Adropin is a newly identified bioactive protein that is important in energy hemostasis and vascular endothelial function. Lower levels of adropin in patients with type 2 diabetes are related to coronary atherosclerosis, characterized by impaired flowmediated dilatation (FMD). The purpose of the present study was to investigate FMD and plasma levels of adropin and nitrite/nitrate (NOx) in patients with type 2 diabetes at baseline and follow-up after 12 weeks of high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT). Sixty-six persons with type 2 diabetes were divided into HIIT, MICT, and control groups. The HIIT group intervention was 12 intervals (1.5 min) at 85-90% maximal heart rate (HR max ) separated by 2 min at 55-60% HR max in three sessions per week for 12 weeks. MICT training consisted of 42 min of cycling at 70% HR max . Before and after the intervention, FMD was recorded with high-resolution Doppler ultrasound. Plasma levels of adropin and NOx were measured by enzyme-linked immunosorbent assay. After training FMD was significantly higher in the MICT and HIIT groups compared to the control group (P < 0.05). Plasma levels of adropin and NOx were higher in both exercise groups, but the increase was greater in the HIIT group (P < 0.01). Peak oxygen consumption was increased after exercise training in both groups compared to the control group (P < 0.01). Percentage FMD showed a positive correlation with plasma levels of adropin and NOx (both P < 0.01), and a negative correlation with diastolic blood pressure (r = −0.530, P = 0.035) and systolic blood pressure (r = −0.606, P = 0.013) in the HIIT group. The results