Pubertal development in obese children and adolescents

Association between bone age maturity and childhood adiposity

BACKGROUND

Evidence shows that overweight and obesity are associated with advanced bone age (BA).

OBJECTIVE

To analyse the effect of adiposity on BA among Mexican children.

METHODS

This cross-sectional study included 902 children (5-18 years old). Anthropometric measurements, dual-energy X-ray absorptiometry (DXA) and automated hand X-ray-based BA measurements were obtained. BA curves of children stratified by sex and age were created based on nutritional status. We also calculated odds ratios for advanced BA associated with the body mass index (BMI), waist/height ratio and adiposity estimated using DXA (total and truncal fat mass).

RESULTS

Participants with overweight/obesity by BMI (SDS ≥1) advanced earlier in BA than did normal weight participants (6.0 vs. 12.0 years in boys and 6.0 vs. 10.3 in girls, p < 0.01); similarly, participants with a greater body fat percentage (SDS ≥1) exhibited earlier advanced BA (7.5 vs. 10.0 years in boys and 6.0 vs. 9.6 in girls, p < 0.01). Differences were also observed according to the waist/height ratio and truncal fat. Children with a BMI or DXA SDS ≥1 had greater odds of presenting an advanced BA of more than 1 year (OR 1.79-3.55, p < 0.05).

CONCLUSIONS

Increased adiposity in children, mainly in boys, is associated with advanced BA at earlier ages.

Insufficient Bone Mineralization to Sustain Mechanical Load of Weight in Obese Boys: A Cross-Sectional Study

CONTEXT

The increase in bone mineral content (BMC) and density (BMD) measured by dual-energy x-ray absorptiometry (DXA) in obese children may not sustain the mechanical load associated with weight, and the factors influencing bone mineralization are not well known.

OBJECTIVE

We described bone mineralization in boys with overweight/obesity and leanness in relation to body composition.

METHODS

Cross-sectional study in the Pediatric Endocrinology Unit of Angers University Hospital with 249 overweight/obese boys aged 8-18 who underwent DXA and insulin, testosterone, and IGF-1 measurements. Bone mineralization was compared with data from 301 lean boys of similar age and height from NHANES 2011-2015, using the same DXA model. Path analyses were performed to evaluate factors associated with total body less head (TBLH) BMC.

RESULTS

The mean age- and height-adjusted difference in TBLH BMC between obese and lean boys was 241 ± 20 g/cm2. Each 1 kg/m2 increase in BMI was associated with +39 ± 6 g of TBLH BMC in lean subjects vs + 25 ± 3 g in obese subjects (P < .05). Each 1 kg/m2 increase in lean BMI (LBMI) was associated with +78 ± 5 g of TBLH BMC in lean and obese boys, and each 1 kg/m2 increase in fat mass index (FMI) was associated with a decrease of 9 ± 3 g of TBLH BMC. The TBLH BMC was directly positively influenced by LBMI and indirectly and positively influenced by IGF-1, testosterone, and insulin (mediated through height and LBMI). FMI indirectly influenced TBLH BMC, both positively through LBMI and negatively through its negative impact on IGF-1 and testosterone.

CONCLUSION

The increase in bone mineralization in obese children does not adapt to the increase in body mass.

BMI increase during early childhood in boys with cystic fibrosis and early adrenarche

BACKGROUND

Increase in body mass index (BMI) in early childhood (1-6 years) was found to be a contributing factor for impaired final height in boys with Cystic Fibrosis (CF). Early adrenarche (before age 9 years in boys) may contribute to an impaired final height by triggering an early acceleration of bone age resulting in a compromised growth spurt during puberty. We aimed to analyze the timing of adrenarche in boys with CF and to associate BMI increase in early childhood to timing of adrenarche.

METHODS

Boys with CF, aged 8-9 years, visiting the CF expertize center Utrecht were included. Since 2018, anthropomorphic, pubertal and endocrine data were collected. Early adrenarche in boys was defined as a dehydroepiandrosterone sulfate (DHEAS) ≥ 1 µmol/L before the age of 9 years.

RESULTS

Thirteen boys (mean age 8.55 ± 0.27 years) were enrolled. The median (IQR) DHEAS-level was 1.3 µmol/L (0.71-2.40). Eight boys (61.5%) had an early rise in DHEAS-levels ≥ 1 µmol/L. Mean increase in BMI Z-score between 1 and 6 years of age (ΔBMI1-6 ) was -0.07 ± 0.86. A significant correlation was found between ΔBMI1-6 and DHEAS-levels at the age of 8-9 years (r = 0.624, p = 0.040). In five boys with early rise in DHEAS, accelerated bone age was found (average 1.55 ± 0.96 years).

CONCLUSION

In this small cohort, 61.5% of boys with CF between 8 and 9 years had an early rise of DHEAS, which was correlated to ΔBMI1 -6 between 1 and 6 years. Early adrenarche may be caused by ΔBMI1 -6 .

Beyond the Metabolic Syndrome: Non-Obvious Complications of Obesity in Children

Obesity is currently one of the most significant public health challenges worldwide due to the continuous increase in obesity rates among children, especially younger children. Complications related to obesity, including serious ones, are increasingly being diagnosed in younger children. A search was performed from January 2023 to September 2023 using the PubMed, Cochrane Library, Science Direct, MEDLINE, and EBSCO databases. The focus was on English-language meta-analyses, systematic reviews, randomized clinical trials, and observational studies worldwide. Four main topics were defined as follows: disorders of glucose metabolism; liver disease associated with childhood obesity; the relationship between respiratory disorders and obesity in children; and the effects of obesity on the hypothalamic-pituitary-gonadal axis and puberty. Understanding potential complications and their underlying mechanisms can expedite the diagnostic process and enhance the effectiveness of treatment. We aspire that this study will bring insight into the often-overlooked complications associated with obesity.

Maternal cafeteria diet influences kisspeptin (Kiss1), kisspeptin receptor(Gpr54), and sirtuin (Sirt1) genes, hormonal and metabolic profiles, and reproductive functions in rat offspring in a sex-specific manner†

Kisspeptin (KP, encoded by Kiss1, binding to the Gpr54 receptor) is a neuropeptide conveying information on the metabolic status to the hypothalamic-pituitary-gonadal axis. KP acts together with dynorphin A (encoded by Pdyn) and neurokinin B (encoded by Tac2) to regulate reproduction. KP is crucial for the onset of puberty and is under the control of sirtuin (encoded by Sirt1). We hypothesize that the maternal cafeteria (CAF) diet has adverse effects on the offspring's hormonal, metabolic, and reproductive functions due to sex-specific alterations in the expression of Kiss1, Gpr54, Pdyn, Tac2, and Sirt1 in the hypothalamus, and Kiss1, Gpr54, and Sirt1 in the liver. Rats were fed a CAF diet before pregnancy, during pregnancy, and during lactation. The vaginal opening was monitored. Offspring were sacrificed in three age points: PND 30, PND 35, and PND 60 (females) and PND 40, PND 45, and PND 60 (males). Their metabolic and hormonal status was assessed. mRNA for Kiss1, Gpr54, Pdyn, Tac2, and Sirt1 were measured by real-time PCR in the hypothalamus and/or livers. We found that CAF offspring had lower weight and altered body composition; increased cholesterol and triglyceride levels, sex-specific changes in glucose and insulin levels; sex-dependent changes in Sirt1/Kiss1 mRNA ratio in the hypothalamus; sex-specific alterations in Kiss1 and Sirt1 mRNA in the liver with more diversity in males; and a delayed puberty onset in females. We concluded that the mother's CAF diet leads to sex-specific alterations in metabolic and reproductive outcomes via Kiss1/Gpr54 and Sirt1 systems in offspring.

Associations of Obesity With Growth and Puberty in Children: A Cross-Sectional Study in Fuzhou, China

Objectives: To investigate the associations of obesity with growth and puberty in children. Methods: From November 2017 to December 2019, height, weight, and Tanner stages of 26,879 children aged 3-18 years in Fuzhou, China were assessed. Results: The obese group was significantly taller than the non-obese group after age 4 years for both genders, yet there was no significant difference in height between obese and non-obese group after 15.5 years old for boys and 12.5 years old for girls. The inflection points of significant growth deceleration in obese and non-obese groups were 14.4 and 14.6 years old for boys, and 11.8 and 12.8 years old for girls, respectively. The proportions of testicular development in boys with obesity and non-obesity were 7.96% and 5.08% at 8.5-8.9 years old, respectively, while the proportions of breast development in girls were 17.19% and 3.22% at age 7.5-7.9 years old, respectively. Conclusion: Children with obesity were taller in early childhood, earlier onset of puberty and earlier cessation of growth than children with non-obesity of the same age. However, there was sex dimorphism on the effect of obesity on the incidence of precocious puberty.

