Hair In Boys Research Articles

Prepubertal exposure to polycyclic aromatic hydrocarbons are associated with early pubertal development onset in boys: A longitudinal study

ObjectiveTo investigate the effects of polycyclic aromatic hydrocarbons(PAHs) on puberty in boys. Methods695 subjects were selected from four primary schools in Chongqing, China. 675 urine samples from these boys were collected four PAH metabolites: 1-hydroxypyrene, 2-hydroxynaphthoic, 2-hydroxyfluorene, and 9-hydroxyphenanthrene. Pubertal development of 695 boys was assessed at follow-up visits starting in December 2015 and occurring every six months thereafter until now, data used in this article ending in June 2021. A total of 12 follow-up visits were performed. Cox proportional hazards regression models were used to analyze the relationship between PAH metabolite concentrations and indicators of pubertal timing. ResultsThe mean age at puberty onset of testicular volume, facial hair, pubic hair, first ejaculation, and axillary hair in boys was 11.66, 12.43, 12.51, 12.72 and 13.70 years, respectively. Cox proportional hazards regression models showed that boys with moderate level of 1-OHPyr exposure was associated with earlier testicular development (hazard ratio [HR] = 1.276, 95% confidence interval [CI]: 1.006–1.619), with moderate level of 2-OHNap were at higher risk of early testicular development (HR = 1.273, 95% CI: 1.002–1.617) and early axillary hair development (HR = 1.355, 95% CI: 1.040–1.764), with moderate level of 2-OHFlu was associated with earlier pubic hair development (HR = 1.256, 95% CI: 1.001–1.577), with high level of 9-OHPhe were at higher risk of early fisrt ejaculation (HR = 1.333, 95% CI: 1.005–1.767) and early facial hair development (HR = 1.393, 95% CI: 1.059–1.831). ConclusionPrepubertal exposure to PAHs may be associated with earlier pubertal development in boys.

Association between sexual maturation and anterior disc displacement of temporomandibular joint in adolescents aged 13-14years.

To investigate the association between sexual maturation and anterior disc displacement (ADD) of temporomandibular joint (TMJ). Adolescents aged 13-14years old, attending the first grade of one private junior school, were recruited. Magnetic resonance imaging (MRI) was used to confirm ADD, in addition, the serum levels of sex hormones were tested. Secondary sex characteristics, psychological evaluations, oral health-related behaviors, and sociodemographic characteristics were also collected. A total of 440 teenagers were included, of which the prevalence of ADD was 17.7%. Subgroup analysis revealed that age at menarche in girls and nocturnal emission, laryngeal prominence, voice change, and facial hair in boys showed significant differences between the ADD group and the normal population (all p < 0.05). The serum levels of prolactin in girls (12.23 and 9.82ng/ml) and testosterone in boys (3.65 and 2.48ng/dl) were significantly higher in the ADD group compared to the normal population, respectively (both p < 0.05). This study suggested that sexual maturation has a significant association with ADD both in boys and girls. The increased serum levels of testosterone in boys and prolactin in girls might contribute to the occurrence of TMJ ADD. This study provides key data to support and inform longitudinal studies as well as to explain why ADD prefers in adolescents. Main findings can also be used to prevent the occurrence of ADD and secondary jaw deformities.

The prevalence of precocious puberty among children in Qufu City, Shandong Province, China, a population-based study

ObjectiveWe sought to investigate the prevalence of precocious puberty in children aged 6–10 years in Qufu City, Shandong Province, China.MethodsA total of 5,169 primary school students from grades 1–3 were recruited by population-based multi-stage stratified cluster random sampling. Professional pediatricians conducted physical examinations in October 2020. Precocious puberty is defined as the onset of secondary sexual characteristics in boys aged &amp;lt; 9 years or girls &amp;lt; 8 years or menstruation in girls &amp;lt; 10 years old. Tanner staging was used to record the development of breast and pubic hair in girls and testicular volume and pubic hair in boys. According to the standards of the International Obesity Task Force, we diagnosed overweight, obesity, or severe obesity. In obese girls, a combination of palpation and ultrasound was used to evaluate breast development. The difference was tested by chi-squared test, and all data were statistically analyzed using IBM SPSS version 25.0.ResultsThe unadjusted and adjusted prevalence rates of precocious puberty were 5.01% (11.53% for girls and 1.41% for boys) and 6.29% (14.23% for girls and 1.54% for boys), respectively. The prevalence of precocious puberty in urban (5.34%) dwellers was much higher than that in suburban residents (2.36%, P &amp;lt; 0.05). The prevalence of precocious puberty in the overweight (21.43% for girls and 1.97% for boys), obesity (35.48% for girls and 4.6% for boys), and severe obesity (32.35% for girls and 3.38% for boys) groups were higher than that in the normal weight group (4% for girls and 0.54% for boys, P &amp;lt; 0.05).ConclusionThe prevalence of precocious puberty is high, and overweight and obesity are related to precocious puberty in Qufu, Shandong Province, China.

