Delayed puberty in obese boys: comparison with constitutional delayed puberty and response to testosterone therapy

Central precocious puberty in boys: secular trend and clinical features

OBJECTIVE

Recent studies suggest that boys enter puberty at a younger age, and the incidence of male central precocious puberty (CPP) is increasing. In this study, we explore the incidence of male CPP and identify key clinical and auxological indicators for organic CPP (OCPP).

DESIGN

A retrospective registry-based study.

METHODS

The medical records of 43 boys treated with CPP at the Helsinki University Hospital between 1985 and 2014 were reviewed. Clinical, auxological, and endocrine data of the CPP patients were included in the analyses.

RESULTS

Based on brain MRI, 26% of patients had OCPP. Between 2010 and 2014, the CPP incidence in boys was 0.34 per 10 000 (95% CI 0.20-0.60). Between 1990 and 2014, the male CPP incidence increased (incidence rate ratio [IRR] 1.10, P = .001). This increase was driven by rising idiopathic CPP (ICPP) incidence (IRR 1.11, 95% CI 1.05-1.19, P < .001), while OCPP incidence remained stable (P = .41). Compared with the patients with ICPP, the patients with OCPP were younger (P = .006), were shorter (P = .003), and had higher basal serum testosterone levels (P = .038). Combining 2 to 4 of these readily available clinical cues resulted in good to excellent (all, area under the curve 0.84-0.97, P < .001) overall performance, differentiating organic etiology from idiopathic.

CONCLUSIONS

The estimated incidence of CPP in boys was 0.34 per 10 000, with 26% of cases associated with intracranial pathology. The increase in CPP incidence was driven by rising ICPP rates. Patients with OCPP were characterized by shorter stature, younger age, and higher basal testosterone levels, providing valuable cues for differentiation in addition to brain MRI. Utilizing multiple cues could guide diagnostic decision-making.

Testosterone Levels in Adolescents and Young Men with Type 1 Diabetes and Their Association with Diabetic Nephropathy

Simple Summary

Type 2 diabetes(T2D) has been known to be related with obesity, insulin-resistance, impaired glucose control. Low testosterone levels and hypogonadism are also known as clinical characteristics of T2D patients. On the contrary, type 1 diabetes(T1D) happens when insulin is insufficient rather than insulin-resistance. Relationship between T1D and testosterone has not been established enough. In the study, patients with T1D showed higher testosterone levels than the general population. We could also find that higher testosterone levels have positive relationship with nephropathy, one of complications in diabetic patients. Therefore, periodic check-up for testostrone levels may be helpful for preventing nephropathy in T1D.

Abstract

The association between serum testosterone levels and type 1 diabetes (T1D), especially in adolescents and young adults, has not been fully investigated. We aimed to compare testosterone levels between adolescents/young men with T1D and controls and to determine the factors affecting testosterone levels. We enrolled 47 men with T1D and 32 controls aged 15–29 years. We evaluated anthropometric measurements, lipid profiles, diabetic complications, and levels of serum luteinizing hormone, follicle-stimulating hormone, hemoglobin A1c, 24-h urine albumin, insulin autoantibody, and total serum testosterone. We assessed the correlation between serum testosterone levels and clinical characteristics. Total testosterone levels were higher in T1D patients than in controls (694.6 ± 182.2 vs. 554.1 ± 147.3 ng/dL, p = 0.001), and 24-h urine albumin level positively correlated with total testosterone levels (correlation coefficient 0.415, p = 0.004). T1D patients with nephropathy showed higher total testosterone levels than those without nephropathy (778.4 ± 198.9 vs. 655.4 ± 162.5 ng/dL, p = 0.029). However, diabetic nephropathy and testosterone levels were not significantly associated after adjusting for confounders (β ± SE 77.5 ± 55.2, p = 0.169). Further longitudinal studies are imperative to confirm a causal relationship between testosterone levels and T1D.

Various causative factors and associated complications of childhood obesity in Jeddah, western region, Saudi Arabia

OBJECTIVE

to investigate the causative factors and complications attributable to obesity in children living in jeddah, saudi arabia.

METHODS

this is a retrospective study encompassing a sample size of 151 children and adolescents between the ages of 4 and 20 years. data was collectived through revieweing medical records, medical files on the hospital electironic system and clinical interviews conducted with legal guardians. date of study was from january to june 2018, and was carried in jeddah, western region, saudi arabia.

