Between-visit Reproducibility of Pain Perception and Cerebrovascular Responses During the Cold Pressor Test

The cold pressor test (CPT) is commonly used to compare cardiovascular and cerebrovascular reactivity between populations and/or after interventions. Past studies have examined between-visit reproducibility in cardiovascular reactivity during the CPT but did not assess pain or cerebrovascular data. Therefore, our retrospective analysis examines the reproducibility of pain and cerebrovascular responses during the CPT. Purpose: Based on past work suggesting moderate blood pressure (BP) response reproducibility during the CPT, we tested the hypothesis that cerebrovascular responses have moderate between-visit reproducibility during the CPT. METHODS: During two experimental visits ≥48 hours apart, we continuously measured middle cerebral artery blood velocity (MCAv) via transcranial Doppler, beat-to-beat BP via finger photoplethysmography, and end-tidal CO 2 (ET-CO 2 ) during a 10-minute baseline and a 2-minute CPT (hand in 0.35[0.07]°C ice bath). We assessed pain perception using a 10 cm visual analog scale. The left anchor [0 cm] was "no pain" and the right anchor [10 cm] was "worst imaginable pain." We report data as mean±SD or median[IQR] and calculated intraclass correlation coefficients (ICC). Results: We tested 50 young adults (22 females; age=27[9] yrs; BMI=26±3 kg/m 2 ) who were free from overt disease and were not taking pain-modifying medications. Baseline mean MCAv (61±13 cm/s; ICC=0.64), mean BP (87±8 mmHg; ICC=0.71), and ET-CO 2 (49[7] mmHg; ICC=0.84) had good to very good reproducibility. During the CPT, perceived pain had excellent reproducibility (6.4[2.9] cm; ICC=0.91). ΔMean BP (15[11] mmHg; ICC=0.80), Δmean MCAv (-0.7[9.3] cm/s; ICC=0.82), and Δcerebrovascular conductance index (mean MCAv/mean BP; -0.09[0.14]cm/s/mmHg; ICC=0.80) had very good reproducibility. ΔPulsatility index ([peak MCAv-nadir MCAv]/mean MCAv; -0.05[0.11]; ICC=0.53) and ΔET-CO 2 (-3[6] mmHg; ICC=0.58) had moderate reproducibility. Conclusion: Our data suggest excellent reproducibility for pain and very good reproducibility for Δmean MCAv and Δcerebrovascular conductance index during CPTs performed on different days. These data extend our knowledge of the reproducibility of responses to the CPT to include pain and cerebrovascular responses. APS Postdoctoral Fellowship, NIH F32HL154559, NIH K01HL160772, & AHA 23CDA1037938 to JCW; NIH F32HL154565 to LNB; United States Army W81XWH-18-2-0012 to CGC. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.