Изменения некоторых показателей жироотложения и компонентов состава тела в процессе полового созревания у подростков Архангельского региона и г. Москвы

Introduction. This work is devoted to the study of changes in some indicators of subcutaneous fat deposition and body mass components depending on the rate of puberty in adolescents of the Arkhangelsk region and Moscow. Materials and methods. The analysis used data from 1 516 people aged 12 to 16 years in the case of boys and 11 to 15 years in the case of girls. The anthropometric examination, the analysis of the body composition and the assessment of the puberty stage were carried out according to the standard methodology in compliance with bioethical recommendations. Probit analysis was used to determine the timing of pubertal stages. Results and discussion. According to the results obtained, adolescents of all three groups have the usual sequence of appearance of secondary sexual characteristics. In addition, standard patterns are observed: urban schoolchildren go through the stages of puberty earlier than their rural peers. As for the change in anthropometric characteristics depending on the stage of puberty, in this case, the consistency of the changes occurring with the maturation of the mammary glands in girls and the appearance of pubic hair in boys is confirmed. In the former, the amount of body weight and its fat component, as well as the thickness of the skinfolds, are more dependent on the stage of puberty; in the latter, the girth dimensions. Regardless of sex, the examined signs in their absolute magnitude show a tendency to increase, while the relative body fat mass decreases with breast development in girls. In young men, the alternation of the processes of its increase and decrease was recorded as the development of pubic envelopment progressed from stage to stage. The exception is Muscovites, in whom, with the appearance of this sign, there is a sharp significant increase in body fat mass with a further slight fluctuation during puberty. Conclusion. The dependence of the parameters of fat deposition on biological age is more clearly manifested in groups of girls, since for male individuals the degree of maturation is more correlated with the muscular component. In this case, the characteristics of the fat component begin to show a coherent picture at the final stages of puberty.

Prevalence of precocious puberty among Chinese children: a school population-based study.

To investigate the prevalence of precocious puberty in school-based population in Zhongshan, Guangdong, China. We recruited a total of 4058 students in grades 1-3 using a multistage stratified cluster random sampling method in a population-based cross-sectional study. We evaluated height, weight, and development of breast and pubic hair in girls, breast development was evaluated by inspection and palpation combined with ultrasound detection for overweight and obese girls, and testicular volume and development of pubic hair in boys. We estimated overall, sex-, age, and district-specific prevalence of precocious puberty and examined the association between prevalence of precocious puberty and body mass index (BMI). The unadjusted and adjusted prevalence of precocious puberty by Tanner stage was 4.74% (girls:8.78%, boys:2.58%) and 6.19% (girls:11.47%, boys:3.26%), respectively. In both urban and suburban areas, the prevalence of precocious puberty was higher in the overweight and obese group than in the normal-weight group (p < 0.05). The prevalence of precocious puberty among overweight (27.94%) and obese (48.00%) girls was higher than that of normal-weight girls (8.73%) (p value for trend < 0.05). In boys, the prevalence of precocious puberty in the obese (6.78%) group was higher than that in the normal-weight (2.86%) group (p < 0.05). The prevalence of precocious puberty was high in China. Overweight and obesity was related to precocious puberty, but this correlation had gender differences and may be affected by other environmental factors.

Content of essential trace elements in the hair of children with short stature due to somatotropic insufficiency

