Luteinizing hormone, testosterone and inhibin B levels in the peripubertal period and racial/ethnic differences among boys aged 6-11 years: analyses from NHANES III, 1988-1994

Development of Tanner Stage-Age Adjusted CDC Height Curves for Research and Clinical Applications

Background and Objective

Variations in normal pubertal development, pubertal disorders, and race/ethnicity can lead to differences in growth patterns and timing that are not captured by the Centers for Disease Control and Prevention (CDC) height-for-chronological age (CA_Height) charts. Therefore, we sought to develop new Tanner stage-adjusted height-for-age (TSA_Height) charts accounting for these differences.

Study Design

Population-based Tanner staging and anthropometric data for 13 358 children age 8 to 18 years from 3 large US national surveys: National Health Examination Surveys (NHES cycle III); the Hispanic Health and Nutrition Examination Surveys (HHANES) and the third National Health and Nutrition Examination Surveys (NHANES III) were analyzed. TSA_Height semi-parametric models with additive age splines were used to develop smoothed TSA_Height curves accounting for maturation stage and calendar age.

Results

As expected, the TSA_Height curves did not track along the respective percentile curves for the CDC 2000 CA_Height curves. We generated race/ethnicity-nonspecific and race/ethnicity-specific TSA_Height charts stratified by sex and plotted against the CDC 2000 CA_Height curves to account for the pubertal status differences between these models. An online calculator to adjust height for pubertal status was created.

Conclusions

TSA_Height charts provide a much-needed tool to assess and manage linear growth for US children over the course of puberty. These tools may be useful in clinical management of children with pubertal timing variations.

Evaluating the four most important salivary sex steroids during male puberty: testosterone best characterizes pubertal development

Background During pubertal development in healthy boys, increased levels of different sex steroids occur which are responsible for sexual maturation and physical changes. However, relationships between various sex hormones and pubertal development stages have not been sufficiently studied. Methods The investigation included 165 normal boys (mean age 12.7±2.8 years, mean body mass index [BMI] 19.6±4.2 kg/m2). Pubic hair (PH) stages were stratified by Tanner and testicular volume (TV) by means of the Prader orchidometer and assigned to the prepubertal, pubertal and postpubertal development phase. Four different sex steroids (testosterone [TE], dehydroepiandrosterone [DHEA]/dehydroepiandrosterone-sulfate [DHEAS], androstenedione (AE), 17-hydroxyprogesterone [17-OHP]) were measured in saliva by enzyme-linked immunosorbent assay (ELISA) and as serum total steroids by different assays (radioimmunoassay [RIA], chemiluminescence immunoassay [CLIA], electrochemiluminescence immunoassay [ECLIA]). Validation of saliva-based ELISA tests included data related to inter- and intra-assay coefficients of variation (CVs), recovery and linearity. Results Using Spearman rank correlation, salivary steroids significantly correlated (p<0.001) with pubertal development: TE (TV r=0.74 and PH stages r=0.72), DHEA (r=0.58 and 0.62), AE (r=0.38 and 0.45) and 17-OHP (r=0.42 and 0.43). Correlations between salivary and serum concentrations of steroids were also statistically significant (p<0.001). Binomial logistic regression analysis revealed significant correlations between salivary TE and pubertal maturation during the development phases of prepuberty-puberty and puberty-postpuberty. Inclusion of further salivary steroids did not improve analysis results. Conclusions Salivary TE permits a good non-invasive characterization of pubertal maturation stages. The consideration of further salivary sex steroids did not improve diagnostic accuracy.

C-terminal region of teneurin-1 co-localizes with the dystroglycan complex in adult mouse testes and regulates testicular size and testosterone production

Testicular size is directly proportional to fertility potential and is dependent on the integration of developmental proteins, trophic factors, and sex steroids. The teneurins are transmembrane glycoproteins that function as signaling and cell adhesion molecules in the establishment and maintenance of the somatic gonad, gametogenesis, and basement membrane. Moreover, teneurins are thought to function redundantly to the extracellular matrix protein, dystroglycan. Encoded on the last exon of the teneurin genes is a family of bioactive peptides termed the teneurin C-terminal-associated peptides (TCAPs). One of these peptides, TCAP-1, functionally interacts with β-dystroglycan to act as a neuromodulatory peptide with trophic characteristics independent from the teneurins. However, little is known about the localization and relationship between the teneurin-TCAP-1 system and the dystroglycans in the gonad. In the adult mouse testis, immunoreactive TCAP-1 was localized to spermatogonia and spermatocytes and co-localized with β-dystroglycan. However, teneurin-1 was localized to the peritubular myoid cell layer of seminiferous tubules and tubules within the epididymis, and co-localized with α-dystroglycan and α-smooth muscle actin. TCAP-1-binding sites were identified in the germ cell layers and adluminal compartment of the seminiferous tubules, and epithelial cells of the epididymis. In vivo, TCAP-1 administration to adult mice for 9 days increased testicular size, seminiferous and epididymal tubule short-diameter and elevated testosterone levels. TCAP-1-treated mice also showed increased TCAP-1 immunoreactivity in the caput and corpa epididymis. Our data provide novel evidence of TCAP-1 localization in the testes that is distinct from teneurin-1, but is integrated through an association with the dystroglycan complex.

