Summary: In a hypoglycaemic clamp crossover study in type 2 diabetes, tirzepatide preserved the key glucagon counterregulatory response to induced hypoglycaemia, but delayed cortisol and noradrenaline responses and lowered symptom scores at the glucose nadir, while overall hypoglycaemia awareness was unchanged.
PICO Summary
| Element | Detail |
|---|---|
| Population | 42 adults with type 2 diabetes; double-blind crossover with glucose-clamp testing, Austria. |
| Intervention | Tirzepatide 15 mg weekly for 12 weeks before clamp-induced hypoglycaemia (glucose 100 to nadir 45 mg/dL). |
| Comparison | Placebo for 12 weeks, 8–10 week washout between periods. |
| Outcome | HbA1c change -1.5% (tirzepatide) vs +0.5% (placebo). Glucagon response was maintained (p=0.756), as were growth hormone and adrenaline. Cortisol and noradrenaline responses were delayed, with lower hypoglycaemic symptom scores at nadir (p=0.007). The proportion aware of hypoglycaemia did not differ. |
Tirzepatide and the counterregulatory response to hypoglycaemia
RCT crossover · type 2 diabetes · 12 weeks
Tirzepatide lowered HbA1c while preserving the glucagon defence against hypoglycaemia. Symptom scores at the nadir were blunted, but overall hypoglycaemia awareness was unchanged.
Expert Commentary
This is a rigorous, clinically reassuring mechanistic study, and the gold-standard clamp design with each patient as their own control gives its conclusions real weight. The headline is the good news: tirzepatide preserved the glucagon response, which is the body’s fastest and most important defence against falling glucose, consistent with incretins enhancing rather than overriding glucose-dependent regulation. The more nuanced finding deserves attention without alarm, secondary responses, cortisol and noradrenaline, were delayed and symptom scores at the nadir were lower, which could in principle mean a patient feels a low less acutely. I would weigh that against two reassuring facts the study itself provides: overall hypoglycaemia awareness did not differ, and the secondary responses were delayed rather than abolished. The artificiality of a sustained, controlled clamp also limits extrapolation to brief, real-world lows usually treated within minutes. Can I use this with my patients? Yes, sensibly. It supports my existing practice: tirzepatide alone carries low hypoglycaemia risk, but when I combine it with insulin or a sulfonylurea I proactively reduce those agents and reinforce symptom recognition, and I would lean on CGM for higher-risk patients given the subtle blunting of symptoms.
References
Pieber TR, Svehlikova E, Urva S, et al. Counterregulatory response to hypoglycemia during a hypoglycemic clamp in people with type 2 diabetes treated with tirzepatide. Front Endocrinol (Lausanne). 2025;16:1627947. doi:10.3389/fendo.2025.1627947