A Study on the Effect of CGM Alone on Glycemic Metrics in Type 2 Diabetes Patients Not Using Insulin, Without Additional Interventions

This study evaluates the effect of using a real-time continuous glucose monitoring (CGM) system on blood sugar control in people with type 2 diabetes who do not use insulin.

Participants will wear a CGM device (CareSens Air) for a total of two weeks. During the first week, the device will be set to "blinded mode," meaning participants cannot see their glucose readings. During the second week, the device will be switched to "unblinded mode," allowing participants to view their glucose levels and trends in real-time.

The study aims to determine if simply seeing real-time glucose data can help patients improve their blood sugar control (such as increasing the time their blood sugar is in the target range) without receiving additional structured education on diet or exercise. Researchers will compare the glucose data collected during the blinded week with the data from the unblinded week.

Study Overview

• Status: Active, not recruiting
• Conditions: Type 2 Diabetes; Continuous Glucose Monitoring
• Intervention / Treatment: Device: Continuous glucose monitoring

• Study Type: Interventional
• Enrollment (Actual): 120
• Phase: Not Applicable

Contacts and Locations

Study Locations

• South Korea
  • Jongro-Ku
    • Seoul, Jongro-Ku, South Korea, 03181
      • Kangbuk Samsung Hospital

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Patients with Type 2 Diabetes Mellitus (HbA1c ≥ 6.5%, fasting plasma glucose ≥ 126 mg/dL, 2-hour plasma glucose ≥ 200 mg/dL during 75g OGTT, or random plasma glucose ≥ 200 mg/dL with classic symptoms)
2. No medication changes in the past 3 months, and receiving treatment with lifestyle modification or oral antidiabetic drugs or GLP-1 receptor agonists
3. Ages 19 - 80 years old
4. Patients who have voluntarily signed the informed consent form

Exclusion Criteria:

1. Type 1 diabetes patients
2. Insulin users
3. Patients who have changed oral hypoglycemic agents within the past 3 months
4. Patients scheduled for hospitalization within 2 weeks
5. Pregnant women or those planning pregnancy within 1 month
6. Those who do not agree to the program
7. Those deemed unsuitable for participation in this clinical trial by the investigator

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Experimental: Sequential CGM Application (Blinded followed by Unblinded); Single arm consisting of adults with non-insulin-treated type 2 diabetes. All participants undergo a 2-week prospective observation using a real-time CGM device (CareSens Air), transitioning from a blinded baseline period to an unblinded intervention period to evaluate glycemic changes.

Device: Continuous glucose monitoring; All participants are adults with non-insulin-treated type 2 diabetes. Participants will wear a real-time continuous glucose monitoring (rt-CGM) device (CareSens Air) for a total of two weeks. The intervention consists of two consecutive phases: Week 1 (Blinded Mode): Participants wear the CGM but cannot view their glucose readings. This period establishes baseline glycemic data.; Week 2 (Unblinded Mode): The same CGM session continues, but the mode is switched to "unblinded." Participants can view their real-time glucose levels and trend arrows. Throughout the study, no additional structured education (e.g., diet or exercise coaching) or medication adjustments by the investigators are provided. The study evaluates the effect of data visibility alone on glycemic metrics.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Percentage of Time in Range (TIR) 70-180 mg/dL From Week 1 (Blinded) to Week 2 (Unblinded)	Percentage of time glucose readings are within the target range of 70-180 mg/dL.	Week 1 and Week 2

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Percentage of Time in Tight Range (TITR) 70-140 mg/dL From Week 1 (Blinded) to Week 2 (Unblinded)	Percentage of time glucose readings are within the tight target range of 70-140 mg/dL.	Week 1 and Week 2
Change in Percentage of Time Below Range (TBR) <70 mg/dL From Week 1 (Blinded) to Week 2 (Unblinded)	Percentage of time glucose readings are below 70 mg/dL, indicating hypoglycemia.	Week 1 and Week 2
Change in Percentage of Time Below Range (TBR) <54 mg/dL From Week 1 (Blinded) to Week 2 (Unblinded)	Percentage of time glucose readings are below 54 mg/dL, indicating clinically significant hypoglycemia.	Week 1 and Week 2
Change in Percentage of Time Above Range (TAR) >140 mg/dL From Week 1 (Blinded) to Week 2 (Unblinded)	Percentage of time glucose readings are above 140 mg/dL. This metric assesses exposure to hyperglycemia, including mild elevations.	Week 1 and Week 2
Change in Percentage of Time Above Range (TAR) >180 mg/dL From Week 1 (Blinded) to Week 2 (Unblinded)	Percentage of time glucose readings are above 180 mg/dL, indicating hyperglycemia.	Week 1 and Week 2
Change in Percentage of Time Above Range (TAR) >250 mg/dL From Week 1 (Blinded) to Week 2 (Unblinded)	Percentage of time glucose readings are above 250 mg/dL, indicating severe hyperglycemia.	Week 1 and Week 2
Change in Mean Glucose Concentration From Week 1 (Blinded) to Week 2 (Unblinded)	Average glucose concentration (mg/dL) measured by the CGM device.	Week 1 and Week 2
Change in Glucose Standard Deviation (SD) From Week 1 (Blinded) to Week 2 (Unblinded)	Standard Deviation (SD) of glucose readings, measuring glycemic variability.	Week 1 and Week 2
Change in Glucose Coefficient of Variation (CV) From Week 1 (Blinded) to Week 2 (Unblinded)	Coefficient of Variation (CV) calculated as (SD / Mean Glucose) * 100, measuring glycemic variability.	Week 1 and Week 2
Change in Glucose Management Indicator (GMI) From Week 1 (Blinded) to Week 2 (Unblinded)	GMI is an estimated HbA1c level calculated from the mean glucose concentration derived from CGM data.	Week 1 and Week 2

Collaborators and Investigators

• Sponsor: Kangbuk Samsung Hospital
• Collaborators: i-SENS, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): September 30, 2024
• Primary Completion (Actual): July 30, 2025
• Study Completion (Estimated): December 1, 2025

Study Registration Dates

• First Submitted: December 5, 2025
• First Submitted That Met QC Criteria: December 20, 2025
• First Posted (Actual): December 23, 2025

Study Record Updates

• Last Update Posted (Actual): December 23, 2025
• Last Update Submitted That Met QC Criteria: December 20, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Type 2 diabetes; Continuous glucose monitoring; Non-insulin Treated Type 2 Diabetes
• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Glucose Metabolism Disorders; Diabetes Mellitus; Nutritional and Metabolic Diseases; Diabetes Mellitus, Type 2; Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Blood Chemical Analysis; Clinical Chemistry Tests; Diagnostic Techniques, Endocrine; Monitoring, Physiologic; Continuous Glucose Monitoring
• Other Study ID Numbers: KBSMC 2024-06-042

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No