Assessment of circulating sex steroid levels in prepubertal and pubertal boys and girls by a novel ultrasensitive gas chromatography-tandem mass spectrometry method

Intrauterine position effects in a mouse model of maternal immune activation

Rodent models of maternal immune activation (MIA) are increasingly used as experimental tools in preclinical research of immune-mediated neurodevelopmental disorders and mental illnesses. Using a viral-like MIA model that is based on prenatal poly(I:C) exposure in mice, we have recently identified the existence of subgroups of MIA-exposed offspring that show dissociable behavioral, transcriptional, brain network and inflammatory profiles even under conditions of genetic homogeneity and identical MIA. Here, we tested the hypothesis that the intrauterine positions of fetuses, which are known to shape individual variability in litter-bearing mammals through variations in fetal hormone exposure, may contribute to the variable outcomes of MIA in mice. MIA was induced by maternal administration of poly(I:C) on gestation day 12 in C57BL/6N mice. Determining intrauterine positions using delivery by Cesarean section (C-section), we found that MIA-exposed offspring developing between female fetuses only (0M-MIA offspring) displayed significant deficits in sociability and sensorimotor gating at adult age, whereas MIA-exposed offspring developing between one or two males in utero (1/2M-MIA offspring) did not show the same deficits. These intrauterine position effects similarly emerged in male and female offspring. Furthermore, while MIA elevated fetal brain levels of pro- and anti-inflammatory cytokines independently of the precise intrauterine position and sex of adjacent fetuses during the acute phase, fetal brain levels of TNF-α remained elevated in 0M-MIA but not 1/2M-MIA offspring until the post-acute phase in late gestation. As expected, 1/2M offspring generally showed higher testosterone levels in the fetal brain during late gestation as compared to 0M offspring, confirming the transfer of testosterone from male fetuses to adjacent male or female fetuses. Taken together, our findings identify a novel source of within-litter variability contributing to heterogeneous outcomes of short- and long-term effects in a mouse model of MIA. In broader context, our findings highlight that individual differences in fetal exposure to hormonal and inflammatory signals may be a perinatal factor that shapes risk and resilience to MIA.

Hormone Therapy During Infancy or Early Childhood for Patients with Hypogonadotropic Hypogonadism, Klinefelter or Turner Syndrome: Has the Time Come?

Managing patients unable to produce sex steroids using gonadotropins to mimic minipuberty in hypogonadotropic hypogonadism, or sex steroids in patients with Klinefelter or Turner syndrome, is promising. There is a need to pursue research in this area, with large prospective cohorts and long-term data before these treatments can be routinely considered.

Gender-related differences in cardiometabolic risk factors and oxidative stress among prepubertal children with obesity

OBJECTIVES

Gender-related differences in oxidative stress, nitric oxide bioavailability, and cardiometabolic risk factors were examined in a cross-sectional study involving 313 prepubertal children (8-9 years old) from the generation XXI birth-cohort.

METHODS

Anthropometric measurements, cardiometabolic variables, and redox markers were assessed, including plasma and urinary isoprostanes (P-Isop, U-Isop), plasma total antioxidant status (P-TAS), serum myeloperoxidase (MPO), plasma and urinary nitrates and nitrites (P-NOX, U-NOX), and urinary hydrogen peroxide (U-H2O2).

RESULTS

Girls showed higher levels of total/non-HDL cholesterol, triglycerides, and insulin resistance (HOMA-IR) compared to boys. Notably, U-H2O2 values were lower in girls. When stratifying by body mass index (BMI) and gender, both girls and boys exhibited higher MPO concentration and U-Isop values. Uric acid concentration was higher in overweight and obese girls than in normal weight girls, while no significant differences were observed among boys across BMI categories. Furthermore, U-NOX values differed only in boys, with higher levels observed in overweight and obese individuals compared to those with normal weight. Multivariate analysis, adjusted for age and BMI z-score, demonstrated inverse associations between U-H2O2 and pulse wave velocity values, as well as between U-NOX and total or non-HDL cholesterol, exclusively in boys. In girls, a positive association between U-Isop and HOMA-IR values was observed.

CONCLUSIONS

In conclusion, gender differentially impacts oxidative stress, nitric oxide bioavailability, and cardiometabolic risk factors in prepubertal children. Prepubertal girls appear more susceptible to oxidative stress-induced metabolic dysfunction, while in boys, elevated levels of redox and nitric oxide bioavailability markers seem to provide protection against arterial stiffness and lipid homeostasis.

Associations of plasma retinol and α-tocopherol levels with skeletal muscle health in Chinese children

Childhood is a critical period for muscle accumulation. Studies in elders have reported that antioxidant vitamins could improve muscle health. However, limited studies have assessed such associations in children. This study included 243 boys and 183 girls. A seventy-nine-item FFQ was used to investigate dietary nutrients intake. Plasma levels of retinol and α-tocopherol were measured using high-performance liquid chromatography with MS. Dual X-ray absorptiometry was used to assess appendicular skeletal muscle mass (ASM) and total body fat. The ASM index (ASMI) and ASMI Z-score were then calculated. Hand grip strength was measured using a Jamar® Plus+ Hand Dynamometer. Fully adjusted multiple linear regression models showed that for each unit increase in plasma retinol content, ASM, ASMI, left HGS and ASMI Z-score increased by 2·43 × 10-3 kg, 1·33 × 10-3 kg/m2, 3·72 × 10-3 kg and 2·45 × 10-3 in girls, respectively (P < 0·001-0·050). ANCOVA revealed a dose-response relationship between tertiles of plasma retinol level and muscle indicators (Ptrend: 0·001-0·007). The percentage differences between the top and bottom tertiles were 8·38 %, 6·26 %, 13·2 %, 12·1 % and 116 % for ASM, ASMI, left HGS, right HGS and ASMI Z-score in girls, respectively (Pdiff: 0·005-0·020). No such associations were observed in boys. Plasma α-tocopherol levels were not correlated with muscle indicators in either sex. In conclusion, high circulating retinol levels are positively associated with muscle mass and strength in school-age girls.

Interplay between Estrogen, Kynurenine, and AHR Pathways: An immunosuppressive axis with therapeutic potential for breast cancer treatment

Breast cancer is one of the most common malignancies among women worldwide. Estrogen exposure via endogenous and exogenous sources during a lifetime, together with environmental exposure to estrogenic compounds, represent the most significant risk factor for breast cancer development. As breast tumors establish, multiple pathways are deregulated. Among them is the aryl hydrocarbon receptor (AHR) signaling pathway. AHR, a ligand-activated transcription factor associated with the metabolism of polycyclic aromatic hydrocarbons and estrogens, is overexpressed in breast cancer. Furthermore, AHR and estrogen receptor (ER) cross-talk pathways have been observed. Additionally, the Tryptophan (Trp) catabolizing enzymes indolamine-2,3-dioxygenase (IDO) and tryptophan-2,3-dioxygenase (TDO) are overexpressed in breast cancer. IDO/TDO catalyzes the formation of Kynurenine (KYN) and other tryptophan-derived metabolites, which are ligands of AHR. Once KYN activates AHR, it stimulates the expression of the IDO enzyme, increases the level of KYN, and activates non-canonical pathways to control inflammation and immunosuppression in breast tumors. The interplay between E2, AHR, and IDO/TDO/KYN pathways and their impact on the immune system represents an immunosuppressive axis on breast cancer. The potential modulation of the immunosuppressive E2-AHR-IDO/TDO/KYN axis has aroused great expectations in oncotherapy. The present article will review the mechanisms implicated in generating the immunosuppressive axis E2-AHR-IDO/TDO/KYN in breast cancer and the current state of knowledge as a potential therapeutic target.

Assessing tolerability and physiological responses to 17α-estradiol administration in male rhesus macaques

17α-estradiol has recently been shown to extend healthspan and lifespan in male mice through multiple mechanisms. These benefits occur in the absence of significant feminization or deleterious effects on reproductive function, which makes 17α-estradiol a candidate for translation into humans. However, human dosing paradigms for the treatment of aging and chronic disease are yet to be established. Therefore, the goals of the current studies were to assess tolerability of 17α-estradiol treatment, in addition to evaluating metabolic and endocrine responses in male rhesus macaque monkeys during a relatively short treatment period. We found that our dosing regimens (0.30 and 0.20 mg/kg/day) were tolerable as evidenced by a lack of GI distress, changes in blood chemistry or complete blood counts, and unaffected vital signs. We also found that the higher dose did elicit mild benefits on metabolic parameters including body mass, adiposity, and glycosylated hemoglobin. However, both of our 17α-estradiol trial doses elicited significant feminization to include testicular atrophy, increased circulating estrogens, and suppressed circulating androgens and gonadotropins. We suspect that the observed level of feminization results from a saturation of the endogenous conjugation enzymes, thereby promoting a greater concentration of unconjugated 17α-estradiol in serum, which has more biological activity. We also surmise that the elevated level of unconjugated 17α-estradiol was subjected to a greater degree of isomerization to 17β-estradiol, which is aligned with the sevenfold increase in serum 17β-estradiol in 17α-estradiol treated animals in our first trial. Future studies in monkeys, and certainly humans, would likely benefit from the development and implementation of 17α-estradiol transdermal patches, which are commonly prescribed in humans and would circumvent potential issues with bolus dosing effects.

