Does brachial artery flow-mediated dilation scale to anthropometric characteristics?

Flow-mediated dilation (FMD) assesses the health of the vascular endothelium. Despite widespread adoption of scaling practices in cardiac research, scaling for body size or composition has not been used for FMD. The present study investigated the relationships between brachial FMD and body composition in 129 children aged 9–10 (75♀, 54♂), and 50 men aged 16–49. Body composition variables (total, lean, fat mass in the whole body, arm, forearm) were assessed by dual-energy X-ray absorptiometry, FMD was measured in the brachial artery using high-resolution ultrasound. FMD was scaled using simple ratios (y/x) and allometric approaches (y/x b ) after log–log least squares linear regression produced allometric exponents (b). Size independence was confirmed via bivariate correlations (x:y/x; x:y/x b ). No relationships were evident between FMD and body composition variables in adults. Small correlations existed between FMD and measures of segmental fat mass in children (r = −0.18 to −0.19, p