Effects of the switch from dulaglutide to tirzepatide on glycemic control, body weight, and fatty liver: a retrospective study

Objectives Tirzepatide belongs to a new class of anti-diabetic agents that stimulate both glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide receptors, resulting in a greater blood glucose-lowering effect and body weight reduction than glucagon-like peptide-1 analogs. However, data on the effects of switching from glucagon-like peptide-1 analogs to tirzepatide on the blood glucose level, body weight, and liver functions are unavailable. Methods Data from 40 patients with type 2 diabetes who received a prescription change from dulaglutide to tirzepatide were retrospectively analyzed at the 3 and 6 months after the switch. The analyzed data included glycosylated hemoglobin, body weight, aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transpeptidase levels, and fibrosis-4 index. Results Six months after the treatment switch, average reductions of 1.2% and 3.6 kg were observed in the glycosylated hemoglobin and body weight, respectively. The change in glycosylated hemoglobin level was negatively correlated with the baseline glycosylated hemoglobin level. However, body weight reduction was observed regardless of the baseline characteristics. Moreover, the aspartate aminotransferase, alanine aminotransferase, and γ-glutamyl transpeptidase levels decreased 6 months after the switch. Reductions in alanine aminotransferase levels was greater in patients with higher baseline aspartate aminotransferase, alanine aminotransferase, and γ-glutamyl transpeptidase levels. Although the fibrosis-4 index did not improve during the study period, a trend toward a decrease was observed in patients with a higher baseline fibrosis-4 index. Conclusions Switching from dulaglutide to tirzepatide has a beneficial effect on the blood glucose level, body weight, and liver function in patients with type 2 diabetes.