Endocrinology of puberty. I. Normal sexual maturation

The progress of research on crankshaft phenomenon

The Crankshaft Phenomenon (CSP) is a significant complication that can occur after posterior spinal fusion, particularly in growing patients with scoliosis. It results from continued anterior spinal growth while the posterior column remains fused, leading to progressive spinal deformities such as loss of correction, increased vertebral rotation, and rib prominence. This phenomenon has been predominantly observed in pediatric patients with idiopathic, congenital, and neuromuscular scoliosis. Although clinical symptoms may be subtle, radiographic signs are crucial for diagnosis but can be challenging to evaluate due to postoperative changes and instrumentation. Current treatment options are limited, often requiring revision surgeries in cases of progressive deformities. This review aims to provide a comprehensive overview of the current understanding of CSP, including its pathophysiology, diagnostic challenges, risk factors, prevention strategies, and potential treatments.

The impact of pubertal DHEA on the development of visuospatial oscillatory dynamics

The adolescent brain undergoes tremendous structural and functional changes throughout puberty. Previous research has demonstrated that pubertal hormones can modulate sexually dimorphic changes in cortical development, as well as age-related maturation of the neural activity underlying cognitive processes. However, the precise impact of pubertal hormones on these functional changes in the developing human brain remains poorly understood. In the current study, we quantified the neural oscillatory activity serving visuospatial processing using magnetoencephalography, and utilized measures of dehydroepiandrosterone (DHEA) as an index of development during the transition from childhood to adolescence (i.e., puberty). Within a sample of typically developing youth (ages 9-15), a novel association between pubertal DHEA and theta oscillatory activity indicated that less mature children exhibited stronger neural responses in higher-order prefrontal cortices during the visuospatial task. Theta coherence between bilateral prefrontal regions also increased with increasing DHEA, such that network-level theta activity became more distributed with more maturity. Additionally, significant DHEA-by-sex interactions in the gamma range were centered on cortical regions relevant for attention processing. These findings suggest that pubertal DHEA may modulate the development of neural oscillatory activity serving visuospatial processing and attention functions during the pubertal period.

Longitudinal study of body mass index and percentage of overweight in Japanese children grouped by maturity

Childhood obesity is a known risk factor for adult diseases, making its evaluation highly important. However, the evaluation is complex because there is no gold standard method. Body mass index (BMI) and percentage of overweight (POW) are widely used in Japan. However, they have the following limitations: it is difficult to set cutoffs for BMI because it dynamically varies in childhood, and POW has not been studied extensively, especially regarding its difference during maturity. Therefore, our study analyzed BMI/POW in Japanese children grouped by maturity. We used longitudinal school check-up data collected from elementary and junior high schools in 20 municipalities. We made percentile curves of BMI/POW and calculated the percentage of participants considered overweight/obese by sex, age, and maturity. Maximum increment age (MIA) was calculated using the graphical fitting method. We included 35,461 subjects aged 15 in 2018. Early-maturing children had higher BMI. The difference among maturity groups decreased by shifting the percentile curves by differences in MIA. Therefore, the use of BMI might lead to the overestimation of overweight/obesity in early-maturing children and underestimation in late-maturing children. The POW percentile curves were "N"-shaped around the MIA, indicating the inappropriate evaluation during this period. The percentile curves of children categorized as overweight/obese were also "N"-shaped, confirming that MIA affects the evaluation of childhood obesity. The possibility of overestimation/underestimation needs verification with the data of accurate age, pubertal changes, and adult diseases. In conclusion, it is difficult to evaluate childhood obesity only with height and weight.

Pubertal Testosterone Tracks the Developmental Trajectory of Neural Oscillatory Activity Serving Visuospatial Processing

Puberty is a period of substantial hormonal fluctuations that induce dramatic physical, neurological, and behavioral changes. Previous research has demonstrated that pubertal hormones modulate cortical development, as well as sex- and age-specific patterns of cognitive development during childhood and adolescence. However, the influence of pubertal hormones on the brain's functional development, specifically neural oscillatory dynamics, has yet to be fully examined. Thus, in the current study, we used magnetoencephalography to investigate the oscillatory dynamics serving visuospatial perception and attention, and testosterone levels and chronological age as measures of development. Within a sample of typically developing youth, age was associated with changes in alpha, theta, and gamma oscillatory activity. Novel testosterone-by-sex interactions in the gamma range were identified in critical areas of the visual and attention networks. Females had increased gamma activity with increasing testosterone in the right temporal-parietal junction and occipital cortices, while males showed increased gamma activity in the right insula with increasing testosterone. These findings reveal robust developmental alterations in the oscillatory dynamics serving visuospatial processing during childhood and adolescence and provide novel insight into the hormonal basis of sexually dimorphic patterns of functional brain development during the pubertal transition that is at least partially mediated by endogenous testosterone.

Role of Androgens in Female Genitourinary Tissue Structure and Function: Implications in the Genitourinary Syndrome of Menopause

INTRODUCTION

Genitourinary conditions in women increase in prevalence with age. Androgens are prerequisite hormones of estrogen biosynthesis, are produced in larger amounts than estrogens in women, and decrease throughout adulthood. However, research and treatment for genitourinary complaints have traditionally focused on estrogens to the exclusion of other potential hormonal influences.