Pubertal onset in children with perinatal HIV infection in the era of combination antiretroviral treatment

OBJECTIVE

To evaluate associations of perinatal HIV infection, HIV disease severity, and combination antiretroviral treatment with age at pubertal onset.

DESIGN

Analysis of data from two US longitudinal cohort studies (IMPAACT 219C and PHACS AMP), conducted during 2000-2012, including perinatally HIV-infected (PHIV) and HIV-exposed but uninfected (HEU) youth. Tanner stage assessments of pubertal status (breast and pubic hair in girls; genitalia and pubic hair in boys) were conducted annually.

METHODS

We compared the timing of pubertal onset (Tanner stage ≥2) between PHIV and HEU youth using interval-censored models. For PHIV youth, we evaluated associations of HIV disease severity and combination antiretroviral treatment with age at pubertal onset, adjusting for race/ethnicity and birth cohort.

RESULTS

The mean age at pubertal onset was significantly later for the 2086 PHIV youth compared to the 453 HEU children (10.3 vs. 9.6, 10.5 vs. 10.0, 11.3 vs. 10.4, and 11.5 vs. 10.7 years according to female breast, female pubic hair, male genitalia, and male pubic hair staging, respectively, all P < 0.001). PHIV youth with HIV-1 RNA viral load above 10, 000 copies/ml (vs. ≤10, 000 copies/ml) or CD4% below 15% (vs. ≥15%) had significantly later pubertal onset (by 4-13 months). Each additional year of combination antiretroviral treatment was associated with a 0.6-1.2-month earlier mean age at pubertal onset, but this trend did not persist after adjustment for birth cohort.

CONCLUSION

Pubertal onset occurs significantly later in PHIV than in HEU youth, especially among those with more severe HIV disease. However, in the current era, combination antiretroviral treatment may result in more normal timing of pubertal onset.

Sprint performance changes and determinants in afro-Caribbean adolescents between 13 and 15 years old

Afro-Caribbean sprinters often reach high performance levels at an early age. Adolescence is a time of morphological and physiological changes. This study was designed to analyze the evolution in parameters of short sprint performance during adolescence in Afro-Caribbean boys, especially the stride number/body height ratio (SN/BH), which is at the interface of technical and morphological factors. Seventy-one 13-year-old boys performed vertical jumps and short sprint races. The races were filmed with a view to determine stride variables. Anthropometric parameters were also measured. The same tests were performed two years later. Body height and SN/BH were the main predictors of sprint performance. The delta of performance was principally explained by stride length and stride number. Although deterioration in technical parameters was expected, the parameters related to body size and stride length were the main sprint performance predictors rather than explosive force. These results could be useful in developing tests to detect sprint potential in youth.

Male pubertal development: are endocrine-disrupting compounds shifting the norms?

Endocrine-disrupting compounds (EDCs) are synthetic or natural compounds that interfere with endogenous endocrine action. The frequent use of chemicals with endocrine active properties in household products and contamination of soil, water, and food sources by persistent chemical pollutants result in ubiquitous exposures. Wildlife observations and animal toxicological studies reveal adverse effects of EDCs on reproductive health. In humans, a growing number of epidemiological studies report an association with altered pubertal timing and progression. While these data are primarily reported in females, this review will focus on the small number of studies performed in males that report an association of polychlorinated biphenyls with earlier sexual maturity rating and confirm subtle effects of lead, dioxins, and endosulfan on delaying pubertal onset and progression in boys. Recent studies have also demonstrated that EDC exposure may affect pubertal testosterone production without having a noticeable effect on sexual maturity rating. A limitation to understand the effects of EDCs in humans is the potential for confounding due to the long temporal lag from early-life exposures to adult outcomes. The complex interplay of multiple environmental exposures over time also complicates the interpretation of human studies. These studies have identified critical windows of vulnerability during development when exposures to EDCs alter critical pathways and affect postnatal reproductive health. Contemporaneous exposures can also disrupt the hypothalamic-pituitary-gonadal axis. This paper will review the normal process of puberty in males and summarize human data that suggest potential perturbations in pubertal onset and tempo with early-life exposures to EDCs.