Differences of Sex Development: Current Issues and Controversies

Differences of sex development (DSD) encompass a broad range of conditions in which the development of chromosomal, gonadal, or anatomic sex is not typically male or female. Terms used to describe DSD are controversial, and continuously evolving. An individualized, multidisciplinary approach is key to both the diagnosis and management of DSD. Recent advances in DSD care include expanded genetic testing options, a more nuanced approach to gonadal management, and an emphasis on shared decision-making, particularly related to external genital surgical procedures. The timing of DSD surgery is currently being questioned and debated in both medical and advocacy/activism spheres.

Genetic strategies for sex-biased persistence of gut microbes across human life

Although compositional variation in the gut microbiome during human development has been extensively investigated, strain-resolved dynamic changes remain to be fully uncovered. In the current study, shotgun metagenomic sequencing data of 12,415 fecal microbiomes from healthy individuals are employed for strain-level tracking of gut microbiota members to elucidate its evolving biodiversity across the human life span. This detailed longitudinal meta-analysis reveals host sex-related persistence of strains belonging to common, maternally-inherited species, such as Bifidobacterium bifidum and Bifidobacterium longum subsp. longum. Comparative genome analyses, coupled with experiments including intimate interaction between microbes and human intestinal cells, show that specific bacterial glycosyl hydrolases related to host-glycan metabolism may contribute to more efficient colonization in females compared to males. These findings point to an intriguing ancient sex-specific host-microbe coevolution driving the selective persistence in women of key microbial taxa that may be vertically passed on to the next generation.

Sex differences in hepatitis A incidence rates-a multi-year pooled-analysis based on national data from nine high-income countries

BACKGROUND

Possible sex differences in hepatitis A virus (HAV) incidence rates in different age groups are not well documented. We aimed to obtain stable pooled estimates of such differences based on data from a number of high-income countries.

METHODS

We obtained data on incident cases of HAV by sex and age group over a period of 6-25 years from nine countries: Australia, Canada, Czech Republic, Finland, Germany, Israel, Netherland, New Zealand and Spain. Male to female incidence rate ratios (IRR) were computed for each year, by country and age group. For each age group, we used meta-analytic methods to combine the IRRs. Meta-regression was conducted to estimate the effects of age, country, and time period on the IRR.

RESULTS

A male excess in incidence rates was consistently observed in all age groups, although in the youngest and oldest age groups, where the numbers tended to be lower, the lower bounds of the 95% confidence intervals for the IRRs were less than one. In the age groups <1, 1-4, 5-9, 10-14, 15-44, 45-64 and 65+, the pooled IRRs (with 95% CI) over countries and time periods were 1.18 (0.94,1.48), 1.22 (1.16,1.29), 1.07 (1.03,1.11), 1.09 (1.04,1.14), 1.46 (1.30,1.64), 1.32 (1.15,1.51) and 1.10 (0.99,1.23) respectively.

CONCLUSIONS

The excess HAV incidence rates in young males, pooled over a number of countries, suggest that the sex differences are likely to be due at least in part to physiological and biological differences and not just behavioral factors. At older ages, differential exposure plays an important role. These findings, seen in the context of the excess incidence rates in young males for many other infectious diseases, can provide further keys to the mechanisms of the infection.

Role of Estrogen Receptor α in Aging and Chronic Disease

Estrogen receptor alpha (ERα) plays a crucial role in reproductive function in both sexes. It also mediates cellular responses to estrogens in multiple nonreproductive organ systems, many of which regulate systemic metabolic homeostasis and inflammatory processes in mammals. The loss of estrogens and/or ERα agonism during aging is associated with the emergence of several comorbid conditions, particularly in females undergoing the menopausal transition. Emerging data also suggests that male mammals likely benefit from ERα agonism if done in a way that circumvents feminizing characteristics. This has led us, and others, to speculate that tissue-specific ERα agonism may hold therapeutic potential for curtailing aging and chronic disease burden in males and females that are at high-risk of cancer and/or cardiovascular events with traditional estrogen replacement therapies. In this mini-review, we emphasize the role of ERα in the brain and liver, summarizing recent evidence that indicates these two organs systems mediate the beneficial effects of estrogens on metabolism and inflammation during aging. We also discuss how 17α-estradiol administration elicits health benefits in an ERα-dependent manner, which provides proof-of-concept that ERα may be a druggable target for attenuating aging and age-related disease burden.

Association between blood pressure and angiotensin-converting enzymes activity in prepubertal children ∗

OBJECTIVES

Angiotensin-converting enzymes' (ACEs) relationship with blood pressure (BP) during childhood has not been clearly established. We aimed to compare ACE and ACE2 activities between BMI groups in a sample of prepubertal children, and to characterize the association between these enzymes' activities and BP.

METHODS

Cross-sectional study of 313 children aged 8-9 years old, included in the birth cohort Generation XXI (Portugal). Anthropometric measurements and 24-h ambulatory BP monitoring were performed. ACE and ACE2 activities were quantified by fluorometric methods.

RESULTS

Overweight/obese children demonstrated significantly higher ACE and ACE2 activities, when compared to their normal weight counterparts [median (P25-P75), ACE: 39.48 (30.52-48.97) vs. 42.90 (35.62-47.18) vs. 43.38 (33.49-49.89) mU/ml, P for trend = 0.009; ACE2: 10.41 (7.58-15.47) vs. 21.56 (13.34-29.09) vs. 29.00 (22.91-34.32) pM/min per ml, P for trend < 0.001, in normal weight, overweight and obese children, respectively]. In girls, night-time systolic BP (SBP) and diastolic BP (DBP) increased across tertiles of ACE activity ( P < 0.001 and P  = 0.002, respectively). ACE2 activity was associated with higher night-time SBP and DBP in overweight/obese girls ( P  = 0.037 and P  = 0.048, respectively) and night-time DBP in the BMI z-score girl adjusted model ( P  = 0.018). Median ACE2 levels were significantly higher among nondipper girls (16.7 vs. 11.6 pM/min per ml, P  = 0.009).

CONCLUSIONS

Our work shows that obesity is associated with activation of the renin-angiotensin-aldosterone system, with significant increase of ACE and ACE2 activities already in childhood. Also, we report sex differences in the association of ACE and ACE2 activities with BP.

Sex differences matter: Males and females are equal but not the same

Sex differences between males and females can be detected early in life. They are present also later even to a much greater extent affecting our life in adulthood and a wide spectrum of physical, psychological, cognitive, and behavioral characteristics. Moreover, sex differences matter also in individual's health and disease. In this article, we reviewed at first the sex differences in brain organization and function with respect to the underlying biological mechanisms. Since the individual functional differences in the brain, in turn, shape the behavior, sex-specific psychological/behavioral differences that can be observed in infants but also adults are consequently addressed. Finally, we briefly mention sex-dependent variations in susceptibility to selected disorders as well as their pathophysiology, diagnosis, and response to therapy. The understanding of biologically determined variability between males and females can have important implications, especially in gender-specific health care. We have the impression that it is very important to emphasize that sex matters. Males and females are differently programmed by nature, and it must be respected. Even though we as males and females are not the same, we would like to emphasize that we are still equal and together form a worthy colorful continuum.

Analysis of sex steroids in human tears using LC-MS and GC-MS: Considerations and developments to improve method sensitivity and accuracy

Sex steroids play a role in regulation of tear film function and may exert their action locally at the ocular surface. However, measurement of sex steroids in tears is difficult due to small-volume tear samples and very low concentrations of the hormones. This short communication highlights what has been achieved to date in the analysis of tear sex steroids using ultra-performance LC-MS (UPLC-MS) as previously published, and reports further and more recent investigations toward optimising mass spectrometry method sensitivity and accuracy. The published UPLC-MS method successfully measured progesterone, androsterone glucuronide and 5α-androstane-3α,17β-diol in pooled basal tears of postmenopausal women, and fourteen sex steroid standards in methanol. Limitations included sub-optimal limits of detection (LOD) and lower limits of quantification (LLOQ) for some analytes (particularly oestrogens), exclusion of sample matrix effects and no use of internal standards. This update reports on further experiments carried out to improve sensitivity and accuracy. Sample matrix effects, internal standard spiking, and derivatisation with dansyl chloride and oximes were investigated. Dansylation significantly improved the LOD and LLOQ of oestrogens and their metabolites, by a factor of 10 for oestradiol and a factor of 5 for oestrone, but sensitivity of this updated method is not sufficient however for analysis of these oestrogens in human tears. Using gas chromatography-mass spectrometry (GC-MS) as an alternative technique to LC-MS, improved sensitivity for derivatised oestradiol is reported. This work demonstrates the need to develop higher sensitivity methods and points researchers towards specific MS ionisation techniques for future analysis of sex steroids in tears, in order to progress current understanding of the role of sex steroids in tear function and dry eye.