AIM

To summarize and evaluate the evidence that androgens are important for maintaining genitourinary health in women and that lack of androgenic activity can contribute to the development of symptoms of the genitourinary syndrome of menopause.

METHODS

The role of androgens in the pathophysiology, diagnosis, and treatment of genitourinary syndrome of menopause was discussed by an international and multidisciplinary panel during a consensus conference organized by the International Society for the Study of Women's Sexual Health. A subgroup further examined publications from the PubMed database, giving preference to clinical studies or to basic science studies in human tissues.

MAIN OUTCOME MEASURES

Expert opinion evaluating trophic and functional effects of androgens, their differences from estrogenic effects, and regulation of androgen and estrogen receptor expression in female genitourinary tissues.

RESULTS

Androgen receptors have been detected throughout the genitourinary system using immunohistochemical, western blot, ligand binding, and gene expression analyses. Lower circulating testosterone and estradiol concentrations and various genitourinary conditions have been associated with differential expression of androgen and estrogen receptors. Supplementation of androgen and/or estrogen in postmenopausal women (local administration) or in ovariectomized animals (systemic administration) induces tissue-specific responses that include changes in androgen and estrogen receptor expression, cell growth, mucin production, collagen turnover, increased perfusion, and neurotransmitter synthesis.

CONCLUSION

Androgens contribute to the maintenance of genitourinary tissue structure and function. The effects of androgens can be distinct from those of estrogens or can complement estrogenic action. Androgen-mediated processes might be involved in the full or partial resolution of genitourinary syndrome of menopause symptoms in women. Traish AM, Vignozzi L, Simon JA, et al. Role of Androgens in Female Genitourinary Tissue Structure and Function: Implications in the Genitourinary Syndrome of Menopause. Sex Med Rev 2018;6:558-571.

Metals, hormones and sexual maturation in Flemish adolescents in three cross-sectional studies (2002-2015)

Sex hormone levels and timing of sexual maturation are considered important markers for health status of adolescents in puberty, and previous research suggests they might be influenced by metal exposure. In three campaigns of the Flemish Environment and Health Study (FLEHS I 2002-2006; FLEHS II 2007-2011 and FLEHS III 2012-2015), data were collected on internal exposure to metals (Cd, Cu, Pb, Cr, Mn, Tl, Ni, Sb, Hg, As and As species) and sexual maturation in 2671 14-15years old adolescents. All metals were measured in blood and/or urine, except total- and methylmercury which were measured in hair samples. Sex hormone levels were measured in blood serum of adolescent males of the cohorts of FLEHS I and FLESH II. The use of a uniform methodology in successive campaigns allows to confirm associations between exposure and health in different cohorts and over time. Furthermore, mathematical and statistical density correction methods using creatinine or specific gravity were tested for urinary markers. Significant associations between sex hormones and maturity markers were observed in the FLEHS I and II campaigns, when both were assessed together. Regardless of the applied correction method, creatinine correction systematically introduced bias due to associations of creatinine with sex hormones and maturation markers, especially in adolescent males, while this is not the case for specific gravity. A series of exposure-response associations were found, but several involving Cd, Pb, As, Tl and Cu persisted in different FLEHS campaigns. The effects of Pb and Cu on luteinizing hormone, (free) testosterone, (free) oestradiol and maturation support a xenoestrogenic agonistic action on the feedback of oestradiol to the hypothalamus-pituitary-gonadal axis. Our results suggest that specific care should be taken when selecting urine density correction for investigating associations with hormonal and maturation markers in adolescent males. Furthermore, the possibility of xenoestrogenic effects of certain metals in environmentally exposed adolescents warrants further investigation.

Testosterone and cortisol in relation to aggression in a non-clinical sample of boys and girls

Testosterone and cortisol have been proposed to jointly regulate aggressive behavior. However, few empirical studies actually investigated this joint relation in humans, and reported inconsistent findings. Also, samples in these studies were small and/or specific, and consisted largely of males. Therefore, in the current study testosterone and cortisol in relation to aggression were investigated in a non-clinical sample of 259 boys and girls (mean age 16.98 years, SD = 0.42, 56% boys). A positive testosterone/cortisol ratio, that is, high testosterone relative to cortisol, was found to be associated with aggressive behavior, explaining 7% of the variance. The interaction between testosterone and cortisol was not related to aggressive behavior and gender differences were not found. The ratio may reflect an imbalance leaving the individual more prone to rewarding aspects, than fearful of negative implications of aggressive behavior. Current findings indicate that this relation can be generalized to aggression in non-clinical adolescents.

Adolescent endogenous sex hormones and breast density in early adulthood

INTRODUCTION

During adolescence the breasts undergo rapid growth and development under the influence of sex hormones. Although the hormonal etiology of breast cancer is hypothesized, it remains unknown whether adolescent sex hormones are associated with adult breast density, which is a strong risk factor for breast cancer.

METHODS

Percentage of dense breast volume (%DBV) was measured in 2006 by magnetic resonance imaging in 177 women aged 25-29 years who had participated in the Dietary Intervention Study in Children from 1988 to 1997. They had sex hormones and sex hormone-binding globulin (SHBG) measured in serum collected on one to five occasions between 8 and 17 years of age. Multivariable linear mixed-effect regression models were used to evaluate the associations of adolescent sex hormones and SHBG with %DBV.

