Chaudhry Laila A, Coovadia Yasmine, Schwende Brittany K, Berbrier Danielle E, Huckins Will, Saboune Jinan, Skolnik Derek A, Van Berkel Emily K, Mogil Jeffrey S, Usselman Charlotte W
Alan Edwards Centre for Research on Pain, McGill University, 3755 University Ave, Montreal, QC, H3A 2B4, Canada.
Department of Psychology, McGill University, Montreal, Quebec, Canada.
Biol Sex Differ. 2025 Aug 6;16(1):60. doi: 10.1186/s13293-025-00743-2.
Chronic pain is partly maintained by the sympathetic nervous system, whose activity is best measured by muscle sympathetic nerve activity (MSNA). MSNA responses to acute pain have been thoroughly investigated, whereas MSNA responses to longer-lasting pain are poorly understood. Therefore, this study examined the relationship between pain ratings and peroneal MSNA during a tonic cold pressor test (CPT) in male and female participants.
We obtained MSNA measures during a 6 min CPT in 18 young adult (20-33 years) men and women. Verbal pain ratings (0-10) and autonomic outcomes (heart rate [HR], mean arterial blood pressure [MAP], and MSNA) were assessed simultaneously at multiple time points across the CPT.
Pain, HR, and MAP increased in the initial 30s in both sexes. Females increased their MSNA burst frequency (BF) to a greater extent than males. Across the full CPT we observed a positive relationship between pain and HR in males, a positive relationship between pain and MSNA BF in females, and a negative relationship between pain and MSNA burst amplitude in females.
Overall, males displayed a strong relationship between tonic pain and HR, an index of parasympathetic activity, whereas females displayed strong and offsetting relationships between tonic pain and purely sympathetic MSNA variables. These observations suggest sex differences in autonomic mechanisms during tonic pain, which may have relevance to ongoing efforts to modulate pain via manipulations of the autonomic nervous system, as well as sex/gender disparities in chronic pain prevalence.
慢性疼痛部分由交感神经系统维持，其活动通过肌肉交感神经活动（MSNA）来最佳衡量。MSNA对急性疼痛的反应已得到充分研究，而对持续时间更长的疼痛的MSNA反应则了解甚少。因此，本研究在男性和女性参与者的持续性冷加压试验（CPT）期间，检查了疼痛评分与腓总神经MSNA之间的关系。
我们在18名年轻成年人（20 - 33岁）男性和女性进行6分钟CPT期间获取了MSNA测量值。在CPT的多个时间点同时评估言语疼痛评分（0 - 10）和自主神经指标（心率[HR]、平均动脉血压[MAP]和MSNA）。
在最初30秒内，男女的疼痛、HR和MAP均升高。女性比男性更大程度地增加了其MSNA爆发频率（BF）。在整个CPT过程中，我们观察到男性疼痛与HR之间呈正相关，女性疼痛与MSNA BF之间呈正相关，女性疼痛与MSNA爆发幅度之间呈负相关。
总体而言，男性在持续性疼痛与作为副交感神经活动指标的HR之间表现出强烈的关系，而女性在持续性疼痛与纯粹的交感神经MSNA变量之间表现出强烈且相互抵消的关系。这些观察结果表明在持续性疼痛期间自主神经机制存在性别差异，这可能与目前通过自主神经系统调节疼痛的努力以及慢性疼痛患病率的性别差异相关。
