Abstract WE535: Supine Resting Hemodynamics are Unchanged by Anticipation of Same-day Exercise

Introduction: Previous studies have shown that exercise anticipation may exhibit elevated resting blood pressure values when measured immediately prior to exercise testing. Whether a familiarization day is required when participants undergo a brief period of supine rest with a short interval prior to resting measures is unclear. Hypothesis: We hypothesized that resting systolic blood pressure (SBP), diastolic blood pressure (DBP), central SBP, central DBP, and pulse wave velocity (PWV) measured during Visit 1 would be lower than those measured during Visits 2, 3, and 4 due to anticipation of upcoming exercise on the same visit. Methods: Eight adults (n=8; age 21±1 y) completed four laboratory visits with resting hemodynamics being recorded every visit. Resting hemodynamics were measured (SphygmoCor Xcel) following 15 minutes of supine rest including supine brachial systolic (SBP) and diastolic (DBP) blood pressure, central SBP (cSBP) and DBP (cDBP), and carotid–femoral pulse wave velocity (cfPWV). No exercise was completed during visit 1. On visits 2, 3, and 4, the same resting measures were completed with a ~15-minute interval preceding maximal exercise testing. Linear mixed models tested anticipation (visit 1 non-exercise vs visits 2–4) and, secondarily, order effects across visits 2–4. Results: Resting hemodynamics did not differ between the non-exercise visit and exercise days. Group means (visit 1 vs exercise-day average) were: SBP 115.81±7.80 vs 115.36±6.16 mmHg (p=0.80); DBP 67.00±7.40 vs 65.80±7.52 mmHg (p=0.50); cSBP 100.81±6.48 vs 99.82±5.22 mmHg (p=0.56); cDBP 67.69±7.41 vs 66.97±7.39 mmHg (p=0.70); cfPWV 4.95±0.47 vs 4.74±0.34 m/s (p=0.11). Heart rate, likewise, showed no anticipation effect: 60.38±9.41 vs 60.58±12.00 bpm (p=0.93). Across exercise-day order (visits 2, 3, and 4), there were no differences in SBP (116.38±6.00, 113.50±6.35, and 116.21±9.16 mmHg; p=0.43), DBP (64.88±6.99, 65.06±9.73, and 67.46±8.19 mmHg; p=0.47), cSBP (99.81±4.32, 98.31±6.48, and 101.33±8.18 mmHg; p=0.47), cDBP (66.19±6.56, 65.88±9.90, and 68.85±8.19 mmHg; p=0.41), or cfPWV (4.66±0.54, 4.64±0.36, and 4.93±0.28 m/s; p=0.08). HR across visits 2, 3, and 4 was 62.31±13.13, 61.69±13.60, and 57.73±11.26 bpm (p=0.19). Conclusion: Accurate resting values can be determined on the same day as exercise provided a short interval precedes maximal exercise testing. A separate familiarization day does not appear necessary to obtain stable resting hemodynamics in this protocol.