Puberty-timing is everything!

What lies beneath: White matter microstructure in pediatric myalgic encephalomyelitis/chronic fatigue syndrome using diffusion MRI

Recent studies in adults with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) suggest that changes in brain white matter microstructural organization may correlate with core ME/CFS symptoms, and represent a potential biomarker of disease. However, this has yet to be investigated in the pediatric ME/CFS population. We examined group differences in macrostructural and microstructural white matter properties, and their relationship with clinical measures, between adolescents recently diagnosed with ME/CFS and healthy controls. Forty-eight adolescents (25 ME/CFS, 23 controls, mean age 16 years) underwent brain diffusion MRI, and a robust multi-analytic approach was used to evaluate white and gray matter volume, regional brain volume, cortical thickness, fractional anisotropy, mean/axial/radial diffusivity, neurite dispersion and density, fiber density, and fiber cross section. From a clinical perspective, adolescents with ME/CFS showed greater fatigue and pain, poorer sleep quality, and poorer performance on cognitive measures of processing speed and sustained attention compared with controls. However, no significant group differences in white matter properties were observed, with the exception of greater white matter fiber cross section of the left inferior longitudinal fasciculus in the ME/CFS group compared with controls, which did not survive correction for intracranial volume. Overall, our findings suggest that white matter abnormalities may not be predominant in pediatric ME/CFS in the early stages following diagnosis. The discrepancy between our null findings and white matter abnormalities identified in the adult ME/CFS literature could suggest that older age and/or longer illness duration influence changes in brain structure and brain-behavior relationships that are not yet established in adolescence.

Exploring the longitudinal association between body dissatisfaction and body appreciation in Chinese adolescents: A four-wave, random intercept cross-lagged panel model

Although ample research evidence exists regarding the negative association between body dissatisfaction and body appreciation, the longitudinal association between these two constructs remains unclear, especially for adolescents. Thus, this study investigated the longitudinal association between body dissatisfaction and body appreciation and potential gender differences in this relationship in Chinese adolescents using four-wave longitudinal data. A sample of 2566 adolescents (54.10% girls) were included. A Random Intercept Cross-Lagged Panel Model (RI-CLPM) was conducted separately for boys and girls after controlling for baseline age and BMI z-scores. Results at the within-person level showed that for boys, body dissatisfaction at each wave negatively predicted body appreciation at the following wave, and body appreciation at Wave 2 and Wave 3 negatively predicted body dissatisfaction at Wave 3 and Wave 4. For girls, at the within-person level, body dissatisfaction at Wave 1 and Wave 2 negatively predicted body appreciation at Wave 2 and Wave 3, and body appreciation at Wave 3 negatively predicted body dissatisfaction at Wave 4. However, no gender differences in the RI-CLPM were found. The current findings enrich positive and negative body image research by providing evidence for the reciprocal relationships between body dissatisfaction and body appreciation in Chinese adolescents.

Investigation of the Seasonal Variation in Fat Patterning of Ellisras Rural Children and Adolescents, in the Limpopo Province, South Africa

An increase in childhood obesity has become a global concern since childhood obesity often leads to adulthood obesity. This study aimed to investigate whether there is seasonal variation in fat patterning, and whether fat patterning is associated with seasons among the Ellisras population aged 5-15 years. A total of 1986 children and adolescents (1034 boys and 952 girls) aged 5-15 enrolled in this cross-sectional study. Skinfold measurements were obtained using standard procedures. Obesity prevalence was determined using frequency analysis. The correlation between obesity and two seasons was tested using multinomial regression analysis. The results showed that girls aged 11-15 years had significantly (p ≤ 0.03) larger median fat variables (triceps, biceps, and suprailiac) in spring compared to autumn. The prevalence of obesity ranged from 3-11% with boys being more obese (4-11%) than girls (3-7%) aged 5-15. Regression analysis showed a negative significant (p ≤ 0.001) correlation between autumn and obesity by the subscapular/(subscapular+triceps) (SST) ratio, both unadjusted -2.991 (95%CI -3.233:-2.803) and adjusted -2.897 (95% CI -4.331:-1.629). The findings of the study showed that there was seasonal variation in fat patterning among boys and girls in the Ellisras population and that fat patterning is associated with seasons.

Encapsulated Allografts Preclude Host Sensitization and Promote Ovarian Endocrine Function in Ovariectomized Young Rhesus Monkeys and Sensitized Mice

Transplantation of allogeneic donor ovarian tissue holds great potential for female cancer survivors who often experience premature ovarian insufficiency. To avoid complications associated with immune suppression and to protect transplanted ovarian allografts from immune-mediated injury, we have developed an immunoisolating hydrogel-based capsule that supports the function of ovarian allografts without triggering an immune response. Encapsulated ovarian allografts implanted in naïve ovariectomized BALB/c mice responded to the circulating gonadotropins and maintained function for 4 months, as evident by regular estrous cycles and the presence of antral follicles in the retrieved grafts. In contrast to non-encapsulated controls, repeated implantations of encapsulated mouse ovarian allografts did not sensitize naïve BALB/c mice, which was confirmed with undetectable levels of alloantibodies. Further, encapsulated allografts implanted in hosts previously sensitized by the implantation of non-encapsulated allografts restored estrous cycles similarly to our results in naïve recipients. Next, we tested the translational potential and efficiency of the immune-isolating capsule in a rhesus monkey model by implanting encapsulated ovarian auto- and allografts in young ovariectomized animals. The encapsulated ovarian grafts survived and restored basal levels of urinary estrone conjugate and pregnanediol 3-glucuronide during the 4- and 5-month observation periods. We demonstrate, for the first time, that encapsulated ovarian allografts functioned for months in young rhesus monkeys and sensitized mice, while the immunoisolating capsule prevented sensitization and protected the allograft from rejection.

