Endocrine Abstracts

JOINT1783

Background: Patients with classic congenital adrenal hyperplasia (CAH) show an increased prevalence of metabolic comorbidities, with glucocorticoid substitution therapy presenting a possible risk factor, due to unphysiological replacement. Therefore, the aim of this study was to assess the glucose pattern through continuous glucose monitoring (CGM) over 24 hs under different GC replacement regimen.

Methods: Adult patients with a confirmed diagnosis of classic CAH who received a substitution therapy with either conventional hydrocortisone or predniso(lo)ne were included in this study. All patients wore a CGM sensor once, measuring glucose concentration in the tissue every 5 minutes from 1 h after application up to a maximum of 14 days. Three time periods were defined over 24 hs: 6am-2pm, 2pm-10pm and 10pm-6am. Hydrocortisone dose equivalent (HDE) was calculated as prednisone dose multiplied by 4 and prednisolone dose multiplied by 5.

Results: A total of 44 patients with a median (range) age of 33.0 (35.0) years and a median (IQR) BMI of 26.4 (10.4) were included in the analysis (23 female, 21 male; 30 SW, 14 SV), of which 20 (45.5%) received conventional hydrocortisone and 24 (54.5%) predniso(lo)ne as glucocorticoid substitution therapy, with a median (IQR) total daily HDE of 30.0 mg/d (11.9). The median (range) measuring time of the sensor was 13.0 (9.0) days. There was no significant difference concerning median age, BMI or HDE between patients receiving conventional hydrocortisone and predniso(lo)ne. Concerning CGM, patients with predniso(lo)ne showed significantly more often glucose values between 140-<180 mg/dl between 6am-2pm (3.2% vs. 1.0%; P = .030), corresponding to 15.4 vs. 4.8 minutes, whilst patients on conventional HC showed significantly more often glucose concentrations in the normal range of 70-<140 mg/dl between 6am-2pm (98.1% vs. 95.5%; P = .012), corresponding to 470.9 vs. 458.4 minutes. There were no statistically significant differences between 2pm-10pm and 10pm-6am between the two groups. For the total cohort, we found a significant positive correlation between the median evening HDE with the average glucose concentrations (r = .450; P = .002) between 10pm-6am.

Conclusion: Our preliminary data indicate slightly different glucose patterns over 24 hs in patients with CAH receiving different glucocorticoid substitution therapy. The intake of longer acting preparations, as well as higher dosage, seem to be associated with slightly higher glucose concentrations, which should be taken into account when identifying patients with an increased metabolic risk.