Summary: In this post hoc analysis of the SUSTAIN China randomised trial (total n=868; Chinese-only n=605), the glycaemic efficacy of once-weekly subcutaneous semaglutide 0.5 mg and 1.0 mg versus daily sitagliptin 100 mg was not significantly modified by most baseline characteristics, including baseline HbA1c, age, sex, BMI, diabetes duration, and HOMA-beta tertile. Semaglutide was also associated with less glucose variability and a higher HOMA-beta ratio at end of treatment (p<0.05). Because this is an exploratory subgroup analysis, it supports consistency of effect rather than establishing new efficacy.
PICO Summary
| Element | Detail |
|---|---|
| Population | Adults with type 2 diabetes from the SUSTAIN China multicentre, double-blind RCT; total population n=868 and Chinese-only subpopulation n=605 (post hoc analysis). |
| Intervention | Once-weekly subcutaneous semaglutide 0.5 mg or 1.0 mg, analysed across baseline subgroups (age, sex, BMI, baseline HbA1c, diabetes duration, HOMA-beta tertile). |
| Comparison | Once-daily oral sitagliptin 100 mg. |
| Outcome | The semaglutide-versus-sitagliptin effect on HbA1c and body weight was not significantly affected by most baseline characteristics in either population. Attainment of HbA1c 0.05). Seven-point SMPG standard deviation and derived time-in-range indicated less glucose variability with semaglutide, and HOMA-beta ratio to baseline at end of treatment was greater with semaglutide 0.5 and 1.0 mg versus sitagliptin (p<0.05). As a post hoc analysis, comparisons are exploratory; no adjusted effect sizes, 95% CIs, or NNT were reported in the abstract. |
Expert Commentary
This post hoc analysis of SUSTAIN China asks a narrow but practically useful question: does the glycaemic advantage of once-weekly semaglutide over sitagliptin hold up across the kinds of patients seen in clinic? The reassuring answer is that the treatment effect was not meaningfully modified by baseline HbA1c, age, sex, BMI, diabetes duration, or beta-cell function, and that semaglutide was additionally associated with steadier day-to-day glucose and a more favourable HOMA-beta trajectory. The verdict is therefore one of supportive consistency, not new proof of superiority; the parent randomised trial established the efficacy, and this analysis simply shows it travels across subgroups. The weighed limitation is intrinsic to the design: post hoc subgroup analyses are exploratory, are not powered for interaction testing, and carry a real risk of false reassurance from multiple comparisons, so absence of a significant interaction should not be read as proof of uniform benefit. The work was authored in part by employees of the manufacturer, and HOMA-beta is a surrogate rather than a hard outcome, both of which temper enthusiasm. Can I use this with my patients? Yes, for a Chinese or broader adult with type 2 diabetes who is a reasonable candidate for a GLP-1 receptor agonist, this strengthens confidence that semaglutide’s glycaemic benefit is not confined to a narrow phenotype. Confirmatory pre-specified subgroup work would be welcome.
References
Ji L, Lu Y, Shen Z, Hu P, Liu W, Zhang Q, Shi B. Impact of baseline characteristics on the efficacy of once-weekly subcutaneous semaglutide among participants with type 2 diabetes: a post hoc analysis of SUSTAIN China. Diabetes Obes Metab. 2024;26(11):5312-5324. doi:10.1111/dom.15888