Geisler Maria, Herbsleb Marco, Bär Karl-Jürgen, Weiss Thomas
Department of Clinical Psychology, Friedrich-Schiller-University Jena, Jena, Germany.
Department of Sports Medicine and Health Promotion, Friedrich-Schiller-University Jena, Jena, Germany.
Front Psychol. 2020 Sep 18;11:553530. doi: 10.3389/fpsyg.2020.553530. eCollection 2020.
Animals and humans are able to inhibit pain by activating their endogenous pain-inhibition system. Endurance athletes possess a higher pain-tolerance threshold and a greater conditioned pain modulation (CPM) effect than nonathletes, suggesting better endogenous pain inhibition. In addition to CPM, placebo is another prominent paradigm used to test endogenous pain inhibition. However, whether the placebo effect and the CPM effect share the same mechanisms of pain inhibition has not been investigated. If there is a shared mechanism, then endurance athletes should show not only a better CPM effect than nonathletes but also a greater placebo effect. Here, we investigated 16 male endurance athletes and 17 male nonathletes in well-established placebo and CPM paradigms to assess whether endurance athletes have a better endogenous pain-inhibition system than nonathletes. As expected, we find a significantly greater CPM effect in athletes than in nonathletes. In contrast, we could only find a significant placebo effect in nonathletes. Explorative analyses reveal negative associations between the placebo effect and heart rate variability as well as between the placebo effect and interoceptive awareness. Together, the results demonstrate a dissociation of endogenous pain inhibition of CPM and placebo effect between endurance athletes and nonathletes. This suggests that both effects are based, at least in part, on different biological mechanisms.
动物和人类能够通过激活其内源性疼痛抑制系统来抑制疼痛。耐力运动员比非运动员具有更高的疼痛耐受阈值和更强的条件性疼痛调制（CPM）效应，这表明他们具有更好的内源性疼痛抑制能力。除了CPM，安慰剂是另一种用于测试内源性疼痛抑制的重要范式。然而，安慰剂效应和CPM效应是否共享相同的疼痛抑制机制尚未得到研究。如果存在共享机制，那么耐力运动员不仅应比非运动员表现出更好的CPM效应，还应表现出更大的安慰剂效应。在此，我们在成熟的安慰剂和CPM范式中对16名男性耐力运动员和17名男性非运动员进行了研究，以评估耐力运动员是否比非运动员具有更好的内源性疼痛抑制系统。正如预期的那样，我们发现运动员的CPM效应显著大于非运动员。相比之下，我们仅在非运动员中发现了显著的安慰剂效应。探索性分析揭示了安慰剂效应与心率变异性之间以及安慰剂效应与内感受性觉知之间的负相关。总之，结果表明耐力运动员和非运动员在内源性疼痛抑制的CPM和安慰剂效应方面存在分离。这表明这两种效应至少部分基于不同的生物学机制。
