Medical therapy in patients with endogenous hypoglycaemia: Is euglycaemia achievable?

CONTEXT: While the only curative treatment for patients with endogenous hypoglycaemia related to inappropriate insulin or to insulin growth factor 2 (IGF2) secretion is surgery, medical treatment to normalize plasma glucose levels can be useful. OBJECTIVE: The aim of this prospective single centre study was to assess whether patients with endogenous hypoglycaemia, considered euglycaemic with medical treatments, experienced asymptomatic hypo- or hyperglycaemic excursions. PATIENTS AND METHODS: All patients with endogenous hypoglycaemia related to inappropriate insulin or to IGF2 secretion between 2012 and 2016 and considered normoglycaemic with medical treatment (absence of clinical hypoglycaemia and self-monitoring blood glucose in the normal range) were enroled and underwent a six-day continuous glucose monitoring (CGM) recording. RESULTS: Twenty-seven patients (inappropriate insulin secretion n = 25 and IGF2 secretion n = 2), treated with diazoxide (n = 16), somatostatin analogues (n = 7), glucocorticoids (n = 3) or a combination of these treatments (n = 1) were enroled. Twenty-five CGMs were analysed. CGM confirmed normoglycaemia in 11/25 patients (44%). Hypoglycaemias below 0.60 g/L were present in seven patients (28%) and were associated with hyperglycaemic excursions above 1.40 g/L in five patients. Seven patients (28%) had only hyperglycaemic excursions. Based on these results, treatment was modified in 14 patients (56%). CONCLUSION: Despite the disappearance of hypoglycaemia-related clinical symptoms and normalization of blood glucose self-monitoring data, 56% of the patients with endogenous hypoglycaemia treated with medical therapy experienced asymptomatic hypo- and/or hyperglycaemia. Continuous glucose monitoring could be a useful approach to reveal and prevent hypo- or hyperglycaemic excursions.