Cystic Fibrosis, Cystic Fibrosis-related Diabetes
Conditions
Keywords
continuous glucose monitor, oral glucose tolerance test
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.
Interventions
DIAGNOSTIC_TESTOral glucose tolerance 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.
Sponsors
Cystic Fibrosis Foundation
Children's Hospital of Philadelphia
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
10 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Agreement between plasma glucose, CGM measured glucose using the Dexcom G7, and GTT@home glucose | Fasting glucose before OGTT | Differences in fasting glucose will be measured by the difference in mg/dl between plasma glucose, CGM measured glucose, and GTT@home measured glucose. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Difference between plasma glucose and CGM measured glucose after the fasting glucose | Up to 20 minutes after the fasting glucose | Absolute differences between the glucose measurements will be measured in mg/dL |
| Difference between plasma glucose and CGM measured glucose after the 1 hour mark during the OGTT. | Up to 20 minutes after the 1 hour mark in the OGTT | Absolute differences between the glucose measurements will be measured in mg/dL |
| Difference between plasma glucose and CGM measured glucose after the 2 hour mark during the OGTT. | Up to 20 minutes after the 2 hour mark in the OGTT | Absolute differences between the glucose measurements will be measured in mg/dL |
| 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. | Up to 2 hours | Categorical diagnosis of glucose tolerance as measured by plasma glucose, CGM measured glucose using the Dexcom G7, and GTT@home glucose. |
| Impact of wearing a real-time CGM on participants' awareness of the importance of screening for and diagnosing CFRD. | Within 2 weeks after removal of the CGM | 60 minute semi-structured interviews will be conducted with participants. Transcripts will be analyzed using semantic content analysis |
| Perceived benefits and burdens of CGM use | Within 2 weeks after removal of the CGM | Participants will complete a CGM Benefits and Burdens survey, a 16-item measure used to assess perceptions of CGM technology in people with type 1 diabetes. Surveys may be completed on paper or online, as per the participant's preference. The survey is scored on a 5-point scale (agree/disagree scale). |
| The ability of untrained participants to successfully complete the GTT@home kit without any guidance from the research team | Up to 2 hours | Number of steps successfully completed as measured by the GTT@home instruction manual. |
Countries
United States
Outcome results
None listed