Exposure to Glucocorticoids in the First Part of Fetal Life is Associated with Insulin Secretory Defect in Adult Humans

Safety of Antenatal Predniso(lo)ne and Dexamethasone on Fetal, Neonatal and Childhood Outcomes: A Systematic Review

CONTEXT

Due to ethical considerations, antenatal dose finding for prednisolone and dexamethasone in pregnant women is limited, leading to a knowledge gap.

OBJECTIVE

In order to guide the clinician in weighing benefits vs risks, the aim is to systematically review the current literature on the side effects of antenatal predniso(lo)ne and dexamethasone use on the fetus, newborn, and (pre)pubertal child.

EVIDENCE ACQUISITION

The search was performed in PubMed/MEDLINE and Embase using prespecified keywords and Medical Subject Headings. This systematic review investigated studies published until August 2022, with the following inclusion criteria: studies were conducted in humans and assessed side effects of long-term antenatal predniso(lo)ne and dexamethasone use during at least one of the trimesters on the child during the fetal period, neonatal phase, and during childhood.

EVIDENCE SYNTHESIS

In total, 328 papers in PubMed and 193 in Embase were identified. Fifteen studies were eligible for inclusion. Seven records were added through references. Antenatal predniso(lo)ne use may be associated with lower gestational age, but was not associated with miscarriages and stillbirths, congenital abnormalities, differences in blood pressure or low blood glucose levels at birth, or with low bone mass, long-term elevated cortisol and cortisone, or high blood pressure at prepubertal age. Increased risks of antenatal dexamethasone use include association with miscarriages and stillbirths, and from age 16 years, associations with disturbed insulin secretion and higher glucose and cholesterol levels.

CONCLUSIONS

Based on the limited evidence found, predniso(lo)ne may have less side effects compared with dexamethasone in short- and long-term outcomes. Current literature shows minimal risk of side effects in the newborn from administration of a prenatal predniso(lo)ne dose of up to 10 mg per day.

Modulation of fetoplacental growth, development and reproductive function by endocrine disrupters

Maternal endocrine homeostasis is vital to a successful pregnancy, regulated by several hormones such as human chorionic gonadotropin, estrogen, leptin, glucocorticoid, insulin, prostaglandin, and others. Endocrine stress during pregnancy can modulate nutrient availability from mother to fetus, alter fetoplacental growth and reproductive functions. Endocrine disrupters such as bisphenols (BPs) and phthalates are exposed in our daily life's highest volume. Therefore, they are extensively scrutinized for their effects on metabolism, steroidogenesis, insulin signaling, and inflammation involving obesity, diabetes, and the reproductive system. BPs have their structural similarity to 17-β estradiol and their ability to bind as an agonist or antagonist to estrogen receptors to elicit an adverse response to the function of the endocrine and reproductive system. While adults can negate the adverse effects of these endocrine-disrupting chemicals (EDCs), fetuses do not equip themselves with enzymatic machinery to catabolize their conjugates. Therefore, EDC exposure makes the fetoplacental developmental window vulnerable to programming in utero. On the one hand prenatal BPs and phthalates exposure can impair the structure and function of the ovary and uterus, resulting in placental vascular defects, inappropriate placental expression of angiogenic growth factors due to altered hypothalamic response, expression of nutrient transporters, and epigenetic changes associated with maternal endocrine stress. On the other, their exposure during pregnancy can affect the offspring's metabolic, endocrine and reproductive functions by altering fetoplacental programming. This review highlights the latest development in maternal metabolic and endocrine modulations from exposure to estrogenic mimic chemicals on subcellular and transgenerational changes in placental development and its effects on fetal growth, size, and metabolic & reproductive functions.

Congenital adrenal hyperplasia

Congenital adrenal hyperplasia is a group of autosomal recessive disorders leading to multiple complex hormonal imbalances caused by various enzyme deficiencies in the adrenal steroidogenic pathway. The most common type of congenital adrenal hyperplasia is due to steroid 21-hydroxylase (21-OHase, henceforth 21OH) deficiency. The rare, classic (severe) form caused by 21OH deficiency is characterised by life-threatening adrenal crises and is the most common cause of atypical genitalia in neonates with 46,XX karyotype. After the introduction of life-saving hormone replacement therapy in the 1950s and neonatal screening programmes in many countries, nowadays neonatal survival rates in patients with congenital adrenal hyperplasia are high. However, disease-related mortality is increased and therapeutic management remains challenging, with multiple long-term complications related to treatment and disease affecting growth and development, metabolic and cardiovascular health, and fertility. Non-classic (mild) forms of congenital adrenal hyperplasia caused by 21OH deficiency are more common than the classic ones; they are detected clinically and primarily identified in female patients with hirsutism or impaired fertility. Novel treatment approaches are emerging with the aim of mimicking physiological circadian cortisol rhythm or to reduce adrenal hyperandrogenism independent of the suppressive effect of glucocorticoids.