Prepubertal BMI, pubertal growth patterns, and long-term BMI: Results from a longitudinal analysis in Chinese children and adolescents from 2005 to 2016

OBJECTIVE

To assess the effects of prepubertal BMI on pubertal growth patterns, and the influence of prepubertal BMI and pubertal growth patterns on long-term BMI among Chinese children and adolescents.

METHODS

A total of 9606 individuals aged between 7 and 18 years from longitudinal surveys in Zhongshan city of China from 2005 to 2016 were enrolled. Age at peak height velocity (APHV) and peak height velocity (PHV) were estimated using Super-Imposition by Translation and Rotation (SITAR) model. Associations between prepubertal BMI, APHV, PHV, and long-term overweight and obesity were assessed by linear regression and multinominal logistic regression. Scatter plots were elaborated to show the associations between prepubertal BMI and pubertal growth patterns according to prepubertal BMI categories.

RESULTS

Prepubertal BMI Z-Score was positively correlated with long-term BMI Z-Score, and negatively correlated with APHV in both sexes. In addition, there was a negative association between prepubertal BMI Z-Score and PHV in boys. With 1-year decrease in APHV, risk of long-term underweight decreased by 92%, while overweight increased by 33% in boys. Corresponding risk of long-term underweight and overweight for girls decreased by 42% and increased by 20%, respectively.

CONCLUSION

High prepubertal BMI levels were associated with earlier APHV and lower PHV, and the early onset of pubertal development could increase the risks of long-term overweight and obesity at 17-18 years of age both in boys and girls. Such evidence emphasized the importance of reducing prepubertal obesity risks combined with appropriate pubertal development timing, including later APHV and higher PHV, so as to prevent the obesity and related cardiovascular diseases in adulthood.

The promise of new anti-obesity therapies arising from knowledge of genetic obesity traits

Obesity is a multifactorial and complex disease that often manifests in early childhood with a lifelong burden. Polygenic and monogenic obesity are driven by the interaction between genetic predisposition and environmental factors. Polygenic variants are frequent and confer small effect sizes. Rare monogenic obesity syndromes are caused by defined pathogenic variants in single genes with large effect sizes. Most of these genes are involved in the central nervous regulation of body weight; for example, genes of the leptin-melanocortin pathway. Clinically, patients with monogenic obesity present with impaired satiety, hyperphagia and pronounced food-seeking behaviour in early childhood, which leads to severe early-onset obesity. With the advent of novel pharmacological treatment options emerging for monogenic obesity syndromes that target the central melanocortin pathway, genetic testing is recommended for patients with rapid weight gain in infancy and additional clinical suggestive features. Likewise, patients with obesity associated with hypothalamic damage or other forms of syndromic obesity involving energy regulatory circuits could benefit from these novel pharmacological treatment options. Early identification of patients affected by syndromic obesity will lead to appropriate treatment, thereby preventing the development of obesity sequelae, avoiding failure of conservative treatment approaches and alleviating stigmatization of patients and their families.

Relationship between sexual maturation and anthropometric and blood pressure indicators in teenagers

This study aimed to investigate the relationship between sexual maturation and anthropometric and blood pressure indicators in teenagers. This was a population-based cross-sectional study, conducted with 345 teenagers, aged 10 to 19 years, between 2018 and 2020. In this study, data referent to sociodemographic and anthropometric variables, blood pressure, and sexual maturation were collected. The data analysis was performed by applying the Principle Component Analysis (PCA), which generated three components and then tested the correlation between sexual maturation and the generated components. Most of the teenagers were female (53%), normotensive (66.1%), and with a normal weight (73%). A positive correlation was found between breast development and component 1 and component 2, as well as a negative correlation between the breasts and component 3. In the boys, the development of genitals and pubic hair was positively correlated with component 2 and inversely correlated with component 3. It could therefore be concluded that there is a relationship between sexual maturation and the anthropometric and blood pressure indicators, which proved to be representative variables for cardiovascular risk in teenagers, even if not in their entirety.

Relationship between sexual maturation and anthropometric and blood pressure indicators in teenagers

Abstract This study aimed to investigate the relationship between sexual maturation and anthropometric and blood pressure indicators in teenagers. This was a population-based cross-sectional study, conducted with 345 teenagers, aged 10 to 19 years, between 2018 and 2020. In this study, data referent to sociodemographic and anthropometric variables, blood pressure, and sexual maturation were collected. The data analysis was performed by applying the Principle Component Analysis (PCA), which generated three components and then tested the correlation between sexual maturation and the generated components. Most of the teenagers were female (53%), normotensive (66.1%), and with a normal weight (73%). A positive correlation was found between breast development and component 1 and component 2, as well as a negative correlation between the breasts and component 3. In the boys, the development of genitals and pubic hair was positively correlated with component 2 and inversely correlated with component 3. It could therefore be concluded that there is a relationship between sexual maturation and the anthropometric and blood pressure indicators, which proved to be representative variables for cardiovascular risk in teenagers, even if not in their entirety.

Earlier Age at Menarche Is Associated with Body Fat and Negative Body Image in Adult Life

Earlier age at menarche is one of the well-documented antecedents of a range of adverse health effects in adulthood including obesity and psychopathological effects. Yet, few researchers have examined the potential association of menarcheal age with body fat distribution, self-perception, and body image. We retrospectively tested a sample (N = 392) of adult women (18-80 years) to examine the associations of age at menarche with body composition and body image indices. Analyses of covariance and multivariable logistic and linear regression were fitted adjusting for age, physical activity level, smoking, and alcohol consumption. Further adjustment was made for body mass index (BMI) and percentage of fat mass. Earlier age at menarche was associated with slightly increased odds of higher BMI and abdominal fat percentage; of note is the positive correlation with lower body composition indices including hip and calf circumferences/skinfolds. Additionally, earlier age at menarche was associated with higher scores in the negative body image scales, namely overweight preoccupation and self-classified weight, whereas lower risks were found for higher scores in the positive body image scales, namely appearance evaluation and body area satisfaction scales. These findings remained significant after correcting for body fat percentage. The present results showed positive associations for earlier age at menarche with gross indices of obesity with the associations mainly confined to distribution of body fat in the lower part of the body, whereas an increased risk of negative body image was also found. Future research could refine our understanding of the biological and psychological mechanisms underlying these associations.

Lower Circulating Sertoli and Leydig Cell Hormone Levels During Puberty in Obese Boys: A Cross-sectional Study

CONTEXT

Alterations in semen characteristics and circulating Sertoli and Leydig cell hormones have been described in obese male adults. Whether hormonal alterations occur before adulthood has not been fully evaluated.

OBJECTIVE

We describe circulating Sertoli and Leydig cell hormone levels in overweight-obese (ow/ob) boys through childhood and adolescence in a cross-sectional study.

METHODS

Monocentric study in the Pediatric Endocrinology Unit of Angers University Hospital. Three hundred and fifty-one obese and overweight boys aged 5-19 years underwent physical examination, dual-energy X-ray absorptiometry for body composition, oral glucose tolerance test on insulin and glucose, and measurements of follicle-stimulating hormone, luteinizing hormone, anti-Müllerian hormone (AMH), inhibin B, testosterone, and estradiol. Hormonal levels were compared with normative data obtained from 652 healthy nonoverweight nonobese boys of similar age or Tanner stage.

RESULTS

Median inhibin B and testosterone levels during puberty were significantly lower in ow/ob than in healthy boys (1) from age >12 years and thereafter for inhibin B, and (2) from age >14 years and thereafter for testosterone. At Tanner stages 4 and 5, 26%, 31%, and 18% of inhibin B, testosterone, and AMH values were below the 5th percentile in ow/ob subjects (P < .01). In multiple regression analyses, estradiol and total bone mineral density Z-score were negative predictors of inhibin B, fat mass percentage was a negative predictor of testosterone, and insulin was a negative predictor of AMH.

CONCLUSION

Lower Sertoli and Leydig cell hormone levels during puberty were observed in the ow/ob boys.

Pelvic and breast ultrasound abnormalities and associated metabolic disturbances in girls with premature pubarche due to adrenarche

OBJECTIVE

Premature adrenarche (PA) has been suggested as a risk factor for future health problems, such as metabolic syndrome and early menarche. However, not all girls with PA have these features and it is not certain who will develop them. We propose that these abnormalities might be identified earlier, even before they are visible.

DESIGN

Case-control study.

SETTING

Tertiary care hospital.

PARTICIPANTS

Forty-eight girls with premature pubarche due to PA and age (mean age 7.6 ± 1.0 years), weight, body mass index (BMI), birth weight and gestational age-matched 49 girls with no palpable breast tissue.

MEASUREMENTS

Early pubertal pelvic and breast ultrasonographic changes and their associations with obesity and metabolic parameters were evaluated. Blood samples were collected, breast and pelvic ultrasound examinations were performed and bone ages were assessed.

