Abstract
Dipeptidyl peptidase-4 (DPP-4), namely CD26, is expressed on the surface of immune cells, suggesting that inhibition of DPP-4 might affect the immune system. The current multicenter observational case-control study was carried out to investigate the effects of DPP-4 inhibitor (DPP-4i) administration on Graves' disease (GD) activity. This study comprised patients with GD and type 2 diabetes, who were administered an oral hypoglycemic agent including DPP-4i. Exacerbation of GD was defined as an increase of antithyroid drug dose by 6 months after oral hypoglycemic agent administration. A total of 80 patients were enrolled and divided into an exacerbation group or a non-exacerbation group. The frequency of DPP-4i administration was significantly higher in the exacerbation group (88%) than that in the non-exacerbation group (31%). In multivariate logistic regression analysis, there was a significant association between DPP-4i administration and GD exacerbation (odds ratio 7.39). The current study suggests that DPP-4i administration is associated with GD exacerbation.