Adrenarche does not occur in treated patients with congenital adrenal hyperplasia resulting from 21-hydroxylase deficiency

Effect of complete suppression of androstenedione on auxological development in prepubertal patients with classical congenital adrenal hyperplasia

OBJECTIVES

Children with classical congenital adrenal hyperplasia (CAH) require glucocorticoid (GC) substitution due to impaired cortisol synthesis. To avoid over- or undertreatment, one has to consider auxology as well as biochemical parameters for adrenal derived steroids like androstenedione (A4) and 17-hydroxyprogesterone (17-OHP). There are no established reference values for A4 and 17-OHP in CAH.

METHODS

We performed a retrospective study in 53 prepubertal patients with CAH. Datasets of patients were included if the plasma A4 values of the respective clinical visit were under the limit of quantification. Related 17-OHP values were extracted as well as height/length, weight, dose of hydrocortisone, HC regimen, bone age and stages of pubertal development.

RESULTS

Median hydrocortisone doses were in most observations within the recommended reference ranges. Hydrocortisone has a significant negative influence on 17-OHP values and HSDS. Age has a positive significant influence on 17-OHP, BMI-SDS, and HSDS. Median height standard-deviation-score (HSDS) was beneath 0 at all times, but showed an increasing trend in both sexes. Median body mass index standard-deviation-score (BMI-SDS) was above 0 at all times and showed an increasing trend as well.

CONCLUSIONS

With guideline-compliant doses of hydrocortisone, suppression of A4 at the respective time of day is possible in prepubertal children. Although HC has a significant negative influence on HSDS, increasing values for HSDS and HC are observed with increasing age. Thus, A4 suppression at the respective time point does not hinder regular growth. An increase in body mass index can already be observed as early as in prepuberty.

Biomarkers in congenital adrenal hyperplasia

Monitoring of hormone replacement therapy represents a major challenge in the management of congenital adrenal hyperplasia (CAH). In the absence of clear guidance and standardised monitoring strategies, there is no consensus among clinicians regarding the relevance of various biochemical markers used in practice, leading to wide variability in their application and interpretation. In this review, we summarise the published evidence on biochemical monitoring of CAH. We discuss temporal variations of the most commonly measured biomarkers throughout the day, the interrelationship between different biomarkers, as well as their relationship with different glucocorticoid and mineralocorticoid treatment regimens and clinical outcomes. Our review highlights significant heterogeneity across studies in both aims and methodology. However, we identified key messages for the management of patients with CAH. The approach to hormone replacement therapy should be individualised, based on the individual hormonal profile throughout the day in relation to medication. There are limitations to using 17-hydroxyprogesterone, androstenedione and testosterone, and the role of additional biomarkers such 11-oxygenated androgens which are more disease specific should be further established. Noninvasive monitoring via salivary and urinary steroid measurements is becoming increasingly available and should be considered, especially in the management of children with CAH. Additionally, this review indicates the need for large scale longitudinal studies analysing the interrelation between different monitoring strategies used in clinical practice and health outcomes in children and adults with CAH.

Characteristics of Growth in Children With Classic Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency During Adrenarche and Beyond

CONTEXT

Patients with classic congenital adrenal hyperplasia (CAH) often do not achieve their full growth potential. Adrenarche may accelerate bone maturation and thereby result in decreased growth in CAH.

OBJECTIVE

The study aimed to analyze the impact of growth during adrenarche on final height of adequately treated classic CAH patients.

METHODS

This retrospective, multicenter study (4 academic pediatric endocrinology centers) included 41 patients with classical CAH, born 1990-2012. We assessed skeletal maturation (bone age), growth velocity, and (projected) adult height outcomes, and analyzed potential influencing factors, such as sex, genotype, and glucocorticoid therapy.

