Modified-Release and Conventional Glucocorticoids and Diurnal Androgen Excretion in Congenital Adrenal Hyperplasia

Abstract

Context: The classic androgen synthesis pathway proceeds via dehydroepiandrosterone, androstenedione, and testosterone to 5α-dihydrotestosterone. However, 5α-dihydrotestosterone synthesis can also be achieved by an alternative pathway originating from 17α-hydroxyprogesterone (17OHP), which accumulates in congenital adrenal hyperplasia (CAH). Similarly, recent work has highlighted androstenedione-derived 11-oxygenated 19-carbon steroids as active androgens, and in CAH, androstenedione is generated directly from 17OHP. The exact contribution of alternative pathway activity to androgen excess in CAH and its response to glucocorticoid (GC) therapy is unknown.

Objective: We sought to quantify classic and alternative pathway-mediated androgen synthesis in CAH, their diurnal variation, and their response to conventional GC therapy and modified-release hydrocortisone.

Methods: We used urinary steroid metabolome profiling by gas chromatography-mass spectrometry for 24-hour steroid excretion analysis, studying the impact of conventional GCs (hydrocortisone, prednisolone, and dexamethasone) in 55 adults with CAH and 60 controls. We studied diurnal variation in steroid excretion by comparing 8-hourly collections (23:00-7:00, 7:00-15:00, and 15:00-23:00) in 16 patients with CAH taking conventional GCs and during 6 months of treatment with modified-release hydrocortisone, Chronocort.

Results: Patients with CAH taking conventional GCs showed low excretion of classic pathway androgen metabolites but excess excretion of the alternative pathway signature metabolites 3α,5α-17-hydroxypregnanolone and 11β-hydroxyandrosterone. Chronocort reduced 17OHP and alternative pathway metabolite excretion to near-normal levels more consistently than other GC preparations.

Conclusions: Alternative pathway-mediated androgen synthesis significantly contributes to androgen excess in CAH. Chronocort therapy appears superior to conventional GC therapy in controlling androgen synthesis via alternative pathways through attenuation of their major substrate, 17OHP.

Figure 1.

Schematic overview of steroidogenesis. The graph depicts steroidogenesis, including the classic androgen synthesis pathway (shaded in dark gray) and the 2 alternative androgen synthesis pathways (shaded in light gray; top, 11-oxygenated 19-carbon steroids; bottom, alternative pathway to DHT). 3α,5α-17HP is labeled by its alternative full name, 17-OH-allopregnanolone.

Figure 2.

The 24-hour urinary steroid excretion in 55 patients with CAH and 60 healthy sex- and age-matched controls. For explanation of steroid metabolite abbreviations, see Table 1. (A) 17OHP metabolites. (B) 11-deoxycortisol metabolite. (C) Sum of active androgen metabolites. (D) Signature alternative pathway metabolite. (E) Ratio of alternative pathway/total 5α-reduced androgen metabolites. (F) Major 11-oxygenated androgen pathway metabolite. Data are shown as µg/24 hours and presented as box-and-whisker plots to represent median, interquartile range (box), and 5th and 95th percentiles (whiskers). Urinary excretion of 3α5α-17HP available for 38 of the total CAH cohort. Analyses were undertaken using the Mann-Whitney test. ***P ≤ 0.001 for CAH vs controls. PT, pregnanetriol; THS, tetrahydro-11-deoxycortisol.

Figure 3.

Eight-hourly diurnal urinary steroid metabolite excretion in 16 patients with CAH due to 21OHD and 12 healthy controls. (A) 17OHP metabolites. (B) 11-deoxycortisol metabolite. (C) Sum of active androgen metabolites. (D) Signature alternative pathway metabolite. (E) Ratio of alternative pathway/total 5α-reduced androgen metabolites. (F) Major 11-oxygenated androgen pathway metabolite. Data are shown for night (23:00–07:00; dark gray), morning (07:00–15:00; white), and evening (15:00–23:00; light gray) time periods. Excretion of the major androgen metabolites An + Et is shown for male patients with CAH (n = 8) and matched healthy controls (n = 12). Box-and-whisker plots represent median, interquartile range (box), and 5th and 95th percentiles (whiskers). Comparisons were drawn within CAH and control groups with analyses undertaken using the Friedman test, which was applied to the patients with CAH and the control participants separately. *P ≤ 0.05 for comparison of steroid excretion during different 8-hour periods. ***P ≤ 0.001. PT, pregnanetriol; THS, tetrahydro-11-deoxycortisol.

Figure 4.

Effect of Chronocort treatment on 24-hour urinary steroid metabolite excretion in patients with CAH due to 21OHD. (A) 17OHP metabolites. (B) 11-deoxycortisol metabolite. (C) Sum of active androgen metabolites. (D) Signature alternative pathway metabolite. (E) Ratio of alternative pathway/total 5α-reduced androgen metabolites. (F) Major 11-oxygenated androgen pathway metabolite. Results are shown for patients with CAH at baseline taking conventional GC therapy prior to commencing Chronocort (BL; n = 16), at day 4 of Chronocort treatment (D4; n = 16), and after 6 months of Chronocort treatment (M6; n = 15). Box-and-whisker plots represent median, interquartile range (box), and 5th and 95th percentiles (whiskers). Analyses were undertaken using repeated Wilcoxon tests with Bonferroni correction to compare between matched patients with CAH. *P ≤ 0.05. PT, pregnanetriol; THS, tetrahydro-11-deoxycortisol.

Figure 5.

Urinary steroid excretion in 60 healthy controls and patients with CAH treated with Chronocort (n = 16), conventional immediate-release hydrocortisone (n = 13), prednisolone (n = 27), or dexamethasone (n = 15). (A) Sum of active androgen metabolites. (B) Signature alternative pathway metabolite. (C) 11β-hydroxyandrosterone, the major metabolite of the 11-oxygenated androgen pathway. (D) Sum of 17OHP metabolites. (E) Glucocorticoid metabolite 11-hydroxy-etiocholanolone. (F) Glucocorticoid metabolite 11-oxo-etiocholanolone. Urinary excretion of 3α5α-17HP available for 54 of the total CAH cohort; 16 on Chronocort, 11 on conventional hydrocortisone, 21 on prednisolone, and 6 on dexamethasone. GC treatment was stable for at least 6 months at the time of 24-hour urine collection. Box-and-whisker plots represent median, interquartile range (box), and 5th and 95th percentiles (whiskers). Analyses were undertaken using the Kruskal-Wallis test with post hoc Dunn. *P ≤ 0.05, ***P ≤ 0.001. PT, pregnanetriol; THS, tetrahydro-11-deoxycortisol.