Background: We aimed to assess the therapeutic inertia associated with injectable therapies and the factors influencing glycemic control following these therapies in patients with type 2 diabetes mellitus (T2DM) in South Korea.

Methods: This multicenter, retrospective cohort study included 2,598 T2DM patients aged 20 to 75 years from 10 referral medical centers in South Korea. These patients had been treated with three or four oral antidiabetic drugs (OADs) and were subsequently initiated on insulin (n=1,942) or glucagon-like peptide-1 receptor agonists (GLP-1RAs, n=656) between January 2015 and December 2021. We analyzed the time to initiation of injectable therapy, changes in glycated hemoglobin (HbA1c), and associations between clinical factors and glycemic control.

Results: At the time of injectable therapy initiation, the mean HbA1c was 9.54%, with insulin users having a higher HbA1c level (9.79%) than GLP-1RA users (8.70%). The mean time from starting 3 or 4 OADs to initiating injectable therapy was 3.19 years: 53.5% of patients had started injectable therapy after 2 years, and 24.2% started after 5 years. Among insulin users, older age (P= 0.004), higher body mass index (P=0.035), and lower HbA1c levels at insulin initiation (P<0.001) were associated with better glycemic control. Among GLP-1RA users, only the HbA1c level at therapy initiation (P<0.001) was a significant factor.

Conclusion: This study highlighted significant delays in initiating injectable therapies, particularly insulin, in T2DM patients in South Korea. Early initiation of injectable therapy may improve long-term glycemic control in these patients.

Keywords: Diabetes mellitus, type 2; Glucagon-like peptide-1 receptor agonists; Glycemic control; Insulin; Treatment delay.

背景： 我们旨在评估与注射治疗相关的治疗惰性以及这些治疗后影响2型糖尿病（T2DM）患者血糖控制的因素。

方法： 这是一项多中心、回顾性的队列研究，包括了来自韩国10个转诊医疗机构的2598名年龄在20至75岁之间的T2DM患者。这些患者之前使用了三种或四种口服降糖药（OADs），随后从2015年1月至2021年12月期间开始注射胰岛素（n=1,942）或GLP-1受体激动剂（GLP-1RAs，n=656）。我们分析了患者开始使用注射治疗的时间、糖化血红蛋白（HbA1c）的变化以及临床因素与血糖控制之间的关联。

结果： 在开始注射治疗时，平均HbA1c水平为9.54%，胰岛素使用者的HbA1c水平较高（9.79%），而GLP-1RA使用者较低（8.70%）。从使用三种或四种OADs到开始注射治疗的平均时间是3.19年：53.5%的患者在两年后才开始注射治疗，24.2%的患者则是在五年之后。对于胰岛素使用者而言，年龄较大(P= 0.004)、体重指数较高(P=0.035)，以及在开始使用胰岛素时HbA1c水平较低（P

结论： 本研究强调了韩国T2DM患者在开始使用注射治疗方面存在显著延迟，特别是胰岛素。早期开始注射治疗可能会改善这些患者的长期血糖控制。