β-Cell secretory defects are present in pancreatic insufficient cystic fibrosis with 1-hour oral glucose tolerance test glucose ≥155 mg/dL

BACKGROUND Patients with pancreatic insufficient cystic fibrosis (PI-CF) meeting standard criteria for normal glucose tolerance display impaired β-cell secretory capacity and early-phase insulin secretion defects. We sought evidence of impaired β-cell secretory capacity, a measure of functional β-cell mass, among those with early glucose intolerance (EGI), defined as 1-hour oral glucose tolerance test (OGTT) glucose ≥155 mg/dL (8.6 mmol/L). METHODS A cross-sectional study was conducted in the Penn and CHOP Clinical & Translational Research Centers. PI-CF categorized by OGTT as normal (PI-NGT: 1-hour glucose