European journal of pain : EJP
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Randomized Controlled Trial
What do plasma beta-endorphin levels reveal about endogenous opioid analgesic function?
Plasma levels of beta-endorphin (BE), an endogenous opioid analgesic, are often reported as they relate to acute and chronic pain outcomes. However, little is known about what resting plasma BE levels might reveal about functioning of the endogenous opioid antinociceptive system. This study directly examined associations between resting plasma BE and subsequent endogenous opioid analgesic responses to acute pain in 39 healthy controls and 37 individuals with chronic low back pain (LBP). ⋯ For the ISC task, these links were significantly more prominent in LBP participants (BE × Participant Type Interactions, p's < 0.05). Results suggest that elevated resting plasma BE may be a potential biomarker for reduced endogenous opioid analgesic capacity, particularly among individuals with chronic pain. Potential clinical implications are discussed.
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Randomized Controlled Trial
Coping when pain is a potential threat: the efficacy of acceptance versus cognitive distraction.
This experiment investigated the impact of brief training in acceptance versus distraction-based pain management on experimental pain tolerance in conditions of lower and higher potential threats. One hundred fifty-one pain-free Chinese adults (93 women, 58 men) randomly assigned to acceptance, distraction or pain education control conditions engaged in a cold pressor test (CPT) after reading validated orienting information designed to prime either the safety of the CPT (lower threat) or symptoms and damaging effects of exposure to extreme cold (higher threat). ⋯ Supplementary analyses identified catastrophizing as a partial mediator of training group differences in pain tolerance. In summary, findings suggested acceptance-based coping is superior to distraction as a means of managing experimental pain, particularly when pain sensations are viewed as comparatively low in potential threat.