Mild Cushing's Disease: Definition and Serum Cortisol Dynamics after Transphenoidal Surgery

Presentation Number: SAT-382
Date of Presentation: March 7th, 2015

Fabiola Costenaro1, Ticiana Costa Rodrigues2, Guilherme Alcides Flores Rollin3, Artur Boschi4, Nelson Pires Ferreira5 and Mauro Antonio Czepielewski*4
1PPG Endocrinologia, Porto Alegre, Brazil, 2Universidade Federal do Rio Grande do Sul/Hospital de Clinicas de Porto Alegre, Porto Alegre RS, Brazil, 3Faculdade de Medicina/UFRGS, Porto Alegre, Brazil, 4Faculdade de Medicina UFRGS, Porto Alegre, Brazil, 5Irmandade da Santa Casa de Misericórdia, Porto Alegre, Porto Alegre, Brazil

Abstract

Background: The definition criteria of “mild” Cushing’s Disease (CD) are not established. However, it is important on clinical practice because the increased frequency of patients with mild forms of CD.  The cortisol dynamic of these patients after transphenoidal surgery is poorly described. Patients and Methods: we present an analysis of a cohort with 80 CD patients with 14 of them classified as mild CD based on 24h-Urinary free cortisol (24hUFC) less than 2 times the upper limit of normality (ULN). These patients underwent to transphenoidal surgery without hydrocortisone routine use on perioperative period (PO). Hydrocortisone was administered only if they presented clinical or laboratory adrenal insufficiency. Serum cortisol was performed in the morning of the surgery and each 6h for 48h after PO. Results:  Mild CD patients presented on diagnosis lower body mass index before surgery (33.1 ± 7.5 vs. 28.4± 3.7 kg/ m2, p=0.011), a higher age (43.6± 14 vs. 35.4±11 yrs, p=0.024), lower 2mg dexamethasone test (17.7±12.6 vs. 6.9±4.3 ug/dl, p=0.001) and between the remission patients a higher median peak of serum cortisol at 48h PO (27.2 ± 10.6 µg/dl vs. 9.2 ± 10.6  µg/dl, p=0.04) in comparison to patients with 24h UFC above 2 times the ULN. If we use the cut-off in 3 times or higher values in the ULN of the 24h UFC, these differences in cortisol dynamics were not observed. Clinical characteristics as plethora, supraclavicular pad, myopathy, comorbidities as diabetes, hypertension, osteoporosis/osteopenia, psychosis/depression and definitive adrenal insufficiency were not statistically different between the two groups. Conclusions: Important clinical characteristics of CD where not discriminative of severity of CD in this cohort. Patients with mild CD presented a higher level of serum cortisol in the first 48h after surgery, probably because of a lower previous suppression of normal corticotrophs nearby the adenoma. Therefore, in patients with mild CD a higher level of serum cortisol early after surgery is not an indicative of surgical failure, as it is for severe CD. In these cases the definition of CD remission  must be postpone to a week or a month  after surgery. Based on dynamic of PO serum cortisol we suggest that 24hUFC less than 2 times ULN is an criterium for definition of mild CD.

Grants: Fundo de Incentivo a Pesquisa do HCPA- FIPE.

 

Nothing to Disclose: FC, TCR, GAFR, AB, NPF, MAC