The prevalence and risk factors of premature thelarche and pubarche in 4- to 8-year-old girls

Evaluating breast ultrasonography as a complementary diagnostic method in girls with central precocious puberty

BACKGROUND

Assessment of breast development by physical examination can be difficult in the early stages and in overweight girls.

OBJECTIVE

To investigate ultrasonography (US) for evaluation of early breast development.

MATERIALS AND METHODS

In a prospective study, 125 girls (age 7.1 ± 1.5 years) with breast development before 8 years underwent US breast staging, breast volume, and elastography, in addition to clinical/hormonal evaluation for precocious puberty. Accuracy of US for determining breast development and predicting progression to central precocious puberty was investigated.

RESULTS

Physical examination revealed glandular breast enlargement in 100 and predominantly lipomastia in 25. Breast US in the former confirmed glandular breast development in 92 (group 1, physical examination and US positive), but not in 8 (group 2, physical examination positive, US negative). Comparison of the two groups demonstrated lower Tanner and US staging, bone age/chronological age, basal luteinizing hormone (LH), breast volume, and uterine volume in group 2. In the 25 lipomastia patients, US demonstrated no breast tissue in 19 (group 3, physical examination and US negative), but US stage ≥ II in 6 (group 4, physical examination negative, US positive) without differences in clinical parameters. After follow-up of 19.8 ± 4.2 months, 46/125 subjects were diagnosed with precocious puberty. US stage, total breast volume, and shear-wave speeds were significantly higher in these 46 patients. Multivariate analyses demonstrated breast volume > 3.4 cc had odds ratio of 11.0, sensitivity of 62%, and specificity of 89, in predicting progression to precocious puberty, being second only to stimulated LH for all variables.

CONCLUSION

Breast US is a useful predictive tool for diagnosis of precocious puberty in girls. Higher US stages and higher breast volume on US increased the likelihood of eventual diagnosis of precocious puberty.

Premature Thelarche: An Updated Review

BACKGROUND

Premature thelarche is the most common pubertal disorder in girls. The condition should be differentiated from central precocious puberty which may result in early epiphyseal fusion and reduced adult height, necessitating treatment.

OBJECTIVES

The purpose of this article is to familiarize physicians with the clinical manifestations of premature thelarche and laboratory tests that may help distinguish premature thelarche from central precocious puberty.

METHODS

A search was conducted in September 2022 in PubMed Clinical Queries using the key term "Premature thelarche". The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used to compile the present article.

RESULTS

Premature thelarche denotes isolated breast development before the age of 8 years in girls who do not manifest other signs of pubertal development. The condition is especially prevalent during the first two years of life. The majority of cases of premature thelarche are idiopathic. The condition may result from an unsuppressed hypothalamic-pituitary-gonadal axis in the early years of life, an "overactivation" of the hypothalamic-pituitary axis in early childhood secondary to altered sensitivity to steroids of the hypothalamic receptors controlling sexual maturation, increased circulating free estradiol, increased sensitivity of breast tissue to estrogens, and exposure to exogenous estrogens. The cardinal feature of premature thelarche is breast development which occurs without additional signs of pubertal development in girls under 8 years of age. The enlargement may involve only one breast, both breasts asymmetrically, or both breasts symmetrically. The breast size may fluctuate cyclically. The enlarged breast tissue may be transiently tender. There should be no significant changes in the nipples or areolae and no pubic or axillary hair. The vulva, labia majora, labia minora, and vagina remain prepubertal. Affected girls have a childlike body habitus and do not have mature contours. They are of average height and weight. Growth and osseous maturation, the onset of puberty and menarche, and the pattern of adolescent sexual development remain normal. Most cases of premature thelarche can be diagnosed on clinical grounds. Laboratory tests are seldom indicated. No single test can reliably differentiate premature thelarche from precocious puberty.

CONCLUSION

Premature thelarche is benign, and no therapy is necessary apart from parental reassurance. As enlargement of breasts may be the first sign of central precocious puberty, a prolonged follow- up period every 3 to 6 months with close monitoring of other pubertal events and linear growth is indicated in all instances.

