Waist Size Predicts Heart Disease Danger
Large Waistline Measurement a Sign of Insulin Resistance in Men and Women
Insulin Resistance: A Risk for Diabetes, Heart Disease continued...
Earlier studies have suggested that insulin resistance can be predicted based on other clinical features. These features include body mass index (BMI), weight, hip circumference, and waist-to-hip ratio. But Wahrenberg says waist circumference alone predicts insulin resistance better than any of these other features alone or in combination.
"We are astonished waist circumference is so good a predictor," he says. "We had not expected it would have such good power."
The results also surprise Youfa Wang, MD, PhD, of the Center for Human Nutrition at the Bloomberg School of Public Health at Johns Hopkins University. Wang has studied ways to predict diabetes and heart disease.
"I am astonished," Wang tells WebMD. "It is quite encouraging that waist circumference is a very good predictor of insulin sensitivity and a good screening tool. It is very impressive that this can replace the other measures such as BMI as predictors."
Waist Under 39 Inches? Risks Remain for Many
Wang notes that insulin resistance isn't the real problem. The real problem is heart disease. And one reason why insulin resistance is so dangerous is that it's part of a group of risk factors called the metabolic syndrome. Those risk factors are high blood-fat levels (triglycerides), low levels of HDL "good" cholesterol, very high levels of LDL "bad" cholesterol, high blood pressure, excess body fat around the waist, and clotting abnormalities.
Though Wahrenberg finds that a 39-inch waistline is the cutoff for insulin resistance in both men and women, other dangerous factors may be brewing at smaller waistlines. This appears particularly true for women.
Current guidelines say that a high risk of heart disease and stroke starts when men's waistlines reach 40 inches and women's waistlines reach 34.65 inches.
Wang's recent studies suggest that even these cutoffs may be too high. His work suggests that men already are at risk of heart disease and stroke when their waistlines reach 37.4 inches.