RESULTS

data was entered, coded, cleaned and analysed using statistical package for social science (IBM SPSS), version 22. the analysis was done by assessing the significance of various risk factors ands equalae in their contribution to paediatric obesity by one way ANOVA for nominal variables of more than two categories and independent sample t-test for the nominal variables with two categories. the sample was 47% of the male gender whereas females made for the remaining 53%. the causation of obesity was distributed among the following factors: an unhealthy diet, a sedentary lifestyle, medications such as glucocorticoids, and complications attributed to obesity included gastro-oesophageal reflux, hypertension, precocious puberty, sleep apnoea, psychological disturbances and fatty liver diseases.

CONCLUSION

environmental factors were found to be the most predominant cause, where the majority of children were found to be leading a sedentary lifestyle, following an unhealthy diet, and skipping meals. the msot recurring complications involved psychosocial and behavioural abnormalities, and among the medical consequences, gastro-oesophageal reflux and obstructive sleep apnoea were the most prevalent.

Androgens During Infancy, Childhood, and Adolescence: Physiology and Use in Clinical Practice

We provide an in-depth review of the role of androgens in male maturation and development, from the fetal stage through adolescence into emerging adulthood, and discuss the treatment of disorders of androgen production throughout these time periods. Testosterone, the primary androgen produced by males, has both anabolic and androgenic effects. Androgen exposure induces virilization and anabolic body composition changes during fetal development, influences growth and virilization during infancy, and stimulates development of secondary sexual characteristics, growth acceleration, bone mass accrual, and alterations of body composition during puberty. Disorders of androgen production may be subdivided into hypo- or hypergonadotropic hypogonadism. Hypogonadotropic hypogonadism may be either congenital or acquired (resulting from cranial radiation, trauma, or less common causes). Hypergonadotropic hypogonadism occurs in males with Klinefelter syndrome and may occur in response to pelvic radiation, certain chemotherapeutic agents, and less common causes. These disorders all require testosterone replacement therapy during pubertal maturation and many require lifelong replacement. Androgen (or gonadotropin) therapy is clearly beneficial in those with persistent hypogonadism and self-limited delayed puberty and is now widely used in transgender male adolescents. With more widespread use and newer formulations approved for adults, data from long-term randomized placebo-controlled trials are needed to enable pediatricians to identify the optimal age of initiation, route of administration, and dosing frequency to address the unique needs of their patients.

Various causative factors and associated complications of childhood obesity in Jeddah, Western Region, Saudi Arabia

Objective:

The objective of the study was to investigate the causative factors and complications attributable to obesity in children living in Jeddah, Saudi Arabia.

Methods:

This is a retrospective study encompassing a sample size of 151 children and adolescents between the ages of 4 and 20 years. Data were collected through reviewing medical records, medical files on the hospital electronic system, and clinical interviews conducted with legal guardians. The date of the study was from January to June 2018, and the study was carried out in Jeddah, Western Region, Saudi Arabia.

Results:

Data were entered, coded, cleaned, and analyzed using the Statistical Package for the Social Sciences (IBM SPSS), version 22. The analysis was done by assessing the significance of various risk factors and sequelae in their contribution to pediatric obesity by one-way ANOVA for nominal variables of more than two categories and independent-samples t-test for the nominal variables with two categories. The sample was 47% of the male gender, whereas females made for the remaining 53%. The causation of obesity was distributed among the following factors: an unhealthy diet, a sedentary lifestyle, medications such as glucocorticoids, and complications attributed to obesity including gastroesophageal reflux, hypertension, precocious puberty, sleep apnea, psychological disturbances, and fatty liver diseases.

Conclusion:

Environmental factors were found to be the most predominant cause, where the majority of children were found to be leading a sedentary lifestyle, following an unhealthy diet, and skipping meals. The most recurring complications involved psychosocial and behavioral abnormalities, and among the medical consequences, gastroesophageal reflux and obstructive sleep apnea were the most prevalent.

Sex, puberty, and ethnicity have a strong influence on growth and metabolic comorbidities in children and adolescents with obesity: Report on 1300 patients (the Madrid Cohort)

BACKGROUND

The capacity to correctly assess insulin resistance and its role in further obesity-associated metabolic derangement in children is under debate, and its determinants remain largely unknown.

OBJECTIVE

We investigated the association of the insulin secretion profile with other metabolic derangements and anthropometric features in children and adolescents with obesity, exploring the role of ethnicity.

PATIENTS AND METHODS

Growth and metabolic features, including fasting insulin levels and insulin secretory profile in an oral glucose tolerance test (OGTT), were analyzed according to ethnicity in 1300 patients with obesity (75.8% Caucasians/19.0% Latinos).

