Does IGF-1 play a role in the etiopathogenesis of non-functioning adrenocortical adenoma?

Abstract

The aim of this study was to investigate the possible association of insulin-like growth factor-1 (IGF-1) with the pathogenesis of non-functioning adrenocortical adenomas (NFAs). This study included 50 female patients (mean age 54years) with NFAs, 55 patients (mean age 48years; 20 male, 35 female) with acromegaly and 38 female control subjects (mean age 58years). Body mass index (BMI) and waist circumference (WC) of the subjects were recorded and blood samples for IGF-1 were taken. Insulin resistance was calculated using the homeostatic model assessment (HOMA) score. Since most of the acromegaly patients had been using medicine that could have effected insulin resistance, HOMA scores were calculated only in patients with NFAs and the controls. Computerized tomography or magnetic resonance imaging was taken of the acromegalics and controls to detect adrenal mass frequency. The mean age was similar among the groups. As expected, the serum IGF-1 levels were significantly higher in patients with acromegaly than in patients with NFAs and the controls (p < 0.001). Although BMI, WC, and serum IGF-1 levels were significantly higher (p < 0.001) in patients with NFAs, the HOMA scores were similar between patients with NFAs and control groups. Although none of the control subjects had adrenal masses, NFAs were detected in 14 (25%) out of 55 acromegalic patients. Higher serum IGF-1 levels in patients with NFAs compared to the control group and an increased prevalence of NFAs in acromegaly patients compared to control subjects and the general population suggest an association of IGF-1 with the etiopathogenesis of NFA.