Clinical trial NCT05568134: Alternate Measures of Glucose During OGTT Testing for CFRD
Official title: Correlations Between CGM and Serum Glucose During OGTT Testing for CFRD
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Cystic Fibrosis
Cystic Fibrosis-related Diabetes
Keywords: continuous glucose monitor
oral glucose tolerance test
Lead sponsor: Children's Hospital of Philadelphia
Sponsor class: OTHER
Collaborators: name: Cystic Fibrosis Foundation
First posted: 2022-10-05
Enrollment: 14
Sex: ALL
Minimum age (years): 10
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: A total of 15 subjects with cystic fibrosis (CF) over 10 years of age will be approached to participate.

Brief summary: 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.

Detailed description: 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.

Eligibility criteria: 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

Primary outcomes:
measure: Agreement between plasma glucose, CGM measured glucose using the Dexcom G7, and GTT@home glucose
timeFrame: Fasting glucose before OGTT
measure: Agreement between plasma glucose, CGM measured glucose using the Dexcom G7, and GTT@home glucose
timeFrame: 1 hour mark in OGTT
measure: Agreement between plasma glucose, CGM measured glucose using the Dexcom G7, and GTT@home glucose
timeFrame: 2 hour mark in OGTT
Secondary outcomes:
measure: 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.
timeFrame: Up to 2 hours
measure: Difference between plasma glucose and CGM measured glucose after the fasting glucose
timeFrame: Up to 20 minutes after the fasting glucose
measure: Difference between plasma glucose and CGM measured glucose after the 1 hour mark during the OGTT.
timeFrame: Up to 20 minutes after the 1 hour mark in the OGTT
measure: Difference between plasma glucose and CGM measured glucose after the 2 hour mark during the OGTT.
timeFrame: Up to 20 minutes after the 2 hour mark in the OGTT
measure: The ability of untrained participants to successfully complete the GTT@home kit without any guidance from the research team
timeFrame: Up to 2 hours
measure: Impact of wearing a real-time CGM on participants' awareness of the importance of screening for and diagnosing CFRD.
timeFrame: Within 2 weeks after removal of the CGM
measure: Perceived benefits and burdens of CGM use
timeFrame: Within 2 weeks after removal of the CGM
Other outcomes:
Locations:
city: Philadelphia
country: United States
facility: Children's Hospital of Philadelphia
state: Pennsylvania
Study officials:
References: