Chronic Pain is Associated with a Brain Aging Biomarker in Community-Dwelling Older Adults

Chronic pain is associated with brain atrophy with limited evidence of its impact in the older adult’s brain. We aimed to determine the associations between chronic pain and a brain aging biomarker in persons 60 to 83 years old. Participants of the NEPAL study (n=47) completed demographic, psychological, and pain assessments followed by a QST battery and a T1-weighted MRI. We estimated a brain-predicted age difference that has been previously reported to predict overall mortality risk (brain-PAD; calculated as brain-predicted age minus chronological age), using an established machine-learning model. ANCOVAs and Pearson/Spearman correlations were used to determine associations of brain-PAD with pain, somatosensory and psychological function. Individuals with chronic pain (n=33) had “older” brains for their age compared to those without (n=14, F(1,41)=4.9,p=0.033). Greater average worst pain intensity was associated with an “older” brain (r=0.464,p=0.011). Among participants with chronic pain, those that reported having pain treatments during the past 3 months had “younger” brains compared to those that did not (F(1,27)=12.3, p=0.002). An “older” brain was significantly associated with decreased vibratory (r=0.323,p=0.033) and thermal (r=0.345,p=0.023) detection, deficient endogenous pain inhibition (F(1,25)=4.6,p=0.044), lower positive affect (r =-0.474,p=0.005), a less agreeable (r=-0.439,p=0.020), and less emotionally stable personality (r=-0.387, p=0.042). Our findings suggest that chronic pain is associated with added “age-like” brain atrophy in relatively healthy, community-dwelling older individuals and future studies are needed to determine the directionality of our findings. A brain aging biomarker may help identify people with chronic pain at greater risk of functional decline and poorer health outcomes