Glucose-lowering Drugs as an Adjunct to Insulin Therapy in Chinese Patients With Type 1 Diabetes

Effectiveness and Safety of Glucose-lowering Drugs as an Adjunct to Insulin Therapy in Chinese Patients With Type 1 Diabetes: a Retrospective, Observational Study

To assess the real-world impact of glucose-lowering drugs (GLDs) as an adjunct to insulin in Chinese patients with type 1 diabetes (T1DM).

Does glucose-lowering drugs (GLDs) as an adjunct to insulin improve clinical outcomes in Chinese patients with type 1 diabetes (T1DM) when used long-term in real-world practice?

Study Overview

• Status: Not yet recruiting
• Conditions: Type 1 Diabetes Mellitus
• Intervention / Treatment: Drug: GLD+insulin group

• Study Type: Observational
• Enrollment (Estimated): 500

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

The study population consists of Chinese adult patients with type 1 diabetes mellitus (T1DM) who met the predefined eligibility criteria, enrolled from January 2013 to June 2024. The population is divided into two cohorts: the study cohort (T1DM patients who first used oral GLDs as adjuvant therapy to insulin) and the control cohort (T1DM patients who maintained insulin monotherapy). All participants had an HbA1c level of ≥ 7% at baseline, were ≥ 18 years old, had at least one recorded HbA1c value before treatment initiation, and maintained the required medication regimen for at least 3 months. Patients with DKA, severe comorbidities, stress hyperglycemia, or incomplete medical records were excluded. This study population is representative of real-world T1DM patients with poor long-term blood glucose control who require adjuvant GLDs or maintain insulin monotherapy, ensuring the external validity of the study results.

Description

Inclusion Criteria:

1. The research group consists of T1DM patients who first used oral hypoglycemic drugs from January 2013 to June 2024 and had a glycated hemoglobin level of >= 7%; The control group consisted of T1DM patients who maintained only insulin treatment regimen and had glycated hemoglobin >= 7%;
2. Age >= 18 years old;
3. At least one recorded HbA1c value before the start of treatment;
4. Maintain medication regimen as needed from baseline to at least 3 months;
5. Record the first glycated hemoglobin value after treatment.

Exclusion Criteria:

1. The patient had already used hypoglycemic drugs as an adjunct to insulin therapy before admission;
2. DKA、 Serious infection, perioperative status, severe trauma, pregnancy, patient's past or current involvement in interventional clinical research；
3. The standard for determining stress hyperglycemia by the supervising physician;
4. Patients who have no medication records or have not followed the treatment plan formulated by the doctor.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
GLD+insulin group; Patients with insulin and additional glucose-lowering drugs to treat type 1 diabetes were identified as adjuvant medication users (GLD+insulin group).	Drug: GLD+insulin group; The glucose-lowering drugs included in the analysis were metformin, acarbose and DPP-4i alone or in combination with other agents.
insulin-only group; Patients who did not use glucose-lowering drugs (GLDs) as an adjunct to treat type 1 diabetes in the datasets were identified as insulin-only users (insulin-only group)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
HbA1c	The primary outcome measure is glycated hemoglobin (HbA1c), which reflects the average blood glucose level of Chinese patients with type 1 diabetes mellitus (T1DM) over the past 2-3 months. HbA1c levels will be measured using a standardized clinical detection method at the baseline and follow-up visits of the study, to evaluate the long-term blood glucose control effect of insulin plus GLDs combined therapy compared with insulin monotherapy in real-world practice.	Baseline to 3 months, 6 months, 12 months

Secondary Outcome Measures

Outcome Measure	Time Frame
Absolute and relative insulin doses	Baseline to 3 months, 6 months, 12 months

Collaborators and Investigators

• Sponsor: Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: February 10, 2026
• First Submitted That Met QC Criteria: February 10, 2026
• First Posted (Actual): February 17, 2026

Study Record Updates

• Last Update Posted (Actual): February 17, 2026
• Last Update Submitted That Met QC Criteria: February 10, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Autoimmune Diseases; Immune System Diseases; Glucose Metabolism Disorders; Diabetes Mellitus; Nutritional and Metabolic Diseases; Diabetes Mellitus, Type 1
• Other Study ID Numbers: CCTR-2025C26