Effects of Taekwondo Training on Growth Factors in Normal Korean Children and Adolescents: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The growth of children and adolescents is both an important health indicator and a major public health issue. Many recent studies have investigated the effects of taekwondo on growth factors, but no consensus has yet been reached. This meta-analysis aimed to determine the effects of taekwondo on the growth factors in children and adolescents (aged 8 to 16 years). Randomized controlled trials from PubMed, Web of Science, Cochrane Library, the Research Information Sharing Service, the Korea Citation Index, and the Korean-studies Information Service System were analyzed. The effect sizes (standardized mean differences, SMD) were calculated, the risk of bias and publication bias were assessed, and the effect size and subgroup analyses were pooled. We found that the taekwondo group had significantly higher levels of growth hormones (SMD 1.78, 95% confidence interval [CI] 0.98-2.58, and p < 0.001) and insulin-like growth factors (SMD 1.76, 95% CI 0.60-2.92, and p < 0.001) than the control group. For height, a medium effect size was observed (SMD 0.62, 95% CI -0.56-1.80, and p = 0.300), but the between-group difference was not significant. Thus, taekwondo had significant positive effects on the secretion of growth hormones and insulin-like growth factors in Korean children and adolescents. A longitudinal follow-up is necessary to determine the effect on height. This suggests that taekwondo can be recommended as an appropriate physical exercise for maintaining normal growth in children and adolescents.

Review of electrochemical and optical biosensors for testosterone measurement

Testosterone is an anabolic steroid and a major sex hormone in males. It plays vital roles, including developing the testis, penis, and prostate, increasing muscle and bone, and sperm production. In both men and women, testosterone levels should be in normal ranges. Besides, testosterone and its analogs are major global contributors to doping in sport. Due to the importance of testosterone testing, novel, accurate biosensors have been developed. This review summarizes the various methods for testosterone measurement. Also, recent optical and electrochemical approaches for the detection of testosterone and its analogs have been discussed.

Sex-Specific Cut-Offs of Single Point Insulin Sensitivity Estimator (SPISE) in Predicting Metabolic Syndrome in the Arab Adolescents

The Single Point Insulin Sensitivity Estimator (SPISE) is a novel surrogate marker for insulin sensitivity and was found comparable to the gold standard clamp test as well as for predicting the Metabolic Syndrome (MetS) in several populations. The present study aimed to assess for the first time, the validity of SPISE in predicting MetS among Arab adolescents. In this cross-sectional study, 951 Saudi adolescents aged 10−17 years were randomly recruited from different schools across Riyadh, Saudi Arabia. Anthropometrics were measured and fasting blood samples were collected for the assessment of glucose, lipid profile, adipokines, C-reactive protein and 25 hydroxyvitamin (OH) D. MetS was defined using the National Cholesterol Education Program’s (NCEP) criteria with age-specific thresholds for adolescents. The SPISE as well as insulin resistance (HOMA-IR) indices were calculated. The over-all prevalence of MetS was 8.6% (82 out of 951). SPISE index was significantly lower in MetS than non-MetS participants in both sexes (5.5 ± 2.5 vs. 9.4 ± 3.2, p < 0.001 in boys and 4.4 ± 1.4 vs. 8.6 ± 3.2, p < 0.001 in girls). The SPISE index showed a significant inverse correlation with resistin, leptin, and C-reactive protein, and a significant positive correlation with adiponectin and 25(OH) D. Areas under the curve (AUC) revealed fair and good accuracy for predicting MetS 84.1% and 90.3% in boys and girls, respectively. The sex-specific cut-off proposed was SPISE index ≤6.1 (sensitivity 72.2% and specificity 83.9%) for boys and ≤6.46 (sensitivity 96.3% and specificity 73.4%), for girls. This study suggests that the SPISE index is a simple and promising diagnostic marker of insulin sensitivity and MetS in Arab adolescents.

The dynamics of adolescents’ pubertal maturation, depressive symptoms and friendship networks: stochastic actor-oriented model

This study aimed to examine whether adolescents select friends based on their friends’ levels of depressive symptoms, and to determine whether the potential homophily phenomenon for depressive symptoms is attenuated after considering pubertal maturation and gender. Data were from the first three waves of the Taiwan Youth Project, a longitudinal study that annually surveys 7th graders from 40 junior high schools. Participants were asked at each wave to fill out a survey including depressive symptoms, pubertal maturation, and to name three best friends in school. Stochastic actor-oriented models were built to explore the dynamic changes in friendship networks by estimating the probability of the friendship connections and behavioral changes depending on the individual’s current network position and behavioral status. We used a sample of 2,336 adolescents. From 8 to 9th grade, adolescents tended to select friends who were similar in terms of their levels of depressive symptoms (B = 0.358, SE = 0.131, p < .001), without adjusting for gender and pubertal maturation. This homophily effect based on depressive symptoms became non-significant when pubertal maturation was included. Adolescents’ depressive symptoms did not further influence their friends’ depression levels, after controlling for pubertal maturation and gender. Future studies should further examine the mechanisms and group dynamics within clusters of adolescents who are depressed. Providing a supportive environment and tools is warranted to help adolescents cope with negative emotions within their peer group.

The Developmental Significance of Looks from Middle Childhood to Early Adolescence

Physical appearance during the transition into adolescence matters for youths' socioemotional development. This study explored these implications by adding visual data to the NICHD Study of Early Child Care and Youth Development (n = 1,049) to test how others' ratings of youths' looks (1 = very unattractive to 5 = very attractive) at the beginning (grade 3) and end (grade 9) of this transition shaped their emotional well-being, popularity/likability, and dating/sexual behavior. Results revealed recency effects of grade 9 looks on popularity/likability and dating/sexual behaviors and a lingering amplification effect of grade 3 looks on popularity/likability at the start of high school. Few associations were evident for emotional well-being. Thus, physical appearance offers an important lens for studying adolescent development.

Guilt, Uncertainty, Education Needs, and Knowledge of Mothers With Children Experiencing Precocious Puberty

Introduction. Childhood illnesses not only affect the child, but also the family members. Objective. The purpose of this study was to investigate the guilt, uncertainty, education needs, and knowledge of mothers with children experiencing precocious puberty. Methods. Data were collected in August, 2017. The participants of the study were the mothers of children experiencing precocious puberty. A total of 111 copies of questionnaires were collected. Descriptive statistics, independent t-test, one-way ANOVA, Pearson’s correlation coefficient were used for the analysis, using the SPSS 24.0 program. Results. Mothers of children experiencing precocious puberty require psychological interventions that can alleviate their guilt and uncertainty, as well as enhance their knowledge of the emotional support needed by their children. Conclusion. Mothers with children experiencing precocious puberty had a high level of education needs to know, but the knowledge they knew was insufficient. Future studies need to focus on developing education programs for mothers dealing with their child’s precocious puberty.

