Greater resting muscle sympathetic nerve activity reduces cold pressor autonomic reactivity in older women, but not older men.
Greater resting muscle sympathetic nerve activity reduces cold pressor autonomic reactivity in older women, but not older men.
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较大的静息肌肉交感神经活动会降低老年女性的冷加压自主神经反应，但不会降低老年男性的冷升压自主神经反应性。
DOI：
10.1152/ajpregu.00231.2022
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Fu,Qi
中科院分区：
文献类型：
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作者：
Akins,JohnD;Okada,Yoshiyuki;Hendrix,JosephM;Vongpatanasin,Wanpen;Fu,Qi
以前的工作表明，增强肌肉交感神经活动（MSNA）的反应，冷加压试验（CPT）在老年妇女。然而，鉴于其个体间变异性，基线MSNA对老年人CPT反应性的影响仍然未知。60名志愿者（60 - 83岁; 30名女性）完成了测试，其中在基线和2分钟CPT（104 ° C）期间记录了MSNA（显微神经造影术）、血压（BP）和心率（HR）。受试者数据按基线MSNA（n = 10/组）分类;在高基线男性（HM）和女性（HW）以及低基线男性（LM）和女性（LW）之间进行比较。根据设计，与LM和LW相比，HM和HW具有更高的基线MSNA爆发频率（37 ± 5和38 ± 3 vs. 9 ± 4和15 ± 5爆发/min）和爆发发生率（59 ± 14和60 ± 8 vs. 16 ± 10和23 ± 7爆发/100 hbs;均P <0.001）。而两组患者的基础血压和心率无显著性差异（均P> 0.05）。CPT期间两组血压、心率的增加无显著性差异（均P> 0.05）。相反，HW组的Δ MSNA爆发频率低于LW组（8 ± 9 vs. 22 ± 12爆发/min; P = 0.012），但HM组与LM组相似（17 ± 12 vs. 19 ± 10爆发/min，P = 0.994）。此外，HW组的Δ MSNA爆发发生率低于LW组（9 ± 13 vs. 28 ± 16爆发/100 hbs; P = 0.020），HM组与LM组无差异（21 ± 17 vs. 31 ± 17爆发/100 hbs; P = 0.455）。我们的研究结果表明，在老年妇女的基线活动增加衰减典型CPT介导的MSNA增加，而不改变心血管反应。虽然其潜在机制尚不清楚，但交感神经募集或神经血管转导的改变可能导致这些不同的反应。
Previous work demonstrates augmented muscle sympathetic nerve activity (MSNA) responses to the cold pressor test (CPT) in older women. Given its interindividual variability, however, the influence of baseline MSNA on CPT reactivity in older adults remains unknown. Sixty volunteers (60–83 yr; 30 women) completed testing where MSNA (microneurography), blood pressure (BP), and heart rate (HR) were recorded during baseline and a 2-min CPT (∼4°C). Participant data were terciled by baseline MSNA (n= 10/group); comparisons were made between the high baseline men (HM) and women (HW), and low baseline men (LM) and women (LW). By design, HM and HW, versus LM and LW, had greater baseline MSNA burst frequency (37 ± 5 and 38 ± 3 vs. 9 ± 4 and 15 ± 5 bursts/min) and burst incidence (59 ± 14 and 60 ± 8 vs. 16 ± 10 and 23 ± 7 bursts/100 hbs; bothP< 0.001). However, baseline BP and HR were not different between the groups (allP> 0.05). During the CPT, there were no differences in the increase in BP and HR (allP> 0.05). Conversely, ΔMSNA burst frequency was lower in HW versus LW (8 ± 9 vs. 22 ± 12 bursts/min;P= 0.012) yet was similar in HM vs. LM (17 ± 12 vs. 19 ± 10 bursts/min,P= 0.994). Furthermore, ΔMSNA burst incidence was lower in HW versus LW (9 ± 13 vs. 28 ± 16 bursts/100 hbs;P= 0.020), with no differences between HM versus LM (21 ± 17 vs. 31 ± 17 bursts/100 hbs;P= 0.455). Our findings suggest that heightened baseline activity in older women attenuates the typical CPT-mediated increase in MSNA without changing cardiovascular reactivity. Although the underlying mechanisms remain unknown, altered sympathetic recruitment or neurovascular transduction may contribute to these disparate responses.