Plasma catecholamine responses are consistent among common laboratory stressors

Abstract

Cardiovascular reactivity to stress may be predictive of cardiovascular disease. Sympathoexcitatory responses to mental stress (MS), cold pressor test (CPT), isometric handgrip (HG) and head‐up tilt (HUT) target different physiological mechanisms, but the correlation between response variables is unclear. Our purpose was to test the hypothesis that pressor and catecholamine responses between these stressors would be correlated within subjects. Healthy, normotensive young adults (n=76) underwent MS, CPT, HUT and HG to fatigue. Arterial pressure and HR were monitored, and arterial Epi and NE were sampled during the final 30 sec of each stressor. Percent change from baseline was averaged during MS, CPT, HUT and the final 20% time segment of HG. MAP and SBP were positively correlated between CPT and HG (r = 0.46, 0.52, resp, p < 0.001) but not among other tests. Interestingly, the % increase in NE response to all 4 maneuvers showed robust correlations (MS v CPT r = 0.65; MS v HG r = 0.74; MS v HUT r = 0.53; CPT v HG r = 0.72; CPT v HUT r = 0.68; HG v HUT r = 0.59; p < 0.001 for all). Similar correlations were present for Epi except for comparisons with HUT. This suggests that among the 4 tests, HR and BP responses are generally variable, but NE and Epi responses are remarkably consistent (except Epi for HUT), implying that lab stressors may evoke sympathoexcitation more similarly than previously thought.Support: K23‐RR17520, HL 46493.