TOPLINE:
Compared with body mass index, waist-hip ratio (WHR) had the strongest and most consistent association with all-cause mortality and was the only measurement unaffected by BMI.
METHODOLOGY:
- Cohort study of incident deaths from the U.K. Biobank (2006-2022), including data from 22 centers across the United Kingdom.
- A total of 387,672 participants were divided into a discovery cohort (n = 337,078) and validation cohort (n = 50,594), with the latter consisting of 25,297 deaths and 2,297 controls.
- The discovery cohort was used to derive genetically determined adiposity measures while the validation cohort was used for analyses.
- Exposure-outcome associations were analyzed through observational and mendelian randomization analyses.
TAKEAWAY:
- In adjusted analysis, a J-shaped association was found for both measured BMI and fat mass index (FMI), whereas the association with WHR was linear (hazard ratio 1.41 per standard deviation increase).
- There was a significant association between all three adiposity measures and all-cause mortality, with odds ratio 1.29 per SD change in genetically determined BMI (P = 1.44×10-13), 1.45 per SD change in genetically determined FMI, 1.45 (P = 6.27×10-30), and 1.51 per SD change in genetically determined WHR (P = 2.11×10-9).
- Compared with BMI, WHR had the stronger association with all-cause mortality, although it was not significantly stronger than FMI.
- The association of genetically determined BMI and FMI with all-cause mortality varied across quantiles of observed BMI, but WHR did not (P = .04, P = .02, and P = .58, for BMI, FMI, and WHR, respectively).
IN PRACTICE:
“Current World Health Organization recommendations for optimal BMI range are inaccurate across individuals with various body compositions and therefore suboptimal for clinical guidelines.”
SOURCE:
Study by Irfan Khan, MSc, of the Population Health Research Institute, David Braley Cardiac, Vascular, and Stroke Research Institute, Hamilton, Ont., and colleagues. Published online in JAMA Network Open.
LIMITATIONS:
Study population was genetically homogeneous, White, and British, so results may not be representative of other racial or ethnic groups.
DISCLOSURES:
Study was funded by, and Irfan Khan received support from, the Ontario Graduate Scholarship–Masters Scholarship, awarded by the government of Ontario.
A version of this article first appeared on Medscape.com.