RESULTS

Patients with classic CAH were shorter than peers (-0.4 SDS ± 0.8 SD) and their parents (corrected final height -0.6 SDS ± 1.0 SD). Analysis of growth during adrenarche revealed 2 different growth patterns: patients with accelerating bone age (49%), and patients with nonaccelerating bone age relative to chronological age (BA-CA). Patients with accelerating BA-CA were taller than the normal population during adrenarche years (P = 0.001) and were predicted to achieve lower adult height SDS (-0.9 SDS [95% CI, -1.3; -0.5]) than nonaccelerating patients when assessed during adrenarche (0.2 SDS [95% CI, -0.3; 0.8]). Final adult height was similarly reduced in both accelerating and nonaccelerating BA-CA groups (-0.4 SDS [95% CI, -0.9; 0.1] vs -0.3 SDS [95% CI, [-0.8; 0.1]).

CONCLUSION

Patients with and without significant bone age advancement, and thus differing height prediction during adrenarche, showed similar (predicted) final height when reassessed during pubertal years. Bone age alone should not be used during adrenarche as clinical marker for metabolic control in CAH treatment.

Adrenal androgens, adrenarche, and zona reticularis: A human affair?

In humans, reticularis cells of the adrenal cortex fuel the production of androgen steroids, constituting the driver of numerous morphological changes during childhood. These steps are considered a precocious stage of sexual maturation and are grouped under the term "adrenarche". This review describes the molecular and enzymatic characteristics of the zona reticularis, along with the possible signals and mechanisms that control its emergence and the associated clinical features. We investigate the differences between species and discuss new studies such as genetic lineage tracing and transcriptomic analysis, highlighting the rodent inner cortex's cellular and molecular heterogeneity. The recent development and characterization of mouse models deficient for Prkar1a presenting with adrenocortical reticularis-like features prompt us to review our vision of the mouse adrenal gland maturation. We expect these new insights will help increase our understanding of the adrenarche process and the pathologies associated with its deregulation.

PKA signaling drives reticularis differentiation and sexually dimorphic adrenal cortex renewal

The adrenal cortex undergoes remodeling during fetal and postnatal life. How zona reticularis emerges in the postnatal gland to support adrenarche, a process whereby higher primates increase prepubertal androgen secretion, is unknown. Using cell-fate mapping and gene deletion studies in mice, we show that activation of PKA has no effect on the fetal cortex, while it accelerates regeneration of the adult cortex, triggers zona fasciculata differentiation that is subsequently converted into a functional reticularis-like zone, and drives hypersecretion syndromes. Remarkably, PKA effects are influenced by sex. Indeed, testicular androgens increase WNT signaling that antagonizes PKA, leading to slower adrenocortical cell turnover and delayed phenotype whereas gonadectomy sensitizes males to hypercorticism and reticularis-like formation. Thus, reticularis results from ultimate centripetal conversion of adult cortex under the combined effects of PKA and cell turnover that dictate organ size. We show that PKA-induced progenitor recruitment is sexually dimorphic and may provide a paradigm for overrepresentation of women in adrenal diseases.

A New Model for Adrenarche: Inhibition of 3β-Hydroxysteroid Dehydrogenase Type 2 by Intra-Adrenal Cortisol

We propose that the normal adrenarche-related rise in dehydroepiandrosterone (DHEA) secretion is ultimately caused by the rise in cortisol production occurring during childhood and adolescent growth, by the following mechanisms. (1) The onset of childhood growth leads to a slight fall in serum cortisol concentration due to growth-induced dilution and a decrease in the negative feedback of cortisol upon ACTH secretion. (2) In response, ACTH rises and stimulates increased cortisol synthesis and secretion in the growing body to restore the serum cortisol concentration to normal. (3) The cortisol concentration produced within and taken up by adrenocortical steroidogenic cells may rise during this time. (4) Cortisol competitively inhibits 3β-hydroxysteroid dehydrogenase type 2 (3βHSD2)-mediated conversion of 17αOH-pregnenolone to cortisol, causing a further fall in serum cortisol, a further decrease in the negative feedback of cortisol upon ACTH, a further rise in ACTH, and further stimulation of adrenal steroidogenesis. (5) The cortisol-mediated inhibition of 3βHSD2 also blocks the conversion of DHEA to androstenedione, causing a rise in adrenal DHEA and DHEA sulfate relative to androstenedione secretion. Thus, the combination of normal body growth plus inhibition of 3βHSD2 by intra-adrenal cortisol may cause normal adrenarche. Childhood obesity may hasten this process by causing a pathologic increase in body size that triggers these same processes at an earlier age, resulting in the premature onset of adrenarche.