Pregnancy and Prenatal Management of Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive diseases that may cause cortisol insufficiency together with other hormonal alterations. The most common form is 21-hydroxylase deficiency, in which the lack of pituitary negative feedback causes an increase in ACTH and adrenal androgens. Classical forms of CAHs can lead to severe adrenal failure and female virilization. To date, the appropriate management of pregnant CAH patients is still debated regarding appropriate maternal therapy modifications during pregnancy and the risks and benefits of prenatal treatment of the fetus. We conducted a literature search of relevant papers to collect current evidence and experiences on the topic. The most recent and significant articles were selected, and current international guidelines were consulted to update current recommendations and guide clinical practice. Given the lack of randomized clinical trials and other high-quality scientific evidence, the issue is still debated, and great heterogeneity exists in current practice in terms of risk/benefit evaluation and pharmacological choices for pregnancy and prenatal treatment. Glucocorticoid therapy is advised not only in classical CAH patients but also in non-classical, milder forms. The choice of which glucocorticoid to use, and the safety and benefits of dexamethasone therapy aimed at preventing genital virilization are still debated issues. Several advances, however, have been made, especially in terms of fertility and reproduction. This review aims to present the most recent scientific and real-world updates on pregnancy and prenatal management of CAH, with the presentation of various clinical scenarios and specific case-by-case recommendations.

Prenatal dexamethasone exposure induced pancreatic β-cell dysfunction and glucose intolerance of male offspring rats: Role of the epigenetic repression of ACE2

The prevalence of diabetes in children and adolescents has been rising gradually, which is relevant to adverse environment during development, especially prepartum. We aimed to explore the effects of prenatal dexamethasone exposure (PDE) on β-cell function and glucose homeostasis in juvenile offspring rats. Pregnant Wistar rats were subcutaneously administered with dexamethasone [0.1, 0.2, 0.4mg/(kg.d)] from gestational day 9 to 20. PDE impaired glucose tolerance in the male offspring rather than the females. In male offspring, PDE impaired the development and function of β-cells, accompanied with lower H3K9ac, H3K14ac and H3K27ac levels in the promoter region of angiotensin-converting enzyme 2 (ACE2) as well as suppressed ACE2 expression. Meanwhile, PDE increased expression of glucocorticoid receptor (GR) and histone deacetylase 3 (HDAC3) in fetal pancreas. Dexamethasone also inhibited ACE2 expression and insulin production in vitro. Recombinant expression of ACE2 restored insulin production inhibited by dexamethasone. In addition, dexamethasone activated GR and HDAC3, increased protein interaction of GR with HDAC3, and promoted the binding of GR-HDAC3 complex to ACE2 promoter region. Both RU486 and TSA abolished dexamethasone-induced decline of histone acetylation and ACE2 expression. In summary, suppression of ACE2 is involved in PDE induced β-cell dysfunction and glucose intolerance in juvenile male offspring rats.

Metabolic Consequences of Glucocorticoid Exposure before Birth

Glucocorticoids have an important role in development of the metabolic phenotype in utero. They act as environmental and maturational signals in adapting feto-placental metabolism to maximize the chances of survival both before and at birth. They influence placental nutrient handling and fetal metabolic processes to support fetal growth, fuel storage and energy production with respect to nutrient availability. More specifically, they regulate the transport, utilization and production of a range of nutrients by the feto-placental tissues that enables greater metabolic flexibility in utero while minimizing any further drain on maternal resources during periods of stress. Near term, the natural rise in fetal glucocorticoid concentrations also stimulates key metabolic adaptations that prepare tissues for the new energy demanding functions after birth. Glucocorticoids, therefore, have a central role in the metabolic communication between the mother, placenta and fetus that optimizes offspring metabolic phenotype for survival to reproductive age. This review discusses the effects of maternal and fetal glucocorticoids on the supply and utilization of nutrients by the feto-placental tissues with particular emphasis on studies using quantitative methods to assess metabolism in rodents and sheep in vivo during late pregnancy. It considers the routes of glucocorticoid overexposure in utero, including experimental administration of synthetic glucocorticoids, and the mechanisms by which these hormones control feto-placental metabolism at the molecular, cellular and systems levels. It also briefly examines the consequences of intrauterine glucocorticoid overexposure for postnatal metabolic health and the generational inheritance of metabolic phenotype.

