Risk of new vertebral fractures in patients with adrenal incidentaloma with and without subclinical hypercortisolism: a multicenter longitudinal study

In patients with adrenal incidentalomas (AIs), cross-sectional studies suggested the presence of an association between subclinical hypercortisolism (SH) and an increased prevalence of vertebral fractures (VFx) and spinal deformity index (SDI), which is a clinical index of bone quality. No longitudinal studies investigated the incidence of VFx and SDI changes over time in SH. The aim of this study was to evaluate VFx risk and SDI changes in SH over time. One-hundred-three consecutive AI patients were studied at baseline and after 12 and 24 months. Patients were divided into SH(+) (n = 27) and SH(-) (n = 76) groups on the basis of the presence of two or more among urinary free cortisol greater than 70 µg/24 hours, serum cortisol after 1-mg dexamethasone suppression test greater than 3.0 µg/dL, and adrenocorticotropic hormone (ACTH) less than 10 pg/mL in 2 or more of the 3 evaluations. At baseline and after 24 months, bone mineral density (BMD) by dual-energy X-ray absorptiometry and the presence of VFx and SDI by summing the grade of deformity for each vertebra were evaluated. At the end of follow-up, the SH(+) group showed a higher prevalence of VFx (81.5%) as compared with baseline (55.6%, p = .04) and a worsening of SDI (2.11 ± 1.85 versus 1.11 ± 1.47, p = .032) associated with SH regardless of age, gender, body mass index , BMD, baseline SDI, menopause duration [odds ratio (OR) = 12.3, 95% confidence interval (CI) 4.1-36.5, p = .001]. The incidence of new vertebral fractures was higher in the SH(+) group (48%) than in the SH(-) group (13%; p = .001). It is concluded that subclinical hypercortisolism is associated with an increased risk of VFx and a possible deterioration of bone quality.