Sympathetic Vascular Transduction is Elevated in Hypertensive Premenopausal and Postmenopausal Women

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The transduction of muscle sympathetic nerve activity (MSNA) to vasoconstrictor tone is lower in healthy young women versus both healthy young men and healthy postmenopausal women, and may account for the lower risk of hypertension in young women. However, hypertension can occur before menopause in some women but whether sympathetic transduction is increased in this group is unknown. We aimed to determine whether sympathetic transduction is different in hypertensive (HTN) pre‐ and post‐menopausal women relative to normotensive (NTN) controls. MSNA (peroneal microneurography) and continuous blood pressure (Finometer Pro) were measured in HTN (n=5) and NTN (n=5) premenopausal and HTN (n=4) and NTN (n=6) postmenopausal women. HTN and NTN groups were matched for age (premenopausal; 46±2 vs. 46±5 years, p=0.97, postmenopausal; 59±4 vs. 62 ±2 years; p=0.17). Sympathetic transduction was measured by associating beat‐to‐beat diastolic blood pressure (DBP) with MSNA burst area between the 6th and 8th previous cardiac cycles to account for transduction delay. Transduction was expressed as the slope of the linear regression between burst area and mean DBP, plotted as 1 %.s bins. HTN and NTN were compared within pre‐ or postmenopausal groups by unpaired Student’s T‐test or Mann‐Whitney test, where data were not normally distributed. Data are presented as mean ± SD. Both sympathetic transduction and MSNA were greater in HTN versus NTN premenopausal women (0.16±0.11 vs. 0.03±0.02 mmHg/%.s, p=0.03; 57±17 vs. 32±7 bursts/100 heartbeats, p=0.0185). Sympathetic transduction was also greater in HTN vs. NTN postmenopausal women (0.19±0.08 vs. 0.07±0.02 mmHg/%.s, p=0.02), although MSNA was similar (53±8 vs. 60±15 bursts/100 heartbeats, p=0.4255). Both HTN groups had increased clinic systolic BP and DBP versus the respective NTN group (premenopausal women 153±11/97±6 vs. 119±9/73±8 mmHg, p=0.0007 and p=0.0079; postmenopausal women 155±8/92±15 vs. 123±8/70±7 mmHg, p=0.0095 and p=0.0132 respectively). These results indicate that sympathetic transduction is elevated in both premenopausal and postmenopausal women with HTN vs. NTN controls. As such, increased sympathetic transduction may help to explain the development of hypertension in premenopausal women. These data will assist with more precise management of hypertension in pre‐ and postmenopausal women.Support or Funding InformationZoe Adams is funded by a British Heart Foundation Non‐Clinical PhD Studentship (FS/17/38/32935).