The Role of Pediatric Nutrition as a Modifiable Risk Factor for Precocious Puberty

ADHD and Risk of Precocious Puberty: Considering the Impact of MPH

BACKGROUND/OBJECTIVES

The complex association between attention-deficit/hyperactivity disorder (ADHD) and methylphenidate (MPH) with precocious puberty (PP) is still unclear. This study aims to investigate the association between ADHD, MPH, and PP.

METHODS

This is a nationwide cohort study including a total of 3,342,077 individuals, 186,681 with ADHD and 3,155,396 without. First, we compared the risk of PP between ADHD cases and non-ADHD cases. Second, we compared the risk of PP between MPH users and non-MPH users in patients with ADHD.

RESULTS

Patients with ADHD were at a greater risk of PP (adjusted hazard ratio [aHR], 2.01 [95% CI, 1.91-2.11]). In our moderation analyses, the female gender was a positive additive effect modifier of the association between ADHD and PP, whereas tics and intellectual disability were negative effect modifiers. In patients with ADHD, MPH users had a significantly lower risk of PP (aHR, 0.63 [95% CI 0.57-0.70]), and females had a negative effect modification on the association between MPH and PP.

CONCLUSIONS

Our study found that children with ADHD were at a greater risk of PP. Girls with ADHD were a group particularly vulnerable to PP. Comorbid tics or intellectual disability was associated with a lower risk of PP. Among patients with ADHD, MPH was protective against PP, especially in girls. However, these preliminary results need further validation due to the nature of them being from an electronic database study. Unmeasured confounding factors might affect the association between MPH and PP.

The Metabolic Programming of Pubertal Onset

BACKGROUND

There is increasing evidence that maternal factors such as nutritional status (both under and over-nutrition) and diabetes, alongside prenatal exposure to endocrine disrupting chemicals (EDCs), are associated with early pubertal onset in offspring. Such children are also at increased risk of the metabolic syndrome during adolescence and young adulthood.

AIM

This literature review focuses on the role of the prenatal environment in programming pubertal onset, and the impact of prenatal metabolic stressors on the declining average age of puberty.

METHOD

A review of all relevant literature was conducted in PubMed by the authors.

OUTCOME

The mechanism for this appears to be mediated through metabolic signals, such as leptin and insulin, on the kisspeptin-neuronal nitric oxide-gonadotropin releasing hormone (KiNG) axis. Exposed children have an elevated risk of childhood obesity and display a phenotype of hyperinsunlinaemia and hyperleptinaemia. These metabolic changes permit an earlier attainment of the nutritional "threshold" for puberty. Unfortunately, this cycle may be amplified across subsequent generations, however early intervention may help "rescue" progression of this programming.

Ultra-processed foods intake and sex hormone levels among children and adolescents aged 6-19 years: a cross-sectional study

Background

Sex hormones are crucial for the development of children and adolescents. The increasing consumption of ultra-processed foods (UPFs) among children and adolescents in the United States (US) has raised concerns about their potential impact on health, including hormonal balance.

Methods

Data from 3,354 participants aged 6-19 years from the NHANES 2013-2016 were analyzed. UPF intake was categorized using the NOVA food classification system, and the percentage of total daily energy intake from UPFs was calculated. The serum levels of total testosterone (TT), sex hormone-binding globulin (SHBG), and estradiol (E2) were measured. The free androgen index (FAI) and TT/E2 ratio were calculated to estimate bioavailable testosterone levels and the balance between androgens and estrogens, respectively. Multiple linear regression models, adjusted for potential confounders, estimated the associations.

