GLUCOSE INTOLERANCE IN CYSTIC FIBROSIS (CF)

Abstract

Up to 60% of children with CF develop glucose intolerance (GI). Many CF patients maintain a normal glucose tolerance (NGT) with a low insuline response during the oral glucose tolerance test (OGTT). We studied 48 CF pts. (aged 2-29 years) without clinical manifestations of diabetes mellitus. Assessment included OGTT, hemoglobin A1C, anti-islet antibodies, pulmonary status and liver involvement. The OGTT was considered abnormal when the 2h serum glucose level was higher than 140 mg/dl. There was no significant difference between the 15 pts. with and the 33 pts.without GI in terms of mean age, wheight index, degree of lung and liver involvement. Fasting insulin (ins.), peak ins. response, max. ins./max. glucose ratio, and area under the ins.response curve were not different in GI and NGT group. Peak glucose and peak ins. response were significantly delayed in GI vs NGT pts. (99 min and 117 min vs 55 min and 86 min) and Hb A1C was higher in the former (8,2% vs 7,5%). No circulating anti-islet antibodies were detected in either group. In conclusion, CF patients with GI differ from those with NGT by a delayed glucose and insuline response to OGTT. Serial Hb A1C levels can be used as a simple and reliable method for the prediction of GI in CF.