Endocrine Abstracts

Background: The relationship between obesity, metabolic traits and adrenal incidentaloma (AI) in clinical studies have been discussed mainly in one direction: as the consequences of mild autonomous cortisol secretion in autonomous cortisol secreting AI (ACS) and as possible consequences of minimal hormonal secretion not detectable by current diagnostic methods in non-functioning (NF) AI. However, the observed anabolic and mitogenic effects of insulin on adrenal cortex from preclinical models led to the hypothesis of the potential existence of bilateral relationship between obesity and AI. In clinical studies, obesity as a primary cause of AI and as a main risk estimator of metabolic burden in patients with AI remained largely unaddressed.

Purpose: We compared the incidence and characteristics of non-functional (NF) and autonomous cortisol secreting (ACS) adrenal incidentaloma (AIs) after cohort was stratified by different body mass indexes (BMI) and age groups.

Methods: Cohort study comprising of 432 patients (40,6% male, 59,4% female) with NFAI (n = 290) and ACS (n = 142), of median age 63.4 (54.0–71.6) years and median BMI 28.6 (25.5–31.7) kg/m². The data collection contained 11.132 points including demographic, anthropometric, radiologic, hormonal and metabolic parameters.

Results: We observed 68-87% higher incidence of AI across different age groups in NFAI and ACS if BMI was > 25 kg/m² compared to BMI ≤ 25 kg/m² (Figure1). Patients with ACS were older (P = 0.008), with higher basal cortisol (P < 0.001), lower basal DHEAS (P = 0.001), lower suppression DHEAS (P = 0.027) and higher aldosterone (P = 0.039). AIs with ACS were larger than NFAI. Interestingly, ACS group had lower body mass (P = 0.023) and did not differ in BMI, blood pressure, heart rate, lipid profile, fasting glucose and presence of diabetes mellitus type 2 when compared to NFAI. By contrast, some components of metabolic profile were rather associated with higher BMI and older age, in particular in NFAI.

Conclusion: The incidences of NFAI and ACS were significantly higher in overweight/obese subgroup across the age distribution. Incomplete post-dexamethasone cortisol suppressionwas not a reliable predictor of metabolic alterations, whereas stratification by age and BMI displayed significant differences in some metabolic traits, in particular in NFAI.

Figure 1 Incidence of AI in NFAI (A) and ACS (B) patients stratified by age and BMI ^*

^*The data analyses for patients below 40 years and above 85 years are truncated because less than 5 subjects were included within those age-subgroups.