The number of adrenal incidentaloma (AI) cases has increased in the last few years due to the widespread use of imaging diagnostics. Management requires evaluation of the malignant nature and hormonal activity. The aim of the present study is to assess possible clinical abnormalities in 132 AI patients both at baseline and during follow-up (mean 48.6 ± 12.5 months). In all patients, demographic, anthropometric data, biochemical, metabolic and hormonal data, and 24-h ambulatory blood pressure monitoring were assessed. Mild autonomous cortisol secretions (MACS) were diagnosed in patients without signs and symptoms of overt Cushing’s syndrome and post dexamethasone (DXM) plasma cortisol concentration > 50 nmol/L (>1.8 μg/dL). Patients with overnight DXM-1 mg test positive showed higher values of diastolic blood pressure, glycemia and uric acid levels compared to patients with negative DXM test at baseline. During follow-up, the potential development of MACS in patients with nonfunctional AI showed a prevalence of 29%, though the cardiovascular and metabolic alterations were less pronounced compared to those diagnosed with MACS at baseline. Therefore, follow-ups with AI patients are useful for observing changes in clinical features.