Association between Dietary Habits and Parental Health with Obesity among Children with Precocious Puberty

Precocious puberty, resulting in various physical, mental, and social changes, may have negative consequences for children and their families. In this study, we investigated whether there were differences between parental obesity, children's and parent's awareness of body shape, and dietary habits according to obesity levels in children with precocious puberty. A total of 193 children (93.3% girls) diagnosed with precocious puberty were classified into three groups according to their obesity levels. Negative body shape awareness and dissatisfaction were significantly higher in the obese group than in the normal-weight group, and parents were more likely to perceive their children as fat than the children themselves. In addition, the obesity rate of parents in the obese group was higher, and the body mass indexes of children and parents were significantly correlated. The nutrition quotients (NQs) were revealed to be significantly lower in the obese group with significantly lower scores. The significant factors related to obesity were the awareness of a fatty body image and dissatisfaction, obesity of the parents, and the NQ. The results show that obese children with precocious puberty were more vulnerable to negative lifestyle, family environment, and self-esteem effects than their normal-weight peers. Therefore, various interventions, such as environmental management, psychological support, and nutrition education, are needed that focus on the obesity and health conditions of children with precocious puberty.

The tempo of puberty and its relationship to adolescent health and well-being: A systematic review

AIM

Emerging evidence suggests that pubertal tempo, that is rate of passage through puberty, has relevance to adolescent mood and behaviour. However, its wider health and developmental significance remain unclear. This systematic review sought to clarify the relationship of pubertal tempo to indicators of health and development, and to document tempo definitions and pubertal durations reported in the literature.

METHODS

Eight electronic databases were searched from earliest record to July 2018. Study eligibility: healthy participants; age 8-21 years; ≥2 longitudinal measures of puberty; analysis of tempo against a health or developmental indicator.

RESULTS

Thirty-eight studies met eligibility, and these reported on diverse tempo definitions and seven health- and development-related domains. Data sets with varying tempo definitions converged on an association of rapid pubertal progression to: (a) higher adiposity during childhood and adolescence in both sexes; and (b) lower psychosocial well-being in adolescent males. Later thelarche unanimously predicted faster progression to menarche in females, but this compensation was largely undetected when alternate definitions of pubertal timing and/or tempo were used. Duration of puberty ranged from 2.5-4.1 years.

CONCLUSION

Pubertal tempo may be clinically relevant when considering trajectories of adiposity and psychosocial well-being among adolescents, especially males. Consensus on the definition of tempo would facilitate between-study comparisons.

Resting Level of Insulin-Like Growth Factor-1 Is Not at Play in Cardiac Enlargement in Endurance-Trained Adolescents

Purpose

The study aimed to investigate resting levels of several selected growth and metabolic hormones in a group of 24 endurance-trained adolescents (aged 13–19 years) compared with 24 untrained age- and sex-matched controls, and to investigate if increased cardiac dimensions were related to these hormones at rest with emphasis on insulin-like growth factor-1 (IGF-1).

Methods

The hormones (cortisol, IGF-1, IGF-2, follicle-stimulating hormone, growth hormone, luteinizing hormone, prolactin, and thyroid-stimulating hormone) were analysed with chemiluminescence microparticle immunoassay (CMIA) or multiplex fluorochrome (Luminex) technique. Cardiac dimensions were assessed by echocardiographic examination at rest. Peak oxygen uptake was obtained by a maximal cardiopulmonary exercise test on a treadmill.

Results

Circulating levels of analysed hormones at rest did not differ between the groups. A correlation was found between increased cardiac dimensions and IGF-1 in the controls, but not in the active group. This correlation declined also among the controls when the cardiac parameters were indexed for body surface area.

Conclusion

Increased cardiac dimensions in endurance-trained adolescents could not be related to resting levels of hormones associated with growth and metabolism, including IGF-1 and GH. In addition, the resting levels of these hormones seem not to be affected by intense regular endurance exercise in adolescents. These findings may contribute to the knowledge about cellular signaling that trigger growth as well as cardiac adaptation to endurance training in young athletes.

Assessing Self-concept as a Mediator Between Anger and Resilience in Adolescents With Cancer in Taiwan

BACKGROUND

Anger is considered a common method used by patients to relieve emotional frustrations. However, this emotional response is not a common research focus for adolescents with cancer.

OBJECTIVE

The aim of this study was to determine whether self-concept mediated the relationship between anger and resilience for adolescent patients currently being treated for cancer.

METHODS

A cross-sectional study of 40 adolescents with cancer was conducted. The instruments included the Chinese Beck Self-Concept Inventory, the Chinese Beck Anger Inventory, and the Chinese Resilience Scale. Mediation analysis was also conducted.

RESULTS

The results indicate that (1) variations in anger significantly account for 6.86% of observed variations in self-concept, (2) variations in self-concept significantly account for 52.83% of observed variations in resilience, (3) variations in anger significantly account for 10.96% of observed variations in resilience, and (4) when paths in conditions 1 and 2 were controlled, variations in anger through self-concept significantly account for 54.04% of observed variations in resilience, and variations in anger did not significantly account for observed variations in resilience.

CONCLUSIONS

Gender and age might affect anger control. Despite worse physical functioning and an impacted appearance, participants had normative-to-positive self-concept levels, suggesting that their self-concept might not be affected by cancer. Self-concept might play a mediating role between anger and resilience, thus helping to bridge this knowledge gap.

IMPLICATIONS FOR PRACTICE

The current gap in knowledge regarding the mediating relationship necessitates the implementation of a large-scale study designed to verify the mediating role of self-concept between anger and resilience.

