Endocrine Abstracts

Background: Craniopharyngioma is a benign tumour involving the hypothalamic and pituitary regions that are involved in the production and secretion of oxytocin. Research has shown that dysfunction of the oxytocin system is associated with neurobehavioural and metabolic outcomes, but less is known for its role in patients with craniopharyngioma, largely due to varied study designs and heterogenous methods of assessing the oxytocin system. This systematic review aimed to assess the extent to which the oxytocin system is involved in craniopharyngioma and its association with neurobehavioural and metabolic abnormalities.

Methods: This review was pre-registered on PROSPERO (CRD42023397966). PubMed, EMBASE, PsycInfo, and Cochrane Central Register of Controlled trials were searched from inception to January 19 2023 using key terms craniopharyngioma and oxytocin. Reference lists of included studies and relevant reviews were searched. All observational studies assessing the oxytocin system and neurobehavioural or metabolic (e.g., body mass index) abnormalities in humans with craniopharyngioma were independently reviewed by two authors.

Results: Of 61 articles screened, eight studies were included. One case report found improvements in food preoccupation and BMI z-score which decreased from 1.77 SDS (96th percentile) to 0.82 SDS (79th percentile) following 6 IU/day of intranasal oxytocin over 48 weeks. Another case report found no improvements in food-related obsessive–compulsive behaviours, but did find improvements in social behaviours (dosage 4 IU/day; ~60 weeks). Of studies assessing the endogenous oxytocin system, no significant differences in baseline fasting or post-prandial salivary oxytocin concentrations were reported between craniopharyngioma patients and controls. However, craniopharyngioma patients were found to have blunted-oxytocin release following exercise stimulation and this was associated with greater autistic traits, reduced hedonia for social interactions, and higher state anxiety. One study reported improved emotion identification following single-dose (24 IU) intranasal oxytocin in patients with anterior hypothalamic damage compared to those with anterior and posterior damage.

Conclusions: Definitive conclusions regarding the oxytocin system in craniopharyngioma remain to be established due to the limited studies and lack of homogenous methods used in this population. Nevertheless, this review found that the oxytocin system may be compromised in craniopharyngioma and present a plausible mechanism underlying neurobehavioural and metabolic problems in this population.