Glucagon-like peptide 1 (GLP-1) pathway is essential in islet regeneration, i.e. inhibition of β-cell apoptosis and enhancement of β-cell proliferation, yet involvement of GLP-1 in MEN1 related P-NET has not yet been demonstrated.
In addition, a monohormonal type of pancreatic microadenomatosis was identified that consisted of either insulinomas or glucagon-producing tumors and was not associated with MEN1 or VHL.
There was a nonsignificant trend for elevated chromogranin A, pancreatic polypeptide, gastric inhibitory polypeptide (but not glucagon) and history of bronchopulmonary carcinoid in MEN 1 patients with elevated glycaemia.
The primary biochemical screening programme for MEN-1 includes serum prolactin and insulin growth factor 1 (IGF-1) for pituitary lesions, intact PTH and albumin corrected total serum calcium for the parathyroids and for duodenal/pancreatic tumours serum glucose, insulin, proinsulin, pancreatic polypeptide, glucagon, gastrin and plasma chromogranin A.