Androgens and Androgen Receptors as Determinants of Vascular Sex Differences Across the Lifespan

Androgens, including testosterone and its more potent metabolite dihydrotestosterone, exert multiple actions in the body. Physiologically, they play a critical role in male sex development. In addition, they influence vascular function, including arterial vasodilation and mediation of myogenic tone. Androgens are produced from 9 weeks' gestation in the human fetal testis, as well as in small amounts by the adrenal glands. Serum concentrations vary according to age and sex. The vasculature is a target for direct actions of androgens, which bind to various sex hormone receptors expressed in endothelial and vascular smooth muscle cells. Androgens exert both vasoprotective and vasoinjurious effects, depending on multiple factors including sex-specific effects of androgens, heterogeneity of the vascular endothelium, differential expression of androgen and sex hormone receptors in endothelial and vascular smooth muscle cells, and the chronicity of androgen administration. Long-term administration of androgens induces vasoconstriction and influences endothelial permeability, whereas acute administration may have opposite effects. At the cellular level, androgens stimulate endothelial cell production of nitric oxide and inhibit proinflammatory signalling pathways, inducing vasorelaxation and vasoprotection. However, androgens also activate endothelial production of vasoconstrictors and stimulate recruitment of endothelial progenitor cells. In humans, both androgen deficiency and androgen excess are associated with increased cardiovascular morbidity and mortality. This review discusses how androgens modulate vascular sex differences across the lifespan by considering the actions and production of androgens in both sexes and describes how cardiovascular risk is altered as levels of androgens change with aging.

The Role of Sex in Acute and Chronic Liver Damage

Acute and chronic hepatic damages are caused by xenobiotics or different diseases affecting the liver, characterized by different etiologies and pathological features. It has been demonstrated extensively that liver damage progresses differently in men and women, and some chronic liver diseases show a more favorable prognosis in women than in men. This review aims to update the most recent advances in the comprehension of the molecular basis of the sex difference observed in both acute and chronic liver damage. With this purpose, we report experimental studies on animal models and clinical observations investigating both acute liver failure, e.g., drug-induced liver injury (DILI), and chronic liver diseases, e.g., viral hepatitis, alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), autoimmune liver diseases, and hepatocellular carcinoma (HCC).

Sexual dimorphism of leptin and adiposity in children between 0 and 10 years: a systematic review and meta-analysis

Background

Differences in adolescents and adults by sex in blood levels of leptin and adiposity have been described; however, it is not yet clear if these differences arise from the prepubertal stage in subjects with a normal-weight. Therefore, we examine whether there are differences by sex in levels of blood leptin and adiposity in children with a normal-weight between 0 and 10 years old.

Methods

Search strategy: eligible studies were obtained from three electronic databases (Ovid, Embase and LILACS) and contact with experts. Selection criteria: healthy children up to 10 years of age with normal-weight according to age.

Data collection and analyses: data were extracted by four independent reviewers using a predesigned data collection form. For the analysis, we stratified according to age groups (newborns, 0.25–0.5 years, 3–5.9 years, 6–7.9 years, 8–10 years). The statistical analysis was performed in the R program.

Results

Of the initially identified 13,712 records, 21 were selected in the systematic review and meta-analysis. The sex was associated with the overall effect on blood leptin (pooled MD = 1.72 ng/mL, 95% CI: 1.25–2.19) and body fat percentage (pooled MD = 3.43%, 95% CI: 2.53–4.33), being both higher in girls. This finding was consistent in the majority of age groups.

Conclusion

The results of our meta-analyses support the sexual dimorphism in circulating blood leptin and body fat percentage between girls and boys with normal-weight from prepuberty.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13293-022-00454-y.

Differences by sex in blood leptin and body fat percentage in children are present before 10 years old

Girls have higher circulating leptin and body fat percentage than boys

The sex differences in blood leptin and adiposity in children increase progressively with the age

The Role of Insulin Resistance in Fueling NAFLD Pathogenesis: From Molecular Mechanisms to Clinical Implications

Non-alcoholic fatty liver disease (NAFLD) represents a predominant hepatopathy that is rapidly becoming the most common cause of hepatocellular carcinoma worldwide. The close association with metabolic syndrome’s extrahepatic components has suggested the nature of the systemic metabolic-related disorder based on the interplay between genetic, nutritional, and environmental factors, creating a complex network of yet-unclarified pathogenetic mechanisms in which the role of insulin resistance (IR) could be crucial. This review detailed the clinical and pathogenetic evidence involved in the NAFLD–IR relationship, presenting both the classic and more innovative models. In particular, we focused on the reciprocal effects of IR, oxidative stress, and systemic inflammation on insulin-sensitivity disruption in critical regions such as the hepatic and the adipose tissue, while considering the impact of genetics/epigenetics on the regulation of IR mechanisms as well as nutrients on specific insulin-related gene expression (nutrigenetics and nutrigenomics). In addition, we discussed the emerging capability of the gut microbiota to interfere with physiological signaling of the hormonal pathways responsible for maintaining metabolic homeostasis and by inducing an abnormal activation of the immune system. The translation of these novel findings into clinical practice could promote the expansion of accurate diagnostic/prognostic stratification tools and tailored pharmacological approaches.

The sexual brain, genes, and cognition: A machine-predicted brain sex score explains individual differences in cognitive intelligence and genetic influence in young children

Sex impacts the development of the brain and cognition differently across individuals. However, the literature on brain sex dimorphism in humans is mixed. We aim to investigate the biological underpinnings of the individual variability of sexual dimorphism in the brain and its impact on cognitive performance. To this end, we tested whether the individual difference in brain sex would be linked to that in cognitive performance that is influenced by genetic factors in prepubertal children (N = 9,658, ages 9-10 years old; the Adolescent Brain Cognitive Development study). To capture the interindividual variability of the brain, we estimated the probability of being male or female based on the brain morphometry and connectivity features using machine learning (herein called a brain sex score). The models accurately classified the biological sex with a test ROC-AUC of 93.32%. As a result, a greater brain sex score correlated significantly with greater intelligence (p_fdr  < .001, η p 2 $$ {\eta}_p^2 $$  = .011-.034; adjusted for covariates) and higher cognitive genome-wide polygenic scores (GPSs) (p_fdr  < .001, η p 2 $$ {\eta}_p^2 $$  < .005). Structural equation models revealed that the GPS-intelligence association was significantly modulated by the brain sex score, such that a brain with a higher maleness score (or a lower femaleness score) mediated a positive GPS effect on intelligence (indirect effects = .006-.009; p = .002-.022; sex-stratified analysis). The finding of the sex modulatory effect on the gene-brain-cognition relationship presents a likely biological pathway to the individual and sex differences in the brain and cognitive performance in preadolescence.

Central precocious puberty during COVID-19 pandemic and sleep disturbance: an exploratory study

Background

Increased incidence of central precocious puberty (CPP) after coronavirus infectious disease-19 lockdown has been reported. Our study aims in investigating changes in CPP rates and in sleep patterns in CPP and healthy controls.

Methods

CPP were retrospectively evaluated from April 2020 to April 2021. Parents of girls diagnosed with CPP during lockdown and of matched healthy controls filled out a questionnaire about sleep disturbances (SDSC questionnaire) and sleep schedules.

Results

Thirty-five CPP and 37 controls completed the survey. Incidence of new CPP cases significantly increased in 2020–2021 compared to 2017–2020 (5:100 vs 2:100, p = 0.02). Sleep disturbance rates did not differ between CPP and healthy controls before lockdown. During lockdown, CPP reported higher rates of sleep disturbs for total score (p = 0.005), excessive somnolence (p = 0.049), sleep breathing disorders (p = 0.049), and sleep–wake transition disorders (p = 0.005). Moreover, CPP group more frequently shifted toward later bedtime (p = 0.03) during lockdown compared to controls. Hours of sleep and smartphone exposure around bedtime did not differ between groups.

Conclusions

Our study confirms the observation of increased incidence of CPP after lockdown measures. Additionally, CPP showed higher rates of sleep disturbances and later bedtime compared to controls. The causality link between sleep disturbances and CPP should be further investigated to gain knowledge in this association.

Gender differences in measles incidence rates in a multi-year, pooled analysis, based on national data from seven high income countries

Background

Gender differences in a number of infectious diseases have been reported. The evidence for gender differences in clinical measles incidence rates has been variable and poorly documented over age groups, countries and time periods.

Methods

We obtained data on cases of measles by sex and age group over a period of 11–27 years from seven countries. Male to female incidence rate ratios (IRR) were computed for each year, by country and age group. For each age group, we used meta-analytic methods to combine the IRRs. Meta-regression was conducted to the estimate the effects of age, country, and time period on the IRR.

Results

In the age groups < 1, 1–4, 5–9, 10–14, 15–44, and 45–64 the pooled IRRs (with 95% CI) were 1.07 (1.02–1.11), 1.10 (1.07–1.14), 1.03 (1.00–1.05), 1.05 (0.99–1.11), 1.08 (0.95–1.23), and 0.82 (0.74–0.92) respectively. The excess incidence rates (IR) from measles in males up to age 45 are remarkably consistent across countries and time-periods. In the age group 45–64, there is an excess incidence in women.