RESULTS

Dehydroepiandrosterone sulfate (DHEAS) and SHBG measured in premenarche serum samples were significantly positively associated with %DBV (all P trend ≤0.03) but not when measured in postmenarche samples (all P trend ≥0.42). The multivariable geometric mean of %DBV across quartiles of premenarcheal DHEAS and SHBG increased from 16.7 to 22.1 % and from 14.1 to 24.3 %, respectively. Estrogens, progesterone, androstenedione, and testosterone in pre- or postmenarche serum samples were not associated with %DBV (all P trend ≥0.16).

CONCLUSIONS

Our results suggest that higher premenarcheal DHEAS and SHBG levels are associated with higher %DBV in young women. Whether this association translates into an increased risk of breast cancer later in life is currently unknown.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov Identifier, NCT00458588 April 9, 2007; NCT00000459 October 27, 1999.

Relationships of polychlorinated biphenyls and dichlorodiphenyldichloroethylene (p,p'-DDE) with testosterone levels in adolescent males

BACKGROUND

Concern persists over endocrine-disrupting effects of persistent organic pollutants (POPs) on human growth and sexual maturation. Potential effects of toxicant exposures on testosterone levels during puberty are not well characterized.

OBJECTIVES

In this study we evaluated the relationship between toxicants [polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p´-DDE), hexachlorobenzene (HCB), and lead] and testosterone levels among 127 Akwesasne Mohawk males 10 to < 17 years of age with documented toxicant exposures.

METHODS

Data were collected between February 1996 and January 2000. Fasting blood specimens were collected before breakfast by trained Akwesasne Mohawk staff. Multivariable regression models were used to estimates associations between toxicants and serum testosterone, adjusted for other toxicants, Tanner stage, and potential confounders.

RESULTS

The sum of 16 PCB congeners (Σ16PCBs) that were detected in ≥ 50% of the population was significantly and negatively associated with serum testosterone levels, such that a 10% change in exposure was associated with a 5.6% decrease in testosterone (95% CI: -10.8, -0.5%). Of the 16 congeners, the more persistent ones (Σ8PerPCBs) were related to testosterone, whereas the less persistent ones, possibly reflecting more recent exposure, were not. When PCB congeners were subgrouped, the association was significant for the sum of eight more persistent PCBs (5.7% decrease; 95% CI: -11, -0.4%), and stronger than the sum of six less persistent congeners (3.1% decrease; 95% CI: -7.2, 0.9%). p,p´-DDE was positively but not significantly associated with serum testosterone (5.2% increase with a 10% increase in exposure; 95% CI: -0.5, 10.9%). Neither lead nor HCB was significantly associated with testosterone levels.

CONCLUSIONS

Exposure to PCBs, particularly the more highly persistent congeners, may negatively influence testosterone levels among adolescent males. The positive relationship between p,p´-DDE and testosterone indicates that not all POPs act similarly.

CITATION

Schell LM, Gallo MV, Deane GD, Nelder KR, DeCaprio AP, Jacobs A; Akwesasne Task Force on the Environment. 2014. Relationships of polychlorinated biphenyls and dichlorodiphenyldichloroethylene (p,p´-DDE) with testosterone levels in adolescent males. Environ Health Perspect 122:304-309; http://dx.doi.org/10.1289/ehp.1205984.

Delinquency, androgens, and the family: a test of evolutionary neuroandrogenic theory

There is little doubt that family factors can influence involvement in delinquency, although the full nature and extent of their influences remain unclear. In recent decades, testosterone has been increasingly implicated as a contributor to adolescent offending. The present study sought to determine whether two important types of familial factors--parental socioeconomic status and amicable parent-child relationships--are interacting with testosterone (and possibly other androgens) to affect delinquency. A large sample of North American college students self-reported their involvement in eight categories of delinquency along with self-ratings of various androgen-promoted traits (e.g., muscularity and low-deep voice), parental social status, and the quality of the relationships they had with parents. In both sexes, parent-child relationships and androgens were significantly associated with delinquency but parental social status was not. Factor analysis revealed that the authors' measures of all four categories of variables exhibited strong loadings onto their respective factors. Androgens and amicable parent-child relationships were associated with delinquency but parental social status was not. About one third of the influence of parent-child relationships on delinquency appeared to be attributable to androgens. Findings are discussed from the perspective of the evolutionary neuroandrogenic theory of delinquent and criminal behavior.

Long-term stability of the cortisol awakening response over adolescence

The cortisol awakening response (CAR) has been widely assessed as a measure of hypothalamic-pituitary-adrenal (HPA) axis activity. Short-term stability is high; however, little is known about the long-term stability of the CAR. Because there are indications that development in adolescence influences HPA axis activity, this study investigated the stability of the CAR over adolescence. Participants were 229 boys and 181 girls from an adolescent general population sample who were assessed in three consecutive years, at mean ages of 15.0 (SD=0.4), 16.0 (SD=0.4) and 17.0 (SD=0.4) years. Cortisol was analyzed in saliva sampled at awakening, and 30 and 60min later. Stability was investigated both as rank-order and as mean-level stability. Effects of physical development during adolescence on stability were investigated as well. Rank-order stability was moderate to low, with tracking coefficients (interpretable as stability coefficients over time) of .15 (p<.001) for cortisol at awakening and .24 (p<.001) for cortisol 30 and 60min after awakening. Mean-levels of cortisol at awakening did not change, while the response to awakening increased over the years (linear slopes for cortisol 30 and 60min after awakening all p<.01). The increase may reflect the physical development of the adolescents. This is the first study, in a large population based sample, indicating that the rank-order of the CAR is stable over the course of several years. Interestingly, mean-levels of the cortisol response to awakening increased over the years, suggesting a maturation of HPA axis reactivity in relation to physical development over adolescence. Physical development should therefore be taken into account when investigating the CAR as a measure of HPA axis activity in adolescence.

