In a large multiethnic study, being underweight was linked with an increased risk of early death among postmenopausal women. Also, a higher waist circumference – but not being overweight or slightly obese – was associated with premature mortality, indicating that abdominal fat is more deadly than carrying excess weight.
[Photo: Dr. Zhao Chen]
The study by researchers at the University of Arizona Mel and Enid Zuckerman College of Public Health is published in the Journal of the American Geriatrics Society.
“Our study highlights the fact that although being overweight is often considered to be generally bad for your health, how bad it is can depend on your age and ethnic background,” said Dr. Zhao Chen, chair of the department of epidemiology and biostatistics at the UA Zuckerman College of Public Health.
To evaluate if the relationship between measures of obesity with premature mortality varies by age and race/ethnicity in older women, Dr. Chen and her colleagues analyzed information on 161,808 generally healthy postmenopausal women participating in the Women’s Health Initiative (WHI), a long-term national health study.
During an average follow-up of 11.4 years, the investigators observed a U-shaped curve for the relationship between body mass index (BMI) and mortality, so that women who were underweight or significantly obese had an elevated risk of dying during follow-up. There was also a close to linear relationship between waist circumference and mortality across each racial/ethnic and age group, so that women with wider waists had higher risks of dying. Interestingly, Hispanic women in the study had a lower mortality rate at any given BMI or waist circumference compared with non-Hispanic whites or African-Americans.
The findings suggest that there may be different healthy BMI ranges for older women, and they support growing evidence that abdominal obesity rather than general obesity plays an important role in individuals’ risk of dying early.
“We have used data from the large prospective cohort of the US Women’s Health Initiative to add evidence on the relationship of general and central obesity with all-cause mortality in older women, especially in African American and Hispanic American older women, who have not been well represented in previous research on this topic,” said Dr. Chen. “Our study findings have called public health attention to reduce central obesity in older women from different racial/ethnic groups and to reconsider recommendations on the range of healthy BMI in older women.”
Body Mass Index, Waist Circumference, and Mortality in a Large Multiethnic Postmenopausal Cohort—Results from the Women’s Health Initiative
Journal of The American Geriatrics Society. Feb. 23, 2017
Zhao Chen PhD, Yann C. Klimentidis PhD, Jennifer W. Bea PhD, Kacey C. Ernst PhD, Chengcheng Hu PhD, Rebecca Jackson PhD, Cynthia A. Thomson PhD