GEM: Glycemic Monitoring in Cystic Fibrosis

Sponsor

University of Colorado, Denver (Other)

Overall Status

Completed

CT.gov ID

NCT02211235

Collaborator

(none)

146

Enrollment

Location

45.5

Duration (Months)

3.2

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Current guidelines on the diagnoses and management of cystic fibrosis (CF) related diabetes recommend treatment for diabetes based on diagnostic criteria derived from adults with type 2 diabetes. Increasing evidence supports treating early glucose abnormalities in cystic fibrosis patients to target CF specific outcomes, including lung function and nutrition (BMI-Body Mass Index). However, the criteria and timing of when to start insulin therapy in the 'prediabetic' state are unclear. A more accurate characterization of blood sugar variability in youth with and without CF will help the investigators better interpret continuous glucose monitor (CGM) findings in patients with CF prediabetes and diabetes and more accurately identify those individuals at greatest risk for disease progression.

Condition or Disease	Intervention/Treatment	Phase
Cystic Fibrosis

Study Design

Study Type:

Observational

Actual Enrollment :

146 participants

Observational Model:

Case-Control

Time Perspective:

Prospective

Official Title:

Characterization of Glucose Variability by Continuous Glucose Monitoring in Non-diabetic Youth With and Without Cystic Fibrosis

Study Start Date :

Aug 1, 2014

Actual Primary Completion Date :

May 16, 2018

Actual Study Completion Date :

May 16, 2018

Outcome Measures

Primary Outcome Measures

The percentage of time spent > 140 mg/dl on CGM [7 days]
Percentage of time above normal glucose cut-point.

Secondary Outcome Measures

The percentage of time spent > 120 mg/dl on CGM [7 days]
Measures of glucose variability on CGM
The percentage of time spent > 200 mg/dl on CGM [7 days]
Measures of glucose variability on CGM
The percentage of time spent < 70 mg/dl on CGM [7 days]
Measures of glucose variability on CGM
The percentage of time spent < 60 mg/dl on CGM [7 days]
Measures of glucose variability on CGM
The number of excursions > 200mg/dl in 24 hours for one week [7 days]
Measures of glucose variability including peak glucose, mean glucose and measures of glucose variability on CGM.

Other Outcome Measures

Change in CGM variables and BMI [3 years]
To analyze in youth with CF the relationship between CGM variables and BMI Primary outcome: Change in BMI z-score collected at routine clinical visits over the preceding three years
Change in CGM variables and lung function [3 years]
To analyze in youth with CF the relationship between CGM variables and lung function change in the preceding three years Secondary outcome: Change in forced expiratory volume at one second (FEV1) and forced vital capacity (FVC) measures collected at routine clinical visits over the preceding three years
Characterize the relationships between markers of glycemia [3 days]
To characterize the relationships between alternative markers of glycemia (fructosamine, glycated albumin, and 1,5-anhydroglucitol) and CGM variables in non-diabetic CF youth and healthy controls

Eligibility Criteria

Criteria

Ages Eligible for Study:

6 Years to 25 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Healthy controls (n=45) -

Age 10-25 years
BMI <85th percentile
Baseline health at enrollment

CF controls (n=45) -

Age 10-25 years
Diagnosis of cystic fibrosis (by newborn screen, sweat chloride testing, or genetic testing)
Baseline health at enrollment (no inclusion/exclusion criteria for CF patients based on lung function, BMI, pancreatic insufficiency, or genotype)

CF prediabetes & CFRD (n=70)

Age 10-25 years
Diagnosis of cystic fibrosis (by newborn screen, sweat chloride testing, or genetic testing)
History of abnormal oral glucose tolerance testing (2h-glucose >140, fasting plasma glucose >100,1hr glucose >200)
If taking medication that affects glucose metabolism (ex. Insulin, insulin sensitizers, glucocorticoids, atypical antipsychotics), should be on a stable dose over the past 3 months

Exclusion Criteria:

Healthy controls -

Known diagnosis of diabetes or prediabetes (including type 1, type 2, MODY), abnormal oral glucose tolerance test (OGTT) (ie. fasting plasma glucose ≥100 or 2hr ≥140 mg/dl) or HbA1c ≥ 5.7%
BMI ≥85th percentile
Chronic disease that may affect glucose metabolism or use of medications affecting glucose metabolism in the past 3 months (ex. Insulin, insulin sensitizers, glucocorticoids, atypical antipsychotics)
Presence of type 1 diabetes auto-antibodies in any individuals with a first degree relative with type 1 diabetes (will only include first degree relatives if they have had previous negative auto-antibody screening performed as part of participation in other studies such as the Trial Net studies at the Barbara Davis Center)
Acute illness (ex. Asthma exacerbation, gastroenteritis, febrile illness)
Pregnancy

CF participants -

Diagnosis of type 1 diabetes, type 2 diabetes, or MODY
Varying doses of medication affecting glucose metabolism in the past 3 months
Pulmonary exacerbation associated with hospitalization, or systemic steroid requirement in the preceding 6 weeks
Pregnancy