Adolescent idiopathic scoliosis: is rising growth rate the triggering factor in progression?

The school scoliosis screening programme at Our Lady's Hospital for Sick Children, Dublin, has provided material for an ongoing prospective natural history study of adolescent idiopathic scoliosis. An examination of the clinical course in 339 girls showed that observation of progression of at least 10 degrees, which occurred in 46 girls (13.6%), depended on the timing of diagnosis and related primarily to the child's position on her growth rate curve and her pubertal status, and much less to skeletal maturity as interpreted by iliac crest ossification or bone age. This has implications for the understanding of results in conservative management, screening programmes and natural history.

Scoliosis: a review

Scoliosis, lateral curvature of the spine, has been studied since Hippocrates' time, but remains a disputed subject in orthopaedic surgery, because of its several varieties, unknown cause and unpredictable course. A review of 30 years' experience in a paediatric orthopaedic unit was undertaken to clarify the problem. Patient records, collected prospectively, were examined to demonstrate the incidence, prevalence, extent, course and outcome of the commonest variety, adolescent idiopathic scoliosis. Reference was made to the results of previously published studies. Records from a school screening programme showed that, while slight degrees of spinal curvature were widely prevalent in the community, these were of no clinical significance and major cosmetic deformity was rare: only 8 in 10,000 adolescent girls had Cobb angles of 40 degrees or more and only half of these underwent surgical correction. Evidence to support non-operative treatment could not be demonstrated and it did not reduce the incidence of surgical intervention. Because the course of scoliosis did not seem to correspond with much published work, or with current hypotheses of aetiology, a rethinking of the whole subject is advocated. An alternative model of pathogenesis deriving from developmental biology was proposed. While advances in surgical methods have been significant, the core problems of aetiology and natural history remain. Until they are resolved, all conclusions on management must be provisional. This is where innovative thinking needs to be directed.

Menstrual disorders in adolescence

Problems associated with menstruation affect 75% of adolescent females and are a leading reason for visits to physicians. This chapter begins with a review of the timing and characteristics of normal menstruation during adolescence. It then discusses the evaluation and management of adolescents with amenorrhoea, dysmenorrhoea and abnormal uterine bleeding. An approach to adolescent amenorrhoea is presented that utilizes primary versus secondary amenorrhoea, delayed versus normal pubertal development, and the presence or absence of hyperandrogenism as nodal points for decision making. The differential diagnosis of dysmenorrhoea and the management of primary dysmenorrhoea and endometriosis are reviewed. The section on abnormal uterine bleeding contrasts anovulatory dysfunctional uterine bleeding (DUB) with bleeding secondary to problems of pregnancy, uterine pathology, exogenous hormone use and systemic bleeding disorders.

Peripheral blood lymphocyte subsets in adolescents: a longitudinal analysis from the REACH project

Flow cytometry analysis of lymphocyte subset markers was performed for a group of sexually active, human immunodeficiency virus (HIV)-negative adolescents over a 2-year period to establish normative data. Data were collected in the REACH Project (Reaching for Excellence in Adolescent Care and Health), a multicenter, longitudinal study of HIV-positive and high-risk HIV-negative adolescents. Two- and three-color flow cytometry data were collected every 6 months for these subjects. We determined the effects of gender, race, and age on the following lymphocyte subset markers: total CD4(+) cells, CD4(+) naïve cells, CD4(+) memory cells, all CD8(+) cells, CD8(+) naïve cells, CD8(+) memory cells, CD16(+) natural killer cells, and CD19(+) B cells. Gender was the demographic characteristic most frequently associated with differences in lymphocyte subset measures. Females had higher total CD4(+) cell and CD4(+) memory cells counts and lower CD16(+) cell counts than males. Age was associated with higher CD4(+) memory cell counts as well as higher CD8(+) memory cell counts. For CD19(+) cells, there was an interaction between age and gender, with males having significantly lower CD19(+) cell counts with increasing age, whereas there was no age effect for females. Race and/or ethnicity was associated with differences in total CD8(+) cell counts and CD8(+) memory cell counts, although both of these associations involved an interaction with gender.

Adolescent idiopathic scoliosis: the effect of brace treatment on the incidence of surgery

STUDY DESIGN

Retrospective analysis of outcome in terms of incidence of surgery for adolescent idiopathic scoliosis during a period when bracing was not practiced.

OBJECTIVES

To determine whether centers with an active bracing policy have lower numbers undergoing surgery for adolescent idiopathic scoliosis than a center where nonintervention is the practice.

BACKGROUND DATA

Two major recent publications have claimed that bracing significantly improves the outcome in adolescent idiopathic scoliosis. However, one had no control subjects and the other did not examine the final status of the subjects under review. While statistically significant differences in progression have been observed, what will convince patients to submit to an onerous treatment is the conviction that it will make a substantial difference, such as the avoidance of surgery.