Conclusions

The consistency of the excess incidence rates in young males suggest that the sex differences are more likely due to physiological and biological differences and not behavioral factors. At older ages, differential exposure can play a part. These findings can provide further keys to the understanding of mechanisms of infection and tailoring vaccination schedules.

Role of senescence in the chronic health consequences of COVID-19

While the full impact of COVID-19 is not yet clear, early studies have indicated that upwards of 10% of patients experience COVID-19 symptoms longer than 3 weeks, known as Long-Hauler's Syndrome or PACS (postacute sequelae of SARS-CoV-2 infection). There is little known about risk factors or predictors of susceptibility for Long-Hauler's Syndrome, but older adults are at greater risk for severe outcomes and mortality from COVID-19. The pillars of aging (including cellular senescence, telomere dysfunction, impaired proteostasis, mitochondrial dysfunction, deregulated nutrient sensing, genomic instability, progenitor cell exhaustion, altered intercellular communication, and epigenetic alterations) that contribute to age-related dysfunction and chronic diseases (the "Geroscience Hypothesis") may interfere with defenses against viral infection and consequences of these infections. Heightening of the low-grade inflammation that is associated with aging may generate an exaggerated response to an acute COVID-19 infection. Innate immune system dysfunction that leads to decreased senescent cell removal and/or increased senescent cell formation could contribute to accumulation of senescent cells with both aging and viral infections. These processes may contribute to increased risk for long-term COVID-19 sequelae in older or chronically ill patients. Hence, senolytics and other geroscience interventions that may prolong healthspan and alleviate chronic diseases and multimorbidity linked to fundamental aging processes might be an option for delaying, preventing, or alleviating Long-Hauler's Syndrome.

Chronic HIV Infection and Aging: Application of a Geroscience-Guided Approach

ABSTRACT

The ability of virally suppressive antiretroviral therapy use to extend the life span of people with HIV (PWH) implies that the age of PWH will also increase. Among PWH, extended survival comes at a cost of earlier onset and increased rates of aging-associated comorbidities and geriatric syndromes, with persistent inflammation and immune dysregulation consequent to chronic HIV infection and to antiretroviral therapy use contributing to an overall decrease in health span. The geroscience hypothesis proposes that the root causes of most aging-related chronic diseases and conditions is the aging process itself. Hence, therapeutically targeting fundamental aging processes could have a greater impact on alleviating or delaying aging-associated comorbidities than addressing each disease individually. Extending the geroscience hypothesis to PWH, we speculate that targeting basic mechanisms of aging will improve overall health with age. Clinical features and pathophysiologic mechanisms of chronic diseases in PWH qualitatively resemble those seen in older adults without HIV. Therefore, drugs that target any of the pillars of aging, including metformin, rapamycin, and nicotinamide adenine dinucleotide precursors, may also slow the rate of onset of age-associated comorbidities and geriatric syndromes in PWH. Drugs that selectively induce apoptosis of senescent cells, termed senolytics, may also improve health span among PWH. Preliminary evidence suggests that senescent cell burden is increased in PWH, implying that senescent cells are an excellent therapeutic target for extending health span. Recently initiated clinical trials evaluating senolytics in age-related diseases offer insights into the design and potential implementation of similar trials for PWH.

The association between growth patterns and blood pressure in children and adolescents: A cross-sectional study of seven provinces in China

Aimed to investigate the associations between different growth patterns with high blood pressure, and further examine the mediation effect of BMI between growth patterns and high blood pressure among children and adolescents. A total of 31581 children and adolescents aged 7-18 years were selected based on the stratified cluster sampling method. Logistics regression models were used to calculate the odds rations (ORs) and 95% confidence interval (95%CI) of the association between different growth patterns and high blood pressure. Mediation effect analyses were applied to estimate the effect of BMI on the increase of blood pressure levels in different growth patterns. In different sex and ages, compared to reference group of normal growth, blood pressure levels and prevalence of high blood pressure of the catch-up growth were higher, but that of the catch-down growth were lower. The prevalence of high blood pressure was 11.69%, 16.06%, and 9.68% in normal growth, catch-up growth, and catch-down growth, respectively. In total, compared with the normal growth pattern, the ORs (95%CI) of high blood pressure, high systolic blood pressure and high diastolic blood pressure in the catch-up growth were 1.171(1.073,1.280), 1.110(1.001,1.230) and 1.141(1.025,1.270) (p < .05), respectively. Additionally, the mediation effect of current BMI existed in the association between blood pressure levels and different growth patterns, particularly in boys. Our findings suggested that different growth patterns after birth could modify blood pressure, and the potential risks of high blood pressure could be increased by catch-up growth at childhood and adolescence.

CYP11B1 variants influence skeletal maturation via alternative splicing

We performed genome-wide association study meta-analysis to identify genetic determinants of skeletal age (SA) deviating in multiple growth disorders. The joint meta-analysis (N = 4557) in two multiethnic cohorts of school-aged children identified one locus, CYP11B1 (expression confined to the adrenal gland), robustly associated with SA (rs6471570-A; β = 0.14; P = 6.2 × 10^-12). rs6410 (a synonymous variant in the first exon of CYP11B1 in high LD with rs6471570), was prioritized for functional follow-up being second most significant and the one closest to the first intron-exon boundary. In 208 adrenal RNA-seq samples from GTEx, C-allele of rs6410 was associated with intron 3 retention (P = 8.11 × 10^-40), exon 4 inclusion (P = 4.29 × 10^-34), and decreased exon 3 and 5 splicing (P = 7.85 × 10^-43), replicated using RT-PCR in 15 adrenal samples. As CYP11B1 encodes 11-β-hydroxylase, involved in adrenal glucocorticoid and mineralocorticoid biosynthesis, our findings highlight the role of adrenal steroidogenesis in SA in healthy children, suggesting alternative splicing as a likely underlying mechanism.

The Polygenic and Monogenic Basis of Paediatric Fractures

PURPOSE OF REVIEW

Fractures are frequently encountered in paediatric practice. Although recurrent fractures in children usually unveil a monogenic syndrome, paediatric fracture risk could be shaped by the individual genetic background influencing the acquisition of bone mineral density, and therefore, the skeletal fragility as shown in adults. Here, we examine paediatric fractures from the perspective of monogenic and complex trait genetics.

RECENT FINDINGS

Large-scale genome-wide studies in children have identified ~44 genetic loci associated with fracture or bone traits whereas ~35 monogenic diseases characterized by paediatric fractures have been described. Genetic variation can predispose to paediatric fractures through monogenic risk variants with a large effect and polygenic risk involving many variants of small effects. Studying genetic factors influencing peak bone attainment might help in identifying individuals at higher risk of developing early-onset osteoporosis and discovering drug targets to be used as bone restorative pharmacotherapies to prevent, or even reverse, bone loss later in life.

Beyond the X Factor: Relevance of Sex Hormones in NAFLD Pathophysiology

Non-alcoholic fatty liver disease (NAFLD) is a major health issue worldwide, being frequently associated with obesity, unbalanced dietary regimens, and reduced physical activity. Despite their greater adiposity and reduced physical activity, women show a lower risk of developing NAFLD in comparison to men, likely a consequence of a sex-specific regulation of liver metabolism. In the liver, sex differences in the uptake, synthesis, oxidation, deposition, and mobilization of lipids, as well as in the regulation of inflammation, are associated with differences in NAFLD prevalence and progression between men and women. Given the major role of sex hormones in driving hepatic sexual dimorphism, this review will focus on the role of sex hormones and their signaling in the regulation of hepatic metabolism and in the molecular mechanisms triggering NAFLD development and progression.

Maternal PCOS status and metformin in pregnancy: Steroid hormones in 5-10 years old children from the PregMet randomized controlled study

Objective

Polycystic ovary syndrome (PCOS) is a common endocrine disorder, with potential effects on offspring both genetically and through altered intrauterine environment. Metformin, which ameliorate hormonal disturbances in non-pregnant women with PCOS is increasingly used in pregnancy. It passes the placenta, and the evidence on potential consequences for offspring endocrine development is scarce. We explore the potential effects of maternal PCOS status and intrauterine metformin exposure on offspring steroid hormone levels.

Design

This is a follow-up study of 5–10 years old children from the PregMet-study–a randomized controlled trial comparing metformin (2000 mg/day) to placebo during PCOS pregnancies. Of the 255 children invited, 117 (46%) were included.

Methods

There was no intervention in this follow-up study. Outcomes were serum levels of androstenedione, testosterone, SHBG, cortisol, 17-hydroxyprogesterone, 11-deoxycortisol and calculated free testosterone converted to gender-and age adjusted z-scores from a Norwegian reference population. These were compared in i) placebo-exposed children versus children from the reference population (z-score zero) by the deviation in z-score by one-sample t-tests and ii) metformin versus placebo-exposed children by two-sample t-tests. Holm-Bonferroni adjustments were performed to account for multiple endpoints.