RESULTS

Girls with PA were taller and their bone ages were higher (p = .049 and p = .005). Fasting blood glucose, insulin, triglycerides, high-density lipoprotein and low-density lipoprotein cholesterol were not different between the groups. Luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol were not different either. Ultrasonography revealed breast gland tissue in 30% of girls with PA and 5% of controls (p = .006). Uterine volume and endometrial thickness were higher in girls with PA (p = .03 and p = .04). Endometrial thickness was positively associated with serum insulin levels in the whole study group and after adjusting for age, diagnosis, BMI, mean ovarian volume and LH, FSH, estradiol levels, this association remained with a borderline p-value (R2  = 0.486, p = .050).

CONCLUSIONS

We found early changes in uterus and breast glands of girls with PA and endometrial thickness was positively associated with insulin levels.

Overweight/Obesity in Childhood and the Risk of Early Puberty: A Systematic Review and Meta-Analysis

PURPOSE

To determine the relationship between childhood overweight/obesity and early puberty in both boys and girls. Specifically, this is the first time to conduct a meta-analysis of the relationship between childhood overweight/obesity and early puberty in boys.

METHODS

Relevant studies were identified from PubMed, Web of Science, and EMBASE searches. The exposure of interest was overweight/obesity in childhood. Childhood was defined internationally as the age range of 0-18 years. The overall risk estimates were pooled using random effects models. Subgroup and sensitivity analyses were performed to explore possible sources of heterogeneity and to assess the robustness of the results.

RESULTS

A total of 10 studies involving 13,338 girls and 12,796 boys were included. Results showed that childhood overweight/obesity were associated with a significantly higher risk of early puberty in girls [odds ratio (OR): 2.22, 95% CI: 1.65-2.99]. Although without statistical significance, a higher risk of early puberty was also found in boys who were overweight/obese in childhood (OR: 1.29, 95% CI: 0.98-1.70). Heterogeneity in the risk estimates of early puberty was partially explained by study design, sample size, follow-up duration, definitions of early puberty and confounders controlled. Sensitivity analyses validated the robustness of the findings.

CONCLUSIONS

Our findings showed that for girls the associate between overweight/obesity and early puberty is definite or strong whereas for males, such an association is possible, prompting that future studies need to further explore the possible relationship between overweight/obesity and early puberty in boys.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021264649, PROSPERO CRD42021264649.

Growth and adrenarche: findings from the CATS observational study

BACKGROUND

There is increasing evidence that patterns of pubertal maturation are associated with different patterns of health risk. This study aimed to explore the associations between anthropometric measures and salivary androgen concentrations in pre-adolescent children.

METHODS

We analysed a stratified random sample (N=1151) of pupils aged 8-9 years old from 43 primary schools in Melbourne, Australia from the Childhood to Adolescence Transition Study. Saliva samples were assayed for dehydroepiandrosterone (DHEA), DHEA-sulfate and testosterone. Anthropometric measures included height, weight, body mass index (BMI) and waist circumference. Associations between (1) anthropometric measures and each androgen, and (2) hormone status with obesity and parental report of pubertal development were investigated using linear regression modelling with general estimating equations.

RESULTS

Greater height, weight, BMI and waist circumference were positively associated with higher androgen concentrations, after adjusting for sex and socioeconomic status. Being overweight or obese was associated with higher testosterone and DHEA concentrations compared with the normal BMI category. Those who were obese were more likely (OR=2.7, 95% CI 1.61 to 4.43, p<0.001) to be in the top tertile of age-adjusted androgen status in both sexes.

CONCLUSION

This study provides clear evidence for an association between obesity and higher androgen levels in mid-childhood. The adrenal transition may be a critical time period for weight management intervention strategies in order to manage the risk for metabolic problems in later life for high-risk individuals.

Linear growth and puberty in childhood obesity: what is new?

Pediatric obesity is a growing and alarming global health problem and represents an important determinant of morbidity. Since nutrition plays an important role in regulating growth and development, the excess weight gain related to overnutrition can affect growth patterns, bone maturation and pubertal development. The purpose of this review is to summarize the current knowledge about the effect of primary obesity on linear growth and pubertal development in children and adolescents. Evidences about regulatory hormones and adipokines that may be involved in the physiology of childhood growth in the context of obesity were also discussed. The most recent literature confirms previous studies indicating that linear growth is accelerated (mainly due to longer trunks rather than longer legs) and bone age is advanced in prepubertal children with obesity, while there is a reduction of pubertal height gain and attainment of normal adult height. Conflicting results are reported on the timing of puberty, specifically in boys. Indeed, previous studies suggested earlier onset of puberty in obese girls and overweight boys, and a delayed puberty in obese boys. Conversely, the most recent studies show more consistently an earlier onset and completion of pubertal development also in boys with obesity. Considering the false belief of health associated with transient taller stature in children and the adverse outcomes related to early puberty, interventions on diet and physical activity are urgently needed to tackle the epidemics of childhood obesity in public health and clinical setting.

The pubertal growth spurt is diminished in children with severe obesity

BACKGROUND

At the population level, there is a negative linear correlation between childhood body mass index (BMI) and pubertal height gain. However, in children with obesity, there are no studies showing whether the severity of obesity affects pubertal height gain. Moreover, how obesity in childhood affects pubertal timing is controversial, especially in boys. We aimed to investigate the impact of severe obesity in childhood on the pubertal growth spurt in both sexes.

METHODS

The study group consisted of 68 patients (32 boys) with childhood onset obesity followed in a Spanish university hospital. The QEPS growth model was used to calculate pubertal growth function estimates for each individual. The highest individual prepubertal BMI SDS value was related to the age at onset of pubertal growth and pubertal height gain. Results were compared to analyses from individuals in a community-based setting (n = 1901) with different weight status.

RESULTS

A higher peak BMI in childhood was associated with less specific pubertal height gain in children with moderate-to-extreme obesity. For boys, the higher the BMI, the earlier the onset of pubertal growth. For girls with obesity, this correlation was not linear.

CONCLUSIONS

Obesity in childhood impairs the pubertal growth spurt in a severity-related fashion.

IMPACT

The higher the BMI in childhood, the lower the pubertal height gain in children with moderate-to-extreme obesity. For boys with obesity, the higher the BMI, the earlier the onset of pubertal growth. The results contribute to the research field of how weight status in childhood is related to pubertal timing and pubertal growth. The results have implications for understanding how childhood obesity is related to further growth.

Night-restricted feeding improves locomotor activity rhythm and modulates nutrient utilization to accelerate growth in rabbits

An unfavorable lifestyle disrupts the circadian rhythm, leading to metabolic dysfunction in adult humans and animals. Increasing evidence suggests that night-restricted feeding (NRF) can effectively prevent ectopic fat deposition caused by circadian rhythm disruption, and reduce the risk of metabolic diseases. However, previous studies have mainly focused on the prevention of obesity in adults by regulating dietary patterns, whereas limited attention has been paid to the effect of NRF on metabolism during growth and development. Here, we used weaning rabbits as models and found that NRF increased body weight gain without increasing feed intake, and promoted insulin-mediated protein synthesis through the mTOR/S6K pathway and muscle formation by upregulating MYOG. NRF improved the circadian clock, promoted PDH-regulated glycolysis and CPT1B-regulated fatty-acid β-oxidation, and reduced fat content in the serum and muscles. In addition, NRF-induced body temperature oscillation might be partly responsible for the improvement in the circadian clock and insulin sensitivity. Time-restricted feeding could be used as a nondrug intervention to prevent obesity and accelerate growth in adolescents.

Obesity Is Associated with Earlier Pubertal Onset in Boys

CONTEXT

Pubertal timing in boys is associated with body mass index (BMI). Studies consistently report an inverse correlation of BMI and pubertal timing within the normal BMI range. However, observations in obese boys are conflicting with different studies reporting either early or delayed pubertal onset in obese boys.

OBJECTIVE

We aimed to assess the association of male pubertal timing with age-specific BMI (zBMI) in obese boys.

DESIGN, SETTING, AND PARTICIPANTS

A total of 218 obese boys (zBMI > +2SD, with a median age at baseline of 10.8 years (range 4.2-17.0), were recruited as part of a prospective outpatient childhood obesity intervention program at Nordsjællands Hospital, Hillerød, Denmark, between 2009 and 2017. Serving as controls, we included 660 healthy boys participating in the population-based COPENHAGEN Puberty Study (-2SD < zBMI ≤ +2SD, 2006-2014). Subanalyses were performed on overweight controls (+1SD < zBMI ≤ +2SD). The clinical assessment of pubertal development by Tanner staging, including testis volume using a Prader's orchidometer, was performed by trained physicians. The timing of pubertal milestones was estimated by probit analyses.

MAIN OUTCOME MEASURES

Timing of testicular volume ≥ 4 mL, genital stage ≥ 2, and pubarche.