METHODS

Since 1991, bracing has not been recommended for children with adolescent idiopathic scoliosis at this center. The scoliosis database was searched for patients with adolescent idiopathic scoliosis who were at least 15 years of age at last review and who had adequate documentation of curve parameters. The incidence of surgery was compared with that of published data from other centers.

RESULTS

A total of 153 children, 11 boys and 142 girls, fitted the criteria. Forty-three of these (28.1%) have undergone surgery. This was not statistically different from the surgery rate reported from an active bracing center.

CONCLUSIONS

If bracing does not reduce the proportion of children with adolescent idiopathic scoliosis who require surgery for cosmetic improvement of their deformity, it cannot be said to provide a meaningful advantage to the patient or the community. Recent studies notwithstanding, the question of the efficacy of orthoses in idiopathic scoliosis remains unresolved.

Adolescent menstrual disorders. Update

Menarche is an important event during adolescence. For most girls, it marks successful progression through puberty and the onset of reproductive capability. Confidential and sensitive discussion of growth and development, body image, menstrual function, and sexual behavior is an important component of the annual health examination. Menstrual problems are common during adolescence and frequently require evaluation and intervention. Although most problems are explained by maturation of the hypothalamic-pituitary-ovarian axis, organic pathology must always be considered and excluded in a logical and cost-effective manner.

The crankshaft phenomenon after posterior Harrington fusion in skeletally immature patients with thoracic or thoracolumbar idiopathic scoliosis followed to maturity

STUDY DESIGN

This retrospective study evaluated the progression of deformity after posterior fusion by reviewing 63 consecutive patients with idiopathic scoliosis who were all in Risser sign 0 at the time of surgery. All patients were observed beyond the time of skeletal maturity. Average follow-up time was 9 years and 8 months (range, 5-16 years).

OBJECTIVES

To investigate the risk factors for the crankshaft phenomenon after posterior fusion and to build a model for predicting the probability of curve progression until maturation of growth.

SUMMARY OF BACKGROUND DATA

There remains considerable controversy concerning the incidence, risk factors, and necessity of combined anterior fusion to prevent the crankshaft phenomenon in patients who are skeletally immature.

METHODS

Serial radiographs were measured for Cobb angle, apical rotation according to Perdriolle, and apical rib-vertebra angle of Mehta. Multivariate and univariate logistic regression analysis was performed using seven potential predictors as independent variables and Cobb angle progression and rotational progression as dependent variables.

RESULTS

Average progression of deformity was 3 degrees Cobb angle (range, -8-16 degrees) and 3 degrees Perdriolle rotation (range, -9-17 degrees). Progression of deformity more than 5 degrees of either Cobb angle or rotation was observed in 22 (35%) of 63 curves with 7 (11%) of 63 curves greater than 10 degrees. Chronologic age and skeletal age were found to be significantly associated with progression of deformity in univariate analysis. In multivariate analysis, only skeletal age seemed to be independently prognostic. The authors tried to build the logistic model using the three factors of chronologic age, skeletal age, and apical rib-vertebra angle. This model correctly classified 81% of all patients as progressive or nonprogressive. The positive predictive value was 90%.

CONCLUSIONS

The results showed that patients with chronologic age of 11 years of younger, especially those with a skeletal age of 10 years or younger, had a high estimated probability of progression of deformity. The progression was fairly moderate, however, with an average Cobb angle of 9 degrees and average rotation of 7 degrees, which neither the patients nor the surgeon believed was of such magnitude as to warrant routine combined anterior fusion.

Glutamate-arginine salts and hormonal responses to exercise

Hormonal changes during exercise is of growing interest because of their role in adaptation, and performance. The production of amino acids (AA) due to the degradation of muscle protein increases during exercise and some AA may be utilized for energy expenditure or as hormonal secretagogues. Thus, one can propose a strategy to reduce muscle protein breakdown and regulate hormones involved in energy metabolism by dietary AA supplementation. We assessed the effects of glutamate-arginine salt (AGs) ingestion on exercise-induced hormonal alterations in highly trained cyclists (age 18-22 yrs). Using an indwelling catheter, we collected multiple blood samples at rest, during warm up, during and after an intense exercise session. Plasma growth hormone (hGH), insulin and cortisol were measured by radioimmunoassay. As reported in previous studies, we observed a marked increase in plasma hGH and cortisol levels during and after exercise in the placebo (Pl) condition as well as a slight decrease in insulin concentration. In addition, we found that the ingestion of AGs had significant effects on some dynamic hormonal changes. AGs had no effect on resting plasma levels of hGH, insulin or cortisol. However, the marked elevation in cortisol and hGH during and after exercise in the placebo condition, was greatly diminished when subjects ingested AGs. Our results show that AGs can modify exercise-induced hormonal changes and raise the possibility that it may be used to alter energy metabolism during endurance exercise.

Blood pressure and self-assessment of female sexual maturation

The relationship of sexual maturation to blood pressure was investigated in a sample (n = 361) of white, non-Hispanic females, aged 7-18 years. Sexual maturation was determined by self-assessment. Systolic and fourth- and fifth-phase diastolic blood pressures increased significantly with increasing maturation. Body mass index, breast development, and pubic hair growth explained 29% of the systolic blood pressure variance and 23% of the fourth- and fifth-phase diastolic blood pressure variances. The interpretation of a child's or adolescent's blood pressure should take into account his or her stage of sexual maturation and body size. A consideration of growth and maturation may contribute to studies of the natural history of blood pressure.