Results

Our results showed that higher intake of UPFs was marginally associated with decreased serum SHBG levels (quartile (Q) 2 vs. Q1: β = -5.3, 95% confidence interval (CI): -17.0, 8.1%; Q3 vs. Q1: β = -14.6, 95%CI: -25.1, -2.5%; Q4 vs. Q1: β = -9.0, 95%CI: -20.3, 3.8%; P trend = 0.081), and significantly associated with increased serum FAI in female adolescents (Q2 vs. Q1: β = 3.2, 95%CI: -3.3, 9.7; Q3 vs. Q1: β = 7.6, 95%CI: -0.7, 16.0; Q4 vs. Q1: β = 9.5, 95%CI: 1.5, 17.6; P trend = 0.019). Additionally, UPF intake showed a marginally positive association with increased serum SHBG levels (P trend = 0.057) in male children and FAI (P trend = 0.150) in male adolescents, respectively. Similar results were observed when participants were stratified by puberty status, except for the association between UPF intake and SHBG in male children. However, there were no associations between UPF consumption and TT, E2, or the TT/E2 ratio, both in males and females.

Conclusion

Higher UPF consumption is associated with increased FAI in adolescents, particularly in girls, indicating higher bioavailable testosterone levels. Future studies should validate these findings with direct free testosterone measurements and more precise dietary intake assessments.

Evaluating Phthalates and Bisphenol in Foods: Risks for Precocious Puberty and Early-Onset Obesity

Recent scientific results indicate that diet is the primary source of exposure to endocrine-disrupting chemicals (EDCs) due to their use in food processing, pesticides, fertilizers, and migration from packaging to food, particularly in plastic or canned foods. Although EDCs are not listed on nutrition labels, their migration from packaging to food could inadvertently lead to food contamination, affecting individuals by inhalation, ingestion, and direct contact. The aim of our narrative review is to investigate the role of phthalates and bisphenol A (BPA) in foods, assessing their risks for precocious puberty (PP) and early-onset obesity, which are two clinical entities that are often associated and that share common pathogenetic mechanisms. The diverse outcomes observed across different studies highlight the complexity of phthalates and BPA effects on the human body, both in terms of early puberty, particularly in girls, and obesity with its metabolic disruptions. Moreover, obesity, which is independently linked to early puberty, might confound the relationship between exposure to these EDCs and pubertal timing. Given the potential public health implications, it is crucial to adopt a precautionary approach, minimizing exposure to these EDCs, especially in vulnerable populations such as children.

Characterization of MicroRNA expression profiles in the ovarian tissue of goats during the sexual maturity period

BACKGROUND

The ovary is an important reproductive organ in mammals, and its development directly affects the sexual maturity and reproductive capacity of individuals. MicroRNAs (miRNAs) are recognized as regulators of reproductive physiological processes in various animals and have been shown to regulate ovarian development through typical targeting and translational repression. However, little is known about the regulatory role of miRNAs in ovarian tissue development during sexual maturity in goats. To comprehensively profile the different physiological stages of sexual maturation in goats, we performed small-RNA sequencing of ovarian tissue samples collected at four specific time points (1 day after birth (D1), 2 months old (M2), 4 months old (M4), and 6 months old (M6)). In addition, we used ELISAs to measure serum levels of reproductive hormones to study their temporal changes.

RESULTS

The results showed that serum levels of gonadotropin-releasing hormone, follicle-stimulating hormone, luteinizing hormone, oestradiol, progesterone, oxytocin, and prolactin were lower in goats at the D1 stage than at the other three developmental stages (P < 0.05). The secretion patterns of these seven hormones show a similar trend, with hormone levels reaching their peaks at 4 months of age. A total of 667 miRNAs were detected in 20 libraries, and 254 differentially expressed miRNAs and 3 groups of miRNA clusters that had unique expression patterns were identified (|log2-fold change|> 1, FDR < 0.05) in the 6 comparison groups. RT‒qPCR was employed to confirm that the expression pattern of the 15 selected miRNAs was consistent with the Illumina sequencing results. Gene ontology analyses revealed significant enrichment of GO terms such as cell proliferation regulation, epithelial cell development, and amino acid transport, as well as important signaling pathways including the MAPK signaling pathway, the PI3K-Akt signaling pathway, and the oestrogen signaling pathway. Further miRNA‒mRNA regulation network analysis revealed that 8 differentially expressed miRNAs (chi-miR-1343, chi-miR-328-3p, chi-miR-877-3p, chi-miR-296-3p, chi-miR-128-5p, chi-miR-331-3p, chi-miR-342-5p and chi-miR-34a) have important regulatory roles in ovarian cell proliferation, hormone secretion and metabolism-related biological processes.

