Endocrine Abstracts

Objective

There are few data on long-term follow-up of patients with nonfunctioning adrenal incidentalomas (NFAIs). We aimed to determine the natural history of NFAI at 10 year follow-up. We also evaluated the associations between baseline body mass index (BMI) and changes of NFAIs’ and patients’ characteristics at follow-up period.

Design

Longitudinal observational study.

Patients

We included 67 patients (20 (29.9%) males, 47 (70.1%) females, mean age 57.9 (52.3–63.9) years and BMI 27.42 (24.07–30.56) (kg/m²)) presenting with NFAI. Twenty patients had BMI < 25 kg/m², 21 BMI 25–30 kg/m² and 26 had BMI > 30 kg/m² at the initial presentation. The mean follow-up period was 10.5 (9.1–11.9) years.

Measurements

Clinical, laboratory and computed tomography (CT) characteristics were assessed and compared with baseline.

Results

Progression to mild autonomous cortisol excess (MACE) was observed in 22 % patients. The progression rate was significantly higher in overweight and obese subjects, given that 5% progression rate was observed in patients with baseline BMI < 25 kg/m², 33.3% in a group with BMI 25–30 kg/m² and 26.7% in a group with BMI > 30 kg/m². Clinically significant tumor enlargement ≥ 10 mm occurred in 8.9% patients. Prevalence of cardiometabolic disorders at follow-up was significantly higher than at baseline, especially in groups with initial BMI ≥ 25 kg/m². At follow-up, 37.9% of patients had additional CT changes in kidneys, 21.2% in gastrointestinal tract, 18.2% in liver region, and 10.4% in pancreas, mostly cysts. Three patients with BMI > 30 kg/m² were referred to further diagnostics to rule out possible malignant disease incidentally found by CT imaging, unrelated to NFAI.

Conclusion

Duration of the follow-up period is an important factor in characterizing the natural history of NFAI. Higher baseline BMI might predict the long-term likelihood of change in hormonal activity and occurrence of metabolic disorders in patients with NFAI. The clinical significance of the highly prevalent concomitant CT findings in this population and the potential role of periodic CT reassessments in obese subjects with NFAI need further evaluations.