Biopsychosocial influence on shoulder pain

Abstract

Tailored treatment based on individual risk factors is an area with promise to improve options for pain relief. Musculoskeletal pain has a biopsychosocial nature, and multiple factors should be considered when determining risk for chronic pain. This study investigated whether subgroups comprised genetic and psychological factors predicted outcomes in preclinical and clinical models of shoulder pain. Classification and regression tree analysis was performed for an exercise-induced shoulder injury cohort (n = 190) to identify high-risk subgroups, and a surgical pain cohort (n = 150) was used for risk validation. Questionnaires for fear of pain and pain catastrophizing were administered before injury and preoperatively. DNA collected from saliva was genotyped for a priori selected genes involved with pain modulation (COMT and AVPR1A) and inflammation (IL1B and TNF/LTA). Recovery was operationalized as a brief pain inventory rating of 0/10 for current pain intensity and <2/10 for worst pain intensity. Follow-up for the preclinical cohort was in daily increments, whereas follow-up for the clinical cohort was at 3, 6, and 12 months postoperatively. Risk subgroups comprised the COMT high pain sensitivity variant and either pain catastrophizing or fear of pain were predictive of heightened shoulder pain responses in the preclinical model. Further analysis in the clinical model identified the COMT high pain sensitivity variant and pain catastrophizing subgroup as the better predictor. Future studies will determine whether these findings can be replicated in other anatomical regions and whether personalized medicine strategies can be developed for this risk subgroup.

Biopsychosocial Influence on Shoulder Pain: Influence of Genetic and Psychological Combinations on Twelve‐Month Postoperative Pain and Disability Outcomes

“…The COMT gene was not further considered because it has already been included in a validated risk subgroup, and this would be redundant with our prior study. 7 Each of the remaining genes is associated with biological process that could plausibly interact with psychological constructs to impact the reporting of shoulder pain. Therefore, these genes were considered appropriate for further investigation in the post-operative cohort.…”

“…Specifically, based on our previous findings, we reduced the number of covariates included in the regression models to exclude medication status and rotator cuff size as they did not impact findings in the clinical cohort. 7 …”

“…We have investigated genetic and psychological factors in pre-clinical 5, 6 and clinical cohorts 7 with the overarching goal of improving prediction of post-operative outcomes. In our line of research we selected a priori candidate genes known to be involved in pain modulation (e.g.…”

“…5, 6 From these pre-clinical analyses we identified risk subgroups, and one comprised of COMT SNP rs6269 and pain castastrophizing not only predicted heightened shoulder pain in the pre-clinical cohort but also predicted 12-month post-operative outcomes among patients undergoing shoulder surgery. 7 …”

“…Our prior approach was translational in nature, with the goal being to first identify candidate interactions in a pre-clinical cohort and then carry those forward for validation in a clinical cohort. 7 This past approach, while rigorous, did not identify genetic and psychological interactions directly in a clinical cohort, which is traditionally how prognostic factors are identified. Therefore, further investigation of these interactions is warranted given that our pre-clinical pain model was not a perfect approximation of post-operative pain.…”