Influence of Pain Intensity and Pain Catastrophizing on Conditioned Pain Modulation in Elderly People With and Without Chronic Pain

OBJECTIVE: To investigate if psychological/cognitive aspects and executive functions can influence conditioned pain modulation (CPM) activity in elderly people with and without chronic pain. METHODS: A cross-sectional unifactorial repeated measures case-control study with 19 adults (89.5% women, age: 73.2±5.6 y) with chronic primary musculoskeletal pain and 38 adults (74.5% women, age: 74.3±4.4 y) without chronic pain was conducted. Pain features, psychological/cognitive (anxiety, depression, pain hypervigilance, and pain catastrophizing), and 2 executive functions (working memory, mental inhibition) were assessed. Subsequently, CPM was evaluated on changes obtained in mechanical (pressure pain threshold-PPT) stimuli with the cold-pressor test paradigm. RESULTS: A significant group X time interaction after controlling all cofounders was found: PPTs were higher after the conditioned stimulus in individuals without chronic pain (CPM increase 15%±10%), whereas PPTs were lower after the conditioned stimulus in those with chronic pain (CPM decrease -11%±7%) when compared with PPTs at baseline. In elderly people with chronic pain, pain intensity and catastrophizing accounted for 28.6% of the variance of the CPM activation index. In elderly people without chronic pain, just pain catastrophizing had significant predictive value accounting for 10.6% of the variance of CPM activation index. DISCUSSION: Elderly people with chronic musculoskeletal pain exhibited impaired CPM activation as compared with adults without chronic pain. Thus, CPM activation was associated with the intensity of pain and, in a lesser extent, with pain catastrophizing, but not with anxiety/depressive levels and executive functions.