Results

Girls of mothers with PCOS (n = 30) had higher mean z-scores of androstenedione (0.73 (95% confidence interval (CI) 0.41 to 1.06), p<0.0001), testosterone (0.76 (0.51 to 1.00), p<0.0001), and free testosterone (0.99 (0.67 to 1.32), p<0.0001) than the reference population. Metformin-exposed boys (n = 31) tended to have higher 11-deoxycortisol z-score than placebo-exposed boys (n = 24) (mean difference 0.65 (95% CI 0.14–1.17), p = 0.014).

Conclusion

Maternal PCOS status was associated with elevated androgens in 5- to 10-year-old daughters, which might indicate earlier maturation and increased risk of developing PCOS. An impact of metformin in pregnancy on steroidogenesis in children born to mothers with PCOS cannot be excluded. Our findings need confirmation in studies that include participants that have entered puberty.

Single random measurement of urinary gonadotropin concentration for screening and monitoring girls with central precocious puberty

PURPOSE

The gold standard for assessing pubertal activation is the gonadotropinreleasing hormone (GnRH) stimulation test (GnRHST), which is invasive, timeconsuming, and inconvenient. This study evaluated whether a single random measurement of urinary luteinizing hormone (LH) concentration could substitute for the GnRHST in diagnosing and monitoring central precocious puberty (CPP) in girls.

METHODS

Fifty-five girls with breast buds before 8 years of age were assessed by both the GnRHST and urinary gonadotropin assays. Based on the GnRHST results, 29 girls were assigned to the CPP group (peak LH≥5 IU/L), and 26 were placed in the premature thelarche (PT) group (peak LH&lt;5 IU/L). Auxological data and urine and serum samples were collected at baseline and after treatment with a GnRH agonist for 12 and 24 weeks.

RESULTS

Although the auxological data did not differ between the 2 groups, the serum levels of insulin-like growth factor-1, basal LH, follicle-stimulating hormone (FSH), estradiol, and peak LH; urinary LH; and peak serum LH/FSH and urinary LH/FSH ratios were higher in the CPP group than in the PT group. Pearson correlation analysis showed a positive correlation between the urinary and serum LH concentrations (r=0.660, P&lt;0.001). Receiver-operating characteristic curve analyses showed that a urinary LH concentration of 0.725 IU/L was a cutoff that significantly predicted positivity on the GnRHST. Urinary LH and FSH concentrations declined significantly during GnRH agonist treatment.

CONCLUSION

A single, random measurement of urinary gonadotropin concentration could be a reliable tool for initial screening and therapeutic monitoring of CPP in girls.

Description of the voided urinary microbiota in asymptomatic prepubertal children - A pilot study

BACKGROUND

Recently, it has been established that the urine of a healthy adult bladder contains a microbiota and that urinary dysbiosis may be involved in the development of urinary tract diseases. The urinary microbiota and its relation to bladder health and disease in children is yet to be established. The objective of the present study was to investigate the voided urinary microbiota in asymptomatic prepubertal children.

STUDY DESIGN

Thirty asymptomatic children (15 boys and 15 girls) participated in the study. Bacterial DNA in "clean-catch" midstream urine (CC MSU) samples was analysed using Illumina MiSeq sequencing of the V4 region of the bacterial 16 S rRNA gene. All children had normal bladder function as ensured by uroflowmetry, ultrasonic post-void residual, and frequency-volume charts. Bladder-related parameters and gender comparisons were analysed statistically by parametric and non-parametric tests. Alpha diversity, beta diversity, and a Venn diagram were used to analyse sequencing data.

RESULTS

All CC MSU samples contained bacterial DNA. The voided urinary microbiota differed significantly between girls and boys in terms of operational taxonomic unit (OTU) richness, Shannon diversity index, and relative abundances of bacterial genera, but not for evenness. The urine of girls was dominated by Prevotella (18.2%), Porphyromonas (12.9%), Ezakiella (8.1%), Prevotella 6 (7.4%), and Dialister (7.0%). Porphyromonas (22.4%) was the most abundant genus in boys, followed by Ezakiella (12.0%), Campylobacter (11.6%), Prevotella (8.6%), and Dialister (3.7%). Girls had 10 unique core OTUs, whereas boys had no unique core OTUs. Porphyromonas appeared as a shared core OTU between genders.

DISCUSSION

Contrary to previous findings, this study found significant differences in the voided urinary bacterial composition among asymptomatic prepubertal children. Moreover, the bacterial composition diverged from that found among healthy adults by other research groups. Among adults, the gender specific urinary microbiota has been hypothesised to be caused by anatomical differences in the reproductive organs and differences in sex hormone levels. This could also be evident for asymptomatic prepubertal children as sex hormone levels are different even at the prepubertal stage. The limitations of the study encompass small sample size and urine collection by CC MSU with risk of contamination from surrounding areas.

CONCLUSIONS

This study documents that CC MSU samples of asymptomatic prepubertal children are not sterile. The composition of the voided urinary microbiota seems gender specific and unequal to that of healthy adults. The role of the urinary microbiota in paediatric urological disorders should be considered in future studies.

The NIMH Intramural Longitudinal Study of the Endocrine and Neurobiological Events Accompanying Puberty: Protocol and rationale for methods and measures

Delineating the relationship between human neurodevelopment and the maturation of the hypothalamic-pituitary-gonadal (HPG) axis during puberty is critical for investigating the increase in vulnerability to neuropsychiatric disorders that is well documented during this period. Preclinical research demonstrates a clear association between gonadal production of sex steroids and neurodevelopment; however, identifying similar associations in humans has been complicated by confounding variables (such as age) and the coactivation of two additional endocrine systems (the adrenal androgenic system and the somatotropic growth axis) and requires further elucidation. In this paper, we present the design of, and preliminary observations from, the ongoing NIMH Intramural Longitudinal Study of the Endocrine and Neurobiological Events Accompanying Puberty. The aim of this study is to directly examine how the increase in sex steroid hormone production following activation of the HPG-axis (i.e., gonadarche) impacts neurodevelopment, and, additionally, to determine how gonadal development and maturation is associated with longitudinal changes in brain structure and function in boys and girls. To disentangle the effects of sex steroids from those of age and other endocrine events on brain development, our study design includes 1) selection criteria that establish a well-characterized baseline cohort of healthy 8-year-old children prior to the onset of puberty (e.g., prior to puberty-related sex steroid hormone production); 2) temporally dense longitudinal, repeated-measures sampling of typically developing children at 8-10 month intervals over a 10-year period between the ages of eight and 18; 3) contemporaneous collection of endocrine and other measures of gonadal, adrenal, and growth axis function at each timepoint; and 4) collection of multimodal neuroimaging measures at these same timepoints, including brain structure (gray and white matter volume, cortical thickness and area, white matter integrity, myelination) and function (reward processing, emotional processing, inhibition/impulsivity, working memory, resting-state network connectivity, regional cerebral blood flow). This report of our ongoing longitudinal study 1) provides a comprehensive review of the endocrine events of puberty; 2) details our overall study design; 3) presents our selection criteria for study entry (e.g., well-characterized prepubertal baseline) along with the endocrinological considerations and guiding principles that underlie these criteria; 4) describes our longitudinal outcome measures and how they specifically relate to investigating the effects of gonadal development on brain development; and 5) documents patterns of fMRI activation and resting-state networks from an early, representative subsample of our cohort of prepubertal 8-year-old children.

Mass Spectrometry-Based Steroid Profiling: Meeting Unmet Clinical Needs

Despite ongoing concerns regarding its clinical application, mass spectrometry (MS)-based steroid assay represents a promising tool in endocrine research. Recent studies indicate that monitoring the blood levels of individual sterols provides improved diagnostic insight into hyperlipidemia compared with immunoassays routinely used in clinical practice. Hypercortisolism and hyperaldosteronism can also be easily evaluated along with successful subtyping of adrenal diseases using MS-based methods, while metabolic signatures of sex steroids provide experimental evidence of abnormal puberty and male infertility. Many MS-based biological and clinical studies are based on liquid chromatography-mass spectrometry (LC-MS) coupled to electrospray ionization and tandem MS scan modes. However, gas chromatography-mass spectrometry (GC-MS) provides better chromatographic separation. Improved chromatographic resolution enables large-scale steroid profiling to allow a bird-eye view and increase the chances of identifying potent biomarkers in endocrine research. In addition to the technical advantages of MS-based assays over immunoassays, minimizing the sample amounts with acceptable analytical sensitivity and standardization of surrogate materials provides cutting-edge tools for precision and personalized medicine.

Aromatase deficiency: A case series of 46, XX Chinese children and a systematic review of the literature

BACKGROUND

Aromatase deficiency (AD) caused by cytochrome P450 family 19 subfamily A polypeptide 1 (CYP19A1) variants is characterized by a deficiency in androgen-to-oestrogen conversion.

OBJECTIVE

To investigate the clinical characteristics and accurate management of aromatase-deficient children.

PATIENTS AND METHODS

We described three 46, XX aromatase-deficient children, searched PubMed with "(aromatase deficiency) AND (46, XX OR ovaries)" and manually searched citations in identified studies for the literature review.

