Post-OGTT hypoglycemia is common in Cystic Fibrosis(CF). The aim of the study is to determine of the role of glucagon in the pathogenesis of hypoglycemia in CF patients. A 3-hour-OGTT was performed fifty-three subjects (44CF,9 age-matched controls). Sixteen (36.4%) subjects had normal glucose tolerance (NGT), 13 (29.5%) had isolated hypoglycemia (IsoHypo), 8 (18.2%) had hypoglycemia with abnormal glucose intolerance (Hypo+AGT), 5 (11.4%) had AGT and 2 (4.5%) had CFRD. After AGT and CFRD were excluded, there was no statistical significance between 4 groups in terms of age, sex, BMI and FEV1.In Hypo+AGT, the peak insulin was delayed compared to IsoHypo.Glucagon response to glycemic fluctuations in OGTT was nearly absent in Hypo+AGT and NGT compared to controls. Whereas it was relatively preserved in IsoHypo though not as robust as the controls. IsoHypo was further divided into two groups according to the presence of pancreatic insufficiency(PI). Insulin and glucagon response to glucose loading in IsoHypoPI(+) were very similar with Hypo+AGT, whereas relatively preserved but not as robust glucagon response and higher insulin response at 30-60.min were persisted in IsoHypoPI(-). In conclusion, impaired glucagon response appears to contribute to hypoglycemia in CF. Decreased robustness of glucagon response detected even in IsoHypoPI(-) supports an intrinsic effect of CFTR gene on glucagon secretion.
15 Sep 2022 - 17 Sep 2022