OGTT at Home Using CGM vs at the Clinic

NCT ID: NCT06862128

Last Updated: 2025-09-24

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 75 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-06-11
• Study Completion Date: 2040-12-31

Brief Summary

This randomized, crossover study evaluates the feasibility and accuracy of a self-administered oral glucose tolerance test (OGTT) at home using continuous glucose monitoring (CGM) compared to a standard clinic-based OGTT. Participants with prediabetes will undergo both home-based and clinic-based OGTTs, with glucose levels measured via CGM and venous plasma glucose. The primary outcome is the correlation between CGM-based glucose values and standard OGTT results. Secondary outcomes include diagnostic agreement, metabolic hormone associations, and feasibility of home-based testing as a diagnostic tool for dysglycemia.

Detailed Description

This study aims to evaluate the feasibility, accuracy, and diagnostic utility of a self-administered oral glucose tolerance test (OGTT) at home using continuous glucose monitoring (CGM) compared to a standard clinic-based OGTT.

Study Design Type: Randomized, crossover study Participants: 75 adults with prediabetes Intervention: Each participant will complete both a home-based OGTT with CGM and a clinic-based OGTT with venous plasma glucose measurement.

Primary Objective To assess the correlation between glucose values obtained from a CGM-based home OGTT and a standard venous OGTT performed in the clinic.

Secondary Objectives Evaluate diagnostic agreement between CGM-derived and venous glucose measurements.

Assess variability in glucose responses between the two methods. Investigate associations between OGTT results and metabolic/sex hormones. Determine feasibility and patient adherence to home-based testing.

Methods Participants will be randomized into two groups: one starting with a clinic-based OGTT, the other with a home-based OGTT, followed by a crossover period. CGM will continuously monitor glucose responses, and standard venous plasma glucose measurements will serve as the reference method.

Clinical Relevance A validated home-based OGTT using CGM could improve access to glucose tolerance testing, reduce patient burden, and enhance early detection of dysglycemia.

Conditions

Pre-diabetes; Diabetes

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: DIAGNOSTIC
• Blinding Strategy: NONE

Study Groups

OGTT at the clinic then at home

OGTT at the clinic then at home

Group Type: EXPERIMENTAL

OGTT at home using CGM

Intervention Type: DIAGNOSTIC_TEST

OGTT at home using CGM

OGTT at the clinic

Intervention Type: DIAGNOSTIC_TEST

OGTT at the clinic

OGTT at home then at the clinic

OGTT at home then at the clinic

Group Type: EXPERIMENTAL

OGTT at home using CGM

Intervention Type: DIAGNOSTIC_TEST

OGTT at home using CGM

OGTT at the clinic

Intervention Type: DIAGNOSTIC_TEST

OGTT at the clinic

Interventions

OGTT at home using CGM

OGTT at home using CGM

Intervention Type: DIAGNOSTIC_TEST

OGTT at the clinic

OGTT at the clinic

Intervention Type: DIAGNOSTIC_TEST

Other Intervention Names

OGTT-home; OGTT-clinic

Eligibility Criteria

Inclusion Criteria

• Prediabetes indicated by ≥2 of the following values, measured at separate occasions or through different analyses during the past 2 years:
• - Fasting venous plasma glucose ≥6.1 but ≤6.9 mmol/L
• - Non-fasting venous plasma glucose ≥7.8 but ≤11.0 mmol/L
• - HbA1c ≥39 but ≤47 mmol/mol
• Access to a smart phone which is compatible with the CGM application and has working Bluetooth connectivity
• Ability to read and respond to online instructions and questionnaires in Swedish.

Exclusion Criteria

• T2D indicated by ≥2 of the following values, measured at different occasions or through different analyses:
• - Fasting venous plasma glucose ≥7.0 mmol/L
• - Non-fasting venous plasma glucose value ≥11.1 mmol/L
• - HbA1c ≥48 mmol/mol
• Previous bariatric surgery e.g., gastric by-pass or gastric sleeve surgery
• Body mass index <20 kg/m2
• Body weight <43 kg
• Current pregnancy
• Need of regular use of GLP-1 receptor agonists, SGLT-2 inhibitors, acetaminophen or ascorbic acid supplements during the study period
• Fear of needle sticks
• Shift work during the study period
• Involvement in the study design, data collection, analysis, or participant recruitment.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Region Jönköping County

OTHER_GOV

Sponsor Role: collaborator

Region Östergötland

OTHER

Sponsor Role: collaborator

Linkoeping University

OTHER_GOV

Sponsor Role: lead

Responsible Party

Peder af Geijerstam

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Peder af Geijerstam, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Linkoeping University

Locations

Primary Health Care Center Bra Liv Rosenhälsan

Huskvarna, Jönköping County, Sweden

Site Status: RECRUITING

Primary Health Care Center Cityhälsan Centrum

Norrköping, Norrköping, Sweden

Site Status: RECRUITING

Primary Care Center Vårdcentralen Kärna

Linköping, Östergötland County, Sweden

Site Status: RECRUITING

Countries

Sweden

Central Contacts

Peder af Geijerstam, MD, PhD

Role: CONTACT

peder.af.geijerstam@liu.se

+46739597426

Facility Contacts

Maria Samefors, MD, PhD

Role: primary

maria.samefors@liu.se

+46102423550

Peder af Geijerstam, MD, PhD

Role: primary

peder.af.geijerstam@liu.se

+46101059140

Karin Rådholm, MD, PhD

Role: primary

karin.radholm@liu.se

+4613281756

Other Identifiers

ogtt_cgm

Identifier Type: -

Identifier Source: org_study_id