Obesity is associated with poor outcomes of corticosteroid treatment in patients with primary immune thrombocytopenia.

Emerging evidence has demonstrated that obesity impacts multiple immune-related diseases. It remains unclear whether and how obesity alters treatment outcomes in patients with primary immune thrombocytopenia (ITP). Thus, we retrospectively investigated 214 treatment-naïve patients who received standard high-dose dexamethasone therapy in Qilu Hospital. Patients with obesity showed significantly lower overall initial response (underweight vs. normal vs. overweight vs. obese: 85.7% vs. 85.2% vs. 72.0% vs. 52.3%, p = 0.001) and initial complete response ([CR], 71.4% vs. 70.4% vs. 53.3% vs. 27.3%, p < 0.001) rates. The same trend was observed in the 6-month sustained response (63.6% vs. 52.3% vs. 35.6% vs. 22.7%, p = 0.03) and sustained CR (36.4% vs. 44.6% vs. 24.4% vs. 9.1%, p = 0.01). The Kaplan-Meier analysis revealed a shortened duration of remission in the obese group (median duration of remission, not reached vs. 16 months vs. 2 months vs. 1 month, p = 0.002). In multivariate regression analysis, obesity was independently associated with poor initial and sustained responses, and an increased risk for relapse. In conclusion, obesity is a negative predictor for outcomes of corticosteroid treatment. A stratified strategy according to body mass index status may facilitate the precision management of ITP.