Effects of a single bout of low-intensity isometric or moderate-intensity aerobic exercise on postexercise hypotension in adults of African and south-Asian descent: a randomized controlled crossover trial

Introduction Current guidelines on physical activity and exercise to manage blood pressure (BP) in adults with hypertension are predominantly based on studies performed in Caucasian populations and little is known about the potency of exercise as a BP-lowering tool in non-Caucasians. Therefore, the “Hypertension, Ethnicity and Exercise” (HYPE 2 X) trial aimed to investigate whether a short bout of aerobic exercise or isometric strength exercise lowers BP in a non-Caucasian population. Methods African and South-Asian descendants living in Suriname (18–65 years) with high-normal BP or grade I hypertension were invited to participate in a randomized controlled crossover trial. Participants completed: a 30-minute aerobic exercise (AEX) treadmill walking/running bout at 40%–60% of heart rate reserve, an isometric handgrip (IHG) session at 30% of maximal handgrip strength and a sitting control session. Office BP was measured 30 min after the experiment and ambulatory mean 8-hours, daytime and nighttime BP. Statistical analyses were performed using linear mixed models. Results A total of 29 adults of African descent [mean age: 48.7 ± 9.9 years, 31% male, mean systolic BP (SBP) and diastolic BP (DBP) were 142.9 ± 11.2 and 88 ± 8.0 mmHg] and 28 adults of South-Asian descent (mean age: 51.5 ± 10.6 years, 46.4% male, mean SBP: 138.2 ± 6.9 and DBP 85.7 ± 4.5 mmHg) were included. In Africans, systolic BP was significantly reduced after AE at post 30 min [−9.0, 95%CI: (−13.4, −4.7) mmHg, p < 0.001], non-significantly reduced during daytime [−4.08, 95%CI (−0.26, −7.75) mmHg, p = 0.08]. Diastolic BP was non-significantly reduced after AEX at post 30 min [−3.46, 95%CI: (−6.56, −0.36) mmHg, p = 0.08] and non-significantly reduced during daytime hours [−3.07, 95%CI: (−0.27, −5.90) mmHg, p = 0.08]. In South-Asians systolic and diastolic BP were significantly reduced after AE at post 30 min [−7.40, 95%CI [−12.2, −2.6] mmHg, p < 0.01/−4.4, 95%CI [−7.5, −1.3] mmHg, p = 0.01]. Conclusion A single bout of AEX resulted in an immediate reduction in office BP at 30-minutes postexercise in both the African and South-Asian groups, while a more favorable reduction in daytime BP was observed in the African group only. A single bout of IHG did not elicit PEH in either ethnicity. Further exploration is needed to assess different intensity levels, volumes, or frequency levels of exercise in non-Caucasian populations.