Background: The inhibition of
sodium-
glucose co-transporter 2 (SGLT-2) has been shown to be beneficial in the treatment of diabetic and non-diabetic patients with
heart failure. The underlying mechanisms are incompletely understood. The present prospective study investigates for the first time the effect of
empagliflozin on various soluble markers of
inflammation in patients with reduced ejection fraction (HFrEF). Methods: We included 50 inpatients with HFrEF and
diabetes mellitus type 2. A total of 25 patients received a
therapy with the SGLT-2-inhibitor
empagliflozin in addition to standard medication; the other 25 patients did not receive
empagliflozin and were considered the control group. Quality of life, functional status and soluble immunological parameters in serum were assessed at baseline and after 3 months. Results: The baseline characteristics of both groups revealed no significant differences. Patients on
empagliflozin demonstrated a significant improvement in the Minnesota living with
heart failure questionnaire (baseline 44.2 ± 20.2 vs. 24 ± 17.7; p < 0.001), in distance in the 6-min walk test (baseline 343 ± 145 m vs. 450 ± 115 m; p < 0.001) and in soluble
interleukin-6 level (baseline 21.7 ± 21.8 pg/mL vs. 13.7 ± 15.8 pg/mL; p = 0.008). There was no significant change of these or other parameters in the control group (p > 0.05 each). Conclusions: The
empagliflozin-induced improvement of quality of life and functional capacity in patients with HFrEF and
type 2 diabetes mellitus is accompanied by a substantial reduction of
interleukin-6 levels. Thus, anti-inflammatory effects may contribute to the benefits of SGLT-2-inhibitors in
heart failure.