RESULTS

Height and bone age were influenced by sex, ethnicity, and insulinemia. Latino patients had higher insulin (P < .001), but similar glycemia both prepubertally and postpubertally, compared with Caucasians. Type 2 diabetes was uncommon (0.1%). Impaired glucose tolerance was associated to higher age, BMI, uric acid, and triglyceride levels (all P < .05), as was fasting hyperinsulinism. Impaired fasting glucose or HbA1c 5.7% to 6.4% showed no association with further metabolic derangement. A delayed insulin peak in the OGTT was associated to more severe metabolic disturbances.

CONCLUSIONS

Obesity-associated hyperglycemia is unusual in our environment whereas fasting and late postprandial hyperinsulinemia are highly prevalent, with this being influenced by race and closely related with lipid metabolism impairment.

Clinical Management of Congenital Hypogonadotropic Hypogonadism

The initiation and maintenance of reproductive capacity in humans is dependent on pulsatile secretion of the hypothalamic hormone GnRH. Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder that results from the failure of the normal episodic GnRH secretion, leading to delayed puberty and infertility. CHH can be associated with an absent sense of smell, also termed Kallmann syndrome, or with other anomalies. CHH is characterized by rich genetic heterogeneity, with mutations in >30 genes identified to date acting either alone or in combination. CHH can be challenging to diagnose, particularly in early adolescence where the clinical picture mirrors that of constitutional delay of growth and puberty. Timely diagnosis and treatment will induce puberty, leading to improved sexual, bone, metabolic, and psychological health. In most cases, patients require lifelong treatment, yet a notable portion of male patients (∼10% to 20%) exhibit a spontaneous recovery of their reproductive function. Finally, fertility can be induced with pulsatile GnRH treatment or gonadotropin regimens in most patients. In summary, this review is a comprehensive synthesis of the current literature available regarding the diagnosis, patient management, and genetic foundations of CHH relative to normal reproductive development.

Central precocious puberty in Boston boys: A 10-year single center experience

Objective

Recent studies in the US and abroad suggest that boys are undergoing puberty at a younger age. It is unknown if this secular trend extends to boys with central precocious puberty (CPP), who sit at the extreme end of the pubertal spectrum, and if neuroimaging should remain a standard diagnostic tool.

Study design

Retrospective chart review of all boys with CPP seen by Endocrinology at a US pediatric hospital from 2001–2010.

Results

Fifty boys had pubertal onset at an average age of 7.31 years (95CI 6.83–7.89), though many did not present until nearly one year thereafter, by which time 30% were mid-to-late pubertal. Boys were predominantly non-Hispanic White and 64% were overweight/obese. The majority (64%) of boys had neurogenic CPP (CNS-CPP) with neurofibromatosis type I being the most common diagnosis. Diagnosis of CPP led to discovery of a neurogenic lesion in only 3 of 32 (9%) CNS-CPP cases. The remaining boys, with idiopathic CPP (36%), were indistinguishable from those with CNS-CPP aside from four boys who endorsed a family history of PP (22% vs. 0% among CNS-CPP cases). Importantly, there was no change in the incidence of male CPP after accounting for the increase in clinic volume during this time period.

Conclusion

In this contemporary Boston-based cohort of 50 boys with CPP, most cases were neurogenic, consistent with older literature. Several idiopathic cases had a family history of PP but were otherwise indistinguishable from CNS-CPP cases. Thus, neuroimaging remains a critical diagnostic tool. We find no evidence for an increase in the prevalence of male CPP.

Male Obesity

Many cross-sectional analyses and longitudinal studies have examined the association between adiposity and pubertal development. In addition, the impact of an increased fat mass on reproduction and fertility in human obese men and in male animal models of obesity has been studied. A trend toward earlier pubertal development and maturation in both sexes has been shown, and the notion that obese boys might progress to puberty at a slower pace than their nonobese peers can no longer be substantiated. Impaired fertility markers and reduced reproductive functions have been observed in obesity. Obesity affects both pubertal development and fertility in men.

Associations of pubertal stage and body mass index with cardiometabolic risk in Hong Kong Chinese children: A cross-sectional study

BACKGROUND

Puberty is associated with a clustering of cardiometabolic risk factors (CMRFs) during adolescence that are manifested in later life. Although anthropometric variables such as body mass index (BMI) can predict cardiometabolic risk in children and adolescents, it is not clear whether there is an interaction between pubertal stage and BMI associated with cardiometabolic risk in this age group. This paper examines the association of pubertal stage and BMI with CMRFs in Hong Kong Chinese children.

