Long-term impact of corticosteroid therapy on adult height in juvenile myasthenia gravis patients: a retrospective multicenter cohort study

Aim: This study aims to assess the final adult height of patients with juvenile myasthenia gravis (JMG) who received glucocorticoid treatment during childhood. Methods: A retrospective cohort study was conducted at two neurology centers in Beijing, China, including patients diagnosed with JMG between March 2006 and April 2022. Participants were stratified into two groups: those receiving long-term corticosteroid therapy (≥ 6 months) and those without such treatment. Further subgroup analysis was performed based on treatment timing (prepubertal vs . postpubertal). Mean differences in adult height were calculated, and binary logistic regression was used to evaluate associations between treatment variables and growth outcomes. Results: Of 120 diagnosed JMG patients, 47 who reached adult height were analyzed. Adult height in the long-term steroid group (168.64 ± 7.58 cm) did not significantly differ from the control group (171.45 ± 9.58 cm) (P = 0.26). A negative correlation was observed between the age at steroid initiation and the final-predicted height difference (r = 0.23, P = 0.04), and between steroid duration and adult height (r = -3.11, P = 0.04). Prepubertal steroid initiation was associated with a significant negative final-predicted height difference (Z = -2.12, P = 0.03) and a higher likelihood of failing to achieve predicted height (χ2 = 6.18, P = 0.03). Prepubertal steroid use emerged as an independent risk factor for not attaining predicted height (OR = 11.07, 95%CI: 1.24-99.15, P = 0.03). Conclusion: In JMG patients, steroid treatment after puberty appears to have a relatively smaller impact on adult final height compared to treatment before puberty.