RESULTS

The mean (95% confidence interval [CI]) age of onset of pubertal event in obese boys was as follows: testicular volume ≥ 4 mL, 11.3 years (11.0-11.6); genital stage ≥ 2, 11.6 yrs (11.3-11.9); and pubarche, 11.9 years (11.5-12.3). Testicular volume ≥ 4 mL occurred significantly earlier in obese boys compared to controls (-2SD < zBMI ≤ +2SD) (P = 0.01). We did not observe significant differences for either the timing of pubarche nor the genital stage ≥ 2 (P = 0.06 and P = 0.94, respectively).

CONCLUSIONS

We demonstrate that testicular enlargement in obese boys occurs significantly earlier compared to a population-based normal-weight reference cohort.

Long-term effects of GnRH agonist treatment on body mass index in girls with idiopathic central precocious puberty

Introduction Studies evaluating effects of gonadotropin-releasing hormone agonist (GnRHa) on weight and body-mass-index (BMI) in girls with idiopathic central precocious puberty (iCPP) include short-term effects. The aim of this study is to investigate changes in BMI during and 2 years after completion of GnRHa to determine the factors that may impact BMI in girls with iCPP. Methods Medical files of 138 girls who completed GnRHa were evaluated. All patients had weight and height measurements at the beginning and end of treatment, and 111 patients had anthropometric measurements 2 years after the completion of treatment. Results In the beginning, 82 (59.4%) had normal weight (NW), 42 (30.4%) were overweight (OW), and 14 (10.2%) were obese (OB). Analysis of BMI-standard deviation score (SDS) in the whole group showed an overall increase during GnRHa treatment (0.92 ± 0.74 vs. 1.20 ± 0.51, p < 0.001). Changes in BMI-SDS (ΔBMI-SDS) during GnRHa differed between NW and OW/OB (0.45 ± 0.31 vs. 0.03 ± 0.20, p < 0.001). BMI-SDSs of both groups returned to baseline scores (or initial levels) 2 years after the completion of treatment. Two factors affecting ΔBMI-SDS in multiple linear regression analyses were baseline BMI and Δheight-SDS, both correlated negatively with ΔBMI-SDS. Conclusions The present study is one of the studies evaluating BMI change over a long period of time in girls with CPP. Although BMI-SDS increased during GnRHa in NW girls, it was reversible in follow-up after treatment. However, BMI-SDS did not change during and in follow-up in OW/OB girls. Conserving BMI-SDS in OW/OB girls may be related to the fact that weight management programs were recommended for these patients. Dietary recommendations should be provided for children with NW who undergo GnRHa, as is the case for OW patients.

Sex Differences in Effects of Obesity on Reproductive Hormones and Glucose Metabolism in Early Puberty

CONTEXT

Obesity is known to impact reproductive function in adults, but little is known about its effects on reproductive hormones during puberty.

OBJECTIVE

To assess sex differences in effects of obesity on reproductive hormones and their relation to insulin sensitivity and secretion.

DESIGN

Cross-sectional study including anthropometrics, serum and urine reproductive hormone concentrations, and intravenous glucose tolerance testing (IVGTT) to assess acute insulin response to glucose (AIRg), and insulin sensitivity (Si).

SETTING

Outpatient academic clinical research center.

PATIENTS

Girls (52%) and boys (48%) who were normal weight (NW; n = 51, BMI-Z score = -0.11 ± 0.77, age = 11.5 ± 1.7 years) and obese (n = 53, BMI-Z score = 2.22 ± 0.33, age = 10.9 ± 1.5 years), Tanner stage 2 to 3.

RESULTS

Boys with obesity had lower total testosterone (P < 0.0001) and higher concentrations of the urinary estradiol metabolite, E1c, (P = 0.046) than boys with NW. Girls with obesity had higher free androgen index (FAI; P = 0.03) than NW girls. Both boys and girls with obesity had lower sex hormone-binding globulin (SHBG; P < 0.0001) than NW. AIRg was inversely related to SHBG in boys (R = 0.6, P < 0.0001) and girls (R = 0.53, P = 0.0001). Si correlated with higher SHBG in boys (R2 = 0.67, P < 0.0001) and girls (R = 0.5, P = 0.0003), higher total testosterone for boys (R = 0.39, P = 0.01), and lower FAI for girls (R = -0.2, P = 0.04).

CONCLUSION

Youth with obesity have lower SHBG than youth with NW, but obesity has differential effects on reproductive hormones in girls versus boys, which are apparent early in puberty. Ongoing longitudinal studies will evaluate the impact of obesity on reproductive hormones in girls and boys as puberty progresses.

Obesity in Childhood and Adolescence, Genetic Factors

Obesity and excess weight are a pandemic phenomenon in the modern world. Childhood and adolescent obesity often ends up in obesity in adults. The costs of obesity and its consequences are staggering for any society, crippling for countries in development. Childhood obesity is also widespread in Macedonia. Metabolic syndrome, dyslipidemia and carbohydrate intolerance are found in significant numbers. Parents and grandparents are often obese. Some of the children are either dysmorphic, or slightly retarded. We have already described patients with Prader-Willi syndrome, Bardet-Biedl syndrome or WAGR syndrome. A genetic screening for mutations in monogenic obesity in children with early, rapid-onset or severe obesity, severe hyperphagia, hypogonadism, intestinal dysfunction, hypopigmentation of hair and skin, postprandial hypoglycaemia, diabetes insipidus, abnormal leptin level and coexistence of lean and obese siblings in the family discovers many genetic forms of obesity. There are about 30 monogenic forms of obesity. In addition, obesity is different in ethnic groups, and the types of monogenic obesity differ. In brief, an increasing number of genes and genetic mechanisms in children continue to be discovered. This sheds new light on the molecular mechanisms of obesity and potentially gives a target for new forms of treatment.

Obesity and Hypogonadism-A Narrative Review Highlighting the Need for High-Quality Data in Adolescents

The prevalence of obesity continues to rise in adult and pediatric populations throughout the world. Obesity has a direct impact on all organ systems, including the reproductive system. This review summarizes current knowledge about the effects of obesity on the male reproductive system across age, highlighting the need for more data in children and adolescents. Male hypogonadism is commonly seen in patients with obesity and affects the onset, duration, and progression of puberty. Different pathophysiologic mechanisms include increased peripheral conversion of testosterone to estrone and increased inflammation due to increased fat, both of which lead to suppression of the hypothalamic-pituitary-gonadotropin (HPG) axis and delayed development of secondary sexual characteristics in adolescent males. Evaluation of the HPG axis in obesity includes a thorough history to exclude other causes of hypogonadism and syndromic associations. Evaluation should also include investigating the complications of low testosterone, including increased visceral fat, decreased bone density, cardiovascular disease risk, and impaired mood and cognition, among others. The mainstay of treatment is weight reduction, but medications such as testosterone and clomiphene citrate used in adults, remain scarcely used in adolescents. Male hypogonadism associated with obesity is common and providers who care for adolescents and young adults with obesity should be aware of its impact and management.

The influence of treatment, age at onset, and metabolic control on height in children and adolescents with type 1 diabetes-A SWEET collaborative study

OBJECTIVE

To describe the association between height, demographics, and treatment in youths with type 1 diabetes participating in an international network for pediatric diabetes centers (SWEET).

METHODS

Data were collected from 55 centers with documented patients' height. All subjects below 20 years of age, diabetes duration >1 year, and without celiac disease were included. World Health Organization growth charts were used to calculate height and body mass index z-scores. Multiple hierarchic regression models adjusting for known confounders were applied.

RESULTS

Data on 22 941 subjects (51.8% male) were analyzed with a median and interquartile range for age 14.8 years (11.2, 17.6), diabetes duration 5.6 years (3.1, 8.9), and height z-score 0.34 (-0.37, 1.03). Children were taller in the youngest age groups: adjusted height z-scores of 0.31 (±0.06) and 0.39 (±0.06), respectively; with shorter diabetes duration (<2 years: 0.36 [±0.06]; 2-<5 years: 0.34 [±0.06]; ≥5 years: 0.21 [±0.06]) and if they were pump users: 0.35 ± 0.05 vs 0.25 ± 0.05 (>three injections/day and 0.19 ± 0.06 [0-3 injections daily]), respectively. High hemoglobin A1c (HbA1c) and low to normal weight were associated with a lower height z-score. Trends were identical in all models except for gender. No gender differences were found except in the final height model where females exhibited higher z-score than males.

CONCLUSION

For youths treated at centers offering modern diabetes management, major growth disturbances are virtually eliminated. For children with a young age at onset, high HbA1c, injections, and/or non-intensive diabetes, treatment still requires attention in order to attain normal growth.

