Endocrine Abstracts

Background and aim: Non-diabetic hypoglycemia is a rare entity that regroups several pathologies. Its exact diagnosis is mostly challenging. Endogenous hyperinsulinism is a curable cause that should be thoroughly screened. The objective of our study was to analyze the ethipathological aspects of hypoglycemia by endogenous hyperinsulinism.

Patients and methods: We conducted a retrospective study at the Endocrinology department of Hedi Chaker University Hospital, Sfax, Tunisia. We involved 10 patients investigated for endogenous hyperinsulinemic hypoglycemia, whose clinical, biochemical, and imaging peculiarities were collected from medical charts.

Results: Ten patients, 6 men and 4 women, with a mean age of 43 years (range 17–68 years) were included. The diagnosis of organic hypoglycemia was established based on Whipple’s triad associating neuroglycopenic signs in all cases, a concomitant mean venous glycemia of 1.8 mmol/l (extremes: 1.2–2.8) with an improvement after glucose intake. Biological investigation results were consistent with an endogenous hyperinsulinemic hypoglycemia (a hypoglycemia concomitant to an insulinemia ≥3 mUI/l (average 19 mUI/l) and a C-peptide level ≥0.6 ng/ml (average 3 ng/ml). Topographic exploration had objectified a pancreatic lesion in 9 patients. All these patients underwent pancreatic surgery. The pancreatic lesion was histopathologically confirmed to be a well-differentiated neuroendocrine tumor in all cases. No pancreatic lesion was identified in one patient. This was a non-syndromic congenital hyperinsulinism most likely secondary to an ATP-sensitive potassium (KATP) channel defect.

Discussion: Non-diabetic hypoglycemia is a rare entity whose main etiology in adults is insulinoma. Congenital forms of hyperinsulinemic hypoglycemia can be transient or persistent, mild or severe. These conditions are present at birth and most become apparent in early infancy.