Salivary morning androstenedione and 17α-OH progesterone levels in childhood and puberty in patients with classic congenital adrenal hyperplasia

BACKGROUND

Treatment of congenital adrenal hyperplasia due to 21-hydroxylase deficiency can be monitored by salivary androstenedione (A-dione) and 17α-hydroxyprogesterone (17OHP) levels. There are no objective criteria for setting relevant target values or data on changes of 17OHP and A-dione during monitoring.

METHODS

We evaluated A-dione and 17OHP levels in nearly 2000 salivary samples collected during long-term treatment of 84 paediatric patients with classic 21-hydroxylase deficiency.

RESULTS

A-dione and 17OHP levels and its ratio 17OHP/A-dione remained constant from 4 to 11 years with no sex-related differences. During puberty, A-dione and 17OHP levels both increased, starting at earlier age in girls than in boys. The ratio 17OHP/A-dione declined. Normalised A-dione concomitant with elevated 17OHP [1.43 nmol/L (0.46-4.41) during prepuberty; 2.36 nmol/L (0.63-8.89) for boys and 1.99 nmol/L (0.32-6.98) for girls during puberty] could be obtained with overall median glucocorticoid doses of 11-15 mg/m2/day. A-dione levels above the upper reference limit (URL), suggesting undertreatment, coincided with 17OHP levels ≥10 times URL. The percentage of A-dione levels above URL was 16% at ages 4-8 years, but increased to 31% for girls at 16 years and 46% for boys at 17 years.

CONCLUSIONS

Normalised A-dione consistent with 17OHP three times URL during prepuberty and normalised A-dione consistent with 4-6 times URL during puberty could be obtained by moderate glucocorticoid dosages. A constant 17OHP/A-dione ratio during prepuberty suggested absence of adrenarche. During puberty, a higher percentage of samples met the criteria for undertreatment, especially of boys.

Amides of non-steroidal anti-inflammatory drugs with thiomorpholine can yield hypolipidemic agents with improved anti-inflammatory activity

Novel amides of non steroidal anti-inflammatory drugs (NSAIDs), α-lipoic acid and indole-3-acetic acid with thiomorpholine were synthesised by a simple method and at high yields (60-92%). All the NSAID derivatives highly decreased lipidemic indices in the plasma of Triton treated hyperlipidemic rats. The most potent compound was the indomethacin derivative, which decreased total cholesterol, triglycerides and LDL cholesterol by 73%, 80% and 83%, respectively. They reduced acute inflammation equally or more than most parent acids. Hence, it could be concluded that amides of common NSAIDs with thiomorpholine acquire considerable hypolipidemic potency, while they preserve or augment their anti-inflammatory activity, thus addressing significant risk factors for atherogenesis.

Cortical bone mineral density in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

BACKGROUND

Prior studies reveal that bone mineral density (BMD) in congenital adrenal hyperplasia (CAH) is mostly in the osteopaenic range and is associated with lifetime glucocorticoid dose. The forearm, a measure of cortical bone density, has not been evaluated.

OBJECTIVE

We aimed to evaluate BMD at various sites, including the forearm, and the factors associated with low BMD in CAH patients.

METHODS

Eighty CAH adults (47 classic, 33 nonclassic) underwent dual-energy-x-ray absorptiometry and laboratory and clinical evaluation. BMD Z-scores at the AP spine, total hip, femoral neck, forearm and whole body were examined in relation to phenotype, body mass index, current glucocorticoid dose, average 5-year glucocorticoid dose, vitamin D, 17-hydroxyprogesterone, androstenedione, testosterone, dehydroepiandrosterone and dehydroepiandrosterone sulphate (DHEAS).