Parametric survival analysis of menarche onset timing among Nigerian girls

BACKGROUND

This study was a response to the dearth of information on the timing of menarche in low-income countries, and the need to update knowledge on the condition. It thereby enables the provision of adequate support to young girls during menarche. The study determined the timing and range of onset of menarche and identified the factors influencing the timing.

METHODS

We used data on girls' sexual and reproductive processes from a nationally representative population survey of girls aged 15-24 years in Nigeria. Descriptive statistics, and survival analysis techniques were used for data analysis at p = 0·05.

FINDING

A quarter of the respondents (26%) had commenced menstruation by age 12. Almost all, (90%) had experienced menstruation by age 17. Girls aged 20-24 years reported later menarche (time ratio 1·066, 95% CI: 1·045-1·087) compared to those aged 15-19 years. An increase of respondents age by one year resulted in 0·8% delay in onset timing. Significant differences were also found in the zone of residence among the sampled population. Compared with girls from the South East, the timing of menstruation was generally delayed among the girls from South-South by 5%, North Central by 9%, South West by 10%, North East by 16% and 17% among girls from the North West.

INTERPRETATION

There was a wide range in menarcheal age in Nigerian girls with a peak at 13-14 years and the possibility of a secular trend in the timing of onset. Early family life education is recommended.

Sleep Quality in Adolescents With Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME)

STUDY OBJECTIVES

Little is known about the type and severity of sleep disturbances in the pediatric chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) population, compared with healthy adolescents. Using a range of objective and subjective measures, the aim of this study was to investigate sleep quality, the relationship between objective and subjective measures of sleep quality, and their associations with anxiety in adolescents with CFS/ME compared with healthy controls.

METHODS

Twenty-one adolescents with CFS/ME aged 13 to 18 years (mean age 15.57 ± 1.40), and 145 healthy adolescents aged 13 to 18 years (mean age 16.2 ± 1.00) wore actigraphy watches continuously for 2 weeks to collect a number of objective sleep variables. The Pittsburgh Sleep Quality Index was used to obtain a subjective measure of sleep quality. Anxiety was measured by the Spence Children's Anxiety scale.

RESULTS

On average over the 2-week period, adolescents with CFS/ME were found to have (1) significantly longer objective sleep onset latency, time in bed, total sleep time, and a later rise time (all P < .005), and (2) significantly poorer subjective sleep quality (P < .001), compared with healthy adolescents. The CFS/ME patient group displayed higher levels of anxiety (P < .05), and in both groups, higher levels of anxiety were significantly related to poorer subjective sleep quality (P < .001).

CONCLUSIONS

This study provides objective and subjective evidence of sleep disturbance in adolescents with CFS/ME compared with healthy adolescent controls.

The mediating role of cortical thickness and gray matter volume on sleep slow-wave activity during adolescence

During the course of adolescence, reductions occur in cortical thickness and gray matter (GM) volume, along with a 65% reduction in slow-wave (delta) activity during sleep (SWA) but empirical data linking these structural brain and functional sleep differences, is lacking. Here, we investigated specifically whether age-related differences in cortical thickness and GM volume and cortical thickness accounted for the typical age-related difference in slow-wave (delta) activity (SWA) during sleep. 132 healthy participants (age 12-21 years) from the National Consortium on Alcohol and NeuroDevelopment in Adolescence study were included in this cross-sectional analysis of baseline polysomnographic, electroencephalographic, and magnetic resonance imaging data. By applying mediation models, we identified a large, direct effect of age on SWA in adolescents, which explained 45% of the variance in ultra-SWA (0.3-1 Hz) and 52% of the variance in delta-SWA (1 to <4 Hz), where SWA was lower in older adolescents, as has been reported previously. In addition, we provide evidence that the structure of several, predominantly frontal, and parietal brain regions, partially mediated this direct age effect, models including measures of brain structure explained an additional 3-9% of the variance in ultra-SWA and 4-5% of the variance in delta-SWA, with no differences between sexes. Replacing age with pubertal status in models produced similar results. As reductions in GM volume and cortical thickness likely indicate synaptic pruning and myelination, these results suggest that diminished SWA in older, more mature adolescents may largely be driven by such processes within a number of frontal and parietal brain regions.

Relationships Between Age at Menarche, Walking Gait Base of Support, and Stance Phase Frontal Plane Knee Biomechanics in Adolescent Girls

BACKGROUND

Age at menarche impacts patterns of pubertal growth and skeletal development. These effects may carry over into variation in biomechanical profiles involved in sports-related traumatic and overuse knee injuries. The present study investigated whether age at menarche is a potential indicator of knee injury risk through its influence on knee biomechanics during normal walking.

OBJECTIVE

To test the hypothesis that earlier menarche is related to postpubertal biomechanical risk factors for knee injuries, including a wider, more immature gait base of support, and greater valgus knee angles and moments.

DESIGN

Cross-sectional observational study.

SETTING

University research facility.

PARTICIPANTS

Healthy, postmenarcheal, adolescent girls.

METHODS

Age at menarche was obtained by recall questionnaire. Pubertal growth and anthropometric data were collected by using standard methods. Biomechanical data were taken from tests of walking gait at self-selected speed. Reflective marker position data were collected with a 3-dimensional quantitative motion analysis system, and 3 force plates recorded kinetic data.

MAIN OUTCOME MEASURES

Age at menarche; growth and anthropometric measurements; base of support; static knee frontal plane angle; and dynamic knee frontal plane angles and moments during stance.

RESULTS

Earlier menarche was correlated significantly with abbreviated pubertal growth and postpubertal retention of immature traits, including a wider base of support. Earlier menarche and wider base of support were both correlated with more valgus static knee angles, more valgus knee abduction angles and moments at foot-strike, and a more valgus peak knee abduction angle during stance. Peak knee abduction moment during stance was not correlated with age at menarche or base of support.

CONCLUSIONS

Earlier menarche and its effects on growth are associated with retention of a relatively immature gait base of support and a tendency for static and dynamic valgus knee alignment. This biomechanical profile may put girls with earlier menarche at greater risk for sports-related knee injuries.

LEVEL OF EVIDENCE

Not applicable.