METHODS

A cross-sectional school-based study was conducted among 1985 (95.1%) students aged 6 to 18 years. Fasting lipid profile and plasma glucose, blood pressure, body weight, body height and waist circumference were measured. A self-reported pubertal stage questionnaire was used to assess pubertal stage of participants. Two cardiometabolic risk scores, alpha and beta, were constructed to quantify cardiometabolic risk. Cardiometabolic risk score alpha refers to the sum of z-scores of sex-specific, age-adjusted waist circumference, height-adjusted systolic and diastolic blood pressure, fasting plasma glucose, triglyceride and low-density lipoprotein cholesterol, and minus z-score of sex-specific age-adjusted high-density lipoprotein cholesterol. Cardiometabolic risk score beta includes all components of risk score alpha except waist circumference.

RESULTS

The interaction of BMI z-score (ZBMI) and pubertal stage demonstrated a further increase in variance explained in both the cardiometabolic risk scores alpha and beta (0.5% and 0.8% respectively) in boys and (0.7% and 0.5% respectively) in girls.

CONCLUSIONS

Pubertal stage has an interaction effect on the association of cardiometabolic risk by BMI in boys and may have a similar but lesser effect in girls.

Overweight and obesity in children and adolescents

Obesity among children, adolescents and adults has emerged as one of the most serious public health concerns in the 21st century. The worldwide prevalence of childhood obesity has increased remarkably over the past 3 decades. The growing prevalence of childhood obesity has also led to appearance of obesity-related comorbid disease entities at an early age. Childhood obesity can adversely affect nearly every organ system and often causes serious consequences, including hypertension, dyslipidemia, insulin resistance, dysglycemia, fatty liver disease and psychosocial complications. It is also a major contributor to increasing healthcare expenditures. For all these reasons, it is important to prevent childhood obesity as well as to identify overweight and obese children at an early stage so they can begin treatment and attain and maintain a healthy weight. At present, pharmacotherapy options for treatment of pediatric obesity are very limited. Therefore, establishing a comprehensive management program that emphasizes appropriate nutrition, exercise and behavioral modification is crucial. The physician's role should expand beyond the clinical setting to the community to serve as a role model and to advocate for prevention and early treatment of obesity.

Do the interactions between glucocorticoids and sex hormones regulate the development of the metabolic syndrome?

The metabolic syndrome is basically a maturity-onset disease. Typically, its manifestations begin to flourish years after the initial dietary or environmental aggression began. Since most hormonal, metabolic, or defense responses are practically immediate, the procrastinated response do not seem justified. Only in childhood, the damages of the metabolic syndrome appear with minimal delay. Sex affects the incidence of the metabolic syndrome, but this is more an effect of timing than absolute gender differences, females holding better than males up to menopause, when the differences between sexes tend to disappear. The metabolic syndrome is related to an immune response, countered by a permanent increase in glucocorticoids, which keep the immune system at bay but also induce insulin resistance, alter the lipid metabolism, favor fat deposition, mobilize protein, and decrease androgen synthesis. Androgens limit the operation of glucocorticoids, which is also partly blocked by estrogens, since they decrease inflammation (which enhances glucocorticoid release). These facts suggest that the appearance of the metabolic syndrome symptoms depends on the strength (i.e., levels) of androgens and estrogens. The predominance of glucocorticoids and the full manifestation of the syndrome in men are favored by decreased androgen activity. Low androgens can be found in infancy, maturity, advanced age, or because of their inhibition by glucocorticoids (inflammation, stress, medical treatment). Estrogens decrease inflammation and reduce the glucocorticoid response. Low estrogen (infancy, menopause) again allow the predominance of glucocorticoids and the manifestation of the metabolic syndrome. It is postulated that the equilibrium between sex hormones and glucocorticoids may be a critical element in the timing of the manifestation of metabolic syndrome-related pathologies.

Effects of obesity on human sexual development

Puberty is a period of physical and psychological maturation, with long-term effects on health. During the 20(th) century, a secular trend towards earlier puberty occurred in association with improvements in nutrition. The worldwide pandemic of childhood obesity has renewed interest in the relationship between body composition in childhood and the timing and tempo of puberty. Limited evidence suggests that earlier puberty is associated with a tendency towards central fat deposition; therefore, pubertal status needs to be carefully considered in the categorization of childhood and adolescent overweight and obesity. In the other direction, rapid early weight gain is associated with advanced puberty in both sexes, and a clear association exists between increasing BMI and earlier pubertal development in girls. Evidence in boys is less clear, with the majority of studies showing obesity to be associated with earlier puberty and voice break, although a subgroup of boys with obesity exhibits late puberty, perhaps as a variation of constitutional delay in growth and puberty. The possible mechanisms linking adiposity with pubertal timing are numerous, but leptin, adipocytokines and gut peptides are central players. Other possible mediators include genetic variation and environmental factors such as endocrine disrupting chemicals. This Review presents current evidence on this topic, highlighting inconsistencies and opportunities for future research.

