Clinical analysis of pre-existing diabetes mellitus and dipeptidyl peptidase-4 inhibitors in patients with remitting seronegative symmetrical synovitis and pitting edema syndrome.

Objectives: To analyze the association among remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome, diabetes mellitus (DM), and antidiabetic drugs. Methods: We retrospectively analyzed the clinical and serologic manifestations of patients who had RS3PE syndrome with and without pre-existing DM. Then we performed a subanalysis in which patients with pre-existing DM were classified into two groups according to whether they were or were not taking a dipeptidyl peptidase 4 inhibitor (DPP4i), an antidiabetic drug that was suggested to have an association with the pathogenesis of RS3PE syndrome. Results: Pre-existing DM was found in 13 (35.1%) of 37 patients with RS3PE syndrome. No significant differences in age, gender, physical manifestations, and laboratory findings were observed between the patients with DM and those without DM. DPP4i had been administered to 6 of 13 patients with RS3PE and pre-existing DM. We observed no significant differences in manifestations of RS3PE syndrome before treatment; however, one relapse occurred in a patient with poorly controlled DM who had been continuing DPP4i therapy. Conclusion: This study revealed no evidence suggesting an association among RS3PE syndrome, DM, and antidiabetic drugs. DPP4i would be safe for use by most of patients with RS3PE syndrome. However, elderly patients and patients with poorly controlled DM might require careful observation.