CONCLUSIONS

Overall, our study investigated the changes in serum hormone and miRNA levels in the ovaries. These data provide a valuable resource for understanding the molecular regulatory mechanisms of miRNAs in ovarian tissue during the sexual maturity period in goats.

Breast and Formula Milk and Early Puberty Onset

Nutrients have an enormous impact on many hormonal systems and aspects of health, and nutrition status is a crucial regulator of growth and pubertal development in children and adolescents. In this narrative review, we explore the connection between these feeding methods and the timing of puberty to provide a clearer understanding of how infant nutrition might contribute to the early development of puberty. Puberty is a key stage in the transition from childhood to adulthood and the timing of puberty represents a significant biological milestone of growth. Breast milk seems to have a pivotal role in puberty onset, mainly due to its dynamism, which shape indirectly the gut microbiota in early life, besides direct exposure of the baby to the milk microbiota through gut-breast axis. Concerning breast and formula milk and their effects on the onset of puberty, a protective role of the former occurs. As for the potential harmful effects of soy-based formulas and the isoflavones that they contain, the studies reported demonstrate conflicting opinions, underlining the need for further research on this topic. A healthy and well-nourished diet from the earliest stages of life has significant preventive potential for overall well-being, reducing the risk of many health problems later in life.

Association between Vitamin D Levels, Puberty Timing, and Age at Menarche

Pubertal development represents the process of physical maturation where an adolescent reaches sexual maturity and attains reproductive function. The effects of vitamin D are mainly mediated by the vitamin D receptor (VDR), which is expressed in almost all body cells, including the ovary and human pituitary gland and animal hypothalamus. Thus, vitamin D has gained great interest as pathogenic factor of pubertal disorders and fertility. This narrative review aimed to provide a broad overview of the available literature regarding the association between vitamin D levels, puberty timing, and age at menarche. A review of the data on the involvement of micronutrient deficiency, as a modifiable cause of pubertal disorders, is important for the prediction and prevention of deficiencies as well as for fertility protection and should be considered a public health priority. Reported data support that vitamin D is a regulator of neuroendocrine and ovarian physiology and, more in detail, a deficiency of vitamin D is involved in altered pubertal timing. Considering the long-term consequences of early pubertal development and early menarche, the detection of modifiable causes is crucial in preventive strategies. Future studies in humans and with an increased scale are needed to elucidate the vitamin D role in sexual maturation and puberty development.

Prosopagnosia (face blindness) and child health during the COVID-19 pandemic

Prosopagnosia or 'face blindness' is the inability to recognise people's faces. There are two types: congenital or developmental prosopagnosia, which is the most common, and acquired prosopagnosia, which may occur secondary to brain tumours, stroke or other brain disorders. The authors of this article explored if mask wearing as a result of the restrictions imposed by the coronavirus disease 2019 (COVID-19) pandemic may affect social and developmental outcomes in children, including the development of prosopagnosia. Limited research on this topic is available and, although some relevant publications were found, no definitive evidence of mask-induced prosopagnosia in children was identified. However, nurses should be aware of this issue and discuss coping strategies to support children with the condition. Longitudinal studies on outcomes in children from different age groups who grew up during the COVID-19 pandemic will provide further insight.

The Impact of Modifiable Environmental, Nutritional, and Lifestyle Factors on Puberty, Reproductive Function, and Fertility in Children and Adolescents

The survival of a species depends on its ability to reproduce [...].