Obesity and the pubertal transition in girls and boys

Childhood obesity has become a major health concern in recent decades, especially with regard to metabolic abnormalities that impart a high risk for future cardiovascular disease. Recent data suggest that excess adiposity during childhood may influence pubertal development as well. In particular, excess adiposity during childhood may advance puberty in girls and delay puberty in boys. Obesity in peripubertal girls may also be associated with hyperandrogenemia and a high risk of adolescent polycystic ovary syndrome. How obesity may perturb various hormonal aspects of pubertal development remains unclear, but potential mechanisms are discussed herein. Insulin resistance and compensatory hyperinsulinemia may represent a common thread contributing to many of the pubertal changes reported to occur with childhood obesity. Our understanding of obesity's impact on pubertal development is in its infancy, and more research into pathophysiological mechanisms and longer-term sequelae is important.

Testosterone, obesity and insulin resistance in young males: evidence for an association between gonadal dysfunction and insulin resistance during puberty

OBJECTIVE

To assess the relationships among obesity, insulin sensitivity, and testosterone in pubertal boys.

PARTICIPANTS

This study included 20 lean, obese, and type 2 diabetic (T2DM) males, the majority of whom underwent a hyperinsulinemic-euglycemic clamp (n=16).

METHODS

Glucose disposal (M value), serum testosterone, and body mass index (BMI) z-score were measured. Differences in testosterone were evaluated by group (lean vs. obese vs. T2DM), while regression was performed to evaluate the relationships among testosterone, obesity and insulin sensitivity.

RESULTS

Controlling for Tanner stage, testosterone concentration was significantly lower in obese (p=0.02) and T2DM males (p=0.001) compared to lean males. Furthermore, M value was significantly associated with serum testosterone, even after controlling for BMI and Tanner stage.

CONCLUSIONS

These data suggest that obese adolescent boys have lower serum testosterone than controls of the same Tanner stage, and echo the data in adult males associating obesity and insulin resistance with hypogonadism.

Obesity induced bronchopulmonary hyperresponsiveness in Tunisian women

OBJECTIVE

The specific objective of this investigation was to determine whether bronchopulmonary responsiveness (BPR) to methacholine (MCH) was associated with the body mass index (BMI) of Tunisian women.

SUBJECTS

In all, 160 healthy nonsmoker women (52 lean, 45 overweight and 63 obese) were recruited and examined in the Clinical Laboratory of Physiology located in the Medical School of Sousse. The average ages (+/-s.e.) of the three categories of lean, overweight and obese subjects were 27.7+/-1.1, 33.2+/-1.7 and 37.5+/-1.3 years, respectively. Their corresponding mean BMIs (+/-s.e.) were 21.9+/-0.3, 27.7+/-0.2 and 36.5+/-0.8 kg m(-2), respectively.

MEASUREMENTS

Before their inclusion into the study, subjects were screened for their lung status by measuring their pulmonary function testing parameters using a whole body plethysmograph. BPR was assessed, using a cumulative concentration response curve technique, by measuring with a spirometer the decrease in forced expiratory volume in 1 s (FEV(1)) in response to a cumulative dose of MCH.

RESULTS

After adjusting for age, significant differences in both FEV(1) and forced vital capacity (VC) were found between the obese and lean groups (P<0.01), as well as between the obese and overweight groups (P<0.01). In addition, forced expiratory flow between 25 and 75% of VC was significantly different between the obese and lean groups (P<0.001), as well as between the lean and overweight groups (P=0.015). The mean maximum fall of FEV(1) in response to MCH challenge was significantly higher for the obese group (12.0%) than for the overweight (9.8%) or the lean (6.6%) group (P<0.01). Furthermore, the efficacy of the MCH agonist promoting the maximal response (E(max)) and its potency or effective dose producing 50% of the maximal response (ED(50)) were both associated with BMI (the higher the BMI, the higher the E(max) and the lower the ED(50)).

