Endocrine Abstracts

Introduction: Patients with primary adrenal insufficiency (Addison’s disease) and patients with congenital adrenal hyperplasia (CAH) still tend to receive more glucococorticoids than the normal endogenous production in healthy subjects. CAH patients start glucocorticoid treatment usually with diagnosis in their early childhood, whereas Addison’s patients have a later onset of their disease and start of their treatment.

Objective: To compare patients with Addison’s disease and CAH in regard to their bone mineral density (BMD), the duration of glucocorticoid therapy and the impact of glucocorticoid pharmacogenetics.

Design, setting and participants: In a cross-sectional study patients from one university endocrine outpatient clinic were included (84 patients with Addison’s disease, 42 patients with CAH). Bone mineral density (BMD) was measured using DXA scan. Blood samples were analysed for bone markers and 24 h urinary samples were analyzed for bone resorption markers.

Results: Patients with Addison’s disease were significantly older (55.1±15.2 vs 39.9±13.8y, P<0.001) and taller (168±10 vs 160±11 cm, P<0.001) than CAH patients, but showed no difference in BMI. Time since diagnosis was shorter in Addison’s patients (14.9±10.4 vs 30.5±13.5y, P<0.001). The calculated hydrocortisone equivalent glucocorticoid dose per body surface was higher in CAH than Addison’s patients (15.6±7.2 vs 11.9±2.4 mg/m², P<0.001). No differences were seen in serum Ca, aP, ostase, PTH, 25-vitamin D₃, 1,25-vitamin D₃, osteocalcin or urinary cross-links. Femoral neck BMD Z-scores were significantly lower in patients with CAH compared to patients with Addison’s disease (−0.59±1.17 vs 0.0±0.99, P<0.01); also Z-scores for femoral Ward’s region were lower in CAH patients (−0.96±1.04 vs −0.28±1.03, P<0.005). No difference was found in lumbar spine Z-scores.

Conclusions: BMD at femoral neck and femoral Ward’s region were lower in CAH than Addison’s disease patients, indicating undesirable effects of higher glucocorticoid dose, usage of longer acting glucocorticoids, and longer duration of replacement therapy.