RESULTS

Reduced BMD (T-score <-1 at hip, spine, or forearm) was present in 52% and was more common in classic than nonclassic patients (P = 0·005), with the greatest difference observed at the forearm (P = 0·01). Patients with classic compared to nonclassic CAH, had higher 17-hydroxyprogesterone (P = 0·005), lower DHEAS (P = 0·0002) and higher non-traumatic fracture rate (P = 0·0005). In a multivariate analysis after adjusting for age, gender, height standard deviation, phenotype and cumulative glucocorticoid exposure, higher DHEAS was independently associated with higher BMD at the spine, radius and whole body.

CONCLUSION

Classic CAH patients have lower BMD than nonclassic patients, with the most affected area being the forearm. This first study of forearm BMD in CAH patients suggests that low DHEAS may be associated with weak cortical bone independent of glucocorticoid exposure.

Adrenal androgens and androgen precursors-definition, synthesis, regulation and physiologic actions

The human adrenal produces more 19 carbon (C19) steroids, by mass, than either glucocorticoids or mineralocorticoids. However, the mechanisms regulating adrenal C19 steroid biosynthesis continue to represent one of the most intriguing mysteries of endocrine physiology. This review will discuss the C19 steroids synthesized by the human adrenal and the features within the adrenal that allow production of these steroids. Finally, we consider the effects of these steroids in normal physiology and disorders of adrenal C19 steroid excess.

The steroid metabolome of adrenarche

Adrenarche is an endocrine developmental process whereby humans and select nonhuman primates increase adrenal output of a series of steroids, especially DHEA and DHEAS. The timing of adrenarche varies among primates, but in humans serum levels of DHEAS are seen to increase at around 6 years of age. This phenomenon corresponds with the development and expansion of the zona reticularis of the adrenal gland. The physiological phenomena that trigger the onset of adrenarche are still unknown; however, the biochemical pathways leading to this event have been elucidated in detail. There are numerous reviews examining the process of adrenarche, most of which have focused on the changes within the adrenal as well as the phenotypic results of adrenarche. This article reviews the recent and past studies that show the breadth of changes in the circulating steroid metabolome that occur during the process of adrenarche.

Adrenarche: a cell biological perspective

Adrenarche is a cell biological and endocrinological puzzle. The differentiation of the zona reticularis in childhood in humans requires special techniques for study because it is confined to humans and possibly a small number of other primates. Despite the rapid progress in the definition of adrenocortical stem/progenitor cells in the mouse, the factors that cause the differentiation of adrenocortical cells into zonal cell types have not been identified. There are, however, many candidates in the Wnt, Hedgehog, and other families of signaling molecules. A suitable system for identifying authentic stem cells, capable of differentiation into all zones, has yet to be developed. It is proposed here that the in vitro differentiation of pluripotent cells, combined with appropriate in vitro and in vivo methods for validating authentic adrenocortical stem cells, is a promising approach to solving these questions.

The neurosteroid dehydroepiandrosterone (DHEA) and its metabolites alter 5-HT neuronal activity via modulation of GABAA receptors

Dehydroepiandrosterone (DHEA) and its metabolites, DHEA-sulphate (DHEA-S) and androsterone, have neurosteroid activity. In this study, we examined whether DHEA, DHEA-S and androsterone, can influence serotonin (5-HT) neuronal firing activity via modulation of γ-aminobutryic acid (GABA(A)) receptors. The firing of presumed 5-HT neurones in a slice preparation containing rat dorsal raphe nucleus was inhibited by the GABA(A) receptor agonists 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridinyl-3-ol (THIP) (25 μM) and GABA (100 μM). DHEA (100 and 300 μM) and DHEA-S (1, 10 and 100 μM) caused a rapid and reversible attenuation of the response to THIP. DHEA (100 μM) and DHEA-S (100 μM) also attenuated the effect of GABA. Androsterone (10 and 30 μM) markedly enhanced the inhibitory response to THIP (25 μM). The effect was apparent during androsterone administration but persisted and even increased in magnitude after drug wash-out. The data indicate that GABA(A) receptor-mediated regulation of 5-HT neuronal firing is sensitive to negative modulation by DHEA and its metabolite DHEA-S is sensitive to positive modulation by the metabolite androsterone. The effects of these neurosteroids on GABA(A) receptor-mediated regulation of 5-HT firing may underlie some of the reported behavioural and psychological effects of endogenous and exogenous DHEA.

