Exercise Duration Augments Inter-Arm Systolic Blood Pressure Difference

Abstract

Blood pressure is a universal measurement used to aid in appropriate clinical decision-making and monitor safe exercise participation. Inter-arm systolic blood pressure difference (ISBPD; difference of ≥10mmHg between arms) at rest is associated with vascular disease, arterial stiffness, and premature morbidity and mortality. The incidence ISBPD at rest is low (i.e. commonly reported as 10%), though the occurrence of ISBPD is known to increase with short-term (i.e. <5 min at 6 metabolic equivalents) moderate- intensity aerobic exercise. PURPOSE: To determine the exercise-induced ISBPD response during a prolonged steady-state bout of aerobic exercise. METHODS: Fifty-four individuals were studied on two separate occasions. On an initial visit, anthropometric measures and a VO2peak test on a cycle ergometer were completed. On a subsequent visit, participants cycled at a workload equivalent to 50% of their VO2peak for 30 min. Heart rate (HR) and systolic blood pressure difference (SBPD; measured sequentially using standard auscultation in both arms) were measured at rest, 5, 10, 20, and 30 minutes of exercise (EX-5, EX-10, EX-20, EX-30), and during an active recovery (AR). Descriptive and comparative (one-way ANOVA) statistics were generated. A binary logistic regression analysis was used to determine the change in the odds ratio (OR) of ISBPD given exposure to exercise. RESULTS: The incidence of ISBPD at rest was 19%. The occurrence of ISBPD increased to 35% at EX-5 and EX-10, and 46% at EX-20 and EX-30. Occurrence decreased to 20% during AR. Interestingly, each additional 1mmHg difference in SBPD at rest was associated with an increased OR of ISBPD at EX-5 (1.139), EX- 10 (1.335), EX-20 (1.220), and EX-30 (1.196; p<0.05). Individuals in the highest tertile of systolic blood pressure (SBP) response during exercise presented with the greatest SBPD (10.7 mmHg) at EX-5. Finally, individuals identified as underweight and obese class II were more likely to present with ISBPD at rest and EX-20. CONCLUSION: The occurrence of ISBPD during moderate-intensity aerobic exercise increased with prolonged steady-state aerobic exercise. Body mass index and the magnitude of the SBP response to exercise may be linked to ISBPD incidence.