Body fat evolution as predictor of retinal microvasculature in children

Abstract

OBJECTIVES: Microvascular changes may represent an underlying mechanism through which overweight contributes to cardiovascular disease development. Therefore, the aim of this study was to investigate whether changes in children's body fat over time are associated with the retinal microvasculature, a marker of cardiovascular aging. METHODS: In a longitudinal design, 171 healthy Flemish children (53.8% boys) were followed- up for 7 years (2008-2015), aged 2.7-8.1 years at baseline. Z-scores of body mass index (zBMI; 4.1% overweight), waist circumference (zWC) and fat mass index (zFMI by BODPOD) were obtained using standardized protocols during each visit. Retinal arteriolar (central retinal arteriolar equivalent (CRAE)) and venular equivalents (central retinal venular equivalent (CRVE)) were measured from digital retinal photographs (2015) using IVAN software. Cross-sectional and longitudinal associations between changes in body fat and retinal microvasculature were explored using multivariable regression analysis, while controlling for age, sex, mean arterial pressure, alternate retinal caliber, physical activity, diet and birth weight. RESULTS: In cross-sectional analysis, children with high zFMI had a higher CRVE, but only in boys (beta = 0.25, P = 0.02). In addition, boys with high zFMI had also a lower CRAE to CRVE ratio (beta = -0.26, P = 0.03). No associations were seen with the CRAE, or between zBMI or zWC and the retinal microvasculature. Only changes in zFMI over time were found to be positively associated with the CRVE in boys (beta = 0.38, P = 0.01). CONCLUSIONS: Our analysis over a 7-year period shows that changes in body fat during childhood are already associated with the CRVE (especially in boys).