SHORT-TERM, HIGH-INTENSITY EXERCISE, BUT NOT HISTAMINE BLOCKADE, ALTERS INTERARM BLOOD PRESSURE

Olivia Kocuba1,,2, Lauren Weber2, Jesse Trube2, Brock Jensen2, Michael Holmstrup, FACSM2. 1University of South Carolina, Columbia, SC. 2Slippery Rock University, Slippery Rock, PA. BACKGROUND: Large differences in systolic blood pressure (BP) between arms (IAD; ≥10mmHg absolute difference) have been linked to an increased risk for cardiovascular disease and premature mortality. Further, light- and moderate-intensity aerobic exercise alters IAD and a differential response has been observed based upon resting IAD status. To date, there have not been any investigations into the effect of short-term, maximal-intensity exercise on IAD. Further, post-exercise hypotension is not fully understood, but there is evidence to suggest that the activation of histamine (i.e., H1 and H2) receptors contributes to increased vasodilation. Therefore, histamine-receptor blockade results in suppressed vasodilation and increased BP, and therefore may exacerbate IAD during recovery following acute maximal-intensity exercise. The purpose of this study was to examine the effect of a histamine-receptor blockade on IAD and sustained post-exercise hypotension following an acute bout of high-intensity exercise. METHODS: Apparently healthy individuals were studied in a control condition and following the blockade of histamine H1 (fexofenadine 120mg) or H2 (famotidine 40mg), respectively. BP was simultaneously measured using two automated, auscultatory monitors (SunTech Tango) at rest, immediately following a Wingate test, and at one-, five-, and ten-minute recovery time points. Additionally, continuous hemodynamic monitoring (Physioflow) was performed using a non-invasive device. A two-way, repeated measures ANOVA was used to determine condition and time differences. RESULTS: A significant increase in IAD and systolic BP, and alterations in the hemodynamic response, from rest to immediate post-exercise and into recovery were observed (P\u3c0.05), however, these responses were not different under conditions of histamine blockade (P\u3e0.05). CONCLUSIONS: In apparently healthy individuals, short-term, high-intensity exercise altered the IAD response. The effect of histamine blockade on IAD remains unclear