TOPLINE:
When compared to BMI, waist-hip ratio (WHR) exhibited the highest and most consistent connection with all-cause mortality, and it was the only parameter that was unaffected by BMI.
METHODOLOGY:
Cohort analysis of event fatalities from the UK Biobank (2006-2022), comprising data from 22 UK sites.
A total of 387,672 people were separated into two groups: the discovery cohort (n = 337,078) and the validation cohort (n = 50,594), with the latter including 25,297 fatalities and 2297 controls.
The validation cohort was employed for analysis whereas the discovery cohort was used to produce genetically determined adiposity metrics.
The connections between exposure and outcome were studied using observational and mendelian randomization (MR) methods.
TAKEAWAY:
A J-shaped correlation was identified in adjusted analyses for both measured BMI and fat mass index (FMI), but the association with WHR was linear (hazard ratio 1.41 per SD increase).
All three adiposity measurements were associated with all-cause mortality, with an odds ratio of 1.29 per SD change in genetically determined BMI (P = 1.441013). 1.45 per SD change in genetically determined FMI, 1.45 (P = 6.271030), and 1.51 (P = 2.11109) per SD change in genetically determined WHR.
WHR demonstrated a greater link with all-cause mortality than BMI, but not substantially stronger than FMI.
The relationship between genetically determined BMI and FMI and all-cause mortality changed across quantiles of observed BMI, but not WHR (P =.04, P =.02, and P =.58, respectively, for BMI, FMI, and WHR).
IN ACTION:
“The current World Health Organization recommendations for optimal BMI ranges are inaccurate across individuals with different body compositions and, as a result, suboptimal for clinical guidelines.”