Sympathetic reactivity in young women with a family history of hypertension

Abstract

Young adults with a family history of hypertension (+FH) have increased risk of developing hypertension. Furthermore, the blood pressure (BP) response to sympathoexcitatory stimuli in young adults can predict the future development of hypertension. Therefore, we hypothesized young women with a +FH would have exaggerated cardiovascular and sympathetic reactivity compared with young women without a family history of hypertension (−FH). Beat-by-beat mean arterial pressure (MAP) and muscle sympathetic nerve activity (MSNA) were measured in 14 women +FH (22 ± 1 yr, 21 ± 1 kg/m2, MAP 80 ± 2 mmHg) and 15 women −FH (22 ± 1 yr, 22 ± 1 kg/m2, MAP 78 ± 2 mmHg) during acute sympathoexcitatory maneuvers: cold pressor test, 2 min of isometric handgrip (HG) exercise at 30% of maximal voluntary contraction, and 3 min of postexercise ischemia (PEI; isolated activation of the skeletal muscle metaboreflex). During cold pressor test, the increase in BP was greater in women +FH (ΔMAP: +FH 16 ± 2 vs. −FH 11 ± 1 mmHg, P < 0.05), which was accompanied by an exaggerated increase in MSNA (ΔMSNA: +FH 17 ± 2 vs. −FH 8 ± 2 burst/min, P < 0.05). The increase in BP was greater in +FH during the last minute of HG (ΔMAP: +FH 23 ± 3 vs. −FH 12 ± 1 mmHg, P < 0.05) and during PEI (ΔMAP: +FH 17 ± 3 vs. −FH 9 ± 2 mmHg, P < 0.05). Similarly, the increase in MSNA was greater in +FH during both HG (ΔMSNA: +FH 12 ± 2 vs. −FH 6 ± 2 burst/min, P < 0.05) and PEI (ΔMSNA: +FH 16 ± 2 vs. −FH 4 ± 2 burst/min, P < 0.05). These data demonstrate that +FH women have greater BP and sympathetic reactivity compared with −FH women.