Objective: To examine whether microvasculature at age 11-12 years and in mid-adulthood is predicted by: BMI at six time points across the preceding the decade, and decade-long growth patterns.
Methods: Participants/Design: 1288 children (51% girls) and 1264 parents (87% mothers) in the Longitudinal Study of Australian Children (LSAC), followed biennially since 2004. Exposures: Child BMI z-score (CDC) and parent BMI (kg/m2) at child ages 2-3, 4-5, 6-7, 8-9, 10-11 and 11-12 years. Outcomes: Arteriolar and venular calibre from retinal photographs at the Child Health CheckPoint, LSAC’s biophysical assessment at age 11-12 years. Analyses: Mixed growth curve models identified BMI trajectories (five for children and four for adults). Adjusted linear regression models (age, sex and socioeconomic position) estimated associations of retinal vascular calibre with BMI at each time point/BMI trajectories.
Results: Higher BMI at six time points was modestly associated with adverse retinal arteriolar and venular calibre in both age groups. For children, associations strengthened with age, doubling from 2-3 (arteriolar standardised mean difference (SMD) -0.04 (95%CI -0.09 to 0.00) and venular SMD: 0.04, 95%CI -0.01 to 0.09) to 11-12 years of age (SMD: -0.14, 95%CI -0.18 to -0.09 and SMD: 0.08, 95%CI 0.03 to 0.13, respectively); yet associations were consistent over time in adults. Compared to the ‘consistently average’ BMI trajectory children: those in ‘low to high’ and ‘consistently very high’ trajectories had narrower arteriolar calibre (SMD -0.23 (95%CI -0.43 to -0.03) and -0.36 (95%CI -0.51 to -0.20), respectively). Compared to ‘consistently healthy’ BMI adults, those in the always overweight/obese/severely obese trajectories had narrower arteriolar (SMD -0.22 to -0.37) and wider venular (0.14 to 0.31) calibre.
Conclusions: Adverse microvascular markers at age 11-12 years are predicted by higher BMI from age 2-3 years. Decade-long BMI trajectories show small, but consistent associations, with adverse retinal microvasculature in both age groups.