The use of oral glucocorticoids and the risk of major osteoporotic fracture in patients with myasthenia gravis

SUMMARY: Oral glucocorticoids may increase major osteoporotic fracture risk (MOF) in myasthenia gravis patients. To assess this risk, we performed a case–control study including all Danish patients with a MOF between 1995 and 2011. We also pooled our data with data from another study. We found no increased risk. Osteoporosis prevention remains advisable. PURPOSE/INTRODUCTION: The prolonged use of high doses of oral glucocorticoids (GCs), a common treatment in patients with myasthenia gravis (MG), may increase major osteoporotic fracture (MOF) risk. Previous epidemiological studies did not exclusively focus on patients with MG or had relatively few GC-exposed MG patients. Aims were to evaluate the risk of MOF in MG patients using oral GCs in a large study population and to perform a pooled analysis with data from previous work. METHODS: A population-based case–control study (1995–2011) was conducted using the Danish National Health Service. Cases had sustained a MOF, and controls had not. All were aged ≥ 18 years. Multivariate conditional logistic regression estimated odds ratios (ORs) among MG patients using oral GCs versus non-users. Adjustments were made for comorbidities and comedications. In the pooled analysis, results were pooled by the use of generic inverse variance methods, assuming a random-effects model. RESULTS: We identified 376,858 cases and 376,858 controls. MOF risk was not elevated in MG patients currently using oral GCs compared to MG patients not on oral GCs (OR(adj.): 1.26 (95% CI 0.68–2.33)). The use of the highest cumulative dose of oral GCs (≥ 7 g) did not show an increased risk of MOF among MG patients (OR(adj.): 2.00 (95% CI 0.90–4.44)). Our pooled analysis also showed no association between oral GC use and MOF risk. CONCLUSION: This study showed that oral GC use in patients with MG was not associated with increased risk of MOF in our case–control study and pooled analysis. Osteoporosis prevention in MG patients based on clinical guidelines remains advisable.