Endocrine Abstracts

Introduction: The treatment of choice in Cushing’s disease (CD) is transsphenoidal surgery (TSS). The success of surgical procedure is of particular importance in terms of patient`s prognosis. The aim of this study was the prospective evaluation of compatibility of coupled 1 mg dexamethasone suppression test and 10 μg desmopressin stimulation test (CDDT) with standard criteria of remission in CD.

Methods: The study population consisted of 36 patients with CD operated on using the same protocol and followed-up for a period of at least 18 months (median: 30 months). The adopted criteria of remission were: subnormal serum cortisol level on the 1st postoperative day, normalization of urinary free cortisol and serum cortisol ≤1.8 μg/dl following 1 mg of dexamethasone. In total, 28 patients (77.8%) agreed to undergo CDDT – 15 out of 23 cured (65.2%) and all 13 non-cured subjects. CDDT was performed between 12 and 18 months of follow-up. A positive result of CDDT was indicated by the increase in plasma ACTH and serum cortisol by more than 35 and 20%, respectively.

Results: In total, 15 patients (53.6%) were regarded as surgically cured from Cushing`s disease. In 13 patients (46.4%) persistent hypertcortisolemia was confirmed. Positive result of CDDT was observed in 12 non-cured (92.3%) and in one cured subject (6.7%). Negative result was obtained in 12 cured (80%) and in one non-cured subject (6.7%). Equivocal result was observed in two cured subjects (13.3%). The qualitative results of CDDT were compared with results of standard hormonal assessment performed at the end of follow-up. They were found to be highly compatible (κ=0.846; P<0.001).

Conclusion: Negative result of CDDT can be treated as a confirmation of successful surgical treatment for CD. During follow-up period CDDT can serve as a valuable supplement to hormone assessment performed in basic conditions.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.