Ambulatory Blood Pressure Monitoring in Children and Adults Prenatally Exposed to Dexamethasone Treatment

CONTEXT

The clinical use of dexamethasone (DEX) prenatally to reduce virilization of external genitalia in female fetuses with congenital adrenal hyperplasia (CAH) is efficient but still controversial. It remains challenging to prevent the excessive exposure of DEX in unborn healthy babies during the first trimester of pregnancy.

OBJECTIVE

Since endogenous glucocorticoids contribute to the maintenance of blood pressure (BP) and since events during fetal life may program the fetus and affect future metabolic health, the aim of this study was to analyze ambulatory BP measurements in CAH-unaffected children and adults that were prenatally exposed to DEX treatment.

METHODS

Ambulatory BP measurements were analyzed in 33 (16 female) DEX-treated participants aged 5.1 to 26.3 years (19 participants aged ≤ 18 years) and in 54 (28 female) age- and sex-matched apparently healthy controls aged 5.5 to 25.3 years (27 participants aged ≤ 18 years) with ambulatory normotension.

RESULTS

Participants' age, height, weight, and body mass index were similar between the DEX-treated group and the control group. Heart rate, 24-hour BP, pulse pressure, and nighttime dipping did not statistically significantly differ between DEX-treated participants and controls.

CONCLUSION

Our study suggests that prenatal DEX treatment in CAH-unaffected children and adults does not appear to adversely affect ambulatory BP later in life. Our observations need to be confirmed in larger studies.

Prenatal dexamethasone treatment for classic 21-hydroxylase deficiency in Europe

OBJECTIVE

To assess the current medical practice in Europe regarding prenatal dexamethasone (Pdex) treatment of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency.

DESIGN AND METHODS

A questionnaire was designed and distributed, including 17 questions collecting quantitative and qualitative data. Thirty-six medical centres from 14 European countries responded and 30 out of 36 centres were reference centres of the European Reference Network on Rare Endocrine Conditions, EndoERN.

RESULTS

Pdex treatment is currently provided by 36% of the surveyed centres. The treatment is initiated by different specialties, that is paediatricians, endocrinologists, gynaecologists or geneticists. Regarding the starting point of Pdex, 23% stated to initiate therapy at 4-5 weeks postconception (wpc), 31% at 6 wpc and 46 % as early as pregnancy is confirmed and before 7 wpc at the latest. A dose of 20 µg/kg/day is used. Dose distribution among the centres varies from once to thrice daily. Prenatal diagnostics for treated cases are conducted in 72% of the responding centres. Cases treated per country and year vary between 0.5 and 8.25. Registries for long-term follow-up are only available at 46% of the centres that are using Pdex treatment. National registries are only available in Sweden and France.

CONCLUSIONS

This study reveals a high international variability and discrepancy in the use of Pdex treatment across Europe. It highlights the importance of a European cooperation initiative for a joint international prospective trial to establish evidence-based guidelines on prenatal diagnostics, treatment and follow-up of pregnancies at risk for CAH.

Congenital Adrenal Hyperplasia-Current Insights in Pathophysiology, Diagnostics, and Management

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders affecting cortisol biosynthesis. Reduced activity of an enzyme required for cortisol production leads to chronic overstimulation of the adrenal cortex and accumulation of precursors proximal to the blocked enzymatic step. The most common form of CAH is caused by steroid 21-hydroxylase deficiency due to mutations in CYP21A2. Since the last publication summarizing CAH in Endocrine Reviews in 2000, there have been numerous new developments. These include more detailed understanding of steroidogenic pathways, refinements in neonatal screening, improved diagnostic measurements utilizing chromatography and mass spectrometry coupled with steroid profiling, and improved genotyping methods. Clinical trials of alternative medications and modes of delivery have been recently completed or are under way. Genetic and cell-based treatments are being explored. A large body of data concerning long-term outcomes in patients affected by CAH, including psychosexual well-being, has been enhanced by the establishment of disease registries. This review provides the reader with current insights in CAH with special attention to these new developments.