Hydrocortisone treatment in girls with congenital adrenal hyperplasia inhibits serum dehydroepiandrosterone sulfate and affects the GH-IGF-I system

Sex hormones are modulators of the GH/ IGF-I system. We have hypothesized that the inhibition of DHEAS in treated girls with congenital adrenal hyperplasia (CAH) might affect this modulation. We analyzed serum IGF-I, IGFBP-3 and DHEAS in 17 prepubertal (Pp) and 32 pubertal (Pu) girls with CAH, under hydrocortisone replacement therapy, in the presence of normal (Gr1) or high (Gr2) serum testosterone (T) and androstenedione (A) levels. All groups had appropriate normal controls. Serum DHEAS in patients with CAH was significantly lower than in the respective controls (p < 0.04), except for Pp CAH Gr2. Serum IGF-I, but not serum IGFBP-3, in CAH subgroups was significantly higher than in the respective controls (p < 0.05), except for Pp CAH Gr2. It is concluded that glucocorticoid treatment of girls with CAH results in hypofunction of the adrenal zona reticularis. Low levels of serum DHEAS could be involved in the regulation of IGF-I biological response in target tissues. Additional studies are necessary to confirm these findings.

Impact of antioxidants and HDL on glycated LDL-induced generation of fibrinolytic regulators from vascular endothelial cells

Hyperglycemia and dyslipoproteinemia are biochemical markers of diabetes mellitus (DM). Elevated levels of plasminogen activator inhibitor-1 (PAI-1) with and without reduction of tissue plasminogen activator (tPA) in plasma have been frequently found in patients with DM. Our previous studies indicated that glycation enhances low density lipoprotein (LDL)-induced production of PAI-1 and further decreases tPA generation in vascular endothelial cells (ECs). The present study demonstrated that treatment with antioxidants, butylated hydroxytoluene or vitamin E, blocked native LDL- and glycated LDL-induced changes in PAI-1 and tPA generation in ECs. Native or glycated high density lipoprotein (HDL) did not significantly alter tPA generation in ECs. Glycated but not native HDL (>/=100 microg/mL) moderately increased PAI-1 release from ECs. Cotreatment with native or glycated HDL inhibited LDL-induced or glycated LDL-induced changes in PAI-1 and tPA generation in ECs. The abundance of conjugated dienes was increased in glycated or EC-modified LDL. Treatment with butylated hydroxytoluene, vitamin E, or HDL reduced the abundance of conjugated dienes in glycated or EC-modified LDL. The effects of antioxidants and HDL on LDL-induced or its glycated LDL-induced changes in the generation of PAI-1 and tPA were also found in cultured human coronary artery ECs. The findings of the present study suggest that antioxidants and HDL may attenuate native LDL- or glycated LDL-induced changes in the generation of fibrinolytic regulators from vascular ECs, which possibly results from their inhibition on the lipid peroxidation of LDL particles. Treatment with antioxidants or hypolipidemic agents potentially improves fibrinolytic activity and reduces thrombotic tendencies in patients with DM.

