Does subclinical hypercortisolism adversely affect the bone mineral density of patients with adrenal incidentalomas?

Summaryobjective Subclinical hypercortisolism (SH) is detected increasingly in a substantial proportion of patients with incidentally discovered adrenal adenomas. The clinical implications of SH are currently unclear. Osteoporosis is a well‐known complication of glucocorticoid excess. So far, the impact of SH on bone mineral density (BMD) has been studied in a limited number of reports with discordant results. In the present study we evaluated the BMD in a large cohort of post‐menopausal women with adrenal incidentalomas.patients and measurements Forty‐two post‐menopausal women with incidentally discovered adrenal masses and radiological features highly suggestive of benign adrenal adenomas were investigated. All patients underwent a standard low‐dose dexamethasone suppression test (LDDST; 0·5 mg 6‐hourly for 2 days). The diagnosis of subclinical hypercortisolism (SH) was based on post‐LDDST cortisol concentrations of > 70 nmol/l. According to this criterion patients were subdivided into two groups: with (n = 18; group A) or without (n = 24; group B) SH. There was no significant difference in age, years since menopause and body mass index between these groups. BMD was measured at L2–L4 vertebrae and three sites of the proximal femur by the dual energy X‐ray absorptiometry (DEXA) method.results Post‐menopausal women with SH (group A) exhibited slightly but significantly lower absolute and age‐adjusted BMD values compared to group B patients in the femoral neck (BMD g/cm2: 0·72 ± 0·08 vs. 0·79 ± 0·09; Z‐score: −0·20 ± 0·82 vs. +0·43 ± 0·94, P < 0·05) and trochanter (BMD g/cm2: 0·60 ± 0·09 vs. 0·69 ± 0·10; Z‐score: −0·32 ± 1·0 vs. +0·30 ± 1·05, P < 0·01). BMD measurements of the Ward's triangle were also lower in group A patients but the difference did not reach statistical significance (BMD g/cm2: 0·60 ± 0·10 vs. 0·68 ± 0·13, P = 0·06). There was no difference in the lumbar vertebrae between the two groups (BMD g/cm2: 0·888 ± 0·13 vs. 0·90 ± 0·16, P = 0·78; z‐score: +0·50 ± 1·16 vs. +0·11 ± 1·5, P = 0·36). The number of patients in the osteoporotic range was minimal with no significant difference between the two groups. However, the frequency of osteopenia in group A was significantly greater than in group B patients in the trochanter and Ward's triangle areas. Serum osteocalcin (BGP) levels were significantly lower in group A compared to group B patients (18·6 ± 8·6 vs. 26·2 ± 8·1 ng/ml, P < 0·01); no difference existed regarding parathyroid hormone (PTH) concentrations (43 ± 15·6 vs. 41·2 ± 14·8 pg/ml, P = 0·72).conclusions In this series, post‐menopausal women with subclinical hypercortisolism had lower absolute and age‐adjusted BMD values and a higher rate of osteopaenia in the trabecular loaded and mixed cortical–trabecular bone of proximal femur. These data demonstrate that the subtle hypercortisolism of patients with adrenal incidentalomas may have an adverse effect on the bone mass of these patients.