Effects of moxibustion aroma stimulation and lower-limb warm stimulation on blood pressure and cerebral hemodynamics: a pilot randomized trial

Objective: Sensory and thermal interventions may acutely affect both peripheral cardiovascular regulation and cortical activity, but their comparative effects remain unclear. This study investigated the acute effects of moxibustion aroma stimulation, lower-limb warm stimulation, and their combination on blood pressure (BP), heart rate (HR), and cortical hemodynamics in healthy young adult men. Methods: In this pilot randomized trial, 40 healthy young adult men were randomly assigned to a resting control group, moxibustion aroma stimulation group, lower-limb warm stimulation group, or combined stimulation group (n = 10 each). Each intervention lasted 20 min. Systolic BP (SBP), diastolic BP (DBP), and HR were measured at 0, 5, 10, 15, and 20 min. Functional near-infrared spectroscopy (fNIRS) was used to assess oxygenated hemoglobin (HbO) responses and functional connectivity (FC) in the bilateral prefrontal and motor cortices. Results: Significant time effects were observed for SBP, DBP, and HR (all P < 0.001), together with significant group × time interactions for SBP (P < 0.001), DBP (P = 0.011), and HR (P = 0.037); the overall group effects were not significant. Significant group × stage interactions were observed for HbO in all four ROIs and for all interregional FC measures (all P < 0.001). Late-stage reductions in BP and HR were associated with increases in HbO in selected cortical regions (r = 0.577-0.820, all P < 0.001). Conclusion: Moxibustion aroma stimulation, lower-limb warm stimulation, and combined stimulation were associated with distinct time-dependent patterns of cardiovascular and cortical hemodynamic responses in healthy young adult men. The associations between late-stage reductions in BP/HR and regional increases in HbO suggest concurrent peripheral cardiovascular and cortical hemodynamic changes during stimulation. However, these preliminary findings do not establish a causal central-peripheral regulatory mechanism or demonstrate the superiority of any intervention.