Glucose Tolerance in Children With Cystic Fibrosis (GluTolCF)

Glucose Tolerance and Its Clinical Impact in Children and Adolescents With Cystic Fibrosis

The aim is to describe the association of glucose tolerance measured with three different tools (continuous glucose measurement system - CGMS, oral glucose tolerance testing - OGTT and optional intravenous glucose tolerance testing -IVGTT) with parameters out of lung function and anthropometric parameters in patients with cystic fibrosis.

Study Overview

• Status: Completed
• Conditions: Glucose Intolerance; Cystic Fibrosis
• Intervention / Treatment: Other: Diagnostics for glucose tolerance with 3 different methods.

Detailed Description

Patients with cystic fibrosis (CF) with progressing disease are developing a glucose tolerance which resembles the metabolic state of a diabetic patient because of increasing impairment of endocrine pancreatic function. The prevalence of this diabetic metabolic state is increasing with age, reaching around 20% at the age of 20 years.

Over the last decade, research has already highlighted the negative influence of cystic fibrosis related diabetes (CFRD) on morbidity and mortality after the diagnosis of this condition.

As the deterioration in nutritional status and lung function can already be noticed 2-6 years before the onset of CFRD, the importance of early diagnosis in glucose abnormalities and its treatment therefore is crucial.

The currently used method to evaluate altered glucose metabolism in patients with CF is an annual oral glucose tolerance test (OGTT) with the glucose value after 120 min after oral ingestion of glucose-fluid as reference. This method may detect CFRD much later than we see deterioration of lung function and weight loss. This deterioration and the mortality in CF is related to CFRD.

An alternative diagnostic tool that has gained increasing attention and that is already routinely used in pediatric patients with diabetes mellitus type I is the continuous glucose monitoring system (CGMS) which was shown to be much more sensitive in detecting glucose abnormalities. To assess pancreatic endocrine dysfunction - the pathophysiologic cause for glucose intolerance - intravenous glucose tolerance testing (IVGTT) is the gold standard.

The investigator's aim is to describe the association of glucose tolerance measured with three different tools/assessment procedures (CGMS, OGTT and optional IVGTT) with lung function and anthropometric parameters.

• Study Type: Observational
• Enrollment (Actual): 14

Contacts and Locations

Study Locations

• Switzerland
  • Basel, Switzerland, 4056
    • University childrens hospital Basel, UKBB

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 10 years to 20 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients with genetically determined cystic fibrosis.

Description

Inclusion Criteria:

• Patients with confirmed cystic fibrosis aged between 10-20 years, under medical treatment at the University Children's Hospital Basel UKBB and at the University Children's Hospital, Inselspital Bern

Exclusion Criteria:

• Patients being under medical treatment with systemically administered glucocorticoid drugs or intravenously administered antibiotic treatment within 6 weeks before glucose tolerance testing.
• Patients with acute pulmonary exacerbation, defined by a pediatric pneumologist

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients with Cystic Fibrosis; Patients between 10-20 years of age with genetically determined cystic fibrosis followed at the university children's hospital Basel and university children's hospital Kinderklinik Bern, Switzerland. All patients will get the diagnostics for glucose tolerance with 3 different methods (CGMS, OGTT and optionally IVGTT).	Other: Diagnostics for glucose tolerance with 3 different methods.; A 7-day course of subcutaneous continuous glucose monitoring system (CGMS).; An oral glucose tolerance test done within the 7 day period of CGMS.; Optionally a intravenous glucose tolerance test done within the 7 day period of CGMS.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
% time spent above 8mmol/l, the area under the curve and the mean glucose value (in mmol/l)	These measurements will be gained out of the 7 day CGMS-course (continuous glucose monitoring system).	Beginning at day 1, lasting 7 days
The glucose values given in mmol/l after 30', 60', 90' and 120 minutes during OGTT.	Standard oral glucose tolerance test.	Within the 7 day course of CGMS
First phase insulin secretion and second phase insulin secretion out of IVGTT (intravenous glucose tolerance test).	Standard intravenous glucose tolerance test.	Within the 7 day course of CGMS
FEV1% (forced expiratory volume at one second) out of the lung function testing		Within 3 months of the 7 day course of CGMS
Lung clearance index		Within 3 months of the 7 day course of CGMS
BMI-SDS (standard deviation score).		At day 1 of the CGMS course
HbA1c		Within the 7 day course of CGMS

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Comparing the performance between CGMS and OGTT related to clinical parameters.	The investigators compare the fit of a linear regression between the % time above 8mmol/l (out of CGMS) and the lung clearance index (LCI) with the fit of a linear regression of the 120min glucose value (out of OGTT) and the LCI. The same analysis will be performed comparing the fit of a regression between the % time above 8mmol/l (out of CGMS) and the FEV1% (out of lung function) with the fit of a linear regression of the 120min glucose value (out of OGTT) and the FEV1%. Finally, the same analysis will be performed comparing the fit of a linear regression using the % time above 8mmol/l (out of CGMS) and the BMI-SDS with the fit of a linear regression of the 120min glucose value (out of OGTT) and the BMI-SDS.	7 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Characterising glucose profiles over 24 hours	The investigators will describe computer-based modelling of the glucose curves obtained with the CGMS, aiming to describe inter-/ and intraindividual variability in the profiles.	7 days

Collaborators and Investigators

• Sponsor: Christoph Saner
• Collaborators: University Hospital Inselspital, Berne
• Investigators: Principal Investigator: Christoph Saner, MD, University childrens Hospital, UKBB, Basel Switzerland; Study Director: Urs Zumsteg, Prof, University childrens Hospital, UKBB, Basel Switzerland

Study record dates

Study Major Dates

• Study Start: June 1, 2015
• Primary Completion (Actual): November 18, 2016
• Study Completion (Actual): November 18, 2016

Study Registration Dates

• First Submitted: August 12, 2015
• First Submitted That Met QC Criteria: October 2, 2015
• First Posted (Estimate): October 6, 2015

Study Record Updates

• Last Update Posted (Actual): November 21, 2022
• Last Update Submitted That Met QC Criteria: November 18, 2022
• Last Verified: November 1, 2022

More Information

Terms related to this study

• Keywords: children; cystic fibrosis; glucose intolerance; continuous glucose measurement
• Additional Relevant MeSH Terms: Digestive System Diseases; Pathologic Processes; Glucose Metabolism Disorders; Metabolic Diseases; Respiratory Tract Diseases; Lung Diseases; Infant, Newborn, Diseases; Genetic Diseases, Inborn; Hyperglycemia; Pancreatic Diseases; Fibrosis; Glucose Intolerance; Cystic Fibrosis
• Other Study ID Numbers: EKNZ 2015-143; KEK BE: 102/15 (Other Identifier: Ethics commitee of attending study site)