Glucose Tolerance in Children With Cystic Fibrosis
Condition: Glucose Intolerance; Cystic Fibrosis
MeSH terms: Cystic Fibrosis; Glucose Intolerance; Fibrosis
Study type: Observational

Summary: 
      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.
    

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.
    

Intervention name(s): Diagnostics for glucose tolerance with 3 different methods.
Intervention type(s): Other
Intervention description(s): 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.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Patients with genetically determined cystic fibrosis.
      
Biospecimen description: 
      Glucose, C-Peptide, Insulin, HbA1c in blood specimen.
    
Keywords: children; cystic fibrosis; glucose intolerance; continuous glucose measurement