(020) Association between Cumulative Corticosteroid Dose and Risk of Avascular Necrosis in patients with Systemic Lupus Erythematosus : A nested case-control study

Publication Number: 1016

Background: Corticosteroid (CS) is effective for controlling inflammatory reactions in patients with Systemic lupus erythematosus (SLE), but may have been known to increase risk of avascular necrosis (AVN).

Objectives: We aimed to investigate the association between cumulative dose of CS and the incidence of AVN in newly diagnosed SLE patients.

Methods: We conducted a nested case-control study using Korean National Health Insurance claims database from 2002 to 2018. Cohort of incident diagnosis of SLE (ICD10, M32) with rare intractable disease code (V136) were identified during 2007~2018. Cases, who were diagnosed for any reason with AVN (M870, M871, M873, M878, M879, M905 (ICD-10), were matched up to 10 controls based on gender, age (±5yrs), and date of SLE diagnosis (±6 months). Conditional logistic regression analysis was performed to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of AVN occurrence associated with cumulative dose of CS (prednisolone-equivalent dose (PED)) from diagnosis of SLE to the index date, with adjusting for hypertension, dyslipidemia, immunosuppressants and so forth. Conditional logistic regression analysis was performed to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of AVN occurrence associated with cumulative dose of CS during overall study period or within 1 year before index date. To assess trends of association according to cumulative CS dose, categories of CS dose were set considering distribution of cumulative CS dose in the control group.

Results: Among the 12,375 SLE patients who were newly diagnosed during the inclusion period, a total of 358 AVN patients were identified. Controls without AVN (N=3,276) were identified. In terms of cumulative CS dose, used after first diagnosis of SLE, compared with cumulative CS dose less than 1g, ORs of 1g≤ < 7g and 7g≤ of cumulative dose were 3.37 (95% CI 2.09 – 5.41) and 7.77 (95% CI 4.64 – 13.02), respectively. In the analysis of CS dose during recent 1 year, compared with use of CS ≤0.1g, ORs for 0.1g< ≤1.7g, and 1.7g or more PDE were 1.35 (95% CI 0.96 – 1.90) and 2.03 (95% CI 1.46 – 2.81).

Conclusions: The association between higher cumulative CS dose and increased risk of AVN suggests the need for cautious monitoring of patients who use CS regularly for SLE, particularly with regards to the accumulated dose of corticosteroids.