Long-term use of continuous subcutaneous hydrocortisone infusion therapy in patients with congenital adrenal hyperplasia

Background: In a phase 2 short-term (6 months) study of patients with congenital adrenal hyperplasia (CAH), continuous subcutaneous hydrocortisone infusion (CSHI) was found to be a safe, effective and well-tolerated method of replacing cortisol with improved disease and patient-related outcomes. Objective: To evaluate the safety and efficacy of long-term CSHI. Design: Single-centre, open-label, phase 2 extension study. Patients: Five adults with classic CAH. Measurements: Biomarkers of disease control, metabolic indices and health-related quality-of-life (HRQoL) estimates. Results: Six of eight patients chose to continue on long-term CSHI therapy. Compared to baseline, eighteen months of CSHI resulted in decreased (P = 0.043) 0700-hour ACTH, 17-hydroxyprogesterone, androstenedione and progesterone; increased whole-body lean mass (P = 0.024); and improved HRQoL, especially symptoms of adrenal insufficiency (P = 0.003). Findings at six and eighteen months did not differ, and improvements achieved in androgen control, lean body mass and HRQoL after 6 months of CSHI were maintained at eighteen months. The hydrocortisone dose appeared to decrease with time [6 vs 18 months: 38.3 ± 8.8 vs 33.6 ± 12.2 mg/day (P = 0.062)], especially in women receiving oral contraceptives. Reduction of testicular adrenal rest and adrenal size observed at 6 months remained stable. In one patient, an adrenal adenoma continually decreased over time. Subjective improvement in hirsutism was reported. Conclusions: Long-term use of CSHI is a safe and well-tolerated treatment option in a select set of adults with classic CAH. Improvements observed short term in disease control and subjective health status continued long term.