Daguet Ines, Bergeron-Vezina Kayla, Harvey Marie-Philippe, Martel Marylie, Coulombe-Leveque Alexia, Leonard Guillaume
Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada.
Research Centre on Aging, CIUSSS de l'Estrie - CHUS, Sherbrooke, QC, Canada.
J Pain Res. 2020 Sep 22;13:2333-2341. doi: 10.2147/JPR.S257791. eCollection 2020.
Aging is associated with an impairment of diverse physiological functions, including nociception. For example, older adults in comparison to young adults, show an overall increase in pain thresholds, reflecting a decline in pain sensitivity and changes in the nociceptive pathways. These results are, however, debated as they were not always replicated depending on the stimulus modality, duration, and location. The aim of the current study was to determine how the temporal evolution of pain intensity during a continuous tonic heat pain test is influenced by aging. More specifically, we wanted to 1) assess the effect of age on initial peak and late-phase pain and 2) determine whether potential age effects depend on the stimulation site.
13 young adults (average of 27.9 years old) and 13 older adults (average of 67.5 years old) participated in this study. Experimental heat pain was evoked on an appendicular (forearm) and axial (lower-back) body region, using a thermode (2-minute stimulation at a constant, individually-adjusted temperature). During the nociceptive stimulation, participants used a computerized visual analogue scale to continuously rate their pain.
We show that initial peak (0-30 seconds) pain sensation was significantly lower in older adults compared to young adults, while late-phase (30-120 seconds) pain sensation was similar across the two age groups. These results hold true for both stimulation sites, suggesting the existence of an age effect on both appendicular and axial body regions.
The lower magnitude of initial peak pain observed in older adults, which affects both appendicular and axial body regions, could reflect generalized peripheral or central alterations of the nociceptive system in older adults. These alterations in older adults could have significant clinical impacts, such as an increased vulnerability to injury or an underestimation of the severity of their pain condition.
衰老与多种生理功能受损相关，包括痛觉感受。例如，与年轻人相比，老年人的疼痛阈值总体升高，这反映出疼痛敏感性下降以及伤害性感受通路的变化。然而，这些结果存在争议，因为它们并不总是根据刺激方式、持续时间和位置而被重复验证。本研究的目的是确定在持续的强直热痛测试中疼痛强度的时间演变如何受到衰老的影响。更具体地说，我们想要：1）评估年龄对初始峰值疼痛和晚期疼痛的影响；2）确定潜在的年龄效应是否取决于刺激部位。
13名年轻人（平均年龄27.9岁）和13名老年人（平均年龄67.5岁）参与了本研究。使用热刺激器在四肢（前臂）和躯干（下背部）身体区域诱发实验性热痛（在恒定的、个体调整的温度下刺激2分钟）。在伤害性刺激期间，参与者使用计算机化视觉模拟量表持续评估他们的疼痛程度。
我们发现，与年轻人相比，老年人的初始峰值（0 - 30秒）疼痛感觉明显更低，而两个年龄组的晚期（30 - 120秒）疼痛感觉相似。这些结果在两个刺激部位均成立，表明在四肢和躯干身体区域均存在年龄效应。
在老年人中观察到的初始峰值疼痛程度较低，且这种情况影响四肢和躯干身体区域，这可能反映了老年人伤害性感受系统普遍存在的外周或中枢改变。老年人的这些改变可能具有重大临床影响，例如受伤易感性增加或对其疼痛状况严重程度的低估。