CONCLUSION

Our data clearly show that obesity affects pulmonary function performance in Tunisian women by potentially promoting their bronchial hyperreactivity as suggested by the significant correlation between their BMI and the efficacy of the MCH, as well as its potency.

Association of overweight with asthma prevalence in adolescents in Rio de Janeiro, Brazil

OBJECTIVE

To evaluate the relationship between asthma and overweight in adolescents.

METHODS

Cross-sectional study including 13-14-year-old adolescents in Rio de Janeiro, Brazil. Asthma was defined according to the International Study of Asthma and Allergies in Childhood (ISAAC). Body Mass Index (BMI) was calculated; overweight was defined as BMI > or = 85th percentile. The distribution of asthma and associated symptoms were compared according weight category using the chi(2) test for linear trend. The association between asthma and overweight, controlling for confounding variables, was studied using odds ratios (OR), confidence intervals (95% CI) and logistic regression, stratified by sex.

RESULTS

2,858 (50.1% female) adolescents were studied; 458 (16.1%) were overweight and 13.3% asthmatic. Average BMI was higher among asthmatics (p = 0.01). When stratified, this difference remained only among girls (p = 0.03). Asthma prevalence increased with higher BMI (p = 0.02). Asthma was associated to overweight (OR = 1.51; 95% CI: 1.07-2.13), irrespective of sedentary lifestyle, smoking mother and presence of dog in the domicile, but only among the girls.

CONCLUSIONS

In Rio de Janeiro adolescents, we found a positive association between asthma and overweight, exclusively among girls. This suggests that health policies related to asthma and overweight/obesity in this age group need to take sex into consideration.

Adolescent obesity and puberty: the "perfect storm"

Obesity is the most serious long-term health risk currently facing America's adolescents. Weight gain during adolescence carries a higher risk for adult obesity and the metabolic syndrome. This review highlights early adolescence as a particularly high-risk time for weight gain due to the synergy of naturally occurring metabolic changes along with increasing behavioral risk factors. One of the first potential health effects of abnormal weight gain during this period is earlier puberty, usually manifested as thelarche. The obesity epidemic is clearly implicated in the national trend toward earlier thelarche, although the data are not as strong in relation to menarche. Leptin activation of the hypothalamic-pituitary axis, combined with insulin resistance, and increased adiposity may result in the higher estrogen levels that are linked to breast development. Young adolescents also experience a sharp decline in their level of physical activity, worsening nutritional habits, and other important psychosocial and developmental risk factors that may contribute to obesity and estrogen-dependent disease in later life, including polycystic ovary syndrome and breast cancer. Unfortunately, the very psychosocial factors that contribute to abnormal weight gain during early adolescence make prevention and treatment in this population particularly challenging. Therefore, intervening prior to pubertal onset becomes even more important given the risk factors present once puberty begins.

[Relationship between obesity and asthma]

The prevalences of both obesity and asthma have clearly increased in recent decades, giving rise to speculation that they may be related. Studies have found that obesity precedes and predicts the onset of asthma (time effect), that increased obesity leads to more severe asthma (dose-response effect), that weight reduction (by diet or gastric bypass) improves asthmatic symptoms, and that obesity co-occurs with intermediate asthma phenotypes (obese young girls undergoing early menarche). In the light of that evidence, we can finally suggest a causal relationship between obesity and asthma. Various biological mechanisms (immunologic and inflammatory, hormonal, genetic, nutritional, mechanical, and others related to physical activity) have been put forth to explain the relationship. However, this relation is complex, involving not only the interaction of genetic and environmental factors in triggering both diseases but also the likely participation of several mechanisms at once.

Obesity in adolescence: Implications in orthodontic treatment

The incidence of obesity is increasing in the United States and around the world, and it is likely that obese patients will present for orthodontic therapy in greater numbers in the future. The implications of obesity for psychosocial well-being, bone metabolism, craniofacial growth, and pubertal growth must be assessed in treating obese orthodontic patients. This review article focuses on the relevant issues concerning obesity in regard to orthodontic therapy.

Regulation of appetite in lean and obese adolescents after exercise: role of acylated and desacyl ghrelin

CONTEXT

Increased physical activity is an integral part of weight loss programs in adolescents. We hypothesized that exercise could affect appetite-regulating hormones and the subjective desire to eat, which could partly explain the poor success rate of the existing interventions.

OBJECTIVE

The objective of this study was to investigate prospectively the effects of exercise on acylated ghrelin (AG) and desacyl ghrelin (DG) concentrations and on appetite.

SETTING

The setting for this study was a tertiary care center.