Excess of glucocorticoids during late gestation impairs the recovery of offspring's β-cell function after a postnatal injury

Since prenatal glucocorticoids (GC) excess increases the risk of metabolic dysfunctions in the offspring and its effect on β-cell recovery capacity remains unknown we investigated these aspects in offspring from mice treated with dexamethasone (DEX) in the late pregnancy. Half of the pups were treated with streptozotocin (STZ) on the sixth postnatal day (PN). Functional and molecular analyses were performed in male offspring on PN25 and PN225. Prenatal DEX treatment resulted in low birth weight. At PN25, both the STZ-treated offspring developed hyperglycemia and had lower β-cell mass, in parallel with higher α-cell mass and glucose intolerance, with no impact of prenatal DEX on such parameters. At PN225, the β-cell mass was partially recovered in the STZ-treated mice, but they remained glucose-intolerant, irrespective of being insulin sensitive. Prenatal exposition to DEX predisposed adult offspring to sustained hyperglycemia and perturbed islet function (lower insulin and higher glucagon response to glucose) in parallel with exacerbated glucose intolerance. β-cell-specific knockdown of the Hnf4α in mice from the DS group resulted in exacerbated glucose intolerance. We conclude that high GC exposure during the prenatal period exacerbates the metabolic dysfunctions in adult life of mice exposed to STZ early in life, resulting in a lesser ability to recover the islets' function over time. This study alerts to the importance of proper management of exogenous GCs during pregnancy and a healthy postnatal lifestyle since the combination of adverse factors during the prenatal and postnatal period accentuates the predisposition to metabolic disorders in adult life.

Molecular Mechanisms of Glucocorticoid-Induced Insulin Resistance

Glucocorticoids (GCs) are steroids secreted by the adrenal cortex under the hypothalamic-pituitary-adrenal axis control, one of the major neuro-endocrine systems of the organism. These hormones are involved in tissue repair, immune stability, and metabolic processes, such as the regulation of carbohydrate, lipid, and protein metabolism. Globally, GCs are presented as ‘flight and fight’ hormones and, in that purpose, they are catabolic hormones required to mobilize storage to provide energy for the organism. If acute GC secretion allows fast metabolic adaptations to respond to danger, stress, or metabolic imbalance, long-term GC exposure arising from treatment or Cushing’s syndrome, progressively leads to insulin resistance and, in fine, cardiometabolic disorders. In this review, we briefly summarize the pharmacological actions of GC and metabolic dysregulations observed in patients exposed to an excess of GCs. Next, we describe in detail the molecular mechanisms underlying GC-induced insulin resistance in adipose tissue, liver, muscle, and to a lesser extent in gut, bone, and brain, mainly identified by numerous studies performed in animal models. Finally, we present the paradoxical effects of GCs on beta cell mass and insulin secretion by the pancreas with a specific focus on the direct and indirect (through insulin-sensitive organs) effects of GCs. Overall, a better knowledge of the specific action of GCs on several organs and their molecular targets may help foster the understanding of GCs’ side effects and design new drugs that possess therapeutic benefits without metabolic adverse effects.

Perturbed Beta-Cell Function and Lipid Profile After Early Prenatal Dexamethasone Exposure in Individuals Without CAH

BACKGROUND

Prenatal treatment with dexamethasone (DEX) reduces virilization in girls with congenital adrenal hyperplasia (CAH). The treatment is effective but may result in long-lasting adverse effects. In this study we explore the effects of DEX on metabolism in individuals not having CAH but treated with DEX during the first trimester of fetal life.

METHOD

All DEX-treated participants (n = 40, age range 5.1-26.4 years) and controls (n = 75, age range 4.5-26.6 years) were assessed with fasting blood samples to measure blood count, renal function, glucose homeostasis, and serum lipid profiles.

RESULTS

There were no significant differences between DEX and control participants for birth parameters, weight and height, or body mass index at the time of testing. Analyzing the entire cohort, we found no significant effects of DEX on blood count, renal function, or serum lipid profiles. However, a lower HOMA-β index in the DEX-treated individuals (U = 893.0; P = 0.049) was observed. Post hoc analyses revealed an effect in girls (U = 152.5; P = 0.024) but not in boys (U = 299.5; P = 0.550). The effect on HOMA-β persisted (U = 117.5; P = 0.048) after analyzing data separately in the participants < 16 years of age. In addition, we observed higher plasma glucose levels (F = 14.6; P = 0.001) in the DEX-treated group. The participants ≥ 16 years of age in the DEX-treated group had significantly higher total plasma cholesterol (F = 9.8; P = 0.003) and higher low-density lipoprotein cholesterol levels (F = 7.4; P = 0,009).

CONCLUSION

Prenatal DEX exposure in early pregnancy has negative effects on beta-cell function and lipid profile in individuals without CAH already at a young age.