The Role of Irisin throughout Women's Life Span

Since its discovery, much attention has been drawn to irisin's potential role in metabolic and reproductive diseases. This narrative review summarizes and updates the possible role played by this fascinating molecule in different physiological (puberty and menopause) and pathological (polycystic ovary syndrome (PCOS), functional hypothalamic amenorrhea (FHA), endometriosis, and gestational diabetes) conditions that can affect women throughout their entire lives. Irisin appears to be an important factor for the hypothalamic-pituitary-gonadal axis activation, and appears to play a role in the timing of puberty onset. Serum irisin levels have been proposed as a biomarker for predicting the future development of gestational diabetes (GDM). Its role in PCOS is still controversial, although an "irisin resistance" mechanism has been hypothesized. In addition to its impact on metabolism, irisin also appears to influence bone health. Irisin levels are inversely correlated with the prevalence of fractures in postmenopausal women. Similar mechanisms have also been postulated in young women with FHA. In clinical settings, further controlled, prospective and randomized clinical trials are needed to investigate the casual relationship between irisin levels and the conditions described and, in turn, to establish the role of irisin as a prognostic/diagnostic biomarker or a therapeutic target.

A systematic review on maternal and perinatal factors influencing breast development

BACKGROUND

A secular trend towards earlier age at menarche has been reported, but the trend in breast development is less clear. We reviewed the evidence on the relationship between in utero and early life events and breast onset/development.

METHODS

Eligible studies were identified in PubMed and Embase databases. We selected studies in which female human exposure during fetal or the first years of life was measured or estimated, and associations with breast onset or development were evaluated.

RESULTS

Of the 49 cohort studies and 5 cross-sectional studies identified, 43 provided sufficient data to assess associations. High maternal weight, primiparity, and early weight gain, were related to an increased risk of early breast onset/development in most of the studies that analysed these associations, whereas late breast onset/development was associated with preterm birth. Results were inconsistent for smoking in pregnancy, maternal hypertensive disorders, breastfeeding, diabetes, and small for gestational age. No association emerged for maternal age at delivery, alcohol drinking, and selected drug use during pregnancy, and low birth weight.

CONCLUSIONS

The results of this review show that high maternal weight, primiparity and early weight gain were associated with an increased risk of early breast onset/development. Late breast onset/development was associated with preterm birth. Breast development is a key physical marker of puberty onset, and early puberty development is linked to consequences that can reverberate throughout life. Answering the questions about the interconnections between pre/postnatal environmental exposures and their impact on puberty, represents an important area of multidisciplinary research.

Evaluation of Glucose Metabolism and Cardiovascular Risk Factors in Prepubertal Girls with Premature Pubarche

OBJECTIVE

Premature pubarche (PP) is a risk factor for metabolic syndrome (MS). The aim was to evaluate if glucose-insulin metabolism, cardiovascular risk factors, familial cardiovascular risk factors (FCVRF) created a risk for insulin resistance (IR) and if PP was a risk factor alone for MS in normal weight prepubertal girls with PP.

METHODS

Thirty-five prepubertal, non-obese girls with PP with normal birth weight and 35 age-matched control girls were evaluated for FCVRF, anthropometric measurements, blood pressure, lipid profile, fasting blood glucose-insulin, hemoglobin A1c (HbA1c), sex hormone binding globulin (SHBG), leptin, adiponectin, tumor necrosis factor-alpha (TNF-α), androgen levels, and bone age. Oral glucose tolerance test was performed in PP participants. Homeostasis model of assessment of IR (HOMA-IR), fasting glucose/insulin ratio, atherogenic index (AI), and free androgen index (FAI) were calculated. PP participants were further stratified by FCVRF.

RESULTS

HbA1c, lipid profile, testosterone, leptin, adiponectin, TNF-α, HOMA-IR, glucose/insulin ratio, AI, and fasting glucose-insulin levels were similar. In the PP group FAI was significantly higher (p=0.001), whereas SHBG was significantly lower (p=0.010) than the control group. Leptin levels of FCVRF+ and FCVRF- subgroups were 15.2±9.1 and 9.7±7.2 ng/mL, respectively and the difference was significant (p=0.016).

CONCLUSION

As PP does not appear to be a risk factor alone for impaired glucose metabolism and IR in prepubertal non-obese girls with normal birth weight, it is our opinion that it is unnecessary to examine in detail such cases before puberty. Low SHBG levels in the PP group and high leptin levels in FCVRF+ subgroup might suggest that these may be predictive for MS in the future.