Long-term follow-up of gonadal dysfunction in morbidly obese adolescent boys after bariatric surgery

Background Elevated body mass index (BMI) is associated with hypogonadism in men but this is not well described in adolescents. The aim is to evaluate gonadal dysfunction and the effects of weight loss after gastric banding in obese adolescent boys. Methods Thirty-seven of 54 boys (age 16.2±1.2 years, mean BMI 48.2 kg/m2) enrolled at the Center for Adolescent Bariatric Surgery at Columbia University Medical Center had low total testosterone for Tanner 5 <350 ng/dL. Sixteen had long-term hormonal data for analysis at baseline (T0), 1 year (T1) and 2 years (T2) post-surgery. T-tests, chi-squared (χ2) tests, correlation and linear mixed models were performed. Results At T0, the hypogonadal group had higher systolic blood pressure (SBP) (75th vs. 57th percentile, p=0.02), fasting insulin (19 vs. 9 μIU/mL, p=0.0008) and homeostatic index of insulin resistance (HOMA-IR) (4.2 vs. 1.9, p=0.009) compared to control group. Total testosterone was negatively correlated with fasting insulin and HOMA-IR. In the long-term analysis, BMI, weight, waist circumference (WC), and % excess weight decreased at T1 and T2 compared to T0. Mean total testosterone at T0, T1 and T2 were 268, 304 and 368 ng/dL, respectively (p=0.07). There was a statistically significant negative correlation between BMI and testosterone after 2 years (r=-0.81, p=0.003). Conclusions Low testosterone levels but unaltered gonadotropins are common in this group and associated with insulin resistance. While a significant increase in testosterone was not found over time, the negative relationship between BMI and testosterone persisted, suggesting there may be an optimal threshold for testosterone production with respect to BMI. Long-term studies are needed.

Testicular Function and Bone in Young Men with Severe Childhood-Onset Obesity

BACKGROUND

Previous studies suggest increased risk for hypoandrogenism and fractures in men with obesity. We aimed to describe the effects of severe childhood-onset obesity on the cross talk between metabolic state, testes, and skeleton at late puberty.

METHODS

A cohort of adolescent and young adult males with severe childhood-onset obesity (n = 21, mean age 18.5 years) and an age-matched control group were assessed for testicular hormones and X-ray absorptiometry-derived bone mass.

RESULTS

Current median body mass indexes for the obese and control subjects were 37.4 and 22.9. Severe early-onset obesity manifested with lower free testosterone (median [interquartile range] 244 [194-332] vs. 403 [293-463] pmol/L, p = 0.002). Lower insulin-like 3 (1.02 [0.82-1.23] vs. 1.22 [1.01-1.46] ng/mL, p = 0.045) and lower ratio of testosterone to luteinizing hormone (2.81 [1.96-3.98] vs. 4.10 [3.03-5.83] nmol/IU, p = 0.008) suggested disrupted Leydig cell function. The degree of current obesity inversely correlated with free testosterone (τ = -0.516, p = 0.003), which in turn correlated positively with bone area at all measurement sites in males with childhood-onset obesity.

CONCLUSIONS

Severe childhood-onset obesity is associated with impaired Leydig cell function in young men and lower free testosterone may contribute to impaired skeletal characteristics.

The Impact of Adolescent Obesity on Adult Height

BACKGROUND

Childhood obesity is a major health concern. Excess adiposity during childhood affects growth and puberty. Our aim was to assess whether genetic adult height is compromised in adolescents with obesity.

METHODS

In a retrospective study of 190 obese patients followed at our Pediatric Endocrinology Institute, adult height and delta height (the difference between adult height and mid-parental height) were compared to those of 150 healthy age-matched normal-weight controls. Review of medical files yielded the relevant clinical and anthropometric data of patients, controls, and parents.

RESULTS

Of the 190 obese adolescents, 150 were morbidly obese. The median adult height of morbidly obese males was 174.3 cm, of obese males 174 cm, and of normal-weight males 176 cm (p = 0.025). Delta height of morbidly obese males was -0.5 cm, of obese males -0.8 cm, and of normal-weight males, 3 cm (p < 0.0001). The median adult height of morbidly obese females was 161.3 cm, of obese females 162.8 cm, and of normal-weight females 162 cm (p = 0.37). Delta height of morbidly obese females was -1.85 cm, of obese females -0.95 cm, and of normal-weight females 0.7 cm (p = 0.019). Impairment of potential genetic height was not associated with obesity-related comorbidities.

CONCLUSION

Adolescents with obesity showed impairment of potential genetic adult height as compared to that of normal-weight subjects.

Putative Effects of Obesity on Linear Growth and Puberty

Childhood obesity is a major public health problem that has grown to epidemic proportions throughout the world. Obesity is influenced by genetic and environmental factors. The nutritional status plays an important role in growth and body weight regulation. Excess adiposity during childhood can affect the process of growth and puberty. Obese children are frequently tall for their age, with accelerated epiphyseal growth plate maturation despite low growth hormone levels. Several regulatory hormones may affect the process of linear growth in the constellation of obesity, as high levels of insulin and leptin are observed in obese children. Leptin can act as a skeletal growth factor, with a direct effect on skeletal growth centers. The finding that overweight children, especially girls, tend to mature earlier than lean children has led to the hypothesis that the degree of body fatness may trigger the neuroendocrine events that lead to the onset of puberty. Leptin receptors have been identified in the hypothalamus, as well as in gonadotrope cells, ovarian follicular cells, and Leydig cells. The increased leptin and androgen levels seen in obese children may be implicated in their earlier onset of puberty and accelerated pubertal growth. This review is focused on the interaction between childhood obesity and growth and pubertal processes.
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Association between Obesity and Puberty Timing: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis examined the associations between obesity and puberty timing based on scientific evidence. Eight electronic databases were searched up to February 2017 for eligible studies, and two reviewers screened the articles and extracted the data independently. A total of 11 cohort studies with 4841 subjects met the inclusion criteria. Compared with the group of normal-weight girls, the obese group had more girls with menarche (RR: 1.87, 95% CI: 1.59–2.19, 2 studies). The number of girls with early puberty was significantly higher in the obese group than the normal weight group (RR: 2.44, 95% CI: 1.32–4.52, 5 studies). However, no differences were detected between girls who were obese or normal weight at age of menarche (WMD: −0.53 years, 95% CI: −1.24–0.19, 2 studies). There is no consistent result in the relationship between obesity and timing of pubertal onset in boys. Obesity may contribute to early onset of puberty in girls, while in boys, there is insufficient data. Given the limited number of cohort studies included in this meta-analysis, high-quality studies with strong markers of puberty onset, as well as standardized criteria for defining obesity are needed.

Determinants of Advanced Bone Age in Childhood Obesity

BACKGROUND

Childhood obesity is associated with advanced bone age (BA). Previous studies suggest that androgens, oestrogens, sex hormone-binding globulin, and insulin are responsible for this phenomenon, but results are contradictory and might be biased by confounders. We aim to elucidate this matter by applying a multivariate approach.

METHOD

We performed a correlation analysis of BA standard deviation score (SDS) with age- and sex-specific SDS for androgens, oestrogens, and with indicators of insulin secretion derived from oral glucose tolerance testing, in a group of obese children. A multivariate analysis was performed to investigate which parameters were independently predictive of BA SDS.

RESULTS

In this cohort (n = 101; mean age 10.9 years; mean BA 11.8 years; mean BMI SDS 3.3), BMI SDS was significantly correlated to BA SDS (r = 0.55, p < 0.001). In a regression analysis in the total cohort (B = 0.27, p < 0.001) as well as in females (B = 0.34, p = 0.042), males (B = 0.31, p = 0.006), and pubertal children (B = 0.32, p = 0.046), dehydroepiandrosterone sulphate (DHEAS) showed a positive, independent association with BA SDS. No association with indicators of insulin secretion was found.

CONCLUSION

BMI SDS is highly correlated to BA SDS in obese children. Increased DHEAS has a central role in advanced BA in obese children.
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Perspectives in Pediatric Pathology, Chapter 22. Testicular Involvement in Systemic Diseases

Normal testicular physiology requires appropriate function of endocrine glands and other tissues. Testicular lesions have been described in disorders involving the hypothalamus-hypophysis, thyroid glands, adrenal glands, pancreas, liver, kidney, and gastrointestinal tract. Testicular abnormalities can also associate with chronic anemia, obesity, and neoplasia. Although many of the disorders that affect the above-mentioned glands and tissues are congenital, acquired lesions may result in hypogonadism in children and adolescents.

The association between skeletal maturation and adrenal androgen levels in obese children and adolescents

PURPOSE

This study aimed to investigate the association between skeletal maturation and adrenal androgen levels in obese children and adolescents.

METHODS

Fifty-three children and adolescents (aged 7-15 years) diagnosed as obese or overweight were investigated. Anthropometric measurements, bone age (BA) determination, serum biochemical analyses, and hormonal measurements were performed. The difference between BA and chronological age (BA-CA, dBACA) was calculated and used to represent the degree of advanced skeletal maturation.