Evaluating the child with short stature

Short stature is a common pediatric problem that requires us to decide whether a child's small size represents only normal variation or indicates the presence of an underlying disease. In a population of children two standard deviations (SD) below the mean for height (below the third percentile), about 20 per cent may be expected to have pathologic short stature with the remaining 80 per cent about equally divided between familial short stature and constitutional growth delay. In contrast, most children three SD below the mean for height have pathologic short stature. Set forth in this article is an orderly approach to identify normal variants of short stature and to investigate the causes of pathologic short stature.

Developmental processes in early adolescence. Relations among chronologic age, pubertal stage, height, weight, and serum levels of gonadotropins, sex steroids, and adrenal androgens

Cross-sectional data are presented on 108 young adolescents (56 boys, 52 girls), ages 9 to 14 years. The measures were: for all subjects, pubertal stage (Tanner criteria for genital/breast and pubic hair stage); height and weight; serum hormone concentrations for gonadotropins (luteinizing hormone and follicle-stimulating hormone), sex steroids (testosterone, estradiol, and the computed testosterone to estradiol ratio), adrenal androgens (dehydroepiandrosterone, dehydroepiandrosterone sulfate, and androstenedione), and testosterone-estradiol binding globulin. In addition, testicular volume for boys and menarchial status for girls are reported. The study goal was to provide interrelations among these measures, based on the same sample, and examine their interchangeability. Results suggest that it would be reasonable to compare research across as well as within studies based on different markers. Multiple regression analysis showed that the strongest hormone correlates of pubertal development were androgen levels (primarily testosterone in boys and primarily dehydroepiandrosterone sulphate and androstenedione in girls). Estradiol level in girls was the strongest correlate only for menarchial status. Level of testosterone-estradiol binding globulin, which was lower at successive pubertal stages for boys and showed no consistent differences for girls, may be a useful measure for studying the developmental processes and gender differences during puberty.

Interpretation of children's blood pressure using a physiologic height correction

In a cross-sectional survey of 1834 black, Atlanta schoolchildren we corrected the customary blood pressure (BP) observations for the height of the arterial column extending from the BP cuff to the top (vertex) of the subject's head. Each cuff-to-vertex height was converted to its pressure equivalent in mmHg; then this pressure was subtracted from the observed BP to compute vertex-corrected BP values. The vertex-corrected mean arterial pressure (VMAP) ranged from 22.3 to 83.2 mmHg, but there was no estimated linear association between VMAP and age. For males, mean VMAP was 49.4 mmHg for ages 6-13 and 46.0 mmHg for ages 14-17. For females, mean VMAP was 50.2 mmHg for ages 6-17. Since VMAP appears to be independent of age in most of childhood, its use may simplify the development of pediatric BP reference values. VMAP can also serve as a non-invasive approximation of cerebral perfusion pressure. Investigators of primary hypertension may wish to use VMAP for comparing average BP levels between childhood groups which differ by potentially etiologic characteristics.

Diabetes mellitus and its effects on menarche

In a combined mail and medical record survey of 121 non-diabetic and 90 diabetic girls greater than or equal to 9 years of age, the mean age of menarche in the control non-diabetic population was 13.0 +/- 1.2 years and 13.4 +/- 1.2 years in the diabetics. The diabetic group was divided into those whose onset was before or after age 11 years (DM less than 11, DM greater than or equal to 11). The DM greater than or equal to 11 group had a mean menarchal age of 14.0 +/- 1.2 years and the DM less than 11 group, 13.1 +/- 1.2 (p less than 0.005). The DM greater than or equal to 11 group also differed significantly from the control group. The difference between the two groups suggests that the onset of diabetes near the onset of puberty may have a more disruptive effect on hypothalamic-pituitary-gonadal axis maturation that does the prepubertal onset of diabetes.

Microphallic hypospadias: testosterone therapy prior to surgical repair

The surgical repair of hypospadias may be more difficult in boys with microphallus than in those with a penis of normal size. Temporary enlargement of the abnormally small penis can be achieved by local application or systemic administration of testosterone. We have studied the effect of local application of testosterone cream in seven boys with microphallic hypospadias. Serum testosterone levels and penile size were measured before, during and after treatment. The relative advantages and disadvantages of local testosterone application in comparison with injection are discussed.