During early to mid adolescence, moderate to vigorous physical activity is associated with restoring sleep, psychological functioning, mental toughness and male gender

Numerous studies showed that regular physical activity (PA) is associated with both favourable and restorative sleep and improved psychological functioning (PF). However, there is little research on the topic covering the early to mid-adolescence period. Moreover, curiosity and exploratory behaviour (CEB) and mental toughness (MT) as a result of PA remains thus far uninvestigated, as do possible gender differences. The aim of the present study was to explore the associations between PA, subjective sleep (sS), PF, CEB, and MT during early to mid-adolescence. A total of 1361 participants (mean age = 13.37 years; range: 11-16 years; 51.2% female) took part in the study. They completed questionnaires covering PA, sS, PF, CEB, and MT. Greater PA was related to improved PF, better sS, and increased CEB and MT. Compared to male participants, females reported less PA, poorer sS, and had lower PF and MT scores. The present pattern of results suggests that during early and mid-adolescence greater PA was associated with more favourable sS and better PF, including CEB and MT, and that female participants reported lower scores in PA, sS, and PF. Accordingly, if PA has a favourable impact on sleep and psychological functioning, then data suggest that sports participation should be more tailored to increase motivation among female adolescents.

Could exposure to phthalates speed up or delay pubertal onset and development? A 1.5-year follow-up of a school-based population

PURPOSE

Phthalates may interfere with the timing of pubertal development in adolescence and existing studies have shown inconsistent results. This study aims to assess the associations of pubertal onset and progression with urinary concentrations of phthalate metabolites in school-aged boys and girls.

METHODS

Using isotope-dilution liquid chromatography tandem mass spectrometry, we analyzed 6 phthalate metabolites in urine samples of 430 children (222 boys and 208 girls) aged 9.7 ± 2.2 years (age range 6.1 to 13.8 years) at baseline and 18 months of follow-up. The associations of exposures to phthalates with pubertal development such as the testis, breast and pubic hair were evaluated using ordered logistic regression models, adjusting for baseline development stage, current chronological age, current body fat composition, and parental education.

RESULTS

Urinary mono-n-butyl phthalate (MnBP) was associated with a 39% increase in the odds of presenting lower pubic hair development stages in boys, and mono (2-ethylhexyl) phthalate (MEHP) (p < 0.10), mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) were associated with 54%-65% increase in the odds of presenting higher breast development stages in girls (p < 0.05), while MEHHP and MEOHP were also associated with a 70% increase in the odds of menarche onset (p < 0.05). After adjusting for potential confounding variables, the associations of girls' pubertal onset with MnBP, MMP, MEP and MEHP were significant. The odds of girls' breast onset were 4 to 10 times higher in high MnBP, MMP, MEP or MEHP exposure group than in low exposure group.

CONCLUSIONS

Our findings suggest subtle effects of phthalate metabolites associated with pubertal onset and progression. MnBP exposure may be associated with delayed pubic hair development in boys, while MnBP, MMP, MEP, and MEHP exposures may be associated with breast onset, and MEHP metabolites associated with speedup in breast development progression and earlier menarche onset in girls.

"Sleep well, our tough heroes!"--in adolescence, greater mental toughness is related to better sleep schedules

Mental toughness (MT) is understood as the display of confidence, commitment, challenge, and control. The aim of this study was to explore the extent to which greater MT is associated with subjectively assessed sleep among adolescents. A total of 284 adolescents (M = 18.26 years) completed a series of questionnaires assessing MT, psychological functioning, and sleep. Greater MT was significantly associated with better sleep quality, shorter sleep onset latency, fewer awakenings after sleep onset, and longer sleep duration. Greater MT was also associated with less perceived stress and less depressive symptoms. MT was directly and indirectly associated with sleep quality. Mentally tough adolescents report good sleep quality and sleep schedules, along with psychological wellbeing.

Age-related changes in urinary testosterone levels suggest differences in puberty onset and divergent life history strategies in bonobos and chimpanzees

Research on age-related changes in morphology, social behavior, and cognition suggests that the development of bonobos (Pan paniscus) is delayed in comparison to chimpanzees (Pan troglodytes). However, there is also evidence for earlier reproductive maturation in bonobos. Since developmental changes such as reproductive maturation are induced by a number of endocrine processes, changes in hormone levels are indicators of different developmental stages. Age-related changes in testosterone excretion are an indirect marker for the onset of puberty in human and non-human primates. In this study we investigated patterns of urinary testosterone levels in male and female bonobos and chimpanzees to determine the onset of puberty. In contrast to other studies, we found that both species experience age-related changes in urinary testosterone levels. Older individuals of both sexes had significantly higher urinary testosterone levels than younger individuals, indicating that bonobos and chimpanzees experience juvenile pause. The males of both species showed a similar pattern of age-related changes in urinary testosterone levels, with a sharp increase in levels around the age of eight years. This suggests that species-differences in aggression and male mate competition evolved independently of developmental changes in testosterone levels. Females showed a similar pattern of age-related urinary testosterone increase. However, in female bonobos the onset was about three years earlier than in female chimpanzees. The earlier rise of urinary testosterone levels in female bonobos is in line with reports of their younger age of dispersal, and suggests that female bonobos experience puberty at a younger age than female chimpanzees.

During early and mid-adolescence, greater mental toughness is related to increased sleep quality and quality of life

The aim of this study was to explore the association between mental toughness, subjective sleep, physical activity, and quality of life during early and mid-adolescence. A total of 1475 participants (mean age = 13.4 years; range: 11–16 years) took part in the study. They completed questionnaires related to mental toughness, physical activity, subjective sleep, and quality of life. Greater mental toughness was related to more favorable quality of life and increased subjective sleep. Mental toughness was not related to physical activity. Increased mental toughness, favorable quality of life, and sleep are related during early and mid-adolescence. Against our expectations, mental toughness was not related to physical activity.

Estimating reliable paediatric reference intervals in clinical chemistry and haematology

Very few high-quality studies on paediatric reference intervals for general clinical chemistry and haematology analytes have been performed. Three recent prospective community-based projects utilising blood samples from healthy children in Sweden, Denmark and Canada have substantially improved the situation.

