Immune signatures in chronic anabolic-androgenic steroid users: a proteomic analysis

Abstract Background Anabolic-androgenic steroid (AAS) use is associated with an increased risk of cardiovascular diseases, including acute myocardial infarction and cardiomyopathy. While the underlying pathophysiological mechanisms remain incompletely understood, AAS are hypothesized to influence the immune system by promoting chronic inflammation and altering immune cell profiles. These immune changes may contribute to cardiovascular pathology, including atherosclerosis and myocardial fibrosis. Purpose To assess whether long-term AAS users have alterations in their metabolomic, proteomic, and inflammatory signatures compared to non-using strength-trained athletes, and to investigate the underlying biological mechanisms shaping this immune profile. Methods Male AAS users with at least 3 years of AAS use were compared to strength-trained male athletes who never had been using AAS (controls). The immune profile was characterized using broad plasma proteomic analysis (Olink), followed by bioinformatics analysis. Identified proteins were mapped to their corresponding genes prior to further analyses. Gene Ontology (GO) categorized these genes based on their roles in biological processes, molecular functions, and cellular structures. KEGG pathway analysis was then performed to explore the biological pathways in which these genes were involved. Results Thirty-four AAS users and sixteen non-users were included. Median time of AAS use was 5-10 years. In total, 11 proteins involved in inflammation and tissue remodeling were differentially expressed between the two groups (q<0.1). Among these, six proteins were significantly increased in AAS users, including Interleukin-8, KIM-1, Nuclear factor of activated T-cells (NFATC3), MER tyrosine kinase, Follistatin, and Hepatocyte Growth Factor (p<0.01 and q<0.1 for all) (figure). Further bioinformatic analyses found increased activity in biological processes related to inflammatory processes, cell signaling, and tissue remodeling. Additionally, three signaling pathways – MAPK, cytokine-cytokine receptor interaction, and PI3K-Akt – were more active in AAS users. The first two are associated with cell signaling and inflammation, both associated with tissue remodeling and cardiac fibrosis. Conclusion Long-term AAS users showed signs of immune dysregulation, characterized by increased levels of biomarkers associated with systemic inflammation and tissue remodeling. This may contribute to the pathophysiological mechanisms underlying cardiovascular disease in this population.