Pubertal development: normal, precocious and delayed

The present concepts on the neuroendocrine mechanisms which trigger pubertal development and modulate the progression towards sexual maturity have been reviewed. Essentially, puberty is presented as a continuum, the programming of which is initiated prenatally and which ends in adult life when all hormonal secretions become autoregulated. This continuum is dependent on a delicate equilibrium between CNS neurohormones (GnRH), neurotransmitters (biogenic amines), pituitary gonadotrophin (FSH, LH) secretion and the end-organ response (testis or ovary) through the activation of specific membrane receptors. The gonadal sex steroids (T, OE2) will activate specific cytoplasmic and nuclear receptors of target tissues and exert their biological action. Initially, the activity of the HPGA is manifested by nocturnal LH peaks, followed by increased gonadal secretion of T or OE2. Extremely sensitive to negative feedback by circulating androgen and/or oestrogen in prepuberty, an hypothalamic regulatory system called the gonadostat increases its threshold of sensitivity and eventually becomes autoregulated at a higher feedback level. Progressively, the hypothalamus becomes sensitive to positive feedback action of gonadal hormones, this phenomenon being important for the onset of ovulation. It is likely also that adrenal androgens play a permissive and supportive role in the onset and progression of pubertal development. Finally, full maturity is reached, with final adult height through fusion of the epiphysis, and fertility is achieved. The clinical manifestations of each developmental stage of puberty are described and abnormalities of sexual development reviewed. While over 90 per cent of cases of precocious pubertal development are idiopathic in girls, a space-occupying lesion in the hypothalamic-pituitary region is frequent in boys. Dissociated pubertal signs (premature adrenarche, pubarche, thelarche, menarche) are discussed, together with diagnosis and treatment of precocious puberty, whether it is idiopathic or occurring independently of the activation of the HPGA. In addition to delay of puberty on a constitutional basis, or related to chronic endocrine or non-endocrine diseases, the main clinical entities with gonadal insufficiency, primary (hypergonadotrophic) or secondary (hypogonadotrophic), are reviewed in boys and girls and their investigation and treatment discussed.

Differences in the retinol circulating complex between healthy male and female infants

The concentration of the three components of the retinol circulating complex demonstrates in healthy male infants, but not in females, a transient elevation culminating at 5-6 months after birth. This trimolecular peak is significantly less elevated in bilateral cryptorchid babies. The rise of the retinol related parameters seems directly induced by the testosterone hypersecretion previously described in male infants at 2-3 months. The delay in the liver response in terms of retinol secretion appears to depend on a temporary functional immaturity and/or a transitory depression of the hepatic protein-synthesizing machinery. The surge of the retinol circulating complex could play a crucial role in the O-mannosylation of several glycoproteins involved in male sexual differentiation.

Change in response with age of human articular cartilage to plasma somatomedin activity

Normal male articular cartilage (34 specimens, age range 1--30 years) has been examined in vitro for response to somatomedin (SM) activity. Basal 3H-thymidine and 35S-sulfate incorporation both decreased with increasing age of the cartilage donor. However, enhancement of isotope incorporation which was attained on addition of 10% normal plasma (containing IU SM/ml) was greatest in cartilage from adolescents in the age range 12--17 years. The mean enhancement of 3H-thymidine incorporation (expressed as % basal) was as follows: age 1--10 years = 184 +/- 28 (SE), N = 9; 12--17 years = 436 +/- 101 (11); 18--30 years = 231 +/- 49 (8); and for 35S-sulfate incorporation was 1--10 years = 389 +/- 100 (8); 12--17 years = 824 +/- 273 (11); and 18--30 years = 572 +/- 56 (8). The increased response of cartilage in the 12--17 year group suggests that a greater sensitivity to the somatomedins may contribute to the increased skeletal growth during adolesence.

Hormonal and nutritional status: critical conditions for endemic goiter epidemiology?

Recent advances in protein metabolism and in glycoprotein synthesis bring further insight into endemic goiter epidemiology. Retinol circulates in the blood stream in close parallelism with retinol-binding protein and prealbumin (RBP-PA), a protein complex whose liver secretory rate is dependent upon hormonal and nutritional status. On the other hand, normal glycosylation reaction occurs through the formation of a retinol-linked sugar complex. It is suggested that the relative drop of serum retinol levels, as a result of modified hormonal climate and/or declining protein status, might constitute a critical factor capable of inducing a defective incorporation of mannose into native thyroglobulin, leading to an early depression of the full glycoprotein production. This concept affords a comprehensive explanation of the following unresolved data recorded in goitrous areas: (1) clinical and biochemical discrepancies between subjects living in the same morbid territory, (2) persistence of endemicity in spite of appropriate iodine supplementation, (3) similar prevalence of goiter hypertrophy in male and female prepubertal children, (4) increased frequency of goiter enlargement in the four most vulnerable groups, namely preschool children of both sexes, adolescent girls, pregnant women, and elderly persons, (5) decreased impact of thyroid swelling accompanying improved socio-economic status, even without iodine addition, and (6) resurgence of goitrous hyperplasia as an effect of seasonal or sporadic deterioration of nutritional habits, even when iodine supply remains unchanged.

Psychiatry and endocrinology: an expanding interface

There is growing documentation that a variety of hormones can both influence mood and behavior and be affected by them. Endocrine measures thus provide us with a readily accessible source of information about how the brain mediates between stimuli arising from the external social environment, intrapsychic phenomena, and the body's internal physiological needs. This paper will review recent psychoendocrine research which has in particular suggested several new concepts: (1) the brain itself might be viewed as a "target organ" for certain hormones; (2) specific hormonal correlates of certain clinical psychiatric syndromes, such as anorexia nervosa and depressive illness, might serve as biological markers which could help in the differential diagnosis of these conditions; and (3) peripheral hormonal determinations, by virtue of the role played by central nervous system (CNS) neurotransmitters in endocrine regulation, may provide important specific information about possible CNS biogenic amine abnormalities associated with the pathogenesis of certain psychiatric disorders.