RESULTS

Thirty-one subjects were classified into the obese group and 22 subjects into the overweight group. Insulin resistance as calculated by the homeostasis model assessment of insulin resistance (HOMA-IR) was significantly higher in the obese group than in the overweight group (4.03±2.20 vs. 2.86±1.11, P=0.026). The skeletal maturation of the obese group was advanced, but the dBACA did not differ between the obese and overweight groups statistically (1.43±1.35 vs. 0.91±1.15, P=0.141). Serum dehydroepiandrosterone sulfate (DHEA-S) levels were significantly higher in subjects with dBACA>1 compared to those with dBACA≤1 (104.3±62.2 vs. 59.6±61.0, P=0.014). Correlation analyses demonstrated that dBACA was positively correlated with body mass index standard deviation scores (r=0.35, P=0.010), fasting insulin (r=0.36, P=0.009), HOMA-IR (r=0.30, P=0.031), and insulin-like growth factor-binding protein-3 (r=0.331, P=0.028). In multivariate linear regression analysis, HOMA-IR (P=0.026) and serum DHEA-S (P=0.032) were positively correlated with the degree of advanced skeletal maturation.

CONCLUSION

Advanced skeletal maturation is associated with increased insulin resistance and elevated DHEA-S levels in obese children and adolescents.

Gynecologic and Obstetric Consequences of Obesity in Adolescent Girls

In the past few decades, there has been an overwhelming increase in childhood and adolescent obesity worldwide. Besides the well recognized cardiometabolic complications and other physical conditions associated with obesity, during adolescence, it causes psychological and social distress in a period of life that is already sensitive for a girl. This in turn increases their risk of low self-esteem and depression. Furthermore, obesity diminishes health-related quality of life and years of life. Overweight and obese teenagers are more likely to have gynecologic and obstetric complications, during adolescence and also later in life. Consequences of obese and overweight childhood and adolescence include sexual maturation and reproductive dysfunction, alterations in menstruation, dysmenorrhea, risky sexual behavior, and inefficient use of contraception, polycystic ovary syndrome, bone density abnormalities, macromastia, and an increased risk of breast and endometrial cancer. Obese adolescents are at greater risk of pregnancy and perinatal complications, such as preeclampsia, gestational hypertension and preeclampsia, gestational diabetes mellitus, primary cesarean delivery, and induction of labor, to mention a few. Evidence shows that infants born to obese teenagers are also more likely to have complications including preterm or post-term delivery, small-for-gestational age newborns, macrosomia, meconium aspiration, respiratory distress, and even stillbirth, among others. This comprehensive review focuses on the gynecological and obstetric consequences of obesity in adolescent girls.

Determination of 17OHPreg and DHEAS by LC-MS/MS: Impact of Age, Sex, Pubertal Stage, and BMI on the Δ5 Steroid Pathway

BACKGROUND

Dehydroepiandrosterone sulfate (DHEAS) and 17-hydroxypregnenolone (17OHPreg) are important for understanding the Δ5 pathway (e.g., in adrenarche and obesity). Although mass spectrometry has become the state-of-the-art method for quantifying steroids, there are few comprehensive age-, sex-, and pubertal stage-specific reference ranges for children.

AIMS

To develop a sensitive and reliable ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for simultaneous quantification of DHEAS and 17OHPreg and to establish entire age-, sex- and pubertal stage-specific reference ranges in children.

METHODS

A total of 684 children, 453 (243 female, 210 male) with normal body mass index (BMI; <90th) and 231 (132 female, 99 male) obese subjects (>97th), were categorized into 11 age groups, and age- and Tanner stage (PH)-specific reference ranges were determined.

RESULTS

The limit of detection was 0.05 nmol/L for 17OHPreg and 0.5 nmol/L for DHEAS. Levels of both steroids declined after the neonatal period. Comparisons with RIA assays (Siemens, Munich, Germany) (DHEAS) and an in-house kit (17OHPreg) revealed 0.95 and 0.93, respectively, as coefficients of determination. Although DHEAS-generally higher in boys-increased continuously starting at 3 to 6 years, 17OHPreg remained largely constant. In obese patients, both were significantly elevated, also in part after alignment to Tanner stages (PH).

CONCLUSIONS

UPLC-MS/MS is sensitive and reliable for quantifying DHEAS and 17OHPreg. Our data support differential maturation of CYP17 during adrenarche with successively increasing 17,20-lyase activity but largely constant 17α-hydroxylation activity. Endocrine interpretation of 17OHPreg and DHEAS must consider differential patterns for age, sex, pubertal stage, and BMI.

BMI percentile-for-age overestimates adiposity in early compared with late maturing pubertal children

OBJECTIVE

Early pubertal timing is consistently associated with increased BMI percentile-for-age in pubertal girls, while data in boys are more ambiguous. However, higher BMI percentile-for-age may be a result of the earlier puberty per se rather than vice versa. The aim was to evaluate markers of adiposity in relation to pubertal timing and reproductive hormone levels in healthy pubertal boys and girls.

STUDY DESIGN

Population-based cross-sectional study (The Copenhagen Puberty Study). Eight-hundred and two healthy Caucasian children and adolescents (486 girls) aged 8.5-16.5 years participated. BMI and bioelectric impedance analyses (BIA) were used to estimate adiposity. Clinical pubertal markers (Tanner stages and testicular volume) were evaluated. LH, FSH, estradiol, testosterone, SHBG and IGF1 levels were determined by immunoassays.

RESULTS

In all age groups, higher BMI (all 1 year age-groups, P ≤ 0.041) was found with early compared with late maturation, despite similar BIA-estimated body fat percentage (BIA-BF%). Neither BMI nor BIA-BF% differed for a given stage of maturation. BMI percentile-for-age and prevalence of overweight/obesity were higher in the early compared with late matured pubertal children (all P ≤ 0.038), despite similar BIA-BF%. Pubertal girls with BIA-BF >29% had significantly lower LH and FSH levels compared with normal-weight girls (P ≤ 0.041).

CONCLUSIONS

Early maturational timing was not associated with higher adiposity for a given stage of puberty. Using BMI percentile-for-age overestimated the degree of adiposity in early pubertal compared with late pubertal children.

Androgens and obesity in male adolescents

PURPOSE OF REVIEW

Data on sex steroid levels and pubertal development in obese adolescent boys are scarce and contrasting. The present review summarizes the most recent results obtained with improved methodology to measure low sex steroid levels in children.

RECENT FINDINGS

Obese pubertal boys have lower serum sex hormone-binding globulin and consequently lower total testosterone levels compared to normal-weight peers. However, during pubertal development, free testosterone levels in obese adolescents are not different from controls, indicating preserved androgen exposure as is additionally suggested by similar clinical genital staging (Tanner), serum gonadotropins levels, and serum prostate-specific antigen concentrations compared to nonobese adolescents. In pre and early puberty, total testosterone levels is not decreased, notwithstanding low sex hormone-binding globulin, and free testosterone is slightly increased in obese boys. This may result from increased adrenal activity as revealed by elevated serum androstenedione and dehydroepiandrosterone sulfate. In obese adolescent boys, increased aromatization of testosterone to estradiol tends to accelerate skeletal maturation.

SUMMARY

In obese adolescent boys, free testosterone is a better index than total testosterone levels of androgen status, which is not different from nonobese controls. Increased aromatization of testosterone to estradiol underlies the dissociation between normal clinical sexual maturation and advanced skeletal maturation in the obese adolescent.

Relation of adrenal-derived steroids with bone maturation, mineral density and geometry in healthy prepubertal and early pubertal boys

BACKGROUND

Little is known about the effects of adrenal steroids on skeletal maturation and bone mass acquisition in healthy prepubertal boys.

OBJECTIVE

To study whether adrenal-derived steroids within the physiological range are associated with skeletal maturation, areal and volumetric bone mineral density (aBMD and vBMD) and bone geometry in healthy prepubertal and early pubertal boys.

METHODS

98 healthy prepubertal and early pubertal boys (aged 6-14 y) were studied cross-sectionally. Androstenedione (A) and estrone (E1) were determined by liquid chromatography tandem mass spectrometry and DHEAS was determined by immunoassay. Whole body and lumbar spine aBMD and bone area were determined by dual-energy X-ray absorptiometry. Trabecular (distal site) and cortical (proximal site) vBMD and bone geometry were assessed at the non-dominant forearm and leg using peripheral QCT. Skeletal age was determined by X-ray of the left hand.

RESULTS

Adrenal-derived steroids (DHEAS, A and E1) are positively associated with bone age in prepubertal and early pubertal children, independently of age. There are no associations between the adrenal-derived steroids and the studied parameters of bone size (lumbar spine and whole body bone area, trabecular or cortical area at the radius or tibia, periosteal circumference and cortical thickness at the radius or tibia) or BMD (aBMD or vBMD).

CONCLUSION

In healthy prepubertal and early pubertal boys, serum adrenal-derived steroid levels, are associated with skeletal maturation, independently of age, but not with bone size or (v)BMD. Our data suggest that adrenal derived steroids are not implicated in the accretion of bone mass before puberty in boys.

