Corticosteroids plus metformin versus corticosteroids as front-line treatment for patients with newly diagnosed ITP and pre-existing type 2 diabetes mellitus: A multicentre propensity score-matched study

Corticosteroids are the standard first-line treatment for primary immune thrombocytopenia (ITP), with a high initial response but unsatisfactory sustained response (SR). Additionally, corticosteroids usually lead to hyperglycaemia especially in patients with pre-existing type 2 diabetes mellitus (T2DM). Besides reducing the blood glucose levels, metformin was found to have immunomodulatory effects. We hereby conducted a multicentre propensity score matching analysis of corticosteroids plus metformin versus corticosteroids for newly diagnosed ITP patients with pre-existing T2DM. After matching at a ratio of 1:1, there were 57 patients in each group. Baseline characteristics, comorbidities and other medications including concurrent hypoglycaemic medications were balanced between the two groups. No statistical difference was observed in the initial response rate at day 14. It was notable that patients in the metformin group had a significantly higher SR rate and longer duration of response compared to the non-metformin group. Metformin inclusion was associated with a higher incidence of stomach upset, which were generally tolerable. Our study provided evidence that the addition of metformin to corticosteroids might be a promising front-line treatment for newly diagnosed ITP patients with pre-existing T2DM.