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Findings
What does this study add?
- The study found that tirzepatide improved markers of insulin sensitivity and beta-cell function to a greater extent than dulaglutide.
- The insulin sensitivity effects of tirzepatide were only partly attributed to weight loss – suggesting that dual receptor agonism confers other distinct mechanisms of glycaemic control.
- There was improvement in multiple markers of pancreatic beta-cell function, as shown by dose-dependently increasing HOMA2-B indices and decreasing proinsulin levels, proinsulin/C-peptide ratios, and proinsulin/insulin ratios.
- By decreasing insulin resistance, tirzepatide likely reduces metabolic demand for insulin secretion from pancreatic beta cells, diminishing ongoing beta-cell stress.
- Decreases in fasting glucagon in response to tirzepatide may contribute to reduced HbA1c.
