Long-term effects of ipragliflozin on blood pressure in patients with type 2 diabetes: insights from the randomized PROTECT trial

Although previous reports have shown that sodium-glucose cotransporter-2 (SGLT2) inhibitors have a blood pressure (BP) lowering effect, relevant long-term data is limited. This study aimed to evaluate the effect of the SGLT2 inhibitor ipragliflozin on BP, and associations between BP reduction and changes in cardiometabolic variables in diabetic patients. This was a sub-analysis of the PROTECT trial, a multicenter, randomized, open-label study to assess if ipragliflozin delays carotid atherosclerosis in patients with type 2 diabetes. Participants were randomized to ipragliflozin and control groups. The primary endpoint of the present sub-analysis was the trajectory of systolic BP over 24 months. Correlations between systolic BP changes and cardiometabolic variables were also evaluated. A total of 232 eligible participants with well-balanced baseline characteristics were included in each study group. Throughout the 24-month study period, mean systolic BP was lower in the ipragliflozin group. At 24 months, a between-group difference (ipragliflozin minus control) in mean systolic BP change from baseline was -3.6 mmHg (95% confidence interval, -6.2 to -1.0 mmHg), and the reduction in systolic BP in the ipragliflozin group was consistent across subgroups examined. Changes in systolic BP significantly correlated with those in body mass index in the ipragliflozin group, while no significant correlations with other cardiometabolic variables tested were observed. In conclusion, ipragliflozin treatment was associated with BP reduction throughout the 24-month follow-up period as compared to control treatment. BP reduction correlated with weight loss, which might be one of the mechanisms for the BP lowering effect of SGLT2 inhibitors.