Adrenalectomy reduces the risk of vertebral fractures in patients with monolateral adrenal incidentalomas and subclinical hypercortisolism

Objective: Subclinical hypercortisolism (SH) is associated with increased risk of vertebral fractures (VFx). The effect on bone following recovery from SH is unknown. Design: Of the 605 subjects consecutively referred for monolateral adrenal incidentalomas (AIs) to our outpatient clinics, 55 SH patients (recruited on the basis of the exclusion criteria) were enrolled. We suggested to all patients to undergo adrenalectomy, which was accepted by 32 patients (surgical group, age 61.3 +/- 8.1 years) and refused by 23 patients, who were followed with a conservative management (non-surgical group, age 65.4 +/- 7.1 years). Methods: We diagnosed SH in patients with serum cortisol after 1 mg dexamethasone suppression test (1 mg-DST) >5.0 mu g/dl or with greater than or equal to two criteria among 1 mg-DST >3.0 mu g/dl, urinary free cortisol >70 mu g/24 h and ACTH < 10 pg/ml. We assessed: bone mineral density (BMD) at lumbar spine (LS) and femoral neck (as Z-score) by dual-energy X-ray absorptiometry and the VFx presence by X-ray at baseline and at the end of follow up (surgical group 39.9 +/- 20.9 months and non-surgical group 27.7 +/- 11.1 months). Results: The LS Z-score (DZ-score/year) tended to increase in the surgical group (0.10 +/- 0.20) compared with the non-surgical group (-0.01 +/- 0.27, P=0.08) and in the former, the percentage of patients with new VFx was lower (9.4%) than in the latter (52.2%, P<0.0001). Surgery in AI patients with SH was associated with a 30% VFx risk reduction (odds ratio 0.7, 95% CI 0.01-0.05, P=0.008) regardless of age, gender, follow up duration, 1 mg-DST, LS BMD, and presence of VFx at baseline. Conclusion: In patients with monolateral AI and SH, adrenalectomy reduces the risk of VFx.