Antihypertensive Treatment Fails to Control Blood Pressure During Exercise

Abstract

An exaggerated blood pressure (BP) response to maximal exercise is an independent risk factor for cardiovascular events and mortality. It is unclear whether treating BP to guideline recommended levels could normalize the rise in BP during exercise, which is mediated by the metaboreflex. We aimed to assess the BP response to incremental exercise testing and metaboreflex activation in treated–controlled hypertension (n=16), treated–uncontrolled hypertension (n=16), and untreated hypertension (n=11) and 16 control participants with normal BP (n=16). All groups were matched for age and body mass index. BP was measured during an incremental V o 2 peak test on a cycle ergometer and during metaboreflex isolation using postexercise ischemia. Data were analyzed using 2-way ANOVA with Tukey test for multiple comparisons. Aerobic fitness was similar among groups ( P =0.97). The rise in absolute systolic BP from baseline at peak exercise was similar in controlled, uncontrolled, and untreated hypertension but greater compared with normotensive controls (Δ71±3, 81±7, 79±8.5 versus 47±5 mm Hg; P =0.0001). Metaboreflex sensitivity was also similar in controlled, uncontrolled, and untreated hypertension but augmented compared with normotensive controls (Δsystolic BP: 21±2, 28±2, 25±3 versus 12±2 mm Hg; P <0.0001). An amplified pressor response to exercise occurred in patients taking antihypertensive medication, despite having controlled BP at rest and was potentially caused (in part) by enhanced metaboreflex sensitivity. Poor BP control during exercise, partially mediated by the metaboreflex, may contribute to the heightened risk of an adverse cardiovascular event even in treated–controlled patients.