Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, United States.
Department of Applied Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States.
Am J Physiol Regul Integr Comp Physiol. 2023 Dec 1;325(6):R682-R691. doi: 10.1152/ajpregu.00073.2023. Epub 2023 Oct 2.
Non-Hispanic Black (BL) individuals have the highest prevalence of hypertension and cardiovascular disease (CVD) compared with all other racial/ethnic groups. Previous work focused on racial disparities in sympathetic control and blood pressure (BP) regulation between young BL and White (WH) adults, have mainly included men. Herein, we hypothesized that BL women would exhibit augmented resting sympathetic vascular transduction and greater sympathetic and BP reactivity to cold pressor test (CPT) compared with WH women. Twenty-eight young healthy women (BL: = 14, 22 [Formula: see text] 4 yr; WH: = 14, 22 [Formula: see text] 4 yr) participated. Beat-to-beat BP (Finometer), common femoral artery blood flow (duplex Doppler ultrasound), and muscle sympathetic nerve activity (MSNA; microneurography) were continuously recorded. In a subset (BL = 10, WH = 11), MSNA and BP were recorded at rest and during a 2-min CPT. Resting sympathetic vascular transduction was quantified as changes in leg vascular conductance (LVC) and mean arterial pressure (MAP) following spontaneous bursts of MSNA using signal averaging. Sympathetic and BP reactivity were quantified as changes in MSNA and MAP during the last minute of CPT. There were no differences in nadir LVC following resting MSNA bursts between BL (-8.70 ± 3.43%) and WH women (-7.30 ± 3.74%; = 0.394). Likewise, peak increases in MAP following MSNA bursts were not different between groups (BL: +2.80 ± 1.42 mmHg; vs. WH: +2.99 ± 1.15 mmHg; = 0.683). During CPT, increases in MSNA and MAP were also not different between BL and WH women, with similar transduction estimates between groups (ΔMAP/ΔMSNA; = 0.182). These findings indicate that young, healthy BL women do not exhibit exaggerated sympathetic transduction or augmented sympathetic and BP reactivity during CPT. This study was the first to comprehensively investigate sympathetic vascular transduction and sympathetic and BP reactivity during a cold pressor test in young, healthy BL women. We demonstrated that young BL women do not exhibit exaggerated resting sympathetic vascular transduction and do not have augmented sympathetic or BP reactivity during cold stress compared with their WH counterparts. Collectively, these findings suggest that alterations in sympathetic transduction and reactivity are not apparent in young, healthy BL women.
非西班牙裔黑人(BL)个体的高血压和心血管疾病(CVD)患病率与所有其他种族/族裔群体相比最高。先前的工作主要集中在年轻的 BL 和白人(WH)成年人之间的交感控制和血压(BP)调节方面的种族差异,主要包括男性。在此,我们假设与 WH 女性相比,BL 女性在静息时会表现出增强的交感血管转导作用,以及对冷加压试验(CPT)的交感神经和 BP 反应性增强。28 名年轻健康女性(BL:n = 14,22 [Formula: see text] 4 岁;WH:n = 14,22 [Formula: see text] 4 岁)参与了研究。连续记录了逐拍血压(Finometer)、股总动脉血流(双功能多普勒超声)和肌肉交感神经活动(MSNA;微神经记录)。在一个亚组(BL = 10,WH = 11)中,在休息和 2 分钟 CPT 期间记录 MSNA 和 BP。使用信号平均法,通过股血管导纳(LVC)和平均动脉压(MAP)的自发性 MSNA 爆发来量化静息时的交感血管转导。通过 CPT 最后 1 分钟的 MSNA 和 MAP 的变化来量化交感神经和 BP 的反应性。BL 女性(-8.70 ± 3.43%)和 WH 女性(-7.30 ± 3.74%; = 0.394)在静息 MSNA 爆发后 LVC 的最低值没有差异。同样,MSNA 爆发后 MAP 的峰值增加在两组之间也没有差异(BL:+2.80 ± 1.42 mmHg;vs. WH:+2.99 ± 1.15 mmHg; = 0.683)。在 CPT 期间,BL 和 WH 女性的 MSNA 和 MAP 增加也没有差异,两组之间的转导估计相似(ΔMAP/ΔMSNA; = 0.182)。这些发现表明,年轻健康的 BL 女性在 CPT 期间没有表现出过度的交感神经转导或增强的交感神经和 BP 反应性。这项研究首次全面研究了年轻健康的 BL 女性在冷加压试验期间的交感血管转导以及交感神经和 BP 反应性。我们表明,与 WH 对照组相比,年轻的 BL 女性在静息时没有表现出过度的交感血管转导作用,并且在冷应激期间没有增强的交感神经或 BP 反应性。总的来说,这些发现表明,年轻健康的 BL 女性中没有明显的交感神经转导和反应性改变。