Serum irisin levels increase in girls with central precocious puberty not dependent on BMI: a pilot study

OBJECTIVE

The objective of this study is to investigate the role of serum irisin level in diagnosis of central precocious puberty (CPP) in girls and its major determinants.

METHODS

This study was conducted in 67 girls with CPP, 19 girls with premature thelarche (PT) and 59 normal controls. The major determinants of irisin were assessed by multivariate linear regression (MLR) analysis. Propensity score matching (PSM) analysis was performed to minimize the bias that can result from BMI. A receiver operating characteristic curve was used to obtain the optimal threshold value of irisin.

RESULTS

The girls with CPP and PT had higher irisin levels than controls (P < 0.05). The optimal cutoff value of irisin levels for predicting CPP was 91.88 ng/mL, with a sensitivity of 70.1% and a specificity of 72.9%. MLR analysis showed that BMI was a predictor of irisin (P < 0.05). Serum irisin levels remained higher in the CPP girls than the controls with adjustment for BMI (P < 0.05).

CONCLUSIONS

Increased serum irisin levels with CPP suggest that irisin is involved in puberty. However, due to low sensitivity and specificity, irisin level can only be used as an auxiliary indicator rather than a single diagnostic indicator of CPP.

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.

Investigation of early puberty prevalence and time of addition thelarche to pubarche in girls with premature pubarche: two-year follow-up results

We aimed to determine the prevalence of early puberty in girls with premature pubarche and analyze the time interval between their pubarche and succeeding thelarche. This study included 60 female children with premature pubarche. We retrospectively collected clinical, laboratory, and radiological findings from all participants. We investigated the time interval between pubarche and thelarche in cases wherein premature pubarche was followed by thelarche. The mean age at onset of pubarche was 6.93 ± 0.79 yr old. Among the participants, 16.7% were preterm, 20% were small for gestational age (SGA), and 55% were overweight or obese. The mean time interval between pubarche and thelarche was 11.20 ± 7.41 mo. The mean serum DHEA-S level was higher in the preterm group (p = 0.016), and DHEA-S levels were generally higher in the SGA group (p = 0.004). This study documented the presence of being overweight or obese and having more advanced growth than their genetic potential in half of the patients who had premature pubarche. In addition to these identified risk factors, obesity-independent DHEA-S levels were observed to be higher in patients who had early puberty with the first six months of their follow-up considered to be the most critical time in predicting early puberty.

The critical BMI hypothesis for puberty initiation and the gender prevalence difference: Evidence from an epidemiological survey in Beijing, China

BACKGROUND

Although previous studies suggested that there is a certain level of body fat mass before puberty can be initiated, most studies have focused on girls.

OBJECTIVE

To investigate the relationship between precocious puberty and physical growth in school-aged children in Beijing, China.

METHODS

7590 Chinese children (3591 girls and 3999 boys) aged 6-11 years were recruited in Beijing, China. Body mass index (BMI) categories were defined by WHO Child Growth Standards and central obesity were defined by sex-specific waist-to-height ratio cut-offs (≥0.46 for girls, ≥0.48 for boys). Sexual development was assessed using Tanner criteria.

RESULTS

The prevalence of general obesity and central obesity among boys was higher than that in girls. Girls had a significantly higher precocious puberty rate than boys (5.93% vs. 0.87%), particularly in those aged 7 years old (9.20%). Children in the general obesity and central obesity groups have a higher prevalence of precocious puberty and earlier median ages for the attainment of Tanner B₂/T₂. For girls with Tanner stages≥II at 6-year-old and 7-year-old, the mean BMI was equivalent to the 50th centile of a normal 9.9-year-old and 11.9-year-old girl, respectively. The mean BMI of boys with Tanner stages≥II at 7-year-old and 8-year-old was correspondent to the 50th centile of a normal 14-year-old and 15.3-year-old boy, respectively. For girls, general obesity appears to contribute to the risk of the development of precocious puberty to a greater extent than central obesity does. For boys, central obesity, but not general obesity, was an independent risk factor for precocious puberty.

CONCLUSIONS

The prevalence of childhood obesity and precocious puberty was high in China. Precocious puberty was correlated with a large BMI. Boys had a higher threshold of BMI for puberty development than girls. Children with precocious puberty, particularly those with central obesity, should be aware of adverse cardiovascular events.