Plant-Based Diet during the Prepubertal Period and Age at Menarche: A Systematic Review

This systematic review aimed to analyze the effect of a prepubertal plant-based diet, through dietary patterns and its nutritional components, on the age at menarche. Systematic searches through Medline (EBSCO), Embase, Health & Medical Collection (Proquest), Scopus, and Google Scholar for articles published between January 2000 and September 2022 in English using the keywords of plant-based diet, age at menarche, and their synonyms identified 673 articles. Articles were screened through titles and abstracts, as well as full-text reviews based on inclusion/exclusion criteria and assessment of research quality using the JBI Critical Appraisal Tools with a JBI cut-off final score of >50%, leaving 12 articles in this systematic review presented in the PRISMA 2020 flowchart. Data analysis was conducted descriptively by comparing findings between articles. Age at menarche/puberty was reported as an outcome of food intake through a vegetarian diet, Mediterranean diet, vegetable protein, phytoestrogens and isoflavones, and dietary fiber. Based on the analysis of each subgroup, the plant-based diet did not consistently influence the incidence of menarche. In conclusion, a plant-based diet does not significantly affect age at menarche when it is accompanied by a balanced intake of energy and macro-micronutrients. The principles of balanced nutrition and the assistance of nutritionists are needed in practicing a plant-based lifestyle, especially for children and adolescents who are still in the developmental stage.

Reproducibility and Validity of a Semi-Quantitative Food Frequency Questionnaire for Children Aged 6-12 in Western China

The Food Frequency Questionnaire (FFQ) is often used to assess dietary intake in large-scale epidemiological studies. This study aimed to evaluate the reproducibility and validity of the FFQ newly developed for children aged 6 to 12 in western China. A total of 133 children were included in the analysis, and all the children and their caregivers completed the FFQs twice with a three-month interval period, and three 24 h recalls were carried out one month after the first FFQ. We assessed the relative validity and reproducibility using various methods, such as the Spearman correlation coefficient, intra-class correlation coefficient, weighed Kappa, quartile agreement, and Bland-Altman analysis. The Spearman correlation coefficients for food ranged from 0.30 to 0.84, and for nutrients from 0.46 to 0.82 regarding reproducibility. The food intra-class correlation coefficients ranged from 0.20 to 0.85, while nutrients' ranged from 0.37 to 0.75. In terms of relative validity, the average Spearman correlation coefficients for food were 0.20, and 0.30 for energy and nutrients. The energy-adjusted and de-attenuation coefficients were calculated. Moreover, the average percentage of participants misclassified into the extreme quartile for food and nutrients was 8.0% and 7.0%, respectively. Weighted Kappa values indicated acceptable agreement between the FFQs and 24 h recalls. Furthermore, the percentage of results in the limits of agreement (LOA) were all above 93.0%. In conclusion, The FFQ showed good reproducibility and acceptable relative validity for assessing the dietary intake of children aged 6-12 in western China.

Links between Childhood Obesity, High-Fat Diet, and Central Precocious Puberty

In recent years, the existing relationship between excess overweight and central precocious puberty (CPP) has been reported, especially in girls. Different nutritional choices have been associated with different patterns of puberty. In particular, the involvement of altered biochemical and neuroendocrine pathways and a proinflammatory status has been described in connection with a high-fat diet (HFD). In this narrative review, we present an overview on the relationship between obesity and precocious pubertal development, focusing on the role of HFDs as a contributor to activating the hypothalamus-pituitary-gonadal axis. Although evidence is scarce and studies limited, especially in the paediatric field, the harm of HFDs on PP is a relevant problem that cannot be ignored. Increased knowledge about HFD effects will be useful in developing strategies preventing precocious puberty in children with obesity. Promoting HFD-avoiding behavior may be useful in preserving children's physiological development and protecting reproductive health. Controlling HFDs may represent a target for policy action to improve global health.

Oestrogenic Activity in Girls with Signs of Precocious Puberty as Exposure Biomarker to Endocrine Disrupting Chemicals: A Pilot Study

The relationship between endocrine disrupting chemical (EDC) exposure and Precocious Puberty (PP) was investigated in this pilot study, involving girls with signs of PP (P) and pre-pubertal girls (C). Risk factors for PP were assessed through questionnaires, while 17β-oestradiol (E2) levels and oestrogenic activity were quantified on sera. The oestrogenic activity, expressed as E2 equivalent concentration (EEQ), was applied as EDC exposure biomarker. Questionnaires showed a low EDC knowledge, a high EDC exposure, and a potential relationship between some habits at risk for EDC exposure and PP. EEQs were similar between C and P; however, they were significantly higher in girls living in an urban environment than in girls living in a rural environment, suggesting a potential higher EDC exposure in cities. The results of this pilot study highlighted the need to raise awareness on EDCs and can be considered a starting point to clarify the relationship between EDC exposure and PP.