The content of essential trace elements (zinc, selenium, chrome, magnesium, copper) was studied in 102 children with short stature due to total (n = 66; 54 - boys; mean age 10.23 ± 0.4 years) or partial (n = 36; 26 - boys; mean age 8.91 ± 0.4 years) somatotropic insufficiency.Aim. The aim of our research was a complex studying the content of essential trace elements (zinc, selenium, manganese, chrome, copper) in the hair of children with low growth, caused by somatotropic insufficiency, to determine the additional ways to optimize the treatment of these patients.Methods. The content of insulin-like growth factor-1 (IGF-1) was determined once a morning in the blood sample by radioimmunoassay using standard kits «IRMA IGF-1" firm «Immunotech» (Czech Republic). The body height was measured using stadiometer «System Dr. Keller J.», the body mass - using Seca electronic scales. The atlas of W.W. Greulich, S.P. Pyle (1993 was used to determine the bone age.Results. As a result of our examination a significant decrease in the content of all the studied tracer elements: zinc, selenium, manganese, chrome, copper was noted in the hair of the great majority of children with complete (group I) or partial (group II) somatotropic insufficiency. A sharp decline in zinc content in the hair of patients with complete (78,50 ± 4,31 mcg / g, p˂0.001) and partial (83.94 ± 4.89 mcg / g, p˂0.001) somatotropic insufficiency, compared with reference values and control indices was established. The mean values of selenium, manganese did not differ between themselves and the indices of control group (p˃0.1) in both groups, but they were significantly lower than the reference values. A significant decrease in the chromium content in the hair of girls with the total somatotropic insufficiency comparing to the control group (p˂0.05) was revealed. The tendency to decrease in the content of copper in the hair of boys in the whole group with total somatotropic insufficiency was established.Conclusions. The obtained data indicate the expediency of studying the tracer elements status in children with short stature due to somatotropic insufficiency and of carrying out the corresponding correction, in a case of essential tracer elements deficiency

Sexual Dimorphisms in the Associations of BMI and Body Fat with Indices of Pubertal Development in Girls and Boys

The effect of obesity and concomitant insulin resistance on pubertal development is incompletely elucidated. To determine how measures of adiposity and insulin resistance are associated with pubertal maturation in boys and girls. 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. 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. 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.

The Content of Fluoride, Calcium and Magnesium in the Hair of Young Men of the Bantu Language Group from Tanzania Versus Social Conditioning

The present study aimed at analysing the content of fluorine (F), calcium (Ca) and magnesium (Mg) in the hair of young male students (n = 52) of a secondary school in Mafinga in Tanzania (Africa) who participated in anthropological examinations. Ca and Mg concentrations were determined using atomic absorption spectrophotometer while F levels using a potentiometric method. F in the hair of boys from older group (≥16 years old; n = 24) was significantly higher than in the younger group (<16 years old; n = 28) versus Ca and Mg levels. High carbohydrate diet was predominant—mainly based on corn or bean and meat served once a week, with few fruit and raw vegetables. Collective catering in the dormitory reflected habits and culinary preferences at home. The lack of balanced diet, with majority of the nutritional energy supplied by easily accessible and cheap carbohydrates, was reflected in dietary deficiencies, characterised, among others, by visible skin conditions and tooth decay.

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

To evaluate associations of perinatal HIV infection, HIV disease severity, and combination antiretroviral treatment with age at pubertal onset. Analysis of data from two US longitudinal cohort studies (IMPAACT 219C and PHACS AMP), conducted during 2000-2012, including perinatally HIV-infected (PHIV) and HIV-exposed but uninfected (HEU) youth. Tanner stage assessments of pubertal status (breast and pubic hair in girls; genitalia and pubic hair in boys) were conducted annually. We compared the timing of pubertal onset (Tanner stage ≥2) between PHIV and HEU youth using interval-censored models. For PHIV youth, we evaluated associations of HIV disease severity and combination antiretroviral treatment with age at pubertal onset, adjusting for race/ethnicity and birth cohort. The mean age at pubertal onset was significantly later for the 2086 PHIV youth compared to the 453 HEU children (10.3 vs. 9.6, 10.5 vs. 10.0, 11.3 vs. 10.4, and 11.5 vs. 10.7 years according to female breast, female pubic hair, male genitalia, and male pubic hair staging, respectively, all P < 0.001). PHIV youth with HIV-1 RNA viral load above 10, 000 copies/ml (vs. ≤10, 000 copies/ml) or CD4% below 15% (vs. ≥15%) had significantly later pubertal onset (by 4-13 months). Each additional year of combination antiretroviral treatment was associated with a 0.6-1.2-month earlier mean age at pubertal onset, but this trend did not persist after adjustment for birth cohort. Pubertal onset occurs significantly later in PHIV than in HEU youth, especially among those with more severe HIV disease. However, in the current era, combination antiretroviral treatment may result in more normal timing of pubertal onset.

