[Abnormal glucose tolerance in prepubertal patients with cystic fibrosis]. / Alteraciones hidrocarbonadas en pacientes impúberes con fibrosis quística.

ABSTRACT

INTRODUCTION: Annual screening for abnormal glucose tolerance (AGT) with oral glucose test should begin by age 10 years in cystic fibrosis (CF) patients (Consensus-2010). AIMS: To examine the frequency of AGT and its outcome in prepubertal CF patients and the changes in glycemic and nutritional status and lung function over the preceding year. PATIENTS AND METHODS: Retrospective study of 19 prepubertal CF patients (68% males). All subjects underwent an oral glucose tolerance test (OGTT). Results were classified as normal glucose tolerance (NGT) or AGT (impaired glucose tolerance [IGT], CF related diabetes [CFRD] or indeterminate glucose tolerance [INDET]). We analyzed OGTT (glucose and insulin levels), nutritional status (BMI-SD) and lung function (forced spirometry). Statistical analysis was performed with SPSS program-version-15.0, non parametric tests. RESULTS: Mean age at first OGGT 8.5 years (5.8-9.8). Mean follow-up 2 years (2-3). Initially, 47% patients had AGT and 53% NGT. In follow-up 4/10 NGT patients developed AGT (3 IGT, 1 CFRD). Among initial AGT patients, of 4 INDET 2 developed IGT, 1 CFRD. Mean age of AGT onset 8.6 years (6.4-11.1). In 69% AGT patients a declining BMI-DS and/or lung function was found in the preceding year. In OGTTs performed, fasting and 2h AUC insulin levels were comparable between NGT and AGT; however, insulinogenic index was lower in AGT patients (p=.006). Insulin secretion was delayed in all patients. CONCLUSIONS: The high frequency of AGT in prepubertal CF patients and their negative clinical impact supports the usefulness of an earlier glycemic screening.