Sex steroids in relation to sexual and skeletal maturation in obese male adolescents

BACKGROUND

Childhood obesity is associated with an accelerated skeletal maturation. However, data concerning pubertal development and sex steroid levels in obese adolescents are scarce and contrasting.

OBJECTIVES

To study sex steroids in relation to sexual and skeletal maturation and to serum prostate specific antigen (PSA), as a marker of androgen activity, in obese boys from early to late adolescence.

METHODS

Ninety obese boys (aged 10-19 y) at the start of a residential obesity treatment program and 90 age-matched controls were studied cross-sectionally. Pubertal status was assessed according to the Tanner method. Skeletal age was determined by an x-ray of the left hand. Morning concentrations of total testosterone (TT) and estradiol (E2) were measured by liquid chromatography-tandem mass spectrometry, free T (FT) was measured by equilibrium dialysis, and LH, FSH, SHBG, and PSA were measured by immunoassays.

RESULTS

Genital staging was comparable between the obese and nonobese groups, whereas skeletal bone advancement (mean, 1 y) was present in early and midadolescence in the obese males. Although both median SHBG and TT concentrations were significantly (P < .001) lower in obese subjects during mid and late puberty, median FT, LH, FSH, and PSA levels were comparable to those of controls. In contrast, serum E2 concentrations were significantly (P < .001) higher in the obese group at all pubertal stages.

CONCLUSION

Obese boys have lower circulating SHBG and TT, but similar FT concentrations during mid and late puberty in parallel with a normal pubertal progression and serum PSA levels. Our data indicate that in obese boys, serum FT concentration is a better marker of androgen activity than TT. On the other hand, skeletal maturation and E2 were increased from the beginning of puberty, suggesting a significant contribution of hyperestrogenemia in the advancement of skeletal maturation in obese boys.

Sexual dimorphisms in the associations of BMI and body fat with indices of pubertal development in girls and boys

CONTEXT

The effect of obesity and concomitant insulin resistance on pubertal development is incompletely elucidated.

OBJECTIVE

To determine how measures of adiposity and insulin resistance are associated with pubertal maturation in boys and girls.

SETTING AND DESIGN

Breast and pubic hair Tanner stage and testicular volume by orchidometry were determined by physical examination in 1066 children. Ovarian volume was estimated by trans-abdominal ultrasound. Fat mass, skeletal age, and fasting serum for insulin and glucose, total T, estradiol, estrone, dehydroepiandrosterone-sulfate, and androstenedione were measured at the National Institutes of Health Clinical Research Center. Convenience sample; 52% obese, 59% female.

RESULTS

Logistic regression identified a significant interaction between sex and obesity for prediction of pubertal development (P ≤ .01). There was a negative association between boys' testicular volume and body mass index (BMI)/fat mass but a positive association between girls' breast stage and BMI/fat mass. Ovarian volume in girls was positively associated with insulin resistance but not with BMI/fat mass. There was a positive association between obesity and measures of estrogen exposure (breast development and skeletal age) in both sexes. Positive correlations were seen for girls between BMI and pubic hair development and between insulin resistance and T production, whereas adiposity was negatively associated with pubic hair in boys.

CONCLUSIONS

Significant sexual dimorphisms in the manifestations of pubertal development are seen in obese girls and boys. Two known effects of obesity, increased peripheral conversion of low-potency androgens to estrogens by adipose tissue-aromatase and increased insulin resistance, may be in large part responsible for these differences.

Timing of puberty and physical growth in obese children: a longitudinal study in boys and girls

OBJECTIVE

To assess whether puberty and physical growth vary in obese when compared to normal-weight children.

METHODS

One hundred obese pre-pubertal children (44 boys; mean age (±SD): 9.01 ± 0.62 years; 56 girls; 8.70 ± 0.57 years) were compared to 55 normal-weight controls (27 boys; 9.17 ± 0.26 years; 28 girls; 8.71 ± 0.62 years). All study participants were followed prospectively with 6-monthly follow-up visits. At each study visit, height, weight, body mass index (BMI) and pubertal stage were assessed.

RESULTS

Obese children entered puberty and achieved later stages of puberty earlier than controls (onset of puberty: boys: 11.66 ± 1.00 vs. 12.12 ± 0.91 years, P = 0.049; girls: 9.90 ± 0.78 vs. 10.32 ± 1.70, P = 0.016; late puberty: boys: 13.33 ± 0.71 vs. 14.47 ± 1.00 years, P < 0.001; girls: 11.54 ± 0.99 vs. 12.40 ± 1.02, P = 0.001). Pre-pubertal BMI standard deviation score (SDS) was inversely associated with both age at the onset of puberty (β = -0.506, P < 0.001) and age at late puberty (β = -0.514, P < 0.001). Obese children also showed an earlier age at peak height velocity (PHV) (boys: 12.62 ± 0.82 vs. 13.19 ± 0.96 years, P = 0.01; girls: 11.37 ± 0.89 vs. 12.77 ± 0.76, P < 0.001) and a lower PHV (boys: 7.74 ± 1.49 vs. 9.28 ± 1.64 cm year(-1) , P < 0.001; girls: 7.60 ± 1.64 vs. 8.29 ± 1.03, P = 0.03). Height SDS progressively declined over the study period in the obese group (P for trend <0.001), whereas there were no significant changes in the control group (P for trend = 0.5).

CONCLUSIONS

Obese boys and girls presented an earlier onset of puberty and completion of puberty and an impaired height gain during puberty.

Increased leptin/adiponectin ratio and free leptin index are markers of insulin resistance in obese girls during pubertal development

BACKGROUND

Modifications in body fat in obese patients during puberty determine changes in adipokines that affect insulin sensitivity.

AIMS

We hypothesized that the leptin/adiponectin (L/A) ratio and free leptin index (FLI) are good markers of insulin resistance (IR) and total body fat (TBF) during pubertal development.

METHODS

A prospective study of 32 obese girls (OG) and age-matched control girls (CG) was performed. OG were divided into those that maintained a weight loss (WL) of >1 SD of initial body mass index (BMI) (WL group, n = 25) and those without WL (NWL group, n = 7). Oral glucose tolerance tests (OGTT) were performed to evaluate IR. Correlations of adipokines, L/A, and FLI with BMI, waist circumference, percentage of TBF (%TBF) and IR were performed over pubertal development.

RESULTS

The L/A ratio and FLI were increased in OG at baseline. Both indexes decreased in the WL group as puberty progressed, with no change in CG or NWL. In the WL group, a correlation between L/A and FLI with OGTT and %TBF, and L/A and homeostasis model assessment (HOMA) was found throughout the study.

CONCLUSION

The L/A ratio and FLI are good markers to follow changes in IR and %TBF after WL during puberty. Insulin more accurately reflects the changes in IR than HOMA.

Hyperplastic breast anomalies in the female adolescent breast

Macromastia in adolescents is multifactorial and usually idiopathic, associated with obesity or hormonal imbalances. Less commonly, it can result from virginal or juvenile breast hypertrophy, a rare condition of unknown etiology, where an alarmingly rapid breast enlargement occurs during puberty. Breast hypertrophy in the adolescent population can have significant long-term medical and psychological impacts. Although symptoms can be severe, many plastic surgeons, pediatricians, and parents are often reluctant to surgically treat adolescent macromastia. However, reduction mammoplasty is a safe and effective treatment and may be the only way to alleviate the increased social, psychological, and physical strain caused by macromastia in adolescents.

Study protocol: the Childhood to Adolescence Transition Study (CATS)

Background

Puberty is a multifaceted developmental process that begins in late-childhood with a cascade of endocrine changes that ultimately lead to sexual maturation and reproductive capability. The transition through puberty is marked by an increased risk for the onset of a range of health problems, particularly those related to the control of behaviour and emotion. Early onset puberty is associated with a greater risk of cancers of the reproductive tract and cardiovascular disease. Previous studies have had methodological limitations and have tended to view puberty as a unitary process, with little distinction between adrenarche, gonadarche and linear growth. The Childhood to Adolescence Transition Study (CATS) aims to prospectively examine associations between the timing and stage of the different hormonally-mediated changes, as well as the onset and course of common health and behavioural problems that emerge in the transition from childhood to adolescence. The initial focus of CATS is on adrenarche, the first hormonal process in the pubertal cascade, which begins for most children at around 8 years of age.

Methods/Design

CATS is a longitudinal population-based cohort study. All Grade 3 students (8–9 years of age) from a stratified cluster sample of schools in Melbourne, Australia were invited to take part. In total, 1239 students and a parent/guardian were recruited to participate in the study. Measures are repeated annually and comprise student, parent and teacher questionnaires, and student anthropometric measurements. A saliva sample was collected from students at baseline and will be repeated at later waves, with the primary purpose of measuring hormonal indices of adrenarche and gonadarche.