RESULTS

Two girls and one boy (3.4-9.2 years) with the 46, XX karyotype presented ambiguous genitalia and maternal antenatal virilization, normal-low height, delayed bone age, normal glucose and lipid profiles, markedly elevated follicle-stimulating hormone (FSH) levels and poor oestradiol responses to human menopausal gonadotropin stimulation. Ultrasound revealed normal-sized uterus and ovaries with undetectable follicles. Histopathology revealed primordial follicles and few primary follicles in ovaries. One patient presented granulosa and follicular membrane cell proliferation and interstitial sclerosis. We identified four CYP19A1 variants; c.146_158del and c.344G >A were unreported. We reviewed available data from thirty 46, XX patients (0.2-32 years). Some patients were not diagnosed until puberty/adulthood; three were initially misdiagnosed with congenital adrenocortical hyperplasia. The main characteristics were maternal antenatal virilization (21/29), ambiguous genitalia (mainly Prader IV or III, 19/23), delayed bone age (16/17), low bone mass (5/8), markedly elevated FSH levels and ovarian cysts (13/30).

CONCLUSIONS

46, XX AD is easily neglected or misdiagnosed. Ambiguous genitalia, maternal antenatal virilization and markedly elevated FSH levels are important diagnostic indicators. We described two novel variants, new histopathological features of ovaries and an early management strategy.

Androgens by immunoassay and mass spectrometry in children with 46,XY disorder of sex development

OBJECTIVE

Steroid measurement is a challenge in pediatric endocrinology. Currently, liquid chromatography with tandem mass spectrometry (LC-MS/MS) is considered a gold standard for this purpose. The aim of this study was to compare both LC-MS/MS and immunoassay (IA) for androgens before and after human recombinant chorionic gonadotropin (rhCG) stimulus in children with 46,XY disorders of sex development (DSD).

METHODS

Nineteen patients with 46,XY DSD were evaluated; all of them were prepubertal and non-gonadectomized. Testosterone, dihydrotestosterone (DHT), DHEA and androstenedione were measured by IA and LC-MS/MS before and 7 days after rhCG injection. The correlation between IA and LC-MS/MS was analyzed by the intraclass correlation coefficient (ICC) and Spearman's rank correlation coefficient (SCC). For concordance analysis the Passing and Bablok (PB) regression and the Bland and Altman (BA) method were used.

RESULTS

Testosterone showed excellent correlation (ICC = 0.960 and SCC = 0.964); DHT showed insignificant and moderate correlations as indicated by ICC (0.222) and SCC (0.631), respectively; DHEA showed moderate correlation (ICC = 0.585 and SCC = 0.716); and androstenedione had poor and moderate correlations in ICC (0.363) and SCC (0.735), respectively. Using the PB method, all hormones showed a linear correlation, but proportional and systematic concordance errors were detected for androstenedione, systematic errors for testosterone and no errors for DHEA and DHT. By the BA method, there was a trend of IA to overestimate testosterone and androstenedione and underestimate DHEA and DHT when compared to LC-MS/MS.

CONCLUSION

Traditional IA should be replaced by LC-MS/MS for the androgens measurement in prepubertal children whenever is possible.

17α-Estradiol prevents ovariectomy-mediated obesity and bone loss

Menopause is a natural physiological process in older women that is associated with reduced estrogen production and results in increased risk for obesity, diabetes, and osteoporosis. 17α-estradiol (17α-E2) treatment in males, but not females, reverses several metabolic conditions associated with advancing age, highlighting sexually dimorphic actions on age-related pathologies. In this study we sought to determine if 17α-E2 could prevent ovariectomy (OVX)-mediated detriments on adiposity and bone parameters in females. Eight-week-old female C57BL/6J mice were subjected to SHAM or OVX surgery and received dietary 17α-E2 during a six-week intervention period. We observed that 17α-E2 prevented OVX-induced increases in body weight and adiposity. Similarly, uterine weight and luminal cell thickness were decreased by OVX and prevented by 17α-E2 treatment. Interestingly, 17α-E2 prevented OVX-induced declines in tibial metaphysis cancellous bone. And similarly, 17α-E2 improved bone density parameters in both tibia and femur cancellous bone, primarily in OVX mice. In contrast, to the effects on cancellous bone, cortical bone parameters were largely unaffected by OVX or 17α-E2. In the non-weight bearing lumbar vertebrae, OVX reduced trabecular thickness but not spacing, while 17α-E2 increased trabecular thickness and reduced spacing. Despite this, 17α-E2 did improve bone volume/tissue volume in lumbar vertebrae. Overall, we found that 17α-E2 prevented OVX-induced increases in adiposity and changes in bone mass and architecture, with minimal effects in SHAM-operated mice. We also observed that 17α-E2 rescued uterine tissue mass and lining morphology to control levels without inducing hypertrophy, suggesting that 17α-E2 could be considered as an adjunct to traditional hormone replacement therapies.

Changes in Adrenal Androgens and Steroidogenic Enzyme Activities From Ages 2, 4, to 6 Years: A Prospective Cohort Study

CONTEXT

The levels of adrenal androgens are increased through the action of steroidogenic enzymes with morphological changes in the adrenal zona reticularis.

OBJECTIVE

We investigated longitudinal changes in androgen levels and steroidogenic enzyme activities during early childhood.

DESIGN AND PARTICIPANTS

From a prospective children's cohort, the Environment and Development of Children cohort, 114 boys and 86 girls with available blood samples from ages 2, 4, and 6 years were included.

OUTCOME MEASUREMENTS

Serum concentrations of adrenal androgens using liquid chromatography-tandem mass spectrometry and steroidogenic enzyme activity calculated by the precursor/product ratio.

RESULTS

During ages 2 to 4 years, 17,20-lyase and dehydroepiandrosterone (DHEA) sulfotransferase activities increased (P < 0.01 for both in boys). During ages 4 to 6 years, 17,20-lyase activity persistently increased, but 3β-hydroxysteroid dehydrogenase (HSD) and 17β-HSD activities decreased (P < 0.01 for all). Serum DHEA sulfate (DHEA-S) levels persistently increased from 2, 4, to 6 years, and DHEA, 17-hydroxyprogesterone, and androstenedione levels increased during ages 4 to 6 years (P < 0.01 for all). Serum DHEA-S levels during early childhood were associated with body mass index z-scores (P = 0.001 in only boys).

CONCLUSION

This study supports in vivo human evidence of increased 17,20-lyase and DHEA sulfotransferase activities and decreased 3β-HSD activity during early childhood.

Development of a quantitative method for determination of steroids in human plasma by gas chromatography-negative chemical ionization-tandem mass spectrometry

Sex steroids are involved in biological functions that encompass from the complete sexual development of individuals up to the deregulation of metabolic pathways leading to some pathologies. Steroids are present in blood at low concentration levels from pg mL^-1 to ng mL^-1. For this reason, a high sensitive and selective method based on gas chromatography-negative chemical ionization-tandem mass spectrometry (GC-NCI-MS/MS) is here proposed to quantify either androgens (androstenedione, dehydroepiandrosterone, dihydrotestosterone and testosterone), estrogens (estrone and estradiol) and a progestogen (progesterone) in human plasma. The sample preparation steps, protein precipitation and solid phase extraction, were optimized to ensure the sample matrix removal and to extract steroids with high efficiency. The NCI-MS/MS detection approach was compared with that based on electron impact to evaluate the incidence of the ionization source in the determination of steroids. The quantification limits for determination of these analytes were in a range from 10 pg mL^-1 to 5 ng mL^-1, with a high sensitivity for estrogens, typically found at low concentrations. The proposed method was tested for the determination of steroids in male blood samples, in which 6 out of 7 steroids were detected and quantified to report concentration values in agreement with those described in the literature.

Women in sports: The applicability of reference intervals for 6 commercially available testosterone immunoassays (HemSter Study)

BACKGROUND

Testosterone levels in female athletes are increased due to their physical activity and correlate with their exercise volume. We therefore hypothesized that the reference intervals (RIs) derived from the general population are not applicable for female athletes. The aim of this study was to evaluate the applicability of the given RIs for 6 commercially available testosterone immunoassays in a group of female athletes.

METHODS

Our study included 121 female athletes from various sporting disciplines (water polo, handball, volleyball, football, and basketball). The physical activity score was assessed by the Short Form of the International Physical Activity Questionnaire. Total testosterone was measured in serum samples by the reference LC-MS/MS method and six different immunoassays (Abbott Architect 2^nd Generation Testosterone, Beckman Coulter Access Testosterone, Roche Elecsys Testosterone II, Siemens Atellica® IM Testosterone II (TSTII), Siemens IMMULITE 2000 Total Testosterone, and Snibe MAGLUMI™ Testosterone).

RESULTS

There were statistically significant differences in age (P = 0.042), weight (P = 0.001), height (P < 0.001), and BMI (P < 0.001) between athletes across different sports. Their quantitative measurements of physical activity and testosterone concentration did not differ significantly between subgroups of various sports, P = 0.167 and P = 0.181, respectively. All immunoassays had a positive absolute and relative bias, in comparison with the LC-MS/MS. The manufacturer's RI was not verified for Abbott Architect, Beckman Coulter Access, and Roche Elecsys Testosterone methods, with the highest percentage of athletes above RI for Beckman Coulter (30%).

