Overview

The goal of this clinical trial is to test whether wearing a continuous glucose monitor (CGM) part-time works as well as wearing it full-time in adults with type 2 diabetes who do not use insulin. The main questions it aims to answer are:

• Does wearing CGM part-time (2 weeks per month) control blood sugar as well as wearing it continuously?
• How do the two wearing patterns compare for blood sugar levels throughout the day, weight, blood pressure, and patient satisfaction?

Researchers will compare part-time CGM use to continuous CGM use to see if part-time use is just as effective for blood sugar control.

All participants will:

• Wear a CGM device continuously for 3 months to learn how their blood sugar responds to different foods and activities
• Then be randomly assigned to wear CGM either part-time (2 weeks each month) or continuously for another 3 months
• Replace the CGM sensor on their arm every 2 weeks
• Use a smartphone app to track their blood sugar readings
• Visit the clinic 3 times for blood tests and check-ups
• Receive education on adjusting diet based on their CGM readings
• Keep their current diabetes medications unchanged during the study

The study will last about 6 months total. Participants will use the FreeStyle Libre 2 CGM device, which is already approved for use in people with diabetes.

Eligibility

Inclusion Criteria:

• Adults aged 19 to 80 years at the time of informed consent
• Adults with type 2 diabetes not using insulin
• Patients treated with GLP-1 agonist, oral hypoglycemic agents, and/or lifestyle modifications
• Patients who have maintained stable diabetes treatment for at least 3 months without changes
• HbA1c between 7.5% and 10.0%
• Willing to wear personal continuous glucose monitoring device (CGM)
• Willing to install and use CGM-linked app on personal smartphone with continuous access to WIFI or cellular data
• Able to read and write Korean as judged by investigator
• Willing to use medically acceptable contraception until end of study (sterile status, intrauterine device, or concurrent use of male/female barrier method with spermicide)
• Fully informed about the clinical trial and voluntarily consenting to participate

Exclusion Criteria:

• Type 1 diabetes mellitus
• Gestational diabetes mellitus
• History of pancreatectomy
• Continuous or intermittent insulin therapy for 7 days or more within 3 months
• Oral or IV steroid treatment within 1 month prior to informed consent
• Serious infection, surgery (scheduled or history), or severe trauma within 3 months prior to informed consent
• History of malignancy within 1 year prior to informed consent (except thyroid cancer)
• On hemodialysis or peritoneal dialysis or eGFR \< 30 mL/min/1.73m2
• Unable to avoid the following concomitant medications, devices, or treatments during the study: CGM other than study device, X-ray/MRI/CT scans, radiofrequency thermal therapy, implantable devices such as pacemakers, immunosuppressants, steroids, IV vitamin preparations, cancer treatment, hemodialysis/peritoneal dialysis, insulin therapy
• Uncontrolled thyroid disease or clinically significant severe endocrine disorders (Cushing's syndrome, pheochromocytoma, etc.)
• Severe allergic reaction to skin adhesives (e.g., dyspnea, severe rash, edema)
• Whole blood donation within 60 days, apheresis within 30 days, or blood transfusion within 90 days prior to device application
• Judged by investigator as unable to handle continuous glucose monitoring device
• Pregnant or lactating women
• Planning pregnancy within 1 year
• Otherwise judged by investigator as inappropriate for participation in this clinical trial