The sodium glucose cotransporter 2 inhibitor empagliflozin (EMPA) reduces HbA1c, weight and blood pressure (BP) in patients with type 2 diabetes (T2D). While glucose lowering with EMPA is dependent on renal function, the impact of chronic kidney disease (CKD) on BP reduction with EMPA is less well understood. Our aim was to determine if impaired renal function attenuates antihypertensive effects of EMPA.
A Phase III randomized placebo (PBO)-controlled trial (EMPA-REG BP™) investigated the efficacy and safety of EMPA in patients with T2D and hypertension (defined as mean seated office systolic BP [SBP] 130-159 mmHg and diastolic BP [DBP] 80-99 mmHg at screening). Patients (mean [SD] age 60.2 [9.0] years, HbA1c 7.90 [0.74] %, 24-hour SBP 131.4 [12.3] and 24-hour DBP 75.0 [7.8] mmHg) received EMPA 10 mg (n=276), EMPA 25 mg (n=276) or PBO (n=271) once daily for 12 weeks. We assessed changes from baseline in mean ambulatory 24-hour SBP and HbA1c in subgroups by baseline eGFR (MDRD equation), adjusting for differences in baseline mean 24-hour SBP (for SBP analyses only), HbA1c, region, number of antihypertensive medications, treatment, eGFR and treatment by eGFR interaction between groups.
In patients with normal renal function, or stage 2 or 3 CKD, EMPA significantly reduced HbA1c and mean 24-hour SBP vs PBO (Table). As expected, PBO-corrected HbA1c reductions with EMPA appeared to decrease with decreasing eGFR (Table). In contrast, PBO-corrected reductions in mean 24-hour SBP with EMPA mostly appeared to increase with decreasing eGFR (Table).
Unlike HbA1c, mean 24-hour SBP reductions with EMPA in patients with T2D and hypertension appear to be greater in patients with lower eGFR, indicating that SBP modulation with EMPA may involve pathways other than urinary glucose excretion such as diuretic effects, weight loss, improved glycemic control, reduced arterial stiffness or direct vascular effects.