Study wrapper · #186
Effectiveness of tirzepatide in Japanese patients with type 2 diabetes but no obesity: A sub-analysis of Hokkaido-TZP study data.
Editor's note
A secondary analysis of the real-world, multicentre Hokkaido-TZP study focused on 107 Japanese adults with type 2 diabetes but without obesity (BMI under 25), a group excluded from the Phase 3 SURPASS trials, which required BMI of at least 23. That makes the question genuinely useful, since lean type 2 diabetes is common in Asia and under-evidenced. But the design is observational and small: no control group, 6-month follow-up, and a subgroup carved from a larger cohort, so glycaemic changes cannot be attributed to the drug with trial-level confidence. Researchers reported that over six months tirzepatide was associated with significant HbA1c reductions across all baseline-BMI tertiles, and with a significant overall BMI decrease that was larger in those with higher starting BMI; baseline BMI and dietary consultation independently predicted the degree of BMI reduction. Seven patients discontinued for adverse events, all in the lower- and middle-BMI groups, a tolerability signal worth noting in leaner patients. Weight this as supportive real-world data extending tirzepatide's glycaemic use to non-obese patients, pending controlled confirmation.
Plain-language abstract
Tirzepatide's main trials only enrolled people with a body-mass index (BMI) of at least 23, so there is little evidence for patients who have type 2 diabetes but are not overweight, which is common in Asia. This analysis drew on a real-world Japanese study (Hokkaido-TZP) and focused on 107 patients with type 2 diabetes and a BMI under 25. There was no comparison group, and follow-up lasted six months. Over that time, tirzepatide was associated with meaningful drops in HbA1c (a long-term blood-sugar marker) in all patients, whether their starting BMI was in the lower, middle or higher part of this lean range. Overall BMI also fell significantly, but more so in people who started heavier. Statistical analysis found that starting BMI and receiving dietary advice were independent factors linked to how much BMI dropped. Seven patients stopped treatment because of side effects, and all of them were in the lower- or middle-BMI groups. The authors concluded that tirzepatide was associated with good blood-sugar control even in patients without obesity, while its weight-lowering effect depended on starting weight and lifestyle support.