Sodium–glucose cotransporter 2 inhibitors influence skeletal muscle pathology in patients with heart failure and reduced ejection fraction

Abstract Aims Patients with heart failure and reduced ejection fraction (HFrEF) exhibit skeletal muscle pathology, which contributes to symptoms and decreased quality of life. Sodium–glucose cotransporter 2 inhibitors (SGLT2i) improve clinical outcomes in HFrEF but their mechanism of action remains poorly understood. We aimed, therefore, to determine whether SGLT2i influence skeletal muscle pathology in patients with HFrEF. Methods and results Muscle biopsies from 28 male patients with HFrEF (New York Heart association class I–III) treated with SGLT2i (>12 months) or without SGLT2i were compared. Comprehensive analyses of muscle structure (immunohistochemistry), transcriptome (RNA sequencing), and metabolome (liquid chromatography‐mass spectrometry) were performed, and serum inflammatory profiling (ELISA). Experiments in mice ( n = 16) treated with SGLT2i were also performed. Myofiber atrophy was ~20% less in patients taking SGLT2i ( p = 0.07). Transcriptomics and follow‐up measures identified a unique signature in patients taking SGLT2i related to beneficial effects on atrophy, metabolism, and inflammation. Metabolomics identified influenced tryptophan metabolism in patients taking SGLT2i: kynurenic acid was 24% higher and kynurenine was 32% lower ( p < 0.001). Serum profiling identified that SGLT2i treatment was associated with lower ( p < 0.05) pro‐inflammatory cytokines by 26–64% alongside downstream muscle interleukin (IL)‐6‐JAK/STAT3 signalling ( p = 008 and 0.09). Serum IL‐6 and muscle kynurenine were correlated ( R = 0.65; p < 0.05). Muscle pathology was lower in mice treated with SGLT2i indicative of a conserved mammalian response to treatment. Conclusions Treatment with SGLT2i influenced skeletal muscle pathology in patients with HFrEF and was associated with anti‐atrophic, anti‐inflammatory, and pro‐metabolic effects. These changes may be regulated via IL‐6–kynurenine signalling. Together, clinical improvements following SGLT2i treatment in patients with HFrEF may be partly explained by their positive effects on skeletal muscle pathology.