The Impact of Continuous Glucose Monitoring on Glucose Variability and Weight Loss in Individuals With Prediabetes and Obesity

NCT07423065 | Recruiting

• 1 other identifier: CGM
• Study Type: interventional
• Target: 34
• Locations: 1 country
• Sites: 3

Brief Summary

This randomized, crossover interventional study evaluates the effects of real-time (open) versus blinded continuous glucose monitoring (CGM) on glycemic variability, lifestyle behaviors, and metabolic outcomes in adults with prediabetes and overweight or obesity (BMI ≥ 27 kg/m²). Thirty participants will undergo both open and blinded CGM phases, separated by a washout period. The study aims to assess whether access to real-time glucose data promotes behavioral change and improves metabolic health compared with blinded CGM use.

Conditions

Pre Diabetic; Obesity & Overweight

Keywords

continuous glucose monitoring; obesity; prediabetes; behavior

Outcome Measures

Primary Outcomes (3)

• Change in Glycemic Variability Assessed by Coefficient of Variation from CGM

  Change in glucose coefficient of variation (CV%), calculated from CGM data, comparing open versus blinded CGM phases. Unit of Measure: Percentage (%)

  End of each 12-week CGM phase

• Postprandial Glucose Excursions Measured by CGM

  Mean postprandial glucose excursion (PPGE) following habitual meals, derived from CGM data. Unit of Measure: mmol/L

  End of each 12-week CGM phase

• Change in Mean Daily Energy Intake

  Change in mean daily caloric intake assessed using participant-completed food diaries. Unit of Measure: kcal/day

  End of each 12-week CGM phase

Secondary Outcomes (11)

• Change in Time in Tight Range (3.9-7.8 mmol/L) Measured by Continuous Glucose Monitoring

  End of each 12-week CGM phase

• Change in Glycemic Variability Assessed by Standard Deviation from CGM

  End of each 12-week CGM phase

• Change in Continuous Overall Net Glycemic Action (CONGA) from CGM

  End of each 12-week CGM phase

• Change in Glycemic Complexity Assessed by Entropy-Based Indices from CGM

  End of each 12-week CGM phase

• Postprandial Incremental Area Under the Curve (iAUC) Derived from CGM

  End of each 12-week CGM phase

Study Arms (2)

Open CGM

EXPERIMENTAL

Device: Continuous Glucose Monitoring (CGM)

Blinded CGM

EXPERIMENTAL

Device: Continuous Glucose Monitoring (CGM)

Interventions

Continuous Glucose Monitoring (CGM) DEVICE

Use of a continuous glucose monitoring system to measure interstitial glucose levels. During the open CGM phase, participants have real-time access to glucose data; during the blinded CGM phase, glucose data are masked from participants.

Blinded CGM; Open CGM

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults aged 18-70 years.
• BMI ≥ 27 kg/m² (overweight or obese).
• Prediabetes, confirmed by:
• Impaired fasting glucose (IFG: 5.6-6.9 mmol/L), and/or Impaired glucose tolerance (IGT: 2-hour OGTT glucose 7.8-11.0 mmol/L).
• Stable body weight (±3 kg) in the last 3 months.
• No current use of antidiabetic or weight-loss medications.
• Willingness and ability to wear a CGM device as instructed.
• Capacity to provide written informed consent.
• Recruitment from the Diabetes Outpatient Clinic, Community Health Center Koper (identified and invited from the clinic's database).

You may not qualify if:

• Diagnosis of type 1 or type 2 diabetes mellitus (fasting glucose ≥ 7.0 mmol/L or HbA1c ≥ 6.5%).
• Current or recent (within 3 months) use of:
• Any antidiabetic medication (insulin, metformin, GLP-1RA, SGLT2i, etc.), or anti-obesity pharmacotherapy.
• Pregnancy, breastfeeding, or planned pregnancy during the study period.
• Severe chronic disease that could influence glucose metabolism or study participation (e.g., chronic liver disease, renal failure, active malignancy).
• Endocrine disorders affecting metabolism (e.g., untreated thyroid disease, Cushing's syndrome).
• Severe psychiatric illness or cognitive impairment limiting adherence or comprehension.
• Use of medications known to affect glucose metabolism (e.g., corticosteroids, atypical antipsychotics).
• Implanted electronic medical devices (e.g., pacemaker, defibrillator) that may interfere with CGM function.
• Known allergy or skin reaction to CGM adhesives or device materials.
• Participation in another interventional study within the previous 3 months.

Sponsors & Collaborators

• University of Primorska: lead
• Diabetes Outpatient Clinic, Community Health Center Koper, Slovenia: collaborator
• University Medical Centre Ljubljana: collaborator

Study Sites (3)

University of Primorska, Faculty of Health Sciences

Izola, 6310, Slovenia

RECRUITING

Diabetes Outpatient Clinic, Community Health Center Koper, Slovenia

Koper, 6000, Slovenia

RECRUITING

Department Of endocrinology and diabetes, Medical Faculty, University of Ljubljana

Ljubljana, 1000, Slovenia

RECRUITING

MeSH Terms

Conditions

Glucose Intolerance; Obesity; Overweight; Prediabetic State; Behavior

Interventions

Continuous Glucose Monitoring

Condition Hierarchy (Ancestors)

Hyperglycemia; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Overnutrition; Nutrition Disorders; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Diabetes Mellitus; Endocrine System Diseases

Intervention Hierarchy (Ancestors)

Blood Chemical Analysis; Clinical Chemistry Tests; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Techniques, Endocrine; Monitoring, Physiologic; Investigative Techniques

Study Officials

• Ajda Urbas, MD

  Diabetes Outpatient Clinic, Community Health Center Koper, Slovenia

  PRINCIPAL INVESTIGATOR

• Mojca Jensterle Sever, PhD

  University Medical Centre Ljubljana, Department Of endocrinology and diabetes, Medical Faculty, University of Ljubljana

  STUDY CHAIR

• Zala Jenko Pražnikar, PhD

  University of Primorska, Faculty of Health Sciences

  STUDY CHAIR

Central Study Contacts

Ajda Urbas, medical doctor

CONTACT

0038631626966; ajda.urbas@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assoc. Prof.

Study Record Dates

• First Submitted: January 26, 2026
• First Posted: February 20, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): September 1, 2027
• Last Updated: April 28, 2026

Record last verified: 2026-04

Locations

SL (3)