Association of Allostatic Load with Preoperative Shoulder Symptoms in Patients Undergoing Rotator Cuff Repair

Background Most of the preoperative pain and functional limitations among patients undergoing rotator cuff repair (RCR) cannot be explained by rotator cuff tear size or demographic factors alone. Allostatic load (AL), a measure of cumulative multisystem physiologic stress, may influence pain perception and functional status and has been associated with adverse health outcomes. The purpose of this study was to quantify AL in patients undergoing RCR and evaluate its association with preoperative symptom burden. Methods Fifty patients undergoing RCR were included. AL was quantified using a literature-based composite allostatic load index (ALI) based on binary splits of 12 physiologic variables (ALI_12), with scores ranging from 0 (all biomarkers within) to 12 (all biomarkers outside) their designated thresholds. Incremental contributions of ALI to preoperative symptoms were assessed using multivariable regression models for Penn Shoulder Score (PSS) and its pain, function, and satisfaction subscores, with each model adjusted for seven previously identified predictors of preoperative PSS total: age, sex, race, mental health status measured by the Patient-Reported Outcomes Measurement Information System Global Health-10 mental health score (PROMIS-10 MH), area deprivation index (ADI), prior year opioid use, and anterior-posterior (AP) tear size. Additional analyses evaluated two alternative indices of AL and explored principal component (PC) and canonical correlation analyses. Results ALI demonstrated variability across the cohort and averaged approximately one third of the maximum possible score. However, no statistically significant associations were observed between ALI and preoperative PSS or its individual subscores after adjustment for covariates. Alternative representations of AL and additional analyses yielded similar findings. Conclusion Among fifty patients undergoing RCR, measurable indices of physiologic stress varied substantially but were not meaningfully associated with preoperative symptoms. Whether AL contributes to variability in preoperative symptoms and postoperative outcomes following RCR remains uncertain pending further investigation in larger studies. Level of Evidence Level III; Cross Sectional Design, Prognosis Study