Interleukin-6: A Potential Biomarker for Dysmenorrhea and Disease Severity in Adenomyosis

Background The pathogenesis of adenomyosis remains incompletely understood, and no well-established biomarkers related to its inflammatory mediators have been identified. Aim This retrospective study aimed to investigate the association between interleukin-6 (IL-6) and dysmenorrhea in adenomyosis, as well as factors influencing IL-6 levels in patients with adenomyosis. Methods Patients were categorized based on the presence of dysmenorrhea and lesion subtype. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic utility of IL-6 for dysmenorrhea. Binary logistic regression was employed to identify factors associated with dysmenorrhea and IL-6 levels. Results IL-6 levels were significantly higher in patients with dysmenorrhea compared to those without dysmenorrhea in the total cohort (Z = -3.783, P < 0.001), as well as in both the diffuse subtype group (Z = -2.525, P = 0.012) and the focal subtype group (Z = -2.883, P = 0.004). An IL-6 level of 3.02 pg/mL was identified as the optimal cutoff value for discriminating dysmenorrhea via ROC analysis. Patients with IL-6 levels ≥ 3.02 pg/mL were more likely to experience dysmenorrhea compared to those with IL-6 levels below this threshold. Furthermore, multiple regression analysis revealed a positive correlation between IL-6 levels and uterus volume in both the total cohort and the diffuse subtype group. Conclusion IL-6 was associated with dysmenorrhea in adenomyosis, and its level correlated positively with disease severity.