SECULAR CHANGES IN HEIGHT, BODY WEIGHT, BODY MASS INDEX AND PUBERTAL DEVELOPMENT IN MALE CHILDREN AND ADOLESCENTS IN KRAKOW, POLAND

This study examined the secular changes in height, body weight, body mass index and pubertal development in male children and adolescents in Krakow (Poland) over the past 80 years, with an emphasis on the last decade (2000-2010). The survey of the population of Krakow is a continuation of observations conducted in that area for many years. The analysis aims to determine whether in the last decade Krakow still witnessed the secular trend, and what form the trend took. The body height and weight, and body mass index (BMI), of 1862 boys aged 3.5-18.5 years were analysed, against the background of a survey series from the years 1938 (N = 1801), 1971 (N = 2045), 1983 (N = 3124) and 2000 (N = 2328). The mean body height, in almost all age categories, was greater than in the past; however the final height over the last decade remained the same. The mean values of body weight and BMI increased, especially in the last decade. Also, an acceleration of puberty in boys was observed. The last 10 years saw an over 3-month decrease in the age of initial appearance of pubic hair in boys. In conclusion, the last decade saw cessation of the growing taller trend: maximum body height stabilized at approximately 179 cm, but weight and BMI increased. Also, a distinct acceleration of puberty was noticed. Lack of height increase, at the same time as weight gain and puberty acceleration, indicate a progressing developmental disharmony.

Is puberty starting earlier in urban South Africa?

Age at the initation of pubertal development was estimated for 401 Black (212 boys) and 206 White (100 boys) urban South African adolescents born in Soweto-Johannesburg in 1990. Average age at the initation of puberty, assessed by age at the transition from Tanner Stage 1 to Tanner Stage 2 for breast/genitalia or pubic hair development ranged between 9.8 and 10.5 years. There were no statistically significant differences in age at initiation between genders or ethnic groups. Age at the initation of pubertal development has remained stable over the last 10 to 15 years, with the exception of pubic hair in boys which has declined on average 1.3 years over a decade. There is evidence to suggest that the tempo of pubertal maturation is increasing in girls born in the Soweto-Johannesburg area, however, the evidence is less clear for boys.

Isolated scrotal hair in infancy

Nine male infants who developed scrotal hair with no other signs of virilization were evaluated. Median age for the development of scrotal hair was 4.5 months, and median age at presentation was 7.5 months. Endocrinologic investigations performed in 6 of the infants yielded normal findings. The scrotal hair receded at a mean age of 12 months, suggesting a transient benign event. The development of genital hair in boys under age 9 years is considered precocious, suggesting a possible pathological condition (eg, precocious puberty, congenital adrenal hyperplasia, adrenal or genital tumors), or may be due to premature adrenarche.

Content of lead in human hair from people with various exposure levels in Lithuania

A study has been performed to estimate if hair lead (Pb) can be used assessing environmental and occupational exposure to the metal. From 1994-1997, 622 ceramic plant employees, 520 randomly selected controls from Kaunas without occupational exposure to Pb aged 18-64 years, and 380 10-13 year old children living in Kaunas participated in this study. The concentration of Pb in the hair samples was measured by atomic absorption spectrometry. The geometric mean of Pb in the hair of workers occupationally exposed to Pb was significantly higher than that in persons not exposed to the metal (7.6 microg/g, 95% CI = 6.5-8.7 for exposed workers, 3.2 microg/g, 95% CI = 2.8-3.6 for not exposed workers and 2.6 microg/g, 95% CI = 2.4-2.9 for randomly selected controls, p < 0.05). Pb content in hair of boys and girls was 2.9 microg/g (95% CI = 2.6-3.3) and 3.1 microg/g (95% CI = 2.6-3.6), respectively. Lead in hair was not related to gender. Multiple regression analysis in adults with age as a continuous variable showed a positive relationship between Pb in hair and age. Also different exposure levels were significantly related to Pb in hair. In men, a positive association was found between Pb in hair and smoking. The data obtained suggest that human hair could be used to identify lead exposure in epidemiological surveys.

Use of pattern recognition methods in the interpretation of heavy metal (lead and cadmium) in children's scalp hair.

A study has been performed to identify the exposure to toxic metals and possible adverse effects in children from various rural and industrial areas in southern Poland. The population studied consisted of school children of age 7-12. The concentrations of Pb and Cd were determined by atomic absorption spectrometry. The mean Pb and Cd content in the hair of the sampled individuals was found to be 4.85 +/- 5.91 micrograms g-1 and 0.430 +/- 0.569 micrograms g-1, respectively. The hair of boys (particularly those living in the areas of greater industrial contamination) exhibited statistically significant higher levels of Pb and Cd than the hair of girls from the same area. No relationship was revealed between metal content and either anthropometric indices (weight : height ratio or height : age ratio) or educational achievements.

