High-Intensity Interval Training (HIIT) improves endothelial Glycocalyx and effects associated Micro-RNA Levels

Schmitz B, Niehues H, Lenders M, Thorwesten L, Klose A, Krüger M, Brand E, Brand S

Abstract

Background: Vascular endothlial cells are covered by a functional structure of negatively-charged proteoglycans, glycoproteins and glycosaminoglycans designated as endothelial glycocalyx, Evidenc for shear-mediated glycocalyx remodelling exists, which selectively affects sehear-induced NO production. A thick glycocalyx may promote vasculoprotective functions, whereas endothelial glycocalyx barrier impairment may lead to increased permeability. This study is first to investigate im high-intensity interval training (HIIT) affects functional and structural microvascular parameters including the endothelial glycocaly. In addition, circulating levels of glycocalyx x-associated mircroRNAs (miRNAs) were assessed. Methods: Fifty healthy participants (23.1±3.0 years) persormed four weeks of 4x30s all-out running HIIT withtwo training session/week. Real-time intravital microscopy (sidestream dark-field imaging, CapiScopeHVCS, KK Technologiy, Results: Participants maximal riunning speed was increased at follow-uip (by 3%, p<0.001), while increase in heart rate at submaximal intensities was lower during follow-up exercise testing (p=0,04, r=0.303) and increased exercise performance at follow-up also correlated with increased glycocalyx thickness (p=0.031, r=0.416). Increased sprinting speed at follow-up was associated with an increased number of perfused vessels (p=0.0129, r=0.449). miRNA, -96-5p and -24 were upregulated by HIIT and associated with LA after sprints (p<0.05). Increased exercise miR-143 levels at baseline predicted increased glycoclyx thickness at follow-up (AUCmiR-143=0.92, p=0.008). Conclusion: We conclude that HIIT induces beneficial microvascular changes including an increased number of perfused vessels and thicker endothelial glycocaly already after short-term interventions