Endocrine Abstracts

Adrenal incidentalomas (AI) are a common finding in patients studied by abdominal imaging and approximately 9–17% is found bilaterally. So far, the potential role of hypothalomo-pituitary adrenal (HPA) axis dysregulation in the pathogenesis of AI, especially of those found bilaterally, has not been addressed. The DEXA-CRH test has been previously used to detect dysregulation of the HPA axis; herein, it was used to assess ACTH and cortisol responses in a large group of patients presented with unilateral and bilateral adrenal incidentalomas.

We studied 97 patients (51 with unilateral and 46 with bilateral AI) and 26 normal controls. All subjects underwent a formal low dose dexamethasone suppression test followed by a CRH test (100 ug iv). Patients with AI demonstrated statistically higher ACTH and cortisol responses to the DEXA-CRH test compared to the controls (P<0.05). Although ACTH responses did not differ between patients with unilateral and bilateral incidentalomas, cortisol responses were significantly higher in patients with bilateral AI (P<0.05). According to ACTH responses patients were divided in 3 groups: group A with ACTH max <10 pg/ml (n=48), group B with ACTH max 10–20 pg/ml (n=34) and group C ACTH max >20 pg/ml (n=15). The proportion of patients with bilateral AI in group C was significantly higher than in group A (66.6% vs 37.5%, P<0.05). On the contrary more patients with unilareral AI were found in group A compared to group C (62.5 vs 33.3%, P<0.05).

In conclusion patients with AI demonstrate higher ACTH and cortisol responses to the DEXA-CRH test compared to normal subjects. This finding appears to be more common in patients with bilateral AI and, provides some ground for the potential involvement of HPA dysregulation in the pathogenesis, in at least a subgroup, of AI of patients.

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 research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.