Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, United States.
Department of Psychiatry, Rush University, Chicago, IL, United States.
Pain. 2021 Aug 1;162(8):2204-2213. doi: 10.1097/j.pain.0000000000002165.
We tested whether aerobic exercise training altered morphine analgesic responses or reduced morphine dosages necessary for adequate analgesia. Patients with chronic back pain were randomized to an 18-session aerobic exercise intervention (n = 38) or usual activity control (n = 45). Before and after the intervention, participants underwent 3 laboratory sessions (double-blinded, crossover) to assess effects of saline placebo, i.v. morphine (0.09 mg/kg), and i.v. naloxone (12 mg) on low back pain and evoked heat pain responses. Differences in evoked and back pain measures between the placebo and morphine conditions indexed morphine analgesia, with pre-post intervention changes the primary outcome. Endogenous opioid analgesia was indexed by differences in evoked and low back pain measures between the naloxone and placebo conditions. A Sex X Intervention interaction on the analgesic effects of morphine on visual analogue scale back pain intensity was observed (P = 0.046), with a similar trend for evoked pain threshold (P = 0.093). Male exercisers showed reduced morphine analgesia pre-post intervention, whereas male controls showed increased analgesia (with no differences in females). Of clinical significance were findings that relative to the control group, aerobic exercise produced analgesia more similar to that observed after receiving ≈7 mg morphine preintervention (P < 0.045). Greater pre-post intervention increases in endogenous opioid function (from any source) were significantly associated with larger pre-post intervention decreases in morphine analgesia (P < 0.046). The overall pattern of findings suggests that regular aerobic exercise has limited direct effects on morphine responsiveness, reducing morphine analgesia in males only.
我们测试了有氧运动训练是否会改变吗啡的镇痛反应，或者减少达到充分镇痛所需的吗啡剂量。慢性背痛患者被随机分配到 18 次有氧运动干预组（n = 38）或常规活动对照组（n = 45）。在干预前后，参与者接受了 3 次实验室测试（双盲、交叉），以评估生理盐水安慰剂、静脉注射吗啡（0.09 mg/kg）和静脉注射纳洛酮（12 mg）对腰痛和诱发热痛反应的影响。安慰剂和吗啡条件下诱发痛和腰痛测量值的差异反映了吗啡的镇痛作用，干预前后的变化是主要结果。纳洛酮和安慰剂条件下诱发痛和腰痛测量值的差异反映了内源性阿片类镇痛药的镇痛作用。吗啡对视觉模拟量表腰痛强度的镇痛作用存在性别与干预的交互作用（P = 0.046），诱发痛阈值也存在类似的趋势（P = 0.093）。男性锻炼者在干预前后吗啡的镇痛作用减弱，而男性对照组的镇痛作用增强（女性则没有差异）。有临床意义的发现是，与对照组相比，有氧运动产生的镇痛作用与干预前接受约 7 毫克吗啡后观察到的镇痛作用更相似（P < 0.045）。内源性阿片类药物功能（来自任何来源）的干预前后增加与吗啡镇痛作用的干预前后减少呈显著相关（P < 0.046）。总的研究结果表明，有规律的有氧运动对吗啡的反应性几乎没有直接影响，仅减少男性的吗啡镇痛作用。