CONCLUSIONS

We demonstrated that the upper reference limit provided was too low for some young female athletes. Clinical laboratories should consider implementation of the new proposed RIs.

A Multiscale Agent-Based Model of Ductal Carcinoma In Situ

OBJECTIVE

we present a multiscale agent-based model of Ductal Carcinoma in Situ (DCIS) in order to gain a detailed understanding of the cell-scale population dynamics, phenotypic distributions, and the associated interplay of important molecular signaling pathways that are involved in DCIS ductal invasion into the duct cavity (a process we refer to as duct advance rate here).

METHODS

DCIS is modeled mathematically through a hybridized discrete cell-scale model and a continuum molecular scale model, which are explicitly linked through a bidirectional feedback mechanism.

RESULTS

we find that duct advance rates occur in two distinct phases, characterized by an early exponential population expansion, followed by a long-term steady linear phase of population expansion, a result that is consistent with other modeling work. We further found that the rates were influenced most strongly by endocrine and paracrine signaling intensity, as well as by the effects of cell density induced quiescence within the DCIS population.

CONCLUSION

our model analysis identified a complex interplay between phenotypic diversity that may provide a tumor adaptation mechanism to overcome proliferation limiting conditions, allowing for dynamic shifts in phenotypic populations in response to variation in molecular signaling intensity. Further, sensitivity analysis determined DCIS axial advance rates and calcification rates were most sensitive to cell cycle time variation.

SIGNIFICANCE

this model may serve as a useful tool to study the cell-scale dynamics involved in DCIS initiation and intraductal invasion, and may provide insights into promising areas of future experimental research.

A multi-country, multi-year, meta-analytic evaluation of the sex differences in age-specific pertussis incidence rates

BACKGROUND

Pertussis is frequently reported to be more common in females than in males. However, the variability of the sources of these observations makes it difficult to estimate the magnitude and consistency of the sex differences by age. To address this question, we used meta-analytic methods to analyze pertussis national incidence rates by sex and age group from nine countries between the years 1990 and 2017.

METHODS

For each age group, we used meta-analytic methods to combine the female to male incidence rate ratios (RRs) by country and year. Meta-regression was performed to assess the relative contributions of age, country and time-period to the variation in the incidence RRs.

RESULTS

The pooled female to male incidence RRs (with 95% CI) for ages 0-1, 1-4, 5-9 and 10-14, were 1.03 (1.01-1.06), 1.16 (1.14-1.17), 1.18 (1.15-1.22), 1.15 (1.11-1.18) respectively. For the ages 15-44, 45-64 and 65+ they were 1.65 (1.58-1.72), 1.59 (1.53-1.66), 1.20 (1.16-1.24), respectively. While there were some differences between the countries, the directions were consistent. When including age, country and time in meta-regression analyses, almost all the variation could be attributed to the differences between the age groups.

CONCLUSIONS

The consistency of the excess pertussis incidence rates in females, particularly in infants and very young children, is unlikely to be due to differences in exposure. Other factors that impact on the immune system, including chromosomal differences and hormones, should be further investigated to explain these sex differences. Future studies should consider sex for better understanding the mechanisms affecting disease incidence, with possible implications for management and vaccine development.

Sex-specific Estrogen Levels and Reference Intervals from Infancy to Late Adulthood Determined by LC-MS/MS

CONTEXT

The lack of sensitive and robust analytical methods has hindered the reliable quantification of estrogen metabolites in subjects with low concentrations.

OBJECTIVE

To establish sex-specific reference ranges for estrone (E1) and estradiol (E2) throughout life and to evaluate sex-differences using the state-of-the-art liquid chromatography tandem mass spectrometry (LC-MS/MS) method for quantification of E1, E2, and estriol (E3).

DESIGN

LC-MS/MS method development and construction of estrogen reference ranges.

SETTINGS

Population-based cross-sectional cohorts from the greater Copenhagen and Aarhus areas.

PARTICIPANTS

Healthy participants aged 3 months to 61 years (n = 1838).

RESULTS

An isotope diluted LC-MS/MS method was developed and validated for measurements of serum E1, E2, and E3. Limits of detections (LODs) were 3 pmol/L (E1), 4 pmol/L (E2), and 12 pmol/L (E3), respectively. This sensitive method made it possible to differentiate between male and female concentration levels of E1 and E2 in children. In girls, E2 levels ranged from

CONCLUSION

Reference ranges of simultaneous quantification of E1 and E2 by this novel specific and highly sensitive LC-MS/MS method provide an invaluable tool in clinical practice and in future research studies.

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Key Words

• LC-MS/MS
• childhood
• estradiol
• estrone
• menopause
• menstrual cycle
• mini-puberty
• pubertal development
• reference range

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MESH Headings

• Adolescent
• Adult
• Child
• Child, Preschool
• Chromatography, Liquid/methods
• Chromatography, Liquid/statistics & numerical data
• Estradiol/blood
• Estrone/blood
• Female
• Healthy Volunteers
• Humans
• Infant
• Male
• Middle Aged
• Reference Values
• Sensitivity and Specificity
• Sex Factors
• Tandem Mass Spectrometry/methods
• Tandem Mass Spectrometry/statistics & numerical data
• Young Adult

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Grants

• Innovation Fund Denmark
• ReproUnion collaboration

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Affiliation(s)

Hanne Frederiksen Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark International Center for Research and Research Training in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), University of Copenhagen, Copenhagen, Denmark
Trine Holm Johannsen Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark International Center for Research and Research Training in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), University of Copenhagen, Copenhagen, Denmark
Stine Ehlern Andersen Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
Jakob Albrethsen Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark International Center for Research and Research Training in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), University of Copenhagen, Copenhagen, Denmark
Selma Kløve Landersoe The Fertility Clinic, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
Jørgen Holm Petersen Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark International Center for Research and Research Training in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), University of Copenhagen, Copenhagen, Denmark Department of Biostatistics, University of Copenhagen, Copenhagen, Denmark
Anders Nyboe Andersen The Fertility Clinic, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
Esben Thyssen Vestergaard Paediatrics and Adolescent Medicine, Aarhus University Hospital, Aahus, Denmark
Mia Elbek Schorring Paediatrics and Adolescent Medicine, Aarhus University Hospital, Aahus, Denmark
Allan Linneberg Center for Clinical Research and Disease Prevention, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
Katharina M Main Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark International Center for Research and Research Training in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), University of Copenhagen, Copenhagen, Denmark
Anna-Maria Andersson Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark International Center for Research and Research Training in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), University of Copenhagen, Copenhagen, Denmark
Anders Juul Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark International Center for Research and Research Training in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), University of Copenhagen, Copenhagen, Denmark

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Skeletal maturation in relation to ethnic background in children of school age: The Generation R Study

Ethnicity is a well-established determinant of pediatric maturity, but the underlying genetic and environmental contributions to these ethnic differences are poorly comprehended. We aimed to evaluate the influence of ethnicity on skeletal age (SA), an assessment of pediatric maturation widely used in clinical settings. We included children from the Generation R Study, a multiethnic population-based pregnancy cohort, assessed at a mean age of 9.78 (±0.33) years. SA was evaluated by a trained observer on hand DXA scans using the Greulich and Pyle method. Ethnic background was defined as geographic ancestry (questionnaire-based assessment) (N = 5325) and genetic ancestry (based on admixture analysis) (N = 3413). Associations between the ethnic background and SA were investigated separately in boys and girls, using linear regression models adjusted for age, height and BMI. Based on geographic ancestry, 84% of the children were classified as European, 6% as Asian and 10% as African. Children of European background had on average younger SA than those of Asian or African descent. Asian boys had 0.46 (95% CI 0.26-0.66, p-value < 0.0001) and African boys 0.36 years (95% CI 0.20-0.53, p-value < 0.0001) older SA as compared to European boys. Similarly, Asian girls showed 0.64 (95% CI 0.51-0.77, p-value < 0.0001) and African girls 0.38 years (95% CI 0.27-0.48, p-value < 0.0001) older SA as compared to European girls. A similar pattern was observed in the analysis with genetically-defined ancestry. Furthermore, an increase in the proportion of Asian or African component was associated with older SA in both boys (log[Non-European/European]proportion = 0.10, 95% CI 0.06-0.13, p-value < 0.0001) and girls (log[Non-European/European]proportion = 0.06, 95% CI 0.04-0.08, p-value < 0.0001). In summary, children of Asian and African backgrounds have on average older SA as compared to children of European descent, partially explained by a genetic component.

Hypogonadism in Pediatric Health: Adult Medicine Concepts Fail

The classical definition of hypogonadism, used in adult medicine, as gonadal failure resulting in deficient steroid and gamete production, and its classification into hypergonadotropic and hypogonadotropic refer to primary gonadal and hypothalamic-pituitary disorders respectively and may lead to under- or misdiagnosis in pediatrics. Indeed, in children with primary gonadal failure, gonadotropin levels may be within the reference range for age. Conversely, since gonadotropins and steroids are normally low during childhood, it may prove impossible to show the existence of a hypogonadotropic state before pubertal age. Anti-Müllerian hormone (AMH) and inhibin B arise as more adequate biomarkers to assess gonadal function and increase the possibility of making an earlier diagnosis of hypogonadism in children, which may positively impact on timely management.

