Capillary OGTT Study

Recruiting

• Conditions: Type 1 Diabetes (T1D)

• Registration Number: NCT06815081
• Lead Sponsor: University of Oxford

Brief Summary

Type 1 diabetes (T1D) is a chronic condition, affecting 1 in 490 children under the age of 15 years. It is caused by the immune system damaging the pancreas, the organ which makes insulin. T1D has recognised stages before symptoms develop, providing an opportunity for early diagnosis, education and treatment which may delay the onset of symptoms. Early diagnosis often relies on a test called the oral glucose tolerance test (OGTT), which is commonly used but not well tolerated, possibly because it requires a drip inserted into the vein, and several blood samples taken over 2-3 hours in a healthcare setting.

This study aims to test whether an OGTT using a finger-prick to test glucose, can be done at home. This is the 'GTT@home'. The finger-prick creates a drop of blood, which is done before and two hours after drinking a sugary drink. Investigators will also explore whether a continuous glucose monitor (CGM), which reads glucose levels through the skin could be an alternative. The investigators plan to recruit 90 children and young people, across two groups to assess the GTT@home.

To understand the experiences of those involved in monitoring, the investigators will invite young people, parents and healthcare workers to take part in an interview, to understand the impact of testing to predict clinical T1D.

Group 1 will assess the accuracy of measuring glucose from a finger-prick blood test when compared to a blood test from the vein. The investigators will recruit individuals who are having an OGTT as part of a research study, for clinical care, or if individuals have agreed to have an OGTT for this study. Those with T1D will be invited to wear a CGM to explore its use as an additional, practical alternative.

Group 2 will assess how well the GTT@home test works when done at home and how acceptable it is. This will only be offered to those known to be at risk of T1D.

These studies will help investigators to understand if the GTT@home can be used in routine care.

Detailed Description

Not available

Study Timeline

• Study Start: 2024-02-29
• Status Verified: 2024-12
• Study First Submitted: 2025-01-27
• Study First Submitted QC: 2025-02-04
• Last Update Submitted: 2025-02-04
• Study First Posted: 2025-02-07
• Last Update Posted: 2025-02-07
• Primary Completion: 2025-08-31
• Study Completion: 2025-08-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 90

Inclusion Criteria

Not provided

Exclusion Criteria

Cohort 1

• Any known haemoglobinopathy
• Cystic fibrosis related diabetes
• Non-English speaker

Cohort 2

• Any known haemoglobinopathy
• Known clinical diabetes and on treatment
• Non-English speaker
• No recent weight available (within 3 months of study visit) and unable to obtain new weight measurement

CGM sub-study

• Any known haemoglobinopathy
• Cystic fibrosis related diabetes
• Non-English speaker
• Any active skin issue which would prevent the use of a CGM device

Qualitative sub-study

• Non-English speaker

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
To determine the agreement of capillary blood glucose levels to venous blood glucose levels during a standard OGTT	From enrolment to end of study visit on day 1.	Agreement between capillary and blood glucose measures.
To assess the feasibility of using the capillary OGTT device in the home environment	From enrolment to end of study visit on day 1	1. Proportion of successful glucose readings at 0, 120 minutes; 2. Proportion of errors/missing glucose readings; 3. Proportion of adverse events

Secondary Outcome Measures

Name	Time	Method
To determine the diagnostic accuracy of capillary blood glucose levels at diagnostic thresholds	From enrolment to end of study visit on day 1.	Sensitivity and specificity of capillary glucose at 5.6mmol/L, 7.0mmol/L (fasting), 11.1 mmol/L (60 min), and 7.8mmol/L and 11.1mmol/L (120 min).
Assess the acceptability of the capillary OGTT device	From enrolment to end of study visit on day 1.	Acceptability by questionnaire (Parent +/- child), using either a standard 7-point Likert scale (1 - not painful at all, 7 - very painful) for participants aged 16 and above, or Wong Baker Faces pain scale (0 - no hurt, 10 - hurts worst) for participants aged under 16.
To assess the in-depth experience of participants attending study visits involving a metabolic test or assessment	From enrolment to end of study visit on day 1	Analysis of qualitative interviews from young people.
To assess the in-depth experience of parents attending study visits with their child involving a metabolic test or assessment	From enrolment to end of study visit on day 1.	Analysis of qualitative interviews from parents.
To assess the in-depth views of healthcare professionals involved in the delivery of a metabolic test or assessment of a child	From enrolment to end of study visit on day 1.	Analysis of qualitative interviews from healthcare professionals.

Trial Locations

Locations (4)

Noah's Ark Childrens Hospital for Wales; 🇬🇧 Cardiff, United Kingdom

Royal London Barts Health NHS Trust; 🇬🇧 London, United Kingdom

Nottingham Childrens Hospital; 🇬🇧 Nottingham, United Kingdom

John Radcliffe Hospital; 🇬🇧 Oxford, United Kingdom