PARTICIPANTS

Normal-weight [NW; body mass index (mean +/- se), 20.7 +/- 0.5 kg/m2] and overweight (OW; body mass index, 32.4 +/- 1.7) male adolescents (n = 17/group, age 15.3 +/- 0.2 yr) were studied.

INTERVENTION

Those studied participated in 5 consecutive days of aerobic exercise (1 h/d).

MAIN OUTCOME

Changes in AG and DG concentrations and in appetite during a test meal were studied.

RESULTS

Exercise did not significantly affect insulin sensitivity or body weight. Fasting total (AG and DG) ghrelin concentrations were lower in OW (600 +/- 33 pg/ml) compared with NW (764 +/- 33 pg/ml, P < 0.05) boys and were not affected by exercise. In contrast, there was a differential effect of exercise on both AG and DG (P <or= 0.019). AG significantly increased after exercise, and this increase was greater in NW compared with OW adolescents (P < 0.05). Higher AG concentrations were correlated with an increase in markers of appetite (P < 0.05).

CONCLUSION

Exercise differentially affects AG and DG in NW and OW male adolescents. Our data suggest that total ghrelin does not adequately reflect AG and DG concentrations and that the influence of exercise-induced hormonal changes should be considered to ensure success in weight management.

Impact of body mass index on growth in boys with delayed puberty

It is unclear whether overweight but otherwise healthy boys with delayed puberty have a variation of constitutional delay of growth and maturation (CDGM) or a different etiology for their pubertal delay. To characterize better this group of boys and investigate whether their growth pattern distinguishes them from boys with typical CDGM, growth data were analyzed in eight overweight (BMI SDS > or = 85th percentile) and 37 non-overweight (BMI SDS <85th percentile) boys with delayed puberty. Primary outcome measures included predicted height (PH) and adult height (AH). At diagnosis of delayed puberty, the overweight boys had less delayed bone ages (chronological age [CA] - bone age [BA] = 1.2 +/- 1.0 vs 2.5 +/- 1.1 years, p <0.01), greater height SDS for CA (-0.5 +/- 0.7 vs -2.4 +/- 0.8, p <0.001), and greater height SDS for BA (0.6 +/- 0.9 vs -0.4 +/- 1.1, p <0.05). PH for the overweight boys exceeded their mid-parental height (MPH) by 5.0 +/- 7.2 cm while non-overweight boys were predicted to fall below their MPH by 2.8 +/- 6.3 cm (p <0.01). Available AH data corroborated the differences in PH, with a trend for overweight boys to have greater height relative to their MPH than the non-overweight boys. These observations suggest that in the context of delayed puberty, being overweight may modulate adult height and/or that the etiology of delayed puberty in overweight boys may differ from typical CDGM.

Regulation and disorders of pubertal timing

Disorders of pubertal timing are common and challenging problems for pediatric endocrinologists. Early or late puberty can have immediate effects on a child's psychosocial well-being and may have long-term effects on adult stature. Much is known about the regulation of the hypothalamic-pituitary-gonadal axis, but the triggers of pubertal onset in the general population remain elusive. This article reviews recent data suggesting a possible shift in the age of pubertal onset; current knowledge regarding factors that regulate the onset of puberty; and the etiologies, diagnosis, and treatment of precocious and delayed puberty.

Obesity and asthma, what are the links?

PURPOSE OF REVIEW

Obesity is a major cause of morbidity accounting for approximately 300 000 deaths each year and about 7% of the health care budget with an economic impact greater than US dollar 100 billion annually in the United States. Obesity and its sequelae such as cardiovascular disease, diabetes, arthritis or cancer have been on the rise over the last decades. The parallel time trend with an increasing prevalence of asthma has induced a lively debate about a potential link between both conditions.

RECENT FINDINGS

A number of prospective studies have shown that weight gain can antedate the development of asthma. Effect modification by sex may occur as some studies have shown effects of body mass index on asthma only among females. However, sex differences are not consistent. Several hypotheses have been proposed to explain the epidemiological associations including alterations in airway mechanics and immune responses, hormonal influences and genetic factors.

SUMMARY

There is evidence that obesity and overweight are associated with the development of asthma. Yet, the mechanisms underlying this relation are unclear. Weight reduction among asthmatic patients can result in improvements of lung function demonstrating the potential clinical impact of the findings.

