Endocrine Abstracts

Hypopituitarism is a potential complication of trans-sphenoidal adenomectomy (TSA). Prediction of pituitary function (PF) recovery would inform hormonal replacement strategies. However, the frequency of re-testing of PF is variable across centres. The aim of this study was to determine rates, time and predictors of 6-weeks (6 w) recovery of hypothalamo-pituitary adrenal (HPA) and gonadal function after TSA.

Methods: We performed a single-centre, retrospective (2016–2018) analysis of patients undergoing TSA. Patients with apoplexy, corticotroph adenomas, malignancy or radiotherapy were excluded. HPA assessment: pre-op, post-op short synacthen test (SST) and day 8 post-op 9 am cortisol. Patients failing at 6w were re-tested at 3,6 and 9to12 months. Gonadal axes assessment: FSH, LH, estradiol (women)/testosterone (T, men) pre-op and 6 w post-op. Multiple regression models and ROC analysis were used to identify recovery predicting variables.

Results: Data on 135 patients (mean age 54±17 years; 80 M) were analysed. 29% of patients had normal pre-op PF: they were younger (49±16 vs 59±15 years, P=0.01) and had smaller tumors (5.2±4.6 vs 8.8±10 mL, P=0.02) compared to those with at least one deficit. TV was able to predict the a pituitary deficit 6w post-op (P=0.01). 95% of patients (odds ratio (OR) 8.00, 95% CI 0.90–64.70) with a TV>9 mL (ROC AUC=0.66) had at least one deficit 6w post-op. HPA axes: 37% of patients failed the 6w assessment: 16%, 12%, 5% recovered at 3, 6 and 9–12 months respectively. Pre-op SST 30-minute cortisol, post-op day 8 cortisol and 6 w post-op SST baseline cortisol respectively above or below 430 nmol/L(AUC ROC=0.83), 160 nmol/L (AUC ROC=0.78) and 180 nmol/L (AUC ROC=0.86) were identified as cut-offs for predicting 6 w HPA recovery respectively. None of the patients with all these three cut-offs below the threshold recovered within 12 months post-TSA. 89% of them with all the cut-offs above the threshold recovered HPA function within 6–w (OR 9.125, 95% CI 4.745–17.547). Gonadal axes: 39% of patients failed the 6 w assessment. In men, pre-op T level was associated with 6w gonadal axes deficit. 87% of patients having a pre-op T<7 nmol/L (ROC AUC=0.77) had gonadal deficit at 6 w (OR 11.5, 95% CI 2.27–58.33).

Conclusions: After TSA, PF recovered more frequently in patients with normal pre-op function and smaller tumor. There is the potential to use SST results and pre-op testosterone to predict HPA and gonadal axis recovery. This may aid clinicians to decide on treatment strategy and inform patients regarding likelihood of PF recovery. HPA axis recovery occurs even 12 months post-TSA, emphasizing the importance of periodic reassessment to avoid unnecessary treatment.