Acute effects of high-intensity interval training on microvascular circulation

Objectives: The aim of this study was to explore the acute effects of high-intensity interval training (HIIT) on the microvascular circulation and vascular tumor microenvironment (TME) in a patient with uveal melanoma (UM). Additionally, the acceptance of the applied diagnostics and the exercise protocol in a clinical ophthalmic-oncology setting were evaluated. Methods: This case-control study included a young adult male patient with UM previously treated with radiation and an age-matched healthy control. Participants underwent a baseline assessment of dynamic retinal vessel analysis (DRVA) and cardiopulmonary exercise testing (CPET) to determine endothelial function and intensity for HIIT. Optical coherences tomography angiography (OCTA) was performed before, immediately and 30 min after one session of HIIT. The primary outcome were changes in ocular vessel parameters and whole body oxygen uptake. Results: The UM patient exhibited lower arterial dilation and constriction in the affected eye compared to his healthy eye and both eyes of the healthy control. OCTA revealed heterogeneous patterns of vascular response to HIIT in both participants. The tumor eye showed an increase followed by a significant decrease in vessel density post-exercise, while the healthy control exhibited minor increases. Conclusions: The findings of this study highlighted the potential of UM combined with OCTA and DRVA as a model for examine exercise-induced vascular effects within the TME. However, a pre-treated UM as well as detailed image analyses and further research with longitudinal, randomized controlled designs are essential to validate these findings and address methodological limitations. Such investigations could refine integrative cancer treatment.