CONCLUSION

The present review summarises current reference interval studies for common clinical chemistry and haematology analyses.

Adolescents with greater mental toughness show higher sleep efficiency, more deep sleep and fewer awakenings after sleep onset

PURPOSE

Mental toughness (MT) is understood as the display of confidence, commitment, challenge, and control. Mental toughness is associated with resilience against stress. However, research has not yet focused on the relation between MT and objective sleep. The aim of the present study was therefore to explore the extent to which greater MT is associated with objectively assessed sleep among adolescents.

METHODS

A total of 92 adolescents (35% females; mean age, 18.92 years) completed the Mental Toughness Questionnaire. Participants were split into groups of high and low mental toughness. Objective sleep was recorded via sleep electroencephalograms and subjective sleep was assessed via a questionnaire.

RESULTS

Compared with participants with low MT, participants with high MT had higher sleep efficiency, a lower number of awakenings after sleep onset, less light sleep, and more deep sleep. They also reported lower daytime sleepiness.

CONCLUSIONS

Adolescents reporting higher MT also had objectively better sleep, as recorded via sleep electroencephalograms. A bidirectional association between MT and sleep seems likely; therefore, among adolescence, improving sleep should increase MT, and improving MT should increase sleep.

Long-term evaluation of patients undergoing genitoplasty due to disorders of sex development: results from a 14-year follow-up

PURPOSE

To summarize the experience in treating patients with genitoplasty due to disorders of sex development in China.

METHODS

The operative procedures, gender of rearing, surgical outcome, and psychosocial and family adjustments of 262 patients were reviewed retrospectively.

RESULTS

At initial diagnosis, the mean age was 14.3 ± 2.8 years (range: 2-38 years). There were 96 children, 133 adolescents, and 33 adults. Follow-up was done every 6 months. Patients with female sex assignment had no urinary incontinence or voiding difficulty. Five patients underwent the second surgery (3%); vaginal dilation was performed in 35 patients with postoperative vaginal stenosis; 12 patients (7.4%) were unsatisfactory with the outcome. For patients with male sex assignment, the median length of penis was 2.2 cm in prepubertal patients, 4.2 cm in pubertal patients, and 5.0 cm in adults; 39 patients developed postvoid dribbling (39%); 21 patients underwent a second surgery (21%); urethral dilation was done in 28 patients (28%) due to urethral stricture; 38 patients were unsatisfactory with the outcome (38%). In addition, 136 patients (83%) with female sex assignment and 54 (54%) with male sex assignment had favorable psychosocial adjustment.

CONCLUSIONS

Patients with male sex assignment have more surgical complications and difficulties in psychosocial adjustment as compared to those with female sex assignment.

Early Menarche as an Alternative Reproductive Tactic in Human Females: An Evolutionary Approach to Reproductive Health Issues

The age at which a female reaches sexual maturity is critical in determining her future reproductive health and success. Thus, a worldwide decline in menarcheal age (timing of first menstrual period) may have serious long-term consequences. Early menarcheal timing (first menstrual period before age 12) can have a negative effect on fecundity, as well as the quality and quantity of offspring, and may consequently influence population growth or decline. In this paper, we apply an evolutionary framework to modern human health, and assess both proximate and ultimate consequences of declining menarcheal age. Examination of human reproductive health within an evolutionary framework is innovative and essential, because it illuminates the ultimate consequences of a declining age of menarche and facilitates new ways of thinking about the long-term and intergenerational transmission of health and disease; thus, an evolutionary framework lends itself to innovative public health and policy programs. In this paper, we examine whether or not early menarche is an alternative reproductive tactic that modern human females employ in response to a stressful environment, and whether or not early menarche is ultimately beneficial.

Behavioral deficits and cellular damage following developmental ethanol exposure in rats are attenuated by CP-101,606, an NMDAR antagonist with unique NR2B specificity

NMDAR-mediated excitotoxicity has been implicated in some of the impairments following fetal ethanol exposure. Previous studies suggest that both neuronal cell death and some of the behavioral deficits can be reduced by NMDAR antagonism during withdrawal, including antagonism of a subpopulation of receptors containing NR2B subunits. To further investigate NR2B involvement, we selected a compound, CP-101,606 (CP) which binds selectively to NR2B/2B stoichiometries, for both in vitro and in vivo analyses. For the in vitro study, hippocampal explants were exposed to ethanol for 10 days and then 24 h following removal of ethanol, cellular damage was quantified via propidium iodide fluorescence. In vitro ethanol withdrawal-associated neurotoxicity was prevented by CP (10 and 25 nM). In vivo ethanol exposure was administered on PNDs 1-7 with CP administered 21 h following cessation. Activity (PNDs 20-21), motor skills (PNDs 31-33), and maze navigation (PNDs 43-44) were all susceptible to ethanol insult; treatment with CP (15 mg/kg) rescued these deficits. Our findings show that CP-101,606, a drug that blocks the NR2B/2B receptor, can reduce some of the damaging effects of "3rd trimester" alcohol exposure in our rodent model. Further work is clearly warranted on the neuroprotective potential of this drug in the developing brain.

Sleep and its importance in adolescence and in common adolescent somatic and psychiatric conditions

Restoring sleep is strongly associated with a better physical, cognitive, and psychological well-being. By contrast, poor or disordered sleep is related to impairment of cognitive and psychological functioning and worsened physical health. These associations are well documented not only in adults but also in children and adolescents. Importantly, adolescence is hallmarked by dramatic maturational changes in sleep and its neurobiological regulation, hormonal status, and many psychosocial and physical processes. Thus, the role of sleep in mental and physical health during adolescence and in adolescent patients is complex. However, it has so far received little attention. This review first presents contemporary views about the complex neurobiology of sleep and its functions with important implications for adolescence. Second, existing complex relationships between common adolescent somatic/organic, sleep-related, and psychiatric disorders and certain sleep alterations are discussed. It is concluded that poor or altered sleep in adolescent patients may trigger and maintain many psychiatric and physical disorders or combinations of these conditions, which presumably hinder recovery and may cross into later stages of life. Therefore, timely diagnosis and management of sleep problems appear critical for growth and development in adolescent patients.

