Study Reveals Waist Circumference Enhances Mortality Risk Prediction in Older Women

A recent prospective cohort study has found that including waist circumference alongside Body Mass Index (BMI) significantly enhances the prediction of mortality risk among postmenopausal women. Conducted by a team led by Aaron K. Aragaki, MS, at the Fred Hutchinson Cancer Center in Seattle, the study analyzed all-cause mortality data from the Women's Health Initiative (WHI), which enrolled 139,213 generally healthy postmenopausal women aged between 50 and 79 years from 1993 to 1998, with follow-up continuing through 2021.

The research highlights the limitations of BMI as a singular measure of obesity, arguing that it fails to accurately reflect visceral adiposity, which is crucial for assessing health risks. "Waist circumference is a simple, inexpensive method to assess visceral adiposity and correlates well with visceral fat as assessed by imaging," Aragaki and colleagues noted in their findings published in the Journal of Clinical Epidemiology in July 2025.

The study found that the mortality risk for those with a large waist circumference was significantly higher across various BMI categories. For instance, women classified as having normal weight but with a large waist circumference faced mortality risks comparable to those categorized as obese with a normal waist circumference. The researchers argued that integrating waist circumference into routine assessments could lead to more personalized healthcare strategies for managing obesity and related health risks.

The current waist circumference thresholds, set at 88 cm for women and 102 cm for men, were found inadequate for accurately stratifying risk among individuals diagnosed with obesity. The International Atherosclerosis Society (IAS) and the International Chair on Cardiometabolic Risk (ICCR) Working Group on Visceral Obesity recently proposed new, BMI-specific waist circumference thresholds aimed at improving risk stratification.

Dr. Reema Hamid Dbouk, an assistant professor of obesity medicine at Emory School of Medicine, emphasized the importance of waist circumference in understanding cardiometabolic health. She stated, "BMI is a flawed criterion for the diagnosis of obesity as it reflects total body mass but does not distinguish between fat and lean mass or where fat is distributed." Dr. Dbouk suggested that the integration of waist circumference measurement into clinical practice could facilitate better patient understanding and management of obesity-related health risks.

The findings of this study reinforce the need for healthcare providers to adopt waist circumference measurement as a routine part of patient assessments, especially given its correlation with metabolic health risks. The authors argue that for individuals with elevated waist circumference, more aggressive interventions may be warranted compared to those with similar BMI values but without increased waist size. As the population ages, the implications of these findings could significantly influence public health strategies aimed at reducing obesity-related mortality rates.

Looking forward, more extensive studies are necessary to validate these waist circumference thresholds across different populations, including younger individuals and men, as well as to account for racial and ethnic differences in fat distribution. The WHI program is funded by several institutes within the National Institutes of Health, ensuring a robust methodological framework for ongoing research in this critical area of public health.