Lipid abnormalities in patients with adrenal incidentalomas: role of subclinical hypercortisolism and impaired glucose metabolism.

Background: Subclinical hypercortisolism (SH) has been associated with metabolic complications such as type 2 diabetes mellitus, obesity and dyslipidemia. Scarce data are available regarding the lipid pattern abnormalities in SH, in relation to insulin resistance and impaired glucose metabolism (IGM). We aimed to evaluate the possible influence of SH on lipid pattern in relation to the presence/absence of impaired glucose metabolism.
Methods: In 338 patients with adrenal incidentaloma, the presence of SH, hypertension, dyslipidemia and IGM was evaluated. According to the presence of SH and IGM the patients were divided into 4 groups (IGM+SH+, IGM+SH-, IGM-SH+, IGM-SH-). We recruited 98 subjects without IGM (IGM-) and 100 with IGM (IGM+) as control groups.
Results: The prevalence of dyslipidemia was comparable among Group IGM+SH+, Group IGM+SH- and IGM+ controls (57.9, 58.4, 56%, P = NS). No difference in dyslipidemia prevalence among IGM- patients and IGM- controls was observed. The IGM+SH+ patients had a higher prevalence of dyslipidemia (57.9%) than IGM-SH+ ones (29.1%, P < 0.01). The IGM+SH- patients showed an increased prevalence of hypertension (76.6 vs 54.8%, P < 0.01) and dyslipidemia (58.4 vs 23.8%, P < 0.0001) as compared with IGM-SH- patients. Logistic regression analysis showed that only IGM was associated to dyslipidemia (OR 4.31, 95% CI 2.61-7.12, P = 0.0001) regardless of age, SH and gender.
Conclusions: In the absence of alterations of glucose metabolism the presence of a subtle cortisol excess has no effect on lipid pattern. IGM seems to influence the lipid metabolism regardless of the presence of SH.