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Objectives Body mass index (BMI) is the primary tool for categorising adiposity status and related health outcomes, however does not reflect fat distribution. In 2023, NICE recommends waist circumference to height ratio (WCH) alongside BMI to assess health risk. WCH reflects central adiposity, with a single cut-off ≥0.5 suggesting excess risk. Studies suggest WCH is a BMI alternative for categorising childhood overweight/obesity and early cardiometabolic risk.1 There is little evidence comparing the two across life or related to overweight/obesity health outcomes. We explored the association between WCH from childhood through adulthood and liver steatosis as an exemplar outcome compared to BMI. Methods Avon Longitudinal Study of Parents and Children data were analysed at 7, 11 and 24 years (n=2059). Pearson's correlation coefficients assessed correlation between WCH and BMI at all ages. Kappa values assessed agreement between WCH and BMI in categorising overweight/obesity. Participants were categorised into 8 groups based on presence of overweight/obesity in childhood, adolescence, and adulthood, according to WCH and BMI. Poisson regression models were fitted to generate incidence rate ratios (IRR) for liver steatosis aged 24 for the 8 groups. Models were minimally adjusted for age and sex. Models were repeated, adjusting for potential confounders birthweight, gestation, adult smoking and alcohol consumption status, adolescent energy intake and socioeconomic status. Results WCH and BMI showed strong correlations at 7 (0.82), 15 (0.84) and 24 (0.91) years. Kappa values showed agreement at 7 (0.58), 15 (0.65) and 24 (0.65) years. Differences between minimally/fully adjusted models were marginal; minimally adjusted results are presented. Being overweight/obese in adulthood was associated with an increased risk of steatosis when defined by WCH (IRR 9.34, CI 6.40–13.62) and BMI (IRR 8.83, CI 5.76–13.50). Overweight/obese status in childhood or adolescence in addition to adulthood resulted in higher steatosis incidence for both WCH (IRR 11.38, CI 6.19–20.93 and IRR 14.75, CI 10.04–21.66, respectively) and BMI (IRR 7.63, CI 3.86- 15.08 and IRR 11.56, CI 7.05–18.95, respectively) than adulthood alone. IRRs were consistently higher for WCH than BMI for corresponding groups, suggesting WCH associates with greater risk. Conclusion WCH may prove an alternative to BMI in assessing the relationship between overweight/obesity and liver steatosis. WCH purposively addresses central adiposity which associates more strongly with liver metabolic health. These findings endorse NICE guidelines encouraging incorporation of WCH in health risk assessment. Moreover, the study confirms the role of early overweight/obesity in developing liver steatosis. Reference Yoo, et al. Waist-to-height ratio as a screening tool for obesity and cardiometabolic risk 2016.
Mandal et al. (Tue,) studied this question.