177 Evolution of glycemia, insulinemia and glycosylated hemoglobin in a CF pediatric population

Abstract

Objectives Prevalence of Cystic Fibrosis Related Diabetes (CFRD) increases with age. Early screening is essential. The objective is to document evolution of glycemia, insulinemia and glycosylated hemoglobin levels (HbA1c) in CF pediatric patients (pts). Methods Chart review of 137 pts followed at CHU Sainte-Justine CF Clinic between 1993 and 2014. We collected results from annual oral glucose tolerance test and insulinemia of 119 pancreatic-insufficient (PI) and 18 pancreatic-sufficient pts (PS) aged 10 to 18. We also recorded HbA1c from age 1 to 18. Results Between 10 and 18 years, prevalence of normal glucose tolerance (NGT) decreased from 84 to 61% whereas impaired glucose tolerance and new CFRD increased from 13 to 32% and 3 to 7% respectively in PI. All PS remained NGT. Mean fasting glycemia increased from 5.3 to 5.9 mmol/L in PI but remained stable at 5.0 mmol/L in PS. Two-hour glycemia increased from 6.5 to 7.5 mmol/L in PI vs 5.3 to 6.2 mmol/L in PS. Fasting and 2-hour insulinemia increased from 31.2 to 34.6pmol/L and 162.6 to 268.5pmol/L in PI. PS displayed marked fluctuations of their insulinemia with values ranging from 33.0 to 72.1pmol/L (fasting) and 219 to 365pmol/L (2-hour). Between the age of 1 and 18 years, HbA1c increased gradually from 5.4 to 6.2% in PI vs 5.0 to 5.4% in PS. Conclusion We observed a decrease in glucose tolerance in PI with time characterized by an increase in fasting and 2-hour glycemia and insulinemia between the age of 10 and 18. Increase in 2-hour insulinemia and glycemia might suggest insulin resistance. Interestingly, HbA1c were higher in PI vs PS as early as 1 year old. Our findings emphasize the need for early monitoring of CFRD.