Discussion

CATS is uniquely placed to capture biological and phenotypic indices of the pubertal process from its earliest manifestations, together with anthropometric measures and assessment of child health and development. The cohort will provide rich detail of the development, lifestyle, external circumstances and health of children during the transition from childhood through to adolescence. Baseline associations between the hormonal measures and measures of mental health and behaviour will initially be examined cross-sectionally, and then in later waves longitudinally. CATS will make a unique contribution to the understanding of adrenarche and puberty in children’s health and development.

Breast reduction in adolescents: indication, timing, and a review of the literature

BACKGROUND

Adolescent breast hypertrophy can have long-term negative medical and psychological impacts. In select patients, breast reduction surgery is the best treatment. Unfortunately, many in the general and medical communities hold certain misconceptions regarding the indications and timing of this procedure. Several etiologies of adolescent breast hypertrophy, including juvenile gigantomastia, adolescent macromastia, and obesity-related breast hypertrophy, complicate the issue. It is our hope that this paper will clarify these misconceptions through a combined retrospective and literature review.

METHODS

A retrospective review was conducted looking at adolescent females (≤18 years old) who had undergone bilateral breast reduction surgery. Their preoperative comorbidities, BMI, reduction volume, postoperative complications, and subjective satisfaction were recorded. In addition, a literature review was completed.

RESULTS

34 patients underwent bilateral breast reduction surgery. The average BMI was 29.5 kg/m(2). The average volume resected during bilateral breast reductions was 1820.9 g. Postoperative complications include dehiscence (9%), infection (3%), and poor scarring (6%). There were no cases of recurrence or need for repeat operation. Self-reported patient satisfaction was 97%. All patients described significant improvements in self body-image and participation in social activities. The literature review yielded 25 relevant reported articles, 24 of which are case studies.

CONCLUSION

Reduction mammaplasty is safe and effective. It is the preferred treatment method for breast hypertrophy in the adolescent female and may be the only way to alleviate the increased social, psychological, and physical strain caused by this condition.

Bone size and bone strength are increased in obese male adolescents

CONTEXT

Controversy exists on the effect of obesity on bone development during puberty.

OBJECTIVE

Our objective was to determine differences in volumetric bone mineral density (vBMD) and bone geometry in male obese adolescents (ObAs) in overlap with changes in bone maturation, muscle mass and force development, and circulating sex steroids and IGF-I. We hypothesized that changes in bone parameters are more evident at the weight-bearing site and that changes in serum estradiol are most prominent.

DESIGN, SETTING, AND PARTICIPANTS

We recruited 51 male ObAs (10-19 years) at the entry of a residential weight-loss program and 51 healthy age-matched and 51 bone-age-matched controls.

MAIN OUTCOME MEASURES

vBMD and geometric bone parameters, as well as muscle and fat area were studied at the forearm and lower leg by peripheral quantitative computed tomography. Muscle force was studied by jumping mechanography.

RESULTS

In addition to an advanced bone maturation, differences in trabecular bone parameters (higher vBMD and larger trabecular area) and cortical bone geometry (larger cortical area and periosteal and endosteal circumference) were observed in ObAs both at the radius and tibia at different pubertal stages. After matching for bone age, all differences at the tibia, but only the difference in trabecular vBMD at the radius, remained significant. Larger muscle area and higher maximal force were found in ObAs compared with controls, as well as higher circulating free estrogen, but similar free testosterone and IGF-I levels.

CONCLUSIONS

ObAs have larger and stronger bones at both the forearm and lower leg. The observed differences in bone parameters can be explained by a combination of advanced bone maturation, higher estrogen exposure, and greater mechanical loading resulting from a higher muscle mass and strength.

Testosterone concentrations in young pubertal and post-pubertal obese males

OBJECTIVE

Obesity in adult males is associated with hypogonadotropic hypogonadism. We evaluated the effect of obesity on plasma testosterone concentrations in pubertal and post-pubertal young males.

DESIGN AND METHODS

Morning fasting blood samples were obtained from 25 obese [body mass index (BMI) ≥95th percentile] and 25 lean (BMI <85th percentile) males between the ages 14-20 years with Tanner staging ≥4. Total (TT) and free testosterone (FT) and estradiol concentrations were measured by liquid chromatography tandem mass spectrometry and equilibrium dialysis. Free testosterone was also calculated using SHBG and albumin. C-reactive protein (CRP), insulin and glucose concentrations were measured and homoeostasis model of insulin resistance (HOMA-IR) was calculated.

RESULTS

After controlling for age and Tanner staging, obese males had a significantly lower total testosterone (10·5 vs 21·44 nmol/l), free testosterone (0·22 vs 0·39 nmol/l) and calculated free testosterone (0·26 vs 0·44 nmol/l) concentrations as compared to lean males (P < 0·001 for all). Obese males had higher CRP concentrations (2·8 vs 0·8 mg/l; P < 0·001), and HOMA-IR (3·8 vs 1·1; P < 0·001) than lean males. Free testosterone concentrations were positively related to age and negatively to BMI, HOMA-IR and CRP concentrations. Total and free estradiol concentrations were significantly lower in males with subnormal testosterone concentrations.

CONCLUSION

Testosterone concentrations of young obese pubertal and post-pubertal males are 40-50% lower than those with normal BMI. Obesity in young males is associated with low testosterone concentrations, which are not secondary to an increase in estradiol concentrations. Our results need to be confirmed in a larger number of subjects.

Impact of body mass index on luteinizing hormone secretion in gonadotropin-releasing hormone stimulation tests of boys experiencing precocious puberty

OBJECTIVE

Excess adiposity may influence various aspects of pubertal development, including the timing of pubertal initiation and hormonal parameters during puberty. The aim of the study was to evaluate the impact of body mass index (BMI) on luteinizing hormone (LH) secretion to gonadotropin-releasing hormone (GnRH) stimulation test in boys with precocious puberty.

METHODS

Boys with precocious puberty, who were normal weight, overweight, and obese underwent GnRH stimulation tests between 2003 and 2010. Subjects were classified as normal weight (BMI ≥5th percentile and BMI <85th percentile), overweight (BMI ≥85th percentile and BMI <95th percentile), and obese (BMI ≥95th percentile).

RESULTS

Of 56 children whose data were included in the final analysis, mean age at diagnosis was 8.7 ± 1.0 years. The majority of boys were of normal weight (n = 28, 50%), while 15 children (26%) were overweight, and 13 (23%) obese. Peak LH levels after GnRH stimulation were 19.8 ± 8.8, 9.0 ± 3.5, and 8.1 ± 4.0 mIU/ml among normal weight, overweight, and obese subjects, respectively (p < 0.001 for all comparisons). By multivariate analysis, there was a significant negative association of BMI with peak-stimulated LH level.

CONCLUSIONS

The higher BMI is associated with lower LH response to the GnRH stimulation test in boys experiencing precocious puberty. In boys with precocious puberty, BMI should be considered when interpreting GnRH stimulation test.

Update on statural growth and pubertal development in obese children

Childhood obesity is a growing and alarming problem, associated with several short-term and long-term metabolic and cardiovascular complications. In addition, it has also been suggested that excess adiposity during childhood influences growth and pubertal development. Several studies have shown that during pre-pubertal years, obese patients present higher growth velocity and that this pre-pubertal advantage tends to gradually decrease during puberty, leading to similar final heights between obese and non-obese children. Excess body weight might also influence pubertal onset, leading to earlier timing of puberty in girls. In addition, obese girls are at increased risk of hyperandrogenism and polycystic ovary syndrome. In boys, a clear evidence does not exist: some studies suggesting an earlier puberty associated with the obesity status, whereas other have found a delayed pubertal onset. Overall, the existing evidence of an association between obesity and modification of growth and pubertal patterns underlines a further reason for fighting the epidemics of childhood obesity.

Environmental factors associated with overweight and obesity in taiwanese children

BACKGROUND

We explored the relationship among sociodemographic, behavioural, household environmental and perinatal factors, and risks of childhood overweight and obesity in Taiwan.

METHODS

A total of 7930 children aged 9 to 14 years were recruited from 14 randomly selected Taiwanese communities in 2007 and 2010. Height and weight were measured using standard protocols during school visits. Questionnaires that contained children's family information, birth conditions, exercise habits and household environmental factors were answered by the parents. Associations between risk factors and childhood overweight and obesity were estimated through odds ratio and 95% confidence interval from mixed models.

RESULTS

In this cohort, 32.3% of the children were overweight and 17.5% were obese. Male gender, high birthweight, exposure to in utero maternal smoking and current exposure to household environmental tobacco smoke (stronger effect of maternal than paternal smoking) were positively associated with childhood overweight/obesity. In contrast, higher parental education level, number of siblings, active exercise habits and taking vitamins were associated with reduced risks of childhood obesity. Birthweight revealed a J-shaped relationship with the probability of childhood overweight/obesity.

CONCLUSIONS

This study uncovers several modifiable risk factors for childhood overweight and obesity, and parents are encouraged to provide an anti-obesity environment such as quitting smoking, controlling birthweight of child during pregnancy and building up exercise habits.