ESPE Abstracts

Background: An abnormal blood pressure (BP) circadian rhythm, and in particular a non- dipping phenomenon is associated with increased cardiovascular and cerebrovascular health risks. In patients on steroid replacement therapy non physiological substitution may affect the BP profile.

Objective and hypotheses: i) to evaluate the circadian BP profiles of patients with congenital adrenal hyperplasia (CAH) on steroid replacement therapy, ii) to compare BP profiles of patients receiving hydrocortisone (HC) and fludrocortisone in different dosing schedules.

Method: The study included 60 patients (32 girls) with classic CAH due to 21-hydroxylase deficiency (mean age 9.4 years, range 1.7–17.9). Patients received a mean of 17.1 mg/m² of HC in the following dosing schedules: 25 patients in three equal doses, 15 patients 40% of their daily dose in the morning (M) and in the afternoon (A) and 20% in the evening (E), the remaining 20 patients: 50%M+25%A+25%E. Fludrocortisone (FC) was given to 40 patients: in 26: in two equal daily doses (a), in 11: 2/3M+1/3E (b), and in 3: 1/3M+2/3E(c). The standard 24-h BP monitoring was performed using an Ambulatory BP Monitor (Spacelabs 90217, USA).

Results: 24 h systolic (SBP) and diastolic (DBP) loads>30% were found in 18.3 and 15% of patients. Night SBP and DBP loads>30% were found in 36.6 and 31.6% of patients. 40 (66.6%) patients presented with an abnormal 24-h BP profile with no significant night dip (dip<10%). The results were not dependent on the HC dosing schedule but were dependent on the total HC dose in kg/m² (dip<10%: 17.9 vs dip>10%: 15.3 kg/m², P<0.05), FC dose (dip<10%: 67 mcg vs dip>10%: 59 mcg) and FC dosing schedule: (a) vs (b): mean dip: 12% vs mean dip: 6.3%, P<0,04.

Conclusion: Abnormal 24-h BP profile in CAH patients is not associated with HC dosing schedule but with the HC and FC dose and also FC dosing schedule.