A method for determination of one hundred endogenous steroids in human serum by gas chromatography-tandem mass spectrometry

Steroid profiling helps various pathologies to be rapidly diagnosed. Results from analyses investigating steroidogenic pathways may be used as a tool for uncovering pathology causations and proposals of new therapeutic approaches. The purpose of this study was to address still underutilized application of the advanced GC-MS/MS platform for the multicomponent quantification of endogenous steroids. We developed and validated a GC-MS/MS method for the quantification of 58 unconjugated steroids and 42 polar conjugates of steroids (after hydrolysis) in human blood. The present method was validated not only for blood of men and non-pregnant women but also for blood of pregnant women and for mixed umbilical cord blood. The spectrum of analytes includes common hormones operating via nuclear receptors as well as other bioactive substances like immunomodulatory and neuroactive steroids. Our present results are comparable with those from our previously published GC-MS method as well as the results of others. The present method was extended for corticoids and 17alpha-hydroxylated 5alpha/ß-reduced pregnanes, which are useful for the investigation of alternative "backdoor" pathway. When comparing the analytical characteristics of the present and previous method, the first exhibit by far higher selectivity, and generally higher sensitivity and better precision particularly for 17alpha-hydroxysteroids.

Consistent, Excess Viral Meningitis Incidence Rates in Young Males: A Multi-country, Multi-year, Meta-analysis of National Data. The Importance of Sex as a Biological Variable

BACKGROUND

Sex can be an important biological variable in the immune response to infections and the response to vaccines. The magnitude and consistency in age-specific sex differences in the incidence of viral infections remain unclear.

METHODS

We obtained data from national official agencies on cases of viral meningitis by sex and age group over a period of 6-16 years from five countries: Canada, Czech Republic, Germany, Israel, and Poland. Male to female incidence rate ratios (RR) were computed for each year, by country, and age group. For each age group, we used meta-analysis methodology to combine the incidence RRs. Meta-regression was conducted to the estimate the effects of age, country, and time period on the RR.

FINDINGS

In the age groups < 1, 1-4, 5-9, 10-14, there were consistently higher incidence rates in males, over countries and time. The pooled incidence RRs (with 95% CI) were 1.38 (1.30-1.47), 1.94 (1.85-2.03), 1.98 (1.88-2.07), and 1.58 (1.47-1.71) respectively. In young and middle-age adults there were no differences with pooled incidence RRs of 1.00 (0.97-1.03), and 0.97 (0.94-1.00), respectively. Sensitivity analysis confirms that the results are stable and robust. Meta-regression showed that almost all the variations in the incidence RRs were contributed by age group.

INTERPRETATION

The higher incidence rates from viral meningitis in males under the age of 15 are remarkably consistent across countries and time-periods. These findings emphasize the importance of sex as a biological variable in infectious diseases. This could provide keys to the mechanisms of infection and lead to more personalized treatment and vaccine doses and schedules.

FUNDING

There was no funding source for this article.

Steroidogenic potential of human fetal kidney at early gestational age

Steroidogenic potential of the human fetal kidney (hFK) at the end of first trimester is poorly investigated. Little is known about the ontogeny of steroidogenic enzymes and activities of steroidogenic pathways in the hFK at early pregnancy. Our aim was to explore steroidogenesis and the expression of steroidogenic enzymes in the hFK at gestational weeks (GW) 9-12. Steroids in the hFK were analyzed by gas chromatography/coupled to tandem mass spectrometry. The expression of steroidogenic enzymes in the hFK at GW 9-12 was investigated by qPCR, automated Western blotting and immunohistochemistry. We observed that the hFK produced substantial amount of steroids of the Δ⁵ and Δ⁴ pathways and several steroid precursors in the biosynthesis of DHT via the backdoor pathway but not DHT itself. The levels of steroids and expression of relevant steroidogenic enzymes (e.g., CYP17A1, HSD3B1, HSD3B2, CYP11B1 and AKR1C4) we significantly higher in the hFK at GW11-12 compared to GW9. We also found the expression of sex steroid receptors (e.g., AR, ERα and ERβ) in the hFK at GW9-12. No sex-dependent differences in the levels of all identified steroids and expression of steroidogenic enzymes in the hFK from male and female fetuses were found. Altogether, our data indicate that the hFK at early pregnancy is steroidogenic organ with potential to synthesize multiple steroids that may play an important role in the formation and development of this organ in humans.

Prepubertal ovarian inhibition of Light/Dark Box exploration and novel object investigation in juvenile Siberian hamsters

The overwhelming majority of research on the role of gonadal hormones in behavioral development has focused on perinatal, pubertal, or adult life stages. The juvenile period has been overlooked because it is thought to be a time of gonadal quiescence. In the present study, we tested whether prepubertal gonadectomy impacts the behavior of male and female juvenile hamsters on the Light/Dark Box, Novel Object, and Social Approach tests (Experiment 1) and compared these findings to those obtained after adult gonadectomy (Experiment 2). Prepubertal ovariectomy increased exploration (i.e. time spent in the light zone of the Light/Dark Box) and novel object investigation of juveniles indicating an inhibitory role for the juvenile ovary; social approach was unaffected. In contrast, adult ovariectomy and castration (both prepubertal and adult) had no effect on any behavioral measure. Experiment 3 tested whether rearing hamsters in a short day length (SD), which delays puberty in this species, extends the interval of juvenile ovarian inhibition on exploration and novelty seeking. We also tested whether provision of estradiol reverses the effects of prepubertal ovariectomy. Hormonal manipulations and behavioral tests of Experiment 3 were conducted at ages when long day-reared hamsters are adult (as in Experiment 2), but SD-reared hamsters remain reproductively immature. Ovariectomy again increased exploration in the SD-reared juveniles despite the older age of surgery and testing. Estradiol treatment had no effect. These findings reveal a novel role for the juvenile ovary in exploration and novelty seeking that is unlikely to be mediated exclusively by estradiol.

Gender-Dependent Growth and Insulin-Like Growth Factor-1 Responses to Growth Hormone Therapy in Prepubertal Growth Hormone-Deficient Children

Gender seems to be an important factor influencing the response to recombinant human growth hormone (rhGH) therapy in GH-deficient adolescents and adults. The results of studies evaluating gender-specific response to rhGH therapy in prepubertal GH-deficient children are divergent. The aim of this study was to determine the effect of gender on the growth and insulin-like growth factor-1 (IGF-1) responses in 75 prepubertal GH-deficient children during the first 2 years of rhGH therapy. There were no baseline gender differences in age, bone age, anthropometrical parameters, and IGF-1 SDS for bone age. After the initiation of rhGH therapy, there were no gender-specific differences concerning the reduction of height deficit. Serum IGF-1 levels were higher in the prepubertal GH-deficient girls than in the age-matched boys, but the difference was not significant when expressed as IGF-1 SDS for bone age. The increase in IGF-1 SDS for bone age was significantly greater in girls versus boys after the first 6 months of therapy, comparable between girls and boys after the first year of therapy, and tended to be higher in boys after the second year of therapy. In conclusion, prepubertal GH-deficient girls and boys do not differ significantly in growth response in the first 2 years of rhGH therapy.

Impact of Pubertal Maturation and Chronologic Age on Sex Steroids in Peripubertal Girls

CONTEXT

There is a 4- to 5-year variation in age of breast maturation in girls.

OBJECTIVE

To examine longitudinal changes in sex hormone values relative to chronologic age and time relative to breast maturation.

SETTING AND DESIGN

Longitudinal observational study into which girls were recruited at 6 to 7 years of age and followed up every 6 months.

MAIN OUTCOME MEASURES

Maturation status, chronologic age, race, and fasting blood specimen data were obtained. Hormones were analyzed at 6-month intervals between 2 years before and 1 year after breast maturation, using HPLC tandem mass spectroscopy.

RESULTS

Estradiol and estrone levels correlated with chronologic age (R = 0.350 and 0.444, respectively); time was correlated relative to breast maturation (R = 0.222 and 0.323, respectively; all correlations, P < 0.0001). In generalized estimating equation (GEE) models, chronologic age and time relative to pubertal onset were significantly associated with serum estradiol, with similar results for estrone. Local estimated scatterplot smoothing for estradiol and estrone, by chronologic age, demonstrated differences between black and white girls, especially between 8.5 and 11 years of age, but not by race in time relative to breast maturation. Testosterone level was correlated to chronologic age (R = 0.362) and time relative to breast maturation (R = 0.259); in the GEE model, only chronologic age was significant.

CONCLUSION

Chronologic age as well as time relative to onset of puberty provided unique information regarding estradiol and estrone concentrations in peripubertal girls. Serum estrogen concentrations should be evaluated with reference to chronologic age and race.