Alternate Measures of Glucose During OGTT Testing for CFRD

Children's Hospital of Philadelphia14 enrolled

Overview

Although early detection and treatment of cystic fibrosis-related diabetes (CFRD) can lead to significant clinical improvements and prolong life, rates of screening are poor likely due to the burdensome nature of oral glucose tolerance testing (OGTT). The investigators propose to assess the feasibility and accuracy of two screening tools, continuous glucose monitoring (CGM) and a home OGTT kit (GTT@home). If this pilot study reveals acceptable accuracy of either device, this study will allow for future studies exploring home-based OGTT screening.

The investigators hypothesize that there will be strong agreement between plasma glucose and glucose as measured by either CGM or GTT@home at three different timepoints during an OGTT: fasting, 1-hour, and 2-hours.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Cystic Fibrosis Cystic Fibrosis-related Diabetes

Interventions

Oral glucose tolerance testDIAGNOSTIC_TEST

An oral glucose tolerance test will be completed. A fasting glucose will be measured. Participants will drink 1.75 g/kg of dextrose (up to a maximum of 75 grams) within 10 minutes. Glucose values will be measured at 1 hour and 2 hours.

Eligibility

Sex: ALLMin age: 10 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Diagnosis of cystic fibrosis * ≥ 10 years of age * Fluency in written and spoken English as the GTT@Home is currently only available in English Exclusion Criteria: * Hospitalization or treatment with IV antibiotics or supraphysiologic glucocorticoids within 4 weeks * Major medical or psychiatric disorders other than CF * Use of medications known to impact the accuracy of the Dexcom G7 (hydroxyurea, \>2g acetaminophen per day) * History of severe adhesive reactions that may lead to an inability to tolerate CGM wear

Locations (1)

Children's Hospital of Philadelphia

Philadelphia, Pennsylvania, United States

Outcomes

Primary Outcomes

Agreement between plasma glucose, CGM measured glucose using the Dexcom G7, and GTT@home glucose

Differences in fasting glucose will be measured by the difference in mg/dl between plasma glucose, CGM measured glucose, and GTT@home measured glucose.

Time frame: Fasting glucose before OGTT

Agreement between plasma glucose, CGM measured glucose using the Dexcom G7, and GTT@home glucose

Differences in the 1 hour glucose during the OGTT will be measured by the difference in mg/dl between plasma glucose, CGM measured glucose, and GTT@home measured glucose.

Time frame: 1 hour mark in OGTT

Agreement between plasma glucose, CGM measured glucose using the Dexcom G7, and GTT@home glucose

Differences in the 2 hour glucose during the OGTT will be measured by the difference in mg/dl between plasma glucose, CGM measured glucose, and GTT@home measured glucose.

Time frame: 2 hour mark in OGTT

Secondary Outcomes

Agreement between the categorical diagnosis of normal glucose tolerance (NGT), impaired glucose tolerance (IGT), indeterminate glycemia (INDET), and CFRD as defined by plasma glucose, CGM glucose, and GTT@home glucose.

Categorical diagnosis of glucose tolerance as measured by plasma glucose, CGM measured glucose using the Dexcom G7, and GTT@home glucose.

Time frame: Up to 2 hours

Difference between plasma glucose and CGM measured glucose after the fasting glucose

Absolute differences between the glucose measurements will be measured in mg/dL

Time frame: Up to 20 minutes after the fasting glucose

Difference between plasma glucose and CGM measured glucose after the 1 hour mark during the OGTT.

Data from ClinicalTrials.gov

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