An exploration in health education of an integrated theoretical basis for sexuality education pedagogies for young people

In Health Education, much sexuality education appears to have little evidence of an acknowledged theoretical basis for its knowledge and skills' teaching and learning. The Health Education teacher can frequently be at a loss to decipher what theoretical principles could or should permeate sexuality education curricula, which may be both detracting and distracting from the educational process. This paper explores and analyses a suggested selection of sexuality education pedagogies integrating the theoretical framework of Anderson and Krathwohl and Gardner's Inter-personal Intelligence theories. In response to the earlier maturation of girls and boys, and the concomitant need for better and earlier sexuality education, pedagogies relevant for three age groups, elementary/primary school (7-9 years), middle school (10-12 years) and high school (13-15 years), are identified and analysed as appropriate for these students' cognitive abilities. The integration of these two educational theories has implications for Health Education practitioners, whereby this approach may be useful to assist sexuality educators in identifying and anchoring pedagogies in a more theoretical and structured approach. Providing theoretical starting points, and directions to achieve students' learning goals, may enhance the quality of Health teachers' conceptualizing and planning for implementing quality sexuality education knowledge and skills' teaching and learning.

Pubertal development moderates the importance of environmental influences on depressive symptoms in adolescent girls and boys

Prevalence differences in depressive symptoms between the sexes typically emerge in adolescence, with symptoms more prevalent among girls. Some evidence suggests that variation in onset and progression of puberty might contribute to these differences. This study used a genetically informative, longitudinal (assessed at ages 12, 14, and 17) sample of Finnish adolescent twins (N = 1214, 51.6% female) to test whether etiological influences on depressive symptoms differ as a function of pubertal status. These tests were conducted separately by sex, and explored longitudinal relationships. Results indicated that pubertal development moderates environmental influences on depressive symptoms. These factors are more important on age 14 depressive symptoms among more developed girls relative to their less developed peers, but decrease in influence on age 17 depressive symptoms. The same effects are observed in boys, but are delayed, paralleling the delay in pubertal development in boys compared to girls. Thus, the importance of environmental influences on depressive symptoms during adolescence changes as a function of pubertal development, and the timing of this effect differs across the sexes.

Coming of age in the kisspeptin era: sex differences, development, and puberty

The status of the neuroendocrine reproductive axis differs dramatically during various stages of development, and also differs in several critical ways between the sexes, including its earlier pubertal activation in females than males and the presence of neural circuitry that generates preovulatory hormone surges in females but not males. The reproductive axis is controlled by various hormonal and neural pathways that converge upon forebrain gonadotropin-releasing hormone (GnRH) neurons, and many of the critical age and sex differences in the reproductive axis likely reflect differences in the "upstream" circuits and factors that regulate the GnRH system. Recently, the neural kisspeptin system has been implicated as an important regulator of GnRH neurons. Here I discuss the evidence supporting a critical role of kisspeptin signaling at different stages of life, including early postnatal and pubertal development, as well as in adulthood, focusing primarily on information gleaned from mammalian studies. I also evaluate key aspects of sexual differentiation and development of the brain as it relates to the Kiss1 system, with special emphasis on rodents. In addition to discussing recent advances in the field of kisspeptin biology, this paper will highlight a number of unanswered questions and future challenges for kisspeptin investigators, and will stress the importance of studying the kisspeptin system in both males and females, as well as in multiple species.

An evaluation of a body image intervention based on risk factors for body dissatisfaction: a controlled study with adolescent girls

OBJECTIVE

In this research we aimed to evaluate the efficacy of a theoretically derived school-based body image intervention for young adolescent girls.

METHOD

Participants were 194, female Grade 7 students from two Catholic Secondary Schools in Melbourne, Australia. One school was allocated to the intervention group and the other school was allocated to the control group. The intervention group participated in three 50-min body image intervention sessions, while the control group received their usual classes. All participants completed baseline, post-intervention and 3-month follow-up questionnaires.

RESULTS

The intervention group reported significantly more positive outcomes than the control group on measures of intervention topic knowledge, risk factors for body dissatisfaction, body image, dietary restraint and self-esteem, at post-intervention and follow-up.

DISCUSSION

This study provides support for the efficacy of a theoretically derived school-based body image intervention with adolescent girls.

Perceived stress and weight gain in adolescence: a longitudinal analysis

Although perceived stress has been hypothesized to be a risk factor for obesity, epidemiological studies relating stress to weight gain have shown mixed results. We examined prospective associations between perceived stress and changes in waist circumference and BMI in a large study of adolescents. As part of the Health and Behaviour in Teenagers Study (HABITS), height, weight, and waist circumference were measured annually in 4,065 adolescents aged from 11 to 16. Waist and BMI standard deviation scores (SDS) were used as indices of adiposity. Adolescents completed a measure of perceived stress each year, from which mean stress scores over the 5-year period were also calculated and divided by tertile into lower, moderate, and higher stress. Associations between perceived stress at each year and adiposity 1-4 years later and also adiposity trajectories over the whole period in relation to mean stress were investigated. Analyses were adjusted for age, sex, ethnicity, socioeconomic deprivation, pubertal timing, and smoking. Perceived stress in any year was not related prospectively to increases in waist or BMI SDS 1-4 years later, nor was there any evidence that higher stress over the whole period was associated with greater gains in waist or BMI SDS. However, waist and BMI SDS were significantly higher in the moderate- and higher-stress groups than the lower-stress group across the whole 5-year period. Persistent stress was associated with higher waist circumference and BMI in adolescence, but did not lead to differential changes over 5 years.

Pubertal development in Mexican American girls: the family's perspective

Mexican American (MA) girls are entering puberty earlier than in the past, yet few studies have explored the perceptions surrounding puberty among this group. We conducted separate focus groups for fathers, mothers, and daughters aged 6 to 12 years to explore perceptions of body image, pubertal development, communications, and sources of puberty-related information in MA participants. Our results revealed parental concerns about daughters' weight and pubertal development, as well as differences in their communication with their daughters. Although both parents willingly discussed pubertal issues concerning their daughters, mothers had a more active role in conveying pubertal information to daughters. Among the girls, there was a gap in knowledge about the pubertal process between the younger and older girls. Our findings present opportunities and challenges for addressing obesity as a pubertal risk factor in MA girls; however, more studies are needed to understand family beliefs and sociocultural dynamics surrounding puberty in MAs.

