Graduate School, Niigata University of Health and Welfare, Niigata 950-3198, Japan.
Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, Japan.
Int J Environ Res Public Health. 2021 Dec 16;18(24):13265. doi: 10.3390/ijerph182413265.
The psychological characteristic of having difficulty expressing emotions, known as alexithymia, is associated with hypervigilance to pain and is considered one of the risk factors for chronic pain. The correlation between alexithymia and hypervigilance to pain can be observed even in healthy individuals. However, the factors influencing this correlation remain unknown. We explored the dopamine system, which is known to be involved in emotion and pain. The dopamine-degrading enzyme catechol-O-methyltransferase (COMT) has a genetic polymorphism known to influence dopamine metabolism in the prefrontal cortex. COMT polymorphism reportedly affects various aspects of pain and increases pain sensitivity in Met allele carriers. Therefore, we investigated whether the correlation between alexithymia and hypervigilance to pain is influenced by COMT polymorphism in healthy individuals. The results revealed a significant positive correlation between the "difficulty describing feelings" of the 20-item Toronto Alexithymia Scale and the "attention to changes in pain" of the pain vigilance and awareness questionnaire in COMT Met carriers but not in Val/Val individuals. This finding suggests that the correlation between alexithymia and hypervigilance to pain is influenced by COMT polymorphism.
难以表达情绪的心理特征，即述情障碍，与对疼痛的过度警觉有关，被认为是慢性疼痛的风险因素之一。述情障碍与对疼痛的过度警觉之间的相关性甚至在健康个体中也可以观察到。然而，影响这种相关性的因素尚不清楚。我们探讨了多巴胺系统，已知其参与情绪和疼痛。多巴胺降解酶儿茶酚-O-甲基转移酶（COMT）存在遗传多态性，已知其影响前额叶皮层中的多巴胺代谢。据报道，COMT 多态性影响疼痛的各个方面，并增加了 Met 等位基因携带者的疼痛敏感性。因此，我们调查了在健康个体中，COMT 多态性是否会影响述情障碍与对疼痛的过度警觉之间的相关性。结果表明，多伦多述情障碍量表的 20 项中“难以描述情感”与疼痛警觉和意识问卷中的“对疼痛变化的注意力”之间存在显著正相关，而在 COMT Met 携带者中则不存在这种相关性。这一发现表明，述情障碍与对疼痛的过度警觉之间的相关性受 COMT 多态性的影响。
