, prediabetes or Type 2 diabetes, polycystic ovary syndrome or gout.

The research was conducted by the US Centers for Disease Control and Prevention and was published in The Journal of the American Medical Association (volume 287; pages 356-359; January 16, 2002). About 9,000 men and women participated in the study, which occurred between 1988 and 1994. Metabolic syndrome was more common in older people than in younger people. There were differences along lines of ethnicity and gender, as well. Mexican Americans were more likely to develop the syndrome than people of other ethnic backgrounds. Also, women were more likely to have the syndrome than were men.

A glucose tolerance test can determine if someone is insulin resistant or not. Most people who are insulin resistant still produce enough insulin to maintain a normal blood glucose level.