RESUMEN
BACKGROUND: Diabetes and myelodysplastic syndrome are two conditions that may coexist in a single patient, since both diseases are prevalent in the elderly. The pathophysiology of myelodysplastic syndrome involves recurrent genetic mutations, especially in genes controlling epigenetic regulation. Although the pathophysiology of diabetes is not well understood, several studies suggest a role of epigenetics in type 2 diabetes. CASE PRESENTATION: We report here for the first time the case of a 75-year-old Caucasian man who was treated for both diabetes and acute myeloid leukemia secondary to myelodysplastic syndrome, with a temporal association between glycemic dysregulation and the intake of 5-azacitidine. In fact, 2-3 days after starting each 7-day cycle of 5-azacitidine, he reported higher blood glucose levels, requiring an increased dose of self-administered insulin. CONCLUSION: This observation could help to understand the pathophysiology of these two conditions and could encourage physicians to monitor blood glucose levels in patients under hypomethylating agent with a history of diabetes.