C LIU1, J TIAN1, M JOSE2, T DWYER1,3, A VENN1
1Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia, 2School of Medicine, University of Tasmania, Hobart, Australia, 3The George Institute for Global Health, University of Oxford, Oxford, United Kingdom
Aim: To investigate the relationship of body mass index (BMI) trajectories with kidney damage in midlife.
Background: Considerable evidence indicates that elevated BMI is associated with an increased risk of chronic kidney disease, but the relationship of life-course BMI trajectories with kidney damage in midlife is unknown.
Methods: Data from the Childhood Determinants of Adult Health Study, a cohort study of children (aged 7-15 years) first surveyed in the 1985 Australian School Health and Fitness Survey were analysed. Weight and height were measured or self-reported, and BMI calculated (kg/m²). 1,438 participants with BMI at baseline, ≥ two visits in adulthood (ages 26-50 years) and kidney-related tests in midlife (ages 36-50 years) were included. Latent class growth mixture modelling was used to identify the BMI trajectories. Log-binomial regression was used to determine the association of BMI trajectories (persistently low, progressing to moderate, progressing to moderate/high, progressing to high/very high, adult-onset high) with subclinical kidney damage (SKD) defined as estimated glomerular filtration rate (eGFR) 30-60 mL/min/1.73m² or eGFR > 60 mL/min/1.73m² with urine albumin-creatinine ratio ≥ 2.5mg/mmol in males or 3.5mg/mmol in females, adjusting for childhood age, sex, and the duration of follow-up.
Results: Relative to being in the persistently low trajectory, being in higher BMI trajectories was associated with greater risk of SKD in midlife [adjusted relative risk (aRR)=1.89, 95% confidence interval (CI), 1.10-3.25 for progressing to moderate; aRR=1.91, 95% CI, 0.95-3.81 for progressing to moderate/high; aRR=2.86, 95% CI, 1.03-7.99 for progressing to high/very high; and aRR=2.47, 95% CI, 0.77-7.94 for adult-onset high].
Conclusions: Most participants had increasing BMI trajectories from childhood to midlife that were associated with an increased risk of SKD in midlife.
Conghui Liu completed her Bachelor of Medicine in 2015 and Master of Medicine in 2018. She is now the PhD candidate in the Menzies Institute for Medical Research at the University of Tasmania. Her research interest is about understanding the life-course factors from childhood to adulthood that predict kidney damage in midlife.