Individuals with a larger waist circumference--even with a normal body mass index--have a greater chance of dying than those with smaller circumferences, according to a study published in the Aug. 9/23 issue of Archives of Internal Medicine.
Eric J. Jacobs, PhD, of the American Cancer Society in Atlanta, and colleagues used data from 48,500 men and 56,343 women aged 50 and older who participated in a survey—the Cancer Prevention Study II Nutrition cohort—in 1997, providing information about weight and waist circumference.
The researchers reported the deaths of 9,315 men and 5, 332 women. They adjusted for body mass index (BMI).
Results showed that a very large waist circumference—120 centimeters/47 inches in men and 110 centimeters/42 inches for women—doubled a patient’s risk of death.
According to the researchers, a larger waist circumference was associated with a higher risk of death in all BMI categories: normal, overweight and obese. However, the researchers found that the risk was most strong for women at a normal weight.
Results showed that a 10 centimeter increase in waist circumference in men was associated with an increased relative risk of 1.16 within a normal BMI category, 1.18 within an overweight BMI category and 1.21 within an obese BMI category.
These corresponding numbers for women were 1.25, 1.15 and 1.13, respectively.
The researchers concluded that regardless of BMI, waist circumference is an important risk factor for mortality.
“Future detailed analyses of the relationship between waist circumference and visceral adipose tissue or measures of insulin resistance within categories of BMI could identify biological reasons for potential differences in the strength of the association between waist circumference and mortality," the authors wrote.
In addition, the researchers said that the study results could push the National Institutes of Health to revise the current clinical guidelines for obesity, which were created in the 1990s and may be outdated.
“The NIH guidelines recommend weight loss goals for all patients in the obese category of BMI (30 or greater), but they do not specifically recommend weight loss goals for abdominally obese patients (waist circumference of 88 centimeters or larger in women or 102 centimeters or larger in men) who are in the normal or overweight BMI category unless they also have two or more cardiovascular risk factors or a desire to lose weight.”