Does hypertension exacerbate the age-related exaggerated pressor response to dynamic exercise during post-exercise muscle ischemia?

Abstract

Hypertension is known to augment exercise blood pressure (BP). Aging also potentiates BP response to ischemic dynamic exercise. However, whether hypertension further enhances aging-induced augmented BP response to ischemic dynamic exercise has not yet been investigated. Therefore, we aimed to test the hypothesis that hypertension exacerbates the pressor response to ischemic dynamic exercise in older adults. The participants were classified into the following two groups: nonhypertensive (NHT, n = 13, 60-80 years) and hypertensive (HT, n = 10, 61-78 years). We compared the BP responses to very light-intensity rhythmic handgrip exercise during post-isometric handgrip exercise muscle ischemia (PEMI) simulated as ischemic dynamic exercise between the HT and NHT groups. Both systolic BP (SBP) and diastolic BP (DBP) responses to the rhythmic handgrip exercise during PEMI in the HT group (∆SBP: 48 ± 18 mmHg and ∆DBP: 28 ± 10 mmHg, p = 0.007) were significantly higher than those in the NHT group (∆SBP: 34 ± 17 mmHg and ∆DBP: 20 ± 6 mmHg, p = 0.003). Importantly, resting SBP was a significant independent determinant of DBP response to the rhythmic handgrip exercise during PEMI (β = 0.412, p = 0.047). These results suggest that hypertension further elevates the heightened BP response to ischemic dynamic exercise in older adults.