Effect of an infusion of Gn-RH upon levels of sex hormones in prepubertal and pubertal girls: evidence for relative ovarian insensitivity

Changes in levels of sex steroids and gonadotropins were measured in 16 normal prepubertal and 15 pubertal girls prior to and after a 3 hour infusion of 100 microgrm synthetic gonadotropin releasing hormone (Gn-RH). Plasa estradiol (E2) concentrations rose significantly (p less than 0.02) from 29.7 +/- 4.6 (SE) pg/ml in the basal period to to 46.8 +/- 7.1 at the end of the infusion in the pubertal girls but were unchanged in the prepubertal girls. Estrone (E1), progesterone (P), 17-HYDROXYPROGESTERONE (17OHP), TESTOSTERONE (T), DIHYDROTESTOSTERONE (DHT), and androstenedione (A), dehydroepiandrosterone (DHA) and dehydroepiandrosterone sulfate (DHAS) levels were not altered in either maturity group. Basal plasma E2, E1, T, DHT, DHA and DHAS concentrations significantly correlated with the releasable pool of LH evoked by Gn-RH from the pituitary gonadotropes. We conclude: 1) The ovary is not highly and rapidly responsive to transient elevations of endogenous gonadotropin, and 2) Adrenal androgens may to some extent modulate the maturation of the hypothalamic-pituitary-gonadal system, at least as reflected by the pituitary response to exogenous Gn-RH.

Circulating bound and free estradiol and estrone during normal growth and development and in premature thelarche and isosexual precocity

Serum concentrations of unconjugated estrone, estradiol, and free estradiol, were determined in normal neonates, prepubertal children, adolescents, and adults. The values were compared with those obtained in children with premature thelarche and female sexual precocity. Unconjugated E1 and E2 fell rapidly, and the percentage of FE2 more gradually during the neonatal period and remained low prepubertally. During adolescence girls had greater increases in E1 and E2 while the percentage of FE2 was higher in boys. In premature thelarche only the FE2 was significantly increased. In sexual precocity E1, E2, and FE2 were elevated. Reference standards are provided in Tables I and II for use in the diagnosis of conditions with under- or overproduction of estrogens during growth and development.

Changes in the pituitary-testicular system with age

In order to provide a comprehensive account of pituitary-testicular function in man, 466 subjects, ranging in age from 2 to 101 years, were studied to examine blood levels of the pituitary gonadotrophins (LH and FSH), the sex steroids testosterone and oestradiol, the binding capacity of the sex hormone binding globulin (SHBG), the free testosterone and oestradiol fractions, and the transfer constant for the peripheral conversion of testosterone to oestradiol. The results were compared with clinical indices of testicular size, sexual function and secondary sex hair distribution. Serum LH and FSH were low before puberty, increased in pubertal adolescents to levels somewhat above those of adults and subsequently increased progressively over the age of 40 years. Testosterone levels fell slowly after the age of 40, while there was a slight rise in plasma oestradiol with increasing age. FSH and testosterone showed small seasonal variations in young adult men, the lowest values being seen in winter. SHBG binding capacity was high in two prepubertal boys, fell in adult men, but increased in old age. Free testosterone and oestradiol levels fell in old age. The metabolic clearance rates (MCR) of testosterone and oestradiol also fell in old age, while the conversion of testosterone to oestradiol was increased. Many correlations were observed between various hormonal and clincial measurements. The evidence is consistent with a primary decrease in testicular function over the age of 40 years.

Evaluation and management of the child with delayed pubertal development

The physical and hormonal changes of puberty are presented and the wide range of ages at which the pubertal process may begin is emphasized. The great variability in the timing of onset of adolescence, its rate of progression, and the age of completion are detailed. The causes of delayed adolescence in males and females are considered. The most common form of delayed adolescent development is termed constitutional delay in growth and development, which may occur sporadically, or may be the familial pattern of growth and development or may reflect a suboptimal nutritional environment. The evaluation of such children, including appropriate historical review, physical examination, and laboratory assessment, is outlined. In most patients with constitutional delay in growth and development, strong reassurance is sufficient therapy. In other subjects, treatment with androgens (boys) or estrogens (girls) may be indicated. In patients with primary systemic diseases accociated with delayed maturation, specific treatment which eradicates the illness will often be followed by resumption of growth and development. In subjects with primary disorders of the hypothalamus, pituitary, or gonads, replacement therapy with androgens or estrogens is indicated. If gonadal function is intact, these patients may eventually become fertile with appropriate use of hypothalamic and/or pituitary hormones.

Hormonal changes of adolescence

Pubescence is characterized by many physical, emotional, and hormonal changes. The hypothalamic-pituitary-gonadal system is maintained in a dormant state (with a low level of activity) during prepubertal years by higher central nervous system inhibition. With the onset of adolescence, the reproductive endocrine system becomes increasingly active. The attainment of sexual maturity in terms of secondary sexual characteristics, the production of spermatozoa in the male, and the cyclical female pattern with release of ova are end-points of the developmental process.

Differentiation and development of the male

Male differentiation and development takes place against a tendency towards neutral or feminine differentiation. At each step of development male differentiation results from a suspension of a basic female development and the imposition of male features for which a normal functioning testis is necessary. Once the testis has differentiated early in gestation the establishment and maintenance of normal testicular function will condition male sexual differentiation and maturation. Nature likes to express herself in a rhythmic fashion (circhoral, ultradian, circadian, menstrual, long-term rhythms). To epitomise testicular function throughout development we would propose the term 'ontogenic rhythms' to describe the three periods of maximal testicular activity, fetal, neonatal and adult. This results in the differentiation which eventually determines adult sexual activity.