Endocrine Abstracts

Purpose: The postoperative levels of cortisol and ACTH are the most commonly used markers for the prediction of Cushing’s disease (CD) remission after transsphenoidal surgery (TSS). However, there is still no consensus on the collection time and threshold values of basal cortisol and ACTH levels after surgery to predict remission of CD.

Aim: To study the significance of early postoperative serum cortisol and plasma ACTH testing in the prognosis of CD remission after TSS.

Materials and methods: 101 patients with Cushing’s disease (12 men, 89 women, mean age 41 years (15–72) confirmed after TSS were included. In all patients basal morning serum cortisol and plasma ACTH at 2 days and at 14 days postoperatively were measured. The results of TSS were evaluated one year after surgery Remission criteria were: secondary adrenal insufficiency or combination of normal midnight ACTH and serum cortisol levels, normal 24-hour urine free cortisol (UFC) excretion and serum cortisol suppression less than 50 nmol/l in 1-mg dexamethasone test. The optimal threshold value of hormone levels for prediction of CD remission after TSS was calculated by ROC-analysis.

Results: One year after surgery CD remission was confirmed in 63 patients, whereas in 38 patients hypercortisolism persisted. The optimal value of basal serum cortisol at 2 days after TSS for prediction of CD remission was ≤ 388 nmol/l, with sensitivity 94,9% and specificity 75,9% (P < 0.001), and for 14 days it was ≤ 417,7 nmol/l, with sensitivity 96,4% and specificity 87% (P < 0.001). The optimal value of plasma ACTH at 2 days was ≤ 20 pg/ml with sensitivity and specificity 83.3% and 95.8% respectively (P < 0.001), and at 14 days it was ≤ 41.71 pg/ml, with sensitivity and specificity 94.4% and 88.9%, respectively (P < 0.001).

Conclusion: Serum cortisol and plasma ACTH levels had a comparable high predictive accuracy when measured at 2 days and 14 days after surgery in the prediction of CD remission after TSS. High threshold values of serum cortisol and plasma ACTH in our study could be explained that not only specificity, but sensitivity were calculated for both markers.