Remote ischemic preconditioning in healthy volunteers: a translational pilot randomized controlled trial

Objective Remote ischemic preconditioning (RIPC) has gained recognition as a non-invasive intervention that offers potential cardiovascular benefits and is being increasingly applied in the prevention and treatment of ischemic conditions. However, the underlying mechanisms by which RIPC exerts these effects remain unclear. This study aims to explore the effect of RIPC on plasma proteomics in healthy adults and compare the impact of low-frequency versus high-frequency RIPC interventions. Methods In this single-centre randomized controlled trial, 60 healthy volunteers were allocated (1:1) to low-frequency (once daily) or high-frequency (twice daily) upper-arm RIC for 7 consecutive days. Plasma samples were collected at baseline, day 7 (end of intervention), and day 14 (follow-up). Prespecified vascular-inflammatory proteins were analysed using linear mixed-effects models and expressed as geometric mean ratios (GMRs). Discovery proteomics was performed using Orbitrap mass spectrometry. Results Fifty-eight participants completed follow-up, with >95% adherence and no device-related adverse events. Compared with low-frequency RIC, high-frequency RIC was associated with a transient increase in C-reactive protein at day 7 (GMR 2.24, P=0.029) and day 14 (GMR 3.17, P=0.002). In contrast, proteolytic and chemotactic mediators were significantly reduced, including cathepsin S (day 7 GMR 0.38; P=0.006) and CXCL10 (0.55; P=0.010), with persistence at day 14. Protective markers increased under high-frequency RIC, including glutathione peroxidase-3, brain-derived neurotrophic factor, and fetuin-A. Proteome-wide analysis demonstrated greater remodeling with twice-daily RIC (124 and 152 differentially expressed proteins at days 7 and 14) compared with once-daily RIC (53 and 67 proteins), indicating a frequency-dependent systemic response. Conclusion In healthy adults, twice-daily remote ischemic conditioning induces more pronounced systemic biomarker and proteomic changes than once-daily stimulation. Stimulus frequency appears to be a key determinant of short-term molecular adaptation to RIC and may be relevant for optimizing future cardiovascular trials.