Impact of corticosteroid use on comorbidities in patients with myasthenia gravis in the US National Veterans Affairs Health Network

Background: Corticosteroid use may increase the risk of common comorbidities in patients with myasthenia gravis (MG); however, limited longitudinal data are available to evaluate this risk over time. Methods: This retrospective cohort study used electronic medical record data from the National Veterans Affairs Health Care Network database (January 1999–March 2024) to evaluate the impact of corticosteroid use on the development of selected comorbidities in patients with and without generalized MG. Index date was the first MG diagnosis for the MG cohort and a randomly chosen date for a propensity score-matched non-MG cohort; patients were followed until disenrollment, end-of-study, or death. Results: In total, 10,632 patients with MG and 10,632 matched controls were included; mean follow-up was 7.8 years. Corticosteroids were received by 51.6% of MG and 21.2% of non-MG patients. Both MG and non-MG patients who received corticosteroids had a higher incidence of new-onset comorbidities during follow-up than MG and non-MG patients without corticosteroid use (p < 0.0001). Among MG patients, multivariate analyses showed statistically significant increases in the annualized risk of new-onset diabetes (hazard ratios 1.32–1.76), infections (1.19–1.25), osteoporosis (1.33–1.69), and cardiovascular disease (1.19–1.31) across medium- and high-dose intensities (p < 0.05). Statistically significant increases in annualized risk were observed for glaucoma (hazard ratio 1.81 at high dose; p < 0.05) and depression (1.22 at medium dose; p < 0.05). Conclusions: Increased risks for the development of key comorbidities among patients with MG were associated with corticosteroid use, particularly at higher-dose intensities. Our findings support strategies to minimize corticosteroid usage in MG.