Endocrine Abstracts

Background: Sclerostin is a protein secreted by osteocytes, that inhibits Wnt/ βcatenin signaling and was suggested to play a role in glucocorticoid-induced osteoporosis in mice. In humans data are inconsistent. Patients with primary adrenal insufficiency need lifelong replacement therapy with glucocorticoids and mineralocorticoids, which may influence their bone quality.

Aim: The aim of the study was to evaluate sclerostin concentrations, densitometry parameters, and trabecular bone score in patients with primary adrenal insufficiency in comparison to control group.

Materials and Methods: We included 29 patients (62% females) with diagnose of autoimmune primary adrenal insufficiency (mean age 49.7±11.7 years, mean duration of the disease 13.2± 13.6 years) and 33 healthy subjects (adjusted with age, sex and body mass index). Bone mineral density at the femoral neck, lumbar spine, total body and trabecular bone score were evaluated. Serum sclerostin concentrations were measured.

Results: Mean serum sclerostin concentration was significantly higher in patients with adrenal insufficiency than in control group (44.7±23.5 vs 30.7±10.4 pmol/l, P=0.006). There were no significant differences in densitometry parameters (Tscore, Z-score, bone mineral density) and trabecular bone score in patients with adrenal insufficiency and control group. There was a negative correlation between trabecular bone score and the duration of adrenal insufficiency and age, also a negative correlation between femoral neck and total densitometry parameters and 24-hour urine cortisol. Sclerostin concentration correlated positively only with free thyroxine concentration (R=0.486, P=0.009; no significant correlation with serum TSH), there were no significant correlations with any other clinical or biochemical parameters.

Conclusions: The sclerostin concentration was higher in patients with primary adrenal insufficiency in comparison to control group. This finding needs further studies.