A recent cohort study found that both low and high body roundness index levels are associated with an increased risk of all-cause mortality among U.S. adults.

Published in JAMA Network Open, the study included a nationally representative cohort of 32,995 U.S. adults aged ≥ 20 years. Researchers used data from the National Health and Nutrition Examination Survey (NHANES) spanning 1999 to 2018, linking and tracking mortality data through December 31, 2019. The cohort consisted of noninstitutionalized civilians, with a median follow-up period of nearly 10 years.

Researchers observed that the mean body roundness index (BRI) among US adults increased from 4.8 to 5.6 between 1999 - 2018, with a biennial change of 0.95%. This increase was more pronounced among women, elderly individuals, and those who identified as Mexican American.

The study identified a U-shaped association between BRI and all-cause mortality. Adults with the lowest (BRI < 3.4) and highest (BRI ≥ 6.9) BRI experienced a significantly increased risk of all-cause mortality compared to those in the middle quintile (BRI 4.5 to 5.5). Specifically, the mortality risk was 25% higher for adults with a BRI less than 3.4 and 49% higher for those with a BRI of 6.9 or greater.

These findings suggested that BRI could be a useful anthropometric measure associated with all-cause mortality. The study's results indicated the potential of BRI as a noninvasive screening tool for mortality risk estimation.

The authors declared having no competing interests.