Puberty, obesity and ethnicity

Lay and medical sources state that children enter puberty earlier now than in past decades. Although it is clear that puberty and menarche currently begin at younger ages than they did in past centuries, a comparison of the onset of puberty during the few past decades is more difficult to interpret. African-American girls do start puberty earlier and menarche is earlier than in White girls, and the gap between the two has widened during the past 20 years. This change between ethnic groups might be due to an increasing difference in body mass index (BMI) values. Greater BMI values are associated with pubertal onset or menarche; thus, if BMI continues to increase in childhood, earlier puberty might well be found in the general population in the future. In the absence of accurate data from the past or definitive studies at present, however, it cannot be stated with assurance that puberty today starts significantly earlier than it did in the past 4-5 decades across the whole population.

Delayed puberty: analysis of a large case series from an academic center

Despite the clinical importance of delayed puberty, the understanding of this condition is hampered by the lack of studies evaluating etiologies and predisposing factors among large case series. We performed a retrospective study of clinical and laboratory data from adolescents (< or =18 yr of age) with delayed puberty who had been seen in our clinic between 1/96 and 7/99 (n = 232 subjects; 158 males and 74 females). Family histories of pubertal timing among primary relatives were classified as negative, having at least a tendency to pubertal delay (development > or =1 SD beyond the mean), or diagnostic of delay (development > or =2 SD beyond the mean). The most common cause of delayed puberty was constitutional delay of growth and maturation (CD), which affected 53% of the subjects (63% of males and 30% of females). The remaining subjects could be divided into four categories: those with an underlying condition associated with delayed, but spontaneous, pubertal development [functional hypogonadotropic hypogonadism (FHH)], 19% of subjects; those with permanent hypogonadotropic hypogonadism, 12% of subjects; those with permanent hypergonadotropic hypogonadism, 13% of subjects; and those without clearly classified disorders, 3% of subjects. Like CD, FHH was male predominant, whereas the other categories either affected both genders equally or were predominantly female. In total, 50 different etiologies led to pubertal delay within our case series. Data permitted classification of family histories of pubertal timing among primary relatives in 95 of 122 of the CD and in 25 of 45 of the FHH cases. Analysis revealed at least a tendency to pubertal delay in 77% of the CD and in 64% of the FHH families and a diagnosis of delay in 38% of the CD and 44% of the FHH families. Both parents contributed to the positive family histories. The rates of positive family histories among the CD and FHH groups were approximately twice those seen among the other subjects in our case series. Among all subjects, those with FHH had the most marked growth delay, and girls had the greater bone age delay. Among the boys and at comparable chronological ages, CD and FHH were characterized by greater delays in pubic hair development and bone age than in the other diagnostic groups. Although CD is typically associated with leanness, 22% of our subjects had a BMI SD score at the 85th percentile or above for chronological age. These overweight subjects differed from the rest of the CD group: bone age was less delayed, and height was less affected. Finally, our analysis suggested a possible association between attention deficit disorder with or without hyperactivity and pubertal delay in our CD and FHH subjects. Our study provides valuable data regarding the variety and frequency of diagnoses that lead to delayed puberty. The results underscore the importance of performing a thorough evaluation and family history in adolescents with delayed puberty. Moreover, the data from our case series provide clues for unraveling the mechanism(s) of idiopathic pubertal delay and lead to the hypothesis that the pubertal delay seen among some subjects with FHH and CD may stem in part from similar underlying physiology.

Delayed puberty and response to testosterone in a rat model of colitis

Delayed puberty is a frequent complication of inflammatory bowel disease. The precise etiological mechanisms are not known. In this study, we wanted to determine the relative contribution of undernutrition and inflammation to delayed puberty and the effect of inflammation on the reproductive axis. Puberty was assessed in rats with 2,4,6-trinitrobenzenesulfonic acid induced-colitis, healthy controls, and animals pair fed to match the food intake of the colitic group. The response to testosterone administration was assessed in colitic rats. We found that induction of colitis was associated with hypophagia and reduced weight gain, and undernutrition in healthy females (i.e., pair fed) resulted in a delay in the onset (by 4.8 days, P < 0.001) and progression of puberty (normal estrous cycles in 42%, P = 0.04) compared with controls. However, puberty was further delayed in the colitic group (1.4 days after pair fed) with the absence of normal estrous cycling in all rats. In males, the onset of puberty was also delayed, and weights of accessory sex organs were reduced compared with pair-fed controls. Plasma testosterone concentrations were low, and gonadotropin concentrations were normal in colitic rats. Testosterone treatment normalized puberty in male rats with colitis. In conclusion, in rats with experimental colitis, inflammation appears to potentiate the effect of undernutrition on puberty. The weights of secondary sex organs and the onset of puberty were normalized by testosterone treatment.