Congenital adrenal hyperplasia due to 21-hydroxylase deficiency

More than 90% of cases of congenital adrenal hyperplasia (CAH, the inherited inability to synthesize cortisol) are caused by 21-hydroxylase deficiency. Females with severe, classic 21-hydroxylase deficiency are exposed to excess androgens prenatally and are born with virilized external genitalia. Most patients cannot synthesize sufficient aldosterone to maintain sodium balance and may develop potentially fatal "salt wasting" crises if not treated. The disease is caused by mutations in the CYP21 gene encoding the steroid 21-hydroxylase enzyme. More than 90% of these mutations result from intergenic recombinations between CYP21 and the closely linked CYP21P pseudogene. Approximately 20% are gene deletions due to unequal crossing over during meiosis, whereas the remainder are gene conversions--transfers to CYP21 of deleterious mutations normally present in CYP21P. The degree to which each mutation compromises enzymatic activity is strongly correlated with the clinical severity of the disease in patients carrying it. Prenatal diagnosis by direct mutation detection permits prenatal treatment of affected females to minimize genital virilization. Neonatal screening by hormonal methods identifies affected children before salt wasting crises develop, reducing mortality from this condition. Glucocorticoid and mineralocorticoid replacement are the mainstays of treatment, but more rational dosing and additional therapies are being developed.

Glucosylated glycerophosphoethanolamines are the major LDL glycation products and increase LDL susceptibility to oxidation: evidence of their presence in atherosclerotic lesions

Glycation of both protein and lipid components is believed to be involved in LDL oxidation. However, the relative importance of lipid and protein glycation in the oxidation process has not been established, and products of lipid glycation have not been isolated. Using glucosylated phosphatidylethanolamine (Glc PtdEtn) prepared synthetically, we have identified glycated diacyl and alkenylacyl species among the ethanolamine phospholipids in LDL. Accumulation of these glycation products in LDL incubated with glucose showed a time- and glucose concentration-dependent increase. LDL specifically enriched with Glc PtdEtn (25 nmol/mg protein) showed increased susceptibility to lipid oxidation when dialyzed against a 5-micromol/L Cu(2+) solution. The presence of this glucosylated lipid resulted in a 5-fold increase in production of phospholipid-bound hydroperoxides and 4-fold increase in phospholipid-bound aldehydes. Inclusion of glucosylated phosphatidylethanolamine in the surface lipid monolayer of the LDL resulted in rapid loss of polyunsaturated cholesteryl esters from the interior of the particle during oxidation. Glycated ethanolamine phospholipids were also isolated and identified from atherosclerotic plaques collected from both diabetic and nondiabetic subjects. The present findings provide direct evidence for the previously proposed causative effect of lipid glycation on LDL oxidation.

Influence of glycation on LDL-induced generation of fibrinolytic regulators in vascular endothelial cells

Hyperglycemia and dyslipidemia are two biochemical markers of diabetes mellitus. Increased incidence of cardiovascular disease and impaired fibrinolytic activity have been found in diabetic subjects. Previous studies have demonstrated that low density lipoproteins (LDLs) stimulate the production of plasminogen activator inhibitor-1 (PAI-1) and reduce the generation of tissue plasminogen activator (tPA) in vascular endothelial cells (ECs). The present study investigated the effect of glycated LDL on the production of PAI-1 and tPA in cultured human umbilical vein ECs (HUVECs). Glycation increased the abundance of glucitollysine and conjugated dienes in LDL and amplified the overproduction of PAI-1 and the reduction in tPA generation from HUVECs induced by LDL. The steady-state levels of PAI-1 mRNA in glycated LDL-treated ECs were significantly higher than those in native LDL-treated cells. Actinomycin D blocked the increase in PAI-1 generation induced by glycated LDL. Glycated LDL did not significantly reduce the levels of tPA mRNA but attenuated de novo synthesis of tPA in ECs. Treatment with 25 mmol/L aminoguanidine, an antioxidant and inhibitor of the formation of advanced glycation end products, during glycation normalized glycated LDL-induced generation of PAI-1 and tPA in ECs. The results of the present study indicate that glycation enhances the production of PAI-1 and attenuates tPA synthesis in ECs induced by LDL, which may contribute to the increased incidence of cardiovascular complications in diabetes. Formation of advanced glycation end products or peroxidation may be involved in glycated LDL-induced alterations in the generation of fibrinolytic regulators from ECs.