The albumin-globulin ratio mediates progressive motor function decline in Duchenne muscular dystrophy

The albumin-globulin ratio (AGR) is a well-established marker of systemic infl-ammation. Whether AGR is associated with motor function outcomes or media-tes age-related muscle deterioration in Duchenne muscular dystrophy (DMD) re-mains unclear.In this retrospective cohort study, 201 children with DMD and 202 age- and sex-matched healthy controls were enrolled between January 2013 and December 2023. Logistic and Cox regression analyses were used to assess the impact of the AGR on muscle strength and treatment efficacy. Further me-diation and moderation analyses were conducted to investigate potential underl-ying mechanisms.A statistically significant difference in the AGR was observed between the DMD group and the control group(1.85 ± 0.31 vs. 2.13 ± 0.28, t = − 9.452, p  < 0.001). Logistic regression analyses indicated that lower AGR significant-ly predicted higher Vignos scores at both baseline (adjusted odds ratio[OR] = 0.137, 95% confidence interval [CI]:0.018–0.946, p  = 0.035) and follow-up (adjusted OR = 0.477, 95%CI:0.258–0.882, p  = 0.018). Cox regression analysis further revea-led that a lower AGR was significantly associated with an increased risk of ambulatory loss (adjusted hazard ratio [HR] = 4.863, 95%CI: 2.182–9.935, p  = 0.007). Mediation analyses showed that the associations between age and Vignos s-core (proportion mediated:11.38% at admission, 10.12% at follow-up) and bet-ween age and therapeutic efficacy (proportion mediated:8.96%) were partially mediated through AGR. Moreover, weight exerted a significant negative moder-ating effect on the relationship between age and AGR. Conclusion : AGR partially mediates the age-dependent motor functional decline in DMD and modulates therapeutic responses, body weight being a key regula-tor of AGR levels. AGR may represent a potential therapeutic target for inter-vention.