Clinical and biochemical impact of BCL1 polymorphic genotype of the glucocorticoid receptor gene in patients with adrenal incidentalomas.

BACKGROUND: Adrenal incidentaloma (AI) is a common clinical problem. Subtle hormonal abnormalities are present in a substantial proportion of patients. BCL1 gene polymorphism of the glucocorticoid receptor (GR) is associated with increased sensitivity to glucocorticoid action. The genotype- phenotype associations of this polymomorphism in patients presenting with AI has not been extensively investigated. AIM: A cross-sectional study in secondary/tertiary care centers. SUBJECTS/METHODS: Ninety-five subjects with AI were genotyped for the BCL1 GR gene polymorphism. Patients underwent an oral glucose tolerance test and a dexamethasone suppression test (DST). The presence of subclinical hypercortisolism, features of metabolic syndrome, and osteoporosis/ osteopenia were also assessed. RESULTS: No significant differences in markers of adrenal function between BCL1 carriers and non-carriers were revealed. Also, no difference was found in the features of metabolic syndrome, as well as in bone metabolism and density between these 2 groups. However, DST suppressor patients belonged more frequently to the BCL1 carriers group (41 out of 69 patients, 59.4% vs 9 out of 26 patients, 34.6%, p=0.0039), had smaller total adenoma size (2.4±0.2 cm vs 3.5±0.4 cm, p=0.04), and lower incidence of bilateral adrenal masses (18.8% vs 46.2%, p=0.01). CONCLUSIONS: AI patients who also carry the polymorphic BCL1 variant exhibit smaller size adrenal nodules. Those AI patients with complete DST suppression had a higher incidence of the polymorphic BCL1 variant. However, this study failed to demonstrate any significant impact of BCL1 GR polymorphism on the frequency of cortisol-dependent co-morbidities in patients with AI.

Abnormal Responsiveness to Dexamethasone-Suppressed CRH Test in Patients With Bilateral Adrenal Incidentalomas.

CONTEXT: The bilateral formation of nodules indicates that the pathogenesis of bilateral adrenal incidentalomas (AI) may differ from that of unilateral AI. A possible role of hypothalamo-pituitary-adrenal (HPA) axis dysregulation in their formation has not been investigated. OBJECTIVE: The objective of the study was to evaluate the presence of altered feedback regulation of HPA axis in patients with bilateral AI. DESIGN: The dexamethasone (DEX) suppression-CRH test was used to assess ACTH and cortisol responses in controls and patients with unilateral and bilateral AI. SETTING: The study was conducted at endocrine departments of two tertiary centers. PATIENTS: We studied 24 controls and 39 patients with unilateral and 46 with bilateral AI. INTERVENTIONS: All subjects underwent standard low-dose dexamethasone suppression followed by iv bolus administration of human CRH (100 µg). RESULTS: Bilateral AI had higher levels of ACTH and cortisol after the DEX-CRH challenge compared with both controls (P < .01 for ACTH and P < .001 for cortisol) and unilateral AI (P < .01 for ACTH and cortisol). A positive response, defined as peak ACTH greater than 10 pg/mL at 15 and/or 30 minutes followed by a significant rise in cortisol levels, was noted in 41.3% of bilateral vs 2.6% in unilateral AI (P < .001). Bilateral responders did not differ from nonresponders in demographic or hormonal characteristics, but they had larger total adrenal size compared with nonresponders. CONCLUSIONS: A significant proportion of patients with bilateral AI demonstrate positive responses to the DEX-CRH test compared with unilateral AI, providing ground for potential involvement of HPA axis dysregulation in the pathogenesis, in at least a subgroup, of bilateral AI patients.