Many nonfunctioning adrenal incidentalomas develop autonomous cortisol secretion
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All patients with adrenal incidentalomas experienced deteriorating metabolic parameters, and nearly one-third of patients with nonfunctioning adrenal incidentalomas developed subclinical autonomous cortisol secretion, researchers in Greece reported.
“An increasing amount of data supports a link between subtle [autonomous cortisol secretion] states of [adrenal incidentalomas] and the occurrence of several cardiometabolic abnormalities, such as obesity, insulin resistance, type 2 diabetes, hypertension, dyslipidemia and hyperuricemia, all of which are associated with increased cardiovascular events and mortality,” Labrini Papanastasiou, MD, PhD, of the department of endocrinology and the Diabetes Center at G. Gennimatas General Hospital in Athens, Greece, and colleagues wrote. “However, the evolution of [insulin resistance] with time has not as yet been studied, particularly in relation to alterations of cortisol secretion in patients with [adrenal incidentalomas].”
The researchers a conducted a prospective study on 71 patients with adrenal incidentalomas who were referred for treatment at a tertiary hospital between 2002 and 2012. Mean follow-up was 5.54 years. The patients underwent adrenal imaging, as well as autonomous cortisol secretion testing and oral glucose tolerance testing so that Papanastasiou and colleagues could establish their insulin resistance indices.
Sixteen of 51 patients (31%) with nonfunctioning adrenal incidentalomas experienced conversion to autonomous cortisol secretion at follow-up, and two who had autonomous cortisol secretion reverted to nonfunctioning adrenal incidentalomas, the researchers reported. Seven of the patients with nonfunctioning adrenal incidentalomas (21%) showed high levels of urinary free cortisol and did not convert to autonomous cortisol secretion. Papanastasiou and colleagues wrote that all patients with adrenal incidentalomas experienced insulin resistance deterioration.
Eight participants developed type 2 diabetes (9.8% of patients with nonfunctioning adrenal incidentalomas and 15% of patients with autonomous cortisol secretion), whereas another 14 developed newly diagnosed insulin resistance (17.6% of patients with nonfunctioning adrenal incidentalomas and 25% of patients with autonomous cortisol secretion). Mean adenoma size increased from 2.1 cm to 2.3 cm, the researchers reported, and insulin resistance was correlated with adenoma size increase and post-dexamethasone cortisol levels.
“Insulin resistance showed an incremental continuum trend from normal urinary free cortisol, to high urinary free cortisol, to converted autonomous cortisol secretion and autonomous cortisol secretion patients,” Papanastasiou and colleagues wrote.
“In conclusion, a functional evolution of [nonfunctioning adrenal incidentalomas] to [autonomous cortisol secretion] over time was observed in 31% of patients mostly associated with an increase in adrenal size,” the researchers wrote. “Such individuals carry an intermediate metabolic risk compared to patients with established [autonomous cortisol secretion] and those who remained truly nonfunctioning. Long-term prospective randomized controlled trials are necessary to validate any parameters that might identify patients at high risk of altered cortisol secretion and direct appropriate follow-up investigation to this specific subgroup of [nonfunctioning adrenal incidentalomas] limiting the distress and cost of prolonged and meticulous investigations in the whole group of patients with [adrenal incidentalomas].” – by Andy Polhamus
Disclosure: The researchers report no relevant financial disclosures.