Effects of sodium-glucose co-transporter-2 inhibitors on serum alanine aminotransferase levels in people with type 2 diabetes: A multi-institutional cohort study

Clinical trials have indicated that sodium-glucose co-transporter-2 (SGLT2) inhibitors have a favourable effect on serum alanine aminotransferase (ALT) levels in people with type 2 diabetes (T2D), but supporting evidence from real-world studies is lacking. We identified patients with T2D who initiated SGLT2 inhibitors during the period 2016 to 2017 from Chang Gung Research Database, which covers 1.3 million individuals from seven hospitals (6% of the Taiwan population). We classified patients by baseline ALT level and evaluated changes in ALT values from baseline to 1 year after initiation of SGLT2 inhibitors. We identified 11 690 new users of SGLT2 inhibitors with a mean (SD) age of 59.3 (11.8) years. The mean (SD) glycated haemoglobin and ALT levels were 8.9 (1.7)% and 34.7 (28.9) U/L at baseline, respectively. The mean change in ALT levels was −5.0 U/L (95% confidence interval [CI] –6.4, −3.5) 1 year after initiation of SGLT2 inhibitors. In patients with ALT levels ≤1× the upper limit of normal (ULN), the change in ALT levels was 1.6 U/L (95% CI –0.1, 3.4), while in those with ALT levels >1× ULN, the change in ALT levels was −26.5 U/L (95% CI –28.6, −24.3). The higher the baseline ALT level, the greater the decline after SGLT2 inhibitor treatment. Our findings suggest the initiation of SGLT2 inhibitors for T2D management could improve serum ALT levels in clinical practice, particularly in patients with especially high ALT levels.