Compared with body mass index (BMI), waist-hip ratio (WHR) had the strongest and most consistent association with all-cause mortality and was the only measurement unaffected by BMI.
Cohort study of incident deaths from the UK 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 2297 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 (MR) analyses.
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 (SD) 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).
"Current World Health Organization recommendations for optimal BMI range are inaccurate across individuals with various body compositions and therefore suboptimal for clinical guidelines."
Study by Irfan Khan, MSc, of the Population Health Research Institute, David Braley Cardiac, Vascular, and Stroke Research Institute, Hamilton, Ontario, Canada, and colleagues. Published online September 20, 2023, in JAMA Network Open.
Study population was genetically homogeneous, White, and British so results may not be representative of other racial or ethnic groups.
Study was funded by, and Khan received support from, the Ontario Graduate Scholarship–Masters Scholarship, awarded by the government of Ontario.
Miriam E. Tucker is a freelance journalist based in the Washington, DC, area. She is a regular contributor to Medscape, with other work appearing in the Washington Post, NPR’s Shots blog, and Diabetes Forecast magazine. She is on Twitter @MiriamETucker.
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Cite this: Waist-Hip Ratio a Stronger Mortality Predictor Than BMI - Medscape - Sep 20, 2023.