Self-assessment and physician assessment of sexual maturation in Brazilian boys and girls: Concordance and reproducibility.

This study considered the concordance of self-assessment and physician assessment of sexual maturity status; breasts, and pubic hair in girls, and genitals and pubic hair in boys. The subjects were Brazilian children, youth and young adults, 174 females and 178 males, 6-26 years of age. Each subject evaluated his/her level of sexual maturation and then was examined by a physician. The sexual maturity ratings of the subjects and physicians were compared. Overall, the results showed moderate to high concordance (60.9-71.3%) for both assessments of secondary sex characteristics; better concordance was found for pubic hair (69.7-71.3%) than for the breasts or genitals (60%). Age did not appear to influence the accuracy of self-evaluation; rather, accuracy was more dependent on stage of maturation of the subject. Correlations between self- and physician assessments, and replicate self- and physician assessments were relatively high. © 1994 Wiley-Liss, Inc.

Physical Changes of Puberty

Normal pubertal development is characterized by major physical alterations: sexual maturation, changes in body composition, and rapid skeletal growth. Breast development is the first manifestation of puberty in approximately 85% of girls; the normal age for initial breast development is 8 to 13 years. Menarche generally occurs within 2 years of the onset of breast development, with a mean age in American girls of 12.8 years. In boys, the first manifestation of puberty is testicular enlargement; the normal age for initial signs of puberty is 9 to 14 years in males. Pubic hair in boys generally appears 18 to 24 months after the onset of testicular growth and is often conceived as the initial marker of sexual maturation by male adolescents. Skeletal growth is one of the most striking characteristics of puberty. Linear-growth velocity begins to increase in males at genital stage III and pubic-hair stage II, but peak height velocity is not attained until age 14 years in boys and 12 years in girls. Lean body mass, which primarily reflects muscle mass, begins to increase during early puberty in both boys and girls. Fat mass increases during the late stages of puberty in girls. Sex differences in the adolescent growth spurt produce the characteristics sexual dimorphism in shape and proportions seen in young adults.

Pubic hair in boys due to adrenarche rather than true puberty

Pubic hair sometimes develops in boys before testicular enlargement. We have tested the possibility that this situation can be due to adrenarche rather than true puberty. Eight cases between 5.5 and 12.8 years of age were observed to have stage III pubic hair and prepubertal-size testes. All were healthy; 5 were obese. Plasma dehydroepiandrosterone sulphate (DHAS) levels were 94-228 μg/dl, above the 95% limits for age. Plasma testosterone at 0800-1300 hr was 11-28 ng/dl. Bone age was normal or only slightly advanced. Diurnal blood sampling and ACTH testing were carried out in an 8.6 year old case. Daytime and nighttime testosterone were similar (16-30 ng/dl), ruling out early true sexual precocity. His baseline pattern and response of steroid intermediaries to ACTH was typical of premature adrenarche, ruling out adrenogenital syndrome. In two other cases the pattern of plasma steroid intermediates was normal and DHAS was shown to be normally dexamethasone-suppressible. These studies show that isolated onset of pubic hair in boys without testicular enlargement does not necessarily indicate true puberty or virilization, but is often due to adrenarche as a variation of normal. Furthermore, these results suggest an association between premature adrenarche and obesity.

Pubertal changes in boys and girls in Newcastle upon Tyne.

669 boys and 753 girls born in 1962 and living at home were observed at approximately half-yearly intervals from 9 to 17 years of age. Mean ages of reaching various developmental stages were calculated for voice change and facial hair in boys, menarche and breast development in girls, and for axillary hair in both sexes. Peak height velocity and age at which it occurred were also calculated for both sexes. Means were generally in good agreement with those found about 15 years previously in the Harpenden Growth Study. Most pubertal changes in the present study showed gradients by social class; in boys, development was later in those with fathers in unskilled manual occupations, whereas in girls the greatest differences, where found, were between those with fathers in non-manual occupations and the remainder.

Physical maturation: A study of secondary school children in fife

An account is given of a survey of physical maturation in schoolchildren born in 1949 in Fife. The survey was carried out as part of the routine school medical examinations. The results of the survey compared with earlier work in other areas show no significant change during the past 10 years. The value of surveys of axillary hair in boys as a sign of adolescence is discussed. Though half the girls were prepared for the menarche by their mothers, the proportion of girls ignorant of the physiology of menstruation is high and suggests that simple instruction could be included in “mothercraft” lessons given at an early stage of the secondary school course, or even in primary schools. There is a need for “hygiene” facilities for girls in large primary schools.