FRIDAY, Sept. 4, 2009 (HealthDay News) -- Among the elderly, the ratio of waist size to hip size may be a better determinant of obesity than body mass index, say researchers from the University of California, Los Angeles.
For women between ages 70 and 80, every 0.1 increase in the waist-hip ratio was associated with a 28 percent increase in mortality rate, the research team reported. Therefore, an older woman with 40-inch hips whose waist circumference rose from 32 to 36 inches would have a 28 percent greater chance of premature death.
In elderly men, the researchers found that the death rate increased by 75 percent once waist size exceeded hip size. The study findings were released online in advance of publication in an upcoming print issue of the Annals of Epidemiology.
No such link was found between death and waist circumference alone or body mass index (BMI), a comparison of a person's height to weight commonly used to measure obesity. People who are obese are at risk of premature death from conditions such as diabetes and cardiovascular disease, which are possibly caused by excess weight, the study authors noted in a university news release.
Lead investigator Dr. Preethi Srikanthan, a UCLA assistant professor of endocrinology, said in the news release that "other studies have suggested that both waist size and BMI matter in young and middle-aged adults and that BMI may not be useful in older adults; this is one of the first studies to show that relative waist size does matter in older adults, even if BMI does not matter."
The authors noted that their study may not be definitive as the heights and weights were reported by the participants themselves, and the other measurements were taken only once.
The U.S. Department of Health and Human Services has more about obesity.