Comparative associations of body mass index and waist-to-height ratio with cardiometabolic and functional health risk markers in children aged 6–12 years - the Health Oriented Pedagogical Project (HOPP)

BACKGROUND: Body mass index (BMI) and waist-to-height ratio (WHtR) are widely used markers of adiposity in children, but their relative associations with cardiometabolic and functional health measures remain debated. METHODS: We analyzed data from children aged 6-12 years (n = 2297) in the Health Oriented Pedagogical Project (HOPP) with annual assessments from 2015-2020. Associations between BMI or WHtR and outcomes (body composition, blood lipids, blood pressure, physical activity, and cardiorespiratory fitness/endurance) were examined using linear mixed-effects models with repeated measures (random intercept for child; study year as the repeated factor). BMI and WHtR were evaluated in separate models. RESULTS: Both BMI and WHtR were consistently associated with less favorable profiles across outcomes, including higher adiposity, lower fitness/endurance and MVPA, higher blood pressure, and a more adverse lipid profile (lower HDL and higher non-HDL cholesterol). Across most outcomes, differences between BMI- and WHtR-based models were modest; however, WHtR generally showed slightly stronger associations for lipid measures and fitness-related outcomes. CONCLUSIONS: BMI and WHtR demonstrate largely comparable associations with cardiometabolic and functional health measures in children aged 6-12 years. WHtR may provide complementary information on central adiposity and can be considered alongside BMI in pediatric screening and surveillance.