Endocrine Abstracts

Introduction: Patients with primary adrenal insufficiency (PAI) and patients with congenital adrenal hyperplasia (CAH) receive life-long glucocorticoid (GC) replacement therapy. Today daily GC doses are still higher than the reported adrenal cortisol production rate, and are not able to reproduce the physiological secretion pattern. This might result in long-term morbidities such as osteoporosis. Until now no prospective trial was performed investigating the long-term effect of GC dose changes in PAI and CAH patients.

Subjects and methods: Prospective, longitudinal study including 57 patients with PAI (42 women) and 33 patients with CAH (21 women) over 28.7±5.6 months. Bone mineral density (BMD) was measured by DXA scan. Patients were divided into three groups depending on changes in daily hydrocortisone (HC) equivalent dose (group 1: unchanged 25.2±8.2 mg (n=50); group 2: increased 18.7±10.3 to 25.9±12.0 mg (n=13); group 3: decreased 30.8±8.5 to 21.4±7.2 mg (n=27)).

Results: Patients of group 1 showed unchanged normal Z-scores of lumbar and femoral areas. Patients of group 2 showed a significant decrease in Z-scores of femoral neck and Ward’s triangle (−0.15±1.1 to −0.37±1.0 (P<0.05); −0.45±1.1 to −0.71±1.0 (P<0.05)), whereas patients of group 3 showed a significant increase in Z-scores at lumbar and femoral sites (L1–L2: −0.96±1.1 to −0.76±1.2 (P<0.05); L1–L4: −0.93±1.2 to −0.65±1.5 (P<0.05); total hip: −0.40±1.0 to −0.28±1.0 (P<0.05)). No changes in BMI over time were seen within the groups. No changes in osteocalcin was documented during the study, however beta-crosslabs increased significantly in group 2 over the study period (P<0.05).

Conclusions: For the first time we were able to show that reduction in HC equivalent dose is resulting in an increase in BMD, whereas a dose increase results in a worsening of BMD. This data emphasises to aim at the lowest possible GC replacement dose in AI patients to avoid long-term side effects.