Gut microbiota in obesity and related comorbidities in children and adolescents: the role of biotics in treatment

INTRODUCTION

Obesity is a complex pathology, globally spread, with a multifactorial pathogenesis, strictly linked with lifestyle, hormones, genetic and epigenetic factors. Evidence supports that obesity, and its comorbidities, are related to changes in gut microbiota, partially responsible of the modulation of energy metabolism.

EVIDENCE ACQUISITION

Pediatric obesity has been associated with lower bacterial diversity and differences in composition of the gut microbiota, also varying according to the metabolic status of obese subjects. Indeed, differences in distributions and activity of microorganisms in the gut of metabolically healthy and unhealthy obese children have been highlighted.

EVIDENCE SYNTHESIS

Based on human studies, this review aims to discuss gut microbiota alterations in obese children and adolescents and its role in obese-related complications. Moreover, the role of biotics (probiotics, prebiotics, synbiotics and -marginally- postbiotics) has been analyzed as modulator of obesity-related dysbiosis.

CONCLUSIONS

As a conclusion, a deeper knowledge about biotic mechanisms of action would be of great interest to implement the clinical care of children and adolescents with obesity and related comorbidities.

Diet and Nutrients Intakes during Infancy and Childhood in Relation to Early Puberty: A Systematic Review and Meta-Analysis

The onset of puberty has become earlier over the decades, and nutrients and diet are related to the timing of puberty onset. Hence, we aimed to investigate the association between diet or nutrients in infancy, childhood and early puberty. PubMed, Embase, and Cochrane library were searched systematically up to 15 April 2022. The pooled relative risks (RRs) or regression coefficients (beta) were estimated using the random-effect model or fixed-effect model according to the heterogeneity between studies. Twenty-two articles on diet or nutrients in childhood and six about breastfeeding in infancy were included. The prolonged breastfeeding duration in infancy could reduce the risk of early menarche (beta 0.31, 95% CI: 0.01, 0.60, p = 0.045). The high intake of yogurt was associated with a 35% reduction in the risk of earlier menarche (RR 0.65, 95% CI: 0.47, 0.89, p = 0.008). Girls with severe food insecurity experienced later menarche (RR 0.81, 95% CI: 0.67, 0.98, p = 0.027). Conversely, due to the high intake of protein, the risk of early menarche increased by 8% (RR 1.08, 95% CI: 1.01, 1.16, p = 0.016). High intake of yogurt, longer duration of breastfeeding, and food insecurity decreased the possibility of earlier menarche, while high intake of protein increased that risk. As a modifiable factor, diet and nutrients in infancy and childhood provide new insights into the future prevention of early puberty.

Precocious puberty and microbiota: The role of the sex hormone-gut microbiome axis

Puberty is a critical phase of life associated with physiological changes related to sexual maturation, and represents a complex process regulated by multiple endocrine and genetic controls. Puberty is driven by hormones, and it can impact the gut microbiome (GM). GM differences between sex emerge at puberty onset, confirming a relationship between microbiota and sex hormones. In this narrative review, we present an overview of precocious pubertal development and the changes in the GM in precocious puberty (PP) in order to consider the role of the sex hormone-gut microbiome axis from the perspective of pediatric endocrinology. Bidirectional interactions between the GM and sex hormones have been proposed in different studies. Although the evidence on the interaction between microbiota and sex hormones remains limited in pediatric patients, the evidence that GM alterations may occur in girls with central precocious puberty (CPP) represents an interesting finding for the prediction and prevention of PP. Deepening the understanding of the connection between the sex hormones and the role of microbiota changes can lead to the implementation of microbiota-targeted therapies in pubertal disorders by offering a pediatric endocrinology perspective.