Rapid Onset Pressor Response to Static Handgrip in Young Normotensive Women with a Family History of Hypertension

Older hypertensive adults display exaggerated blood pressure (BP) and muscle sympathetic nerve activity (MSNA) responses at the onset of static muscle contraction. Young normotensive adults with a family history of hypertension (+FH) are at a greater risk for developing future hypertension. We tested the hypothesis that young women with a +FH wouldhave exaggerated increases in BP and MSNA at the onset of static muscle contraction compared to those without a family history of hypertension (‐FH). We retrospectively examined beat‐by‐beat BP, heart rate (HR), and MSNA during the initial 30 seconds of isometric handgrip exercise at 30% of maximum voluntary contraction in 14 +FH (22±1 yrs, 21±1 kg·m ‐2 ) and 14 –FH (22±1 yrs, 22±1 kg·m ‐2 ) women. Resting mean arterial pressure (MAP;+FH 80±2 vs. –FH 79±3 mmHg), HR (+FH 62±3 vs. –FH 66±2 bpm), and MSNA (+FH 7±1 vs. –FH 10±2 bursts·min ‐1 ) were similar between groups (all P >0.05). At exercise onset, the increases in MAP (+FH Δ11±2 vs. –FH Δ4±1 mmHg, P <0.05) was greater in +FH compared to –FH women. The increase in HR was also greater in +FH (+FH Δ 13±2 vs. –FH Δ 4±1 bpm P <0.05). The MSNA responses were not different between groups (+FH Δ3±1 vs. –FH Δ22±1 bursts·30s ‐1 , P =0.29). These data demonstrate that there is an exaggerated pressor response at the onset of static muscle contraction in young normotensive women with a +FH and further suggest that this may be due to greater increases in HR at exercise onset. Research supported by NIH Grant U54‐GM104941 (PI: Binder‐Macleod)