Altered Peripheral Artery Function and Wave Reflection in Boys With Duchenne and Becker Muscular Dystrophy

Duchenne (DMD) and Becker muscular dystrophy (BMD) are muscle-wasting disorders with high cardiovascular (CV) mortality rates. An early sign of myocardial remodeling is left ventricle (LV) dysfunction, which eventually progresses to cardiomyopathy. Null dystrophin on vascular smooth muscle and endothelial cells has been linked to peripheral artery dysfunction in DMD/BMD murine models. Arterial dysfunction alters wave reflection, increasing LV load and contributing to heart failure. Clinically, peripheral artery function and wave reflection remain under-explored in DMD/BMD. Purpose: To characterize peripheral artery microvascular function and wave reflection in boys with DMD (n=22,13±4 years old) and BMD (n=10,14±5 years old) compared with typically-developing controls (n=33,14±4 years old). We hypothesized lower peripheral artery function and augmented wave reflection in boys with DMD and BMD compared with controls. Methods: Pulse wave analysis using oscillometric cuff inflation of the brachial artery was used to assess augmentation index normalized to a heart rate of 75 beats per minute (AIx75) and wave separation analysis to assess forward (Pf) and reflected (Pb) pressure waves, with reflection magnitude (RM) calculated as Pb/Pf. Peripheral artery microvascular function was assessed using index finger pulse amplitude tonometry and calculated as reactive hyperemia index (RHI) in a subset of boys (n; Control=23, BMD=6, DMD=14). Kruskal-Wallis tests assessed group effects, and post-hoc Mann-Whitney U tests and Bonferroni-Holms corrections were applied when group differences were detected. Results: A main effect of group was observed for AIx75 (p<0.001, n 2 =0.50). Post-hoc tests showed a stepwise increase in AIx75 from Controls to BMD (p=0.007, Control:-2.4±10.9 vs. BMD:10.0±14.9%) to DMD (p<0.001, Control:-2.4±10.9 vs. DMD:30.7±19.6%; p=0.006, BMD:10.0±14.9 vs. DMD:30.7±19.6%). RM was also different between groups (p<0.01, n 2 =0.27). Post-hoc tests showed a trend (p=0.08) towards a stepwise increase, although only Controls vs. DMD was significantly different (p<0.001, Control:46±6 vs. DMD:57±10%). A main effect of group was observed for RHI (p<0.001, n 2 =0.15), such that RHI was reduced in boys with DMD vs. Controls (p=0.01; Controls:1.72±0.45 vs. DMD:1.33±0.47a.u.) and BMD (p=0.027; BMD:2.19±0.88 vs. DMD:1.33±0.47a.u.). Conclusions: Preliminary findings suggest impaired peripheral artery microvascular reactivity in boys with DMD and increased wave reflection in DMD/BMD. Noninvasive techniques detect early arterial abnormalities, suggesting their potential as biomarkers of CV dysfunction and progression, and requiring longitudinal studies to explore the role of arterial function in cardiac remodeling in DMD/BMD. Supported by NIH-1R01HLI55764 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.