Role of hypothalamic neuropeptides in the development of hyponatremia in patients after transnasal adenomectomy

BACKGROUND: To date, the causes and predisposing factors for the development of water-electrolyte disturbances after transsphenoidal surgery for hypothalamic-pituitary masses are poorly understood. Neuropeptides such as apelin, copeptin, and brain natriuretic peptide, discovered in recent decades, have been shown in many studies to have a significant effect on the regulation of water-electrolyte metabolism and make them potential hormonal markers of severe postoperative electrolyte complications. AIM: to study the features of secretion of hypothalamic neuropeptides during normal water and salt metabolism in the perioperative period and in the presence of water and electrolyte metabolism disorders. MATERIALS AND METHODS : Patients above 18 years of age who were scheduled to undergo transnasal adenomectomy for underlying disease were included in the study. Patient recruitment was conducted from March 2021 to March 2022. All patients were monitored initially and further in the postoperative period of transnasal adenomectomy for the presence of water-electrolyte disturbances by blood sodium determination, as well as determination of apelin-12, copeptin, brain natriuretic peptide, and oxytocin levels in the first 12–24 hours, then on days 2–3, 4–5 and 6–7 postoperatively. Patients also filled in a diary of well-being and water balance. RESULTS: It has been established that such a water-electrolyte complication as hyponatremia aggravates the postoperative period of transnasal adenomectomy in up to 15% of cases.Our study revealed no significant changes in the levels of apelin and brain natriuretic peptide or their correlation with the level of sodium in patients in both groups, as well as the relationship between neuropeptides. The most interesting effects on water-electrolyte metabolism are demonstrated by the neuropeptides oxytocin and copeptin, the secretion of which has the character of inadequately elevated levels with loss of inverse negative correlation with blood sodium concentration. CONCLUSION: Our study revealed a high incidence of hyponatremia after transnasal adenomectomy — about 15% of cases, in the genesis of which hypothalamic neuropeptides copeptin and oxytocin seem to play a significant role. Oxytocin has the potential to be a hormonal marker of this severe complication.