Is BodyThink an efficacious body image and self-esteem program? A controlled evaluation with adolescents

This study aimed to evaluate the efficacy of BodyThink, a widely disseminated body image and self-esteem program. Participants were 277, grade 7 students from 4 secondary schools in Australia. The intervention group (62 girls, 85 boys) participated in BodyThink during four 50-min lessons, while the control group (65 girls, 65 boys) received their usual classes. All participants completed baseline, postintervention and 3-month follow-up questionnaires. For girls, the intervention group reported higher media literacy and lower internalization of the thin ideal compared to the control group. For boys, the intervention group reported higher media literacy and body satisfaction than the control group. Although some positive outcomes were observed, it would be valuable to find ways to enhance the impact of BodyThink, especially in light of its wide dissemination. Suggestions for improving BodyThink are presented.

Male juveniles with sexual behavior problems: are there differences among racial groups?

This study used archival data on a sample of 186,492 referrals from a southwestern state Juvenile Probation Commission to compare the characteristics of 5,439 male Black, Hispanic, and White juveniles with sexual behavior problems on the five most common sexual offenses in the data set. The characteristics of 181,053 juveniles of the three races without sexual behavior problems were also compared on the basis of the seven most common nonsexual offenses. The bases of comparison were the seven variables: reported incidence of sexual offenses, the primary caregivers or living arrangements, age, suspected sexual abuse, suspected emotional abuse, suspected physical abuse, and special education status, on which racial differences were found. Prevention and treatment implications of findings are discussed.

Female and male rats in late adolescence differ from adults in amphetamine-induced locomotor activity, but not in conditioned place preference for amphetamine

Rodent models display differences in drug-induced behaviour between prepubertal/young adolescents and adults that parallel developmental differences in people; however, little is known as to when the transition to 'adultlike' behaviour occurs. We investigated the differences in locomotor and reward responses to amphetamines in male and female rats in late adolescence and compared them with corresponding adult responses. Long-Evans rats were tested for locomotor activity and conditioned place preference (CPP) for amphetamine (0.25, 0.5 or 1.0 mg/kg), beginning at 45 or 69 days of age. Adolescent female rats moved less to the first injection of amphetamine compared with adult female rats irrespective of dose, whereas adolescent male rats did not differ from adults. Adolescent female rats significantly increased locomotor activity in response to subsequent injections of amphetamine at all three doses, whereas such sensitization was only found at the highest dose for adult female and male rats. No effect of repeated injections at any dose was observed in adolescent male rats. No age differences were observed in CPP, but female rats showed greater CPP during the dioestrous than during the oestrous phase of the cycle. These data suggest that differences in neural systems underlying some behavioural responses to amphetamine continue to mature postpubertally into late adolescence in a sex-specific manner.

Persistent impact of pubertal timing on trends in smoking, food choice, activity, and stress in adolescence

OBJECTIVES

a) To replicate the established association between early puberty and smoking; b) to see whether differences between early and late maturers narrowed with increasing age and differed by gender; and c) to determine whether other health behaviors (food choice, physical activity, sedentary behavior) and stress showed the same association with pubertal timing.

METHODS

The Health and Behaviour in Teenagers Study (HABITS) followed a cohort of 5863 adolescents from ages 11 to 12 years (UK year 7; US grade 6) for 5 years. Puberty was assessed with the Pubertal Development Scale. Three pubertal timing groups were created by identifying adolescents who reached midpuberty relatively early, average, or late, compared with their peers. Longitudinal trends in health behaviors and stress were compared between the three groups.

RESULTS

Smoking rates were higher throughout adolescence among early-maturing students, with no evidence that late-maturers "caught up" when they reached puberty, although group differences narrowed over time. Early-maturing students had higher rates of sedentary behaviors but also reported higher rates of vigorous activity than their "on-time" developing counterparts. Patterns in dietary behaviors and stress showed lower rates of daily breakfast and higher stress among early-maturing girls, but not boys. Overall, the effects were largest in early adolescence (ages 11-13 years) and became smaller at older ages (ages 14-16 years).

CONCLUSION

Early-maturing adolescents are at increased risk for unhealthy behaviors, especially smoking, and although differences attenuate during adolescence, they remain significant at age 16 years. This suggests that early maturation may be a cause of, or is at least a marker for, differences in lifestyle.

Intelligence and salivary testosterone levels in prepubertal children

BACKGROUND

Hormones are one of the regulatory systems influencing brain-cognition interactions and subsequent emotions and behavior in humans and animals. Sex hormones have been found to influence brain structures prenatally, so as to prepare targeted neuronal circuits for activation during and after puberty. Testosterone is believed to affect cognition and thinking in humans as well as between-sex differences in cognitive abilities.

AIM

The aim of this paper was to investigate associations between testosterone and different levels of intelligence in young prepubertal children of both sexes.

METHODS

Two hundred and eighty four prepubertal children of both sexes between 6 and 9 years of age provided saliva samples. Of these, 107 were intellectually gifted (IQ above 130), 100 children of average intelligence--randomly chosen from general population (IQ between 70 and 130), and 77 children mentally challenged (IQ less than 70).

RESULTS

Our results have revealed the differences in salivary testosterone levels in boys grouped according to IQ, intellectually gifted and mentally challenged boys having lower salivary testosterone levels than their peers characterized by average intelligence proposing the common biological characteristic of minority IQ groups on both ends of the Gauss curve. In girls, no differences in salivary testosterone levels were found among IQ groups.

CONCLUSIONS

Our findings are the first that present the relationship between testosterone and the broad range of general IQ in childhood. The boys of average intelligence had significantly higher testosterone levels than both mentally challenged and intellectually gifted boys, with the latter two groups showing no significant difference between each other. The functional implications of the brain-cognition interactions remain to be fully explored with regard to the internal milieu influencing neural substrate.