Acute vascular function responses predict chronic vascular function changes to heating and exercise interventions in young, healthy recreationally active adults

Vascular physiologists frequently use acute stimulus response designs, particularly in the assessment of potential health-promoting interventions, because they are more feasible to execute and provide a controlled environment to characterize responses and examine regulatory factors in comparison to chronic interventions. However, the evidence is unclear on the relationships between acute and chronic responses to vascular stimuli. As such, the objectives of this study were to determine 1) whether acute arterial function responses to blood flow stimulating interventions predict chronic changes to an 8-wk repeated intervention and 2) whether the acute functional responses are associated with chronic structural artery changes. This study was a secondary analysis of a randomized controlled trial. Forty-five young, healthy recreationally active adults who underwent either lower limb heat therapy (HEAT, n = 15), moderate-intensity exercise training (EX, n = 14), or combined training and therapy (HEATEX, n = 16) were included in the analysis. Endothelial function was assessed via brachial artery (BA) flow-mediated dilation (FMD), and arterial stiffness was assessed via central pulse wave velocity (cfPWV) and peripheral pulse wave velocity (ffPWV). BA diameter was measured using ultrasonography. Acute responses were associated with chronic responses for absolute (β = 0.56 [SE = 0.18]; P = 0.003) and relative BA FMD (β = 0.54 [SE = 0.21]; P = 0.013) and ffPWV (β = 0.73 [SE = 0.17]; P < 0.001); however, there was no relationship between the acute BA FMD response (functional) and chronic BA diameter (structural) change (P = 0.36). Acute responses of BA FMD and ffPWV can predict chronic responses in the same indices and may be a method to individualize health interventions.NEW & NOTEWORTHY Acute responses and chronic changes in brachial artery endothelial function and lower limb arterial stiffness are positively associated with each other, indicating that there is potential to use these variables to predict an intervention's utility for improving vascular health.