GLP1R and diabetes mellitus: Finally, a 5-week open-label trial of GLP-1 (2.5 pmol/kg/min infusion) in 12 patients with HF (with or without diabetes) compared with nine patients on standard therapy showed that GLP-1 therapy was associated with significant improvements in LVEF (from 21±3 to 27±3%, P < 0.01), maximal oxygen uptake (from 10.8 ± 0.9 mL O2/min/kg to 13.9 mL O2/min/kg, P < 0.001), and 6-min walking distance (from 232 ± 15 m to 286 ± 12 m, P < 0.001) [62].