Endocrine Abstracts

Patients (pts) with adrenal incidentaloma (AI) may show an increased incidence of several cardiovascular risk factors, as obesity, hypertension, diabetes mellitus and dyslipidemia. As previous data suggested that the increased cardiovascular risk in these pts could be in part mediated by alterations of adipokines, this study was aimed to evaluate plasma IL-6, resistin, CT-1 levels in a wide series of pts with AI.

Ninety-three pts (42 males; 51 females; aged 63.6±9.1 years; BMI 28.2±0.5 kg/cm², mean±S.E.M.) were studied. All adrenal masses were identified as cortical adenoma. In all pts serum cortisol (F), plasma ACTH and urinary free cortisol were determined in basal conditions and after an overnight 1-mg dexamethasone (dexa) test. Plasma IL-6, CT-1 and resistin levels were measured by ELISA methods.

In pts with AI plasma IL-6 levels were greatly elevated (26.5±1.3 vs 2.9±0.4 pg/ml, P<0.001); resistin levels were also higher, though not significantly, than in normal subjects, while CT-1 levels were similar (11.6±0.6 vs 9.6±0.7 ng/ml; 19.2±1.0 pg/ml vs 18.7±1.3, respectively). In all pts adipokine levels did not correlate with cortisol/ACTH levels (either basal or after dexa) or with other clinical (adenoma size, hypertension), metabolic (insulin resistance, diabetes mellitus), hormonal parameters (subclinical Cushing syndrome).

Interestingly, patients with visceral obesity more frequently showed a greater elevation of IL-6 (100 vs 96.6%), resistin (29.8 vs 22.5%) and CT-1 levels (8.8 vs 0%) than the remaining pts.

Conclusion: a) pts with AI may show increased levels of adipokines, apparently not related to the presence of diabetes, metabolic syndrome, insulin resistance, hypertension; b) a direct influence by the adenoma itself on cytokine production has been suggested only by experimental studies; c) whether it is plausible to consider a role for cytokines in AI, starting before cardiovascular complications arise, it will be possibly clarified by future prospective studies.