During the 2025 Peking University Diabetes Forum and Coastal Long Bridge Symposium on Metabolic Diseases,Professor Gu Nan from the Department of Endocrinology, Peking University First Hospital, delivered a report on the current status and challenges of insulin therapy for type 1 diabetes mellitus (T1DM).
Insulin replacement therapy is the core treatment for T1DM, but its clinical application faces multiple challenges.The Guidelines for the Diagnosis and Treatment of Type 1 Diabetes in China (2021 Edition) states that evidence for the efficacy of adjuvant therapeutic agents for T1DM remains very limited, and there are age restrictions in pediatric and adolescent patients.
In clinical practice, non-insulin agents are not universally recommended.They may only be used individually on a discretionary basis after optimized insulin therapy, with adequate evaluation of indications and contraindications, and after obtaining informed consent.This principle provides an important basis for current clinical decision-making regarding adjuvant therapy for T1DM.
Long-term insulin therapy may lead to weight gain (average annual weight gain: 1.5–2.0 kg) and aggravate insulin resistance.Data show that among T1DM patients receiving conventional insulin therapy, the incidence of severe hypoglycemia can reach 1.2 episodes per patient-year, and the proportion of patients with a body mass index (BMI) ≥ 25 kg/m² has exceeded 40%.These issues have driven the research, development and exploration of adjuvant therapeutic agents.
For a long time, it was widely believed in the medical community that β‑cell function declines rapidly after diagnosis in T1DM patients.However, this traditional view has been continuously challenged by multiple studies in recent years.
A study by Keenan et al. including 411 patients with long‑duration T1DM showed that67.4% of patients maintained random serum C‑peptide levels ≥ 0.03–0.20 nmol/L.Moreover, in more than 50% of patients with fasting C‑peptide > 0.17 nmol/L,C‑peptide levels increased more than twofold after the mixed meal tolerance test (MMTT).
Pancreatic autopsies of 9 deceased T1DM patients revealed that insulin‑positive β‑cells were still present in pancreatic tissue even after several decades of disease duration.Another multicenter study further confirmed the prevalence of residual β‑cell function in patients with long‑duration T1DM.
These studies collectively suggest that functionally active residual β‑cell subpopulations may still exist in patients with T1DM,laying an important theoretical foundation for preserving residual β‑cell function and the application of non‑insulin therapeutic agents in T1DM patients.
Research data from the Chinese population further validated this key conclusion.Cheng et al. performed MMTT in 109 T1DM patients with disease duration ≥ 10 years.The results showed that 38.5% of patients had residual β‑cell function,among whom 33.3% had postprandial C‑peptide levels more than twofold higher than fasting levels.
This finding provides key evidence‑based support for individualized treatment of Chinese T1DM patients,suggesting that clinicians should pay attention to dynamic evaluation of β‑cell function in patients with long‑duration T1DM,so as to optimize treatment regimens based on evaluation results and maximally improve patient prognosis.