ESPE Abstracts

Background: Hypoglycemia triggers the secretion of counter-regulatory hormones such as cortisol, GH, and glucagon, all of which are protective mechanisms to restore euglycemia. It has been suggested that CHI patients have abnormal glucagon secretion during hypoglycemia, but the data is limited.

Objective and hypotheses: To investigate the secretion of counter-regulatory hormones including glucagon during hypoglycemia. It’s supposed that these hormones are not low.

Method: Three groups of patients with CHI (n=41), ketosis hypoglycemia (KH, n=19), and type 1 diabetes at the first onset of ketoacidosis (DKA, n=19) were reviewed retrospectively. All patients were admitted to the Department of Endocrinology at our hospital. Blood was collected during hypoglycaemia.

Results: The median glucose levels in CHI patients were 1.34 (range: 0.1–2.5) mmol/l, and the levels were 2.26 (0.71–3.88) mmol/l, (P<0.01) in KH patients. the median glucagon value in CHI patients was 280 (range: 4.8–800) pg/ml compared to142 (64–535) pg/ml in KH patients (P<0.01). Furthermore, glucagon secretion in DKA patients was not low: glucagon levels were 124 (85–299) pg/ml. The glucagon/glucose ratio showed similar results. CHI was 253 (2.8–6580) vs KH: 69 (16–328), P<0.01. Compared to diazoxide-sensitive CHI patients (n=18), Diazoxide-unresponsive CHI patients (n=23) had a higher insulin/glucose ratio, 8.4 (2.9–382) vs 7.1(2.3–40), P<0.05. However, the glucagon/glucose ratio in these two groups of CHI patients was similar: diazoxide sensitive: 202 (87–815) vs insensitive: 253 (3–6580). There were 20 cases of CHI carry mutations at KATP channel gene (ABCC8 or KCNJ11). Glucagon secretion in response to hypoglycemia in patients with KATP channel mutations was similar to the patients with negative mutations for known CHI genes.

Conclusion: Glucagon secretion in the CHI patients of the Chinese population is not impaired. Glucagon secretion had reverse correlation with glucose levels. These data also indicate that hypoglycemia is mainly the driving force for glucagon secretion, despite its causes.