Physical deviation and precocious puberty among school-aged children in Leshan City: an investigative study

Objective

We investigated physical deviation and precocious puberty among school-aged children in Leshan City, to provide a theoretical basis for the management of precocious puberty in children.

Methods

We selected 12 primary schools of Leshan City using a cluster random sampling method and conducted physical examinations among healthy students aged 4 12 years. A total of 11,000 students were recruited (5502 boys and 5498 girls). We measured body mass index (BMI), and participants were tested for precocious puberty according to the Tanner stages and standard maps. Nutritional status was also evaluated.

Results

Obese and overweight children accounted for a high proportion of participants; the prevalence of underweight was the lowest. The prevalence of obesity among boys was higher than that in girls. Precocious puberty was mainly observed in girls, particularly those age 7 years old. The prevalence of precocious puberty among overweight and obese children was higher than that in children with normal weight.

Conclusion

We identified a significant sex difference in precocious puberty among children in Leshan City. Overweight and obesity may be associated with precocious puberty.

Serum Irisin Levels in Central Precocious Puberty and Its Variants

AIM

The exact mechanisms that trigger the onset of puberty are not well known. Adipomyokines are postulated to stimulate the central neural network. In the present study, we investigated irisin levels in girls with central precocious puberty (CPP), slowly progressing precocious puberty (SPPP), or premature thelarche (PT); we also studied prepubertal girls and to determine if this adipomyokine could be used as a marker in this context.

METHODS

A total of 94 girls including 33 with CPP, 31 with precocious puberty (PP) variants (SPPP or PT), and 30 healthy controls were enrolled to the study. The mean irisin levels were compared between groups. The bivariate correlations of irisin levels with clinical and laboratory parameters were assessed. Multivariate linear regression analysis was performed to determine independent predictive factors of irisin levels.

RESULTS

Irisin levels were higher in the CPP group compared with the other groups (CPP group: 723.25 ± 62.35 ng/mL; PP variants group: 529.60 ± 39.66 ng/mL; and control group: 325.03 ± 27.53 ng/mL) (P < 0.001). Irisin levels were positively correlated with body mass index standard deviation scores (BMI-SDS), height-SDS, weight-SDS, bone age, uterus long axis, ovary size, baseline FSH and LH, and peak LH levels. Multivariate linear regression analysis revealed that irisin levels had the strongest correlation with peak LH. The other independent predictive factor of irisin levels was BMI-SDS.

CONCLUSIONS

The mean irisin levels were higher in patients with CPP compared with other groups. The results of this study imply that increased irisin levels may be used as a marker of CPP provided that these findings are confirmed in larger prospective studies.

Factors affecting bone maturation in Chinese girls aged 4-8 years with isolated premature thelarche

Background

In isolated premature thelarche (IPT) girls, bone age (BA) is considered consistent with chronological age. However, some IPT girls confirmed by gonadotropin-releasing hormone (GnRH) stimulation test could show another trend. We analysed BA and possible potentiating factors in a selected group of girls aged 4–8 years with IPT.

Methods

IPT girls confirmed by GnRH stimulation test aged 4–8 years hospitalized from January 2015 to April 2018 at Shenzhen Children’s Hospital were included in this retrospective study. They were divided into two groups with advanced BA of 2 years as the cut-off. Body mass index (BMI) and hormone levels were the main outcome measures, and regression analysis was used to identify independent risk factors. IPT girls were divided into subgroups according to the levels of BMI standard deviation score (SDS), insulin-like growth factor-1 (IGF-1) SDS and dehydroepiandrosterone sulfate (DHEAS) SDS for comparisons of advanced BA.

Results

Overall, 423 subjects were included and classified into the advanced BA group (48.7%, n = 206) and control group (51.3%, n = 217). The advanced BA group had significantly higher BMI SDS, serum DHEAS SDS, IGF-1 SDS, androstenedione and fasting insulin and significantly lower sex hormone binding globulin (all p < 0.001). Serum IGF-1 SDS (OR = 1.926, p<0.001), BMI SDS (OR = 1.427, p = 0.001) and DHEAS SDS (OR = 1.131, p = 0.005) were independent risk factors for significantly advanced BA. In the multiple linear regression model, serum IGF-1 SDS, BMI SDS and DHEAS SDS were the strongest predictors of advanced BA, accounting for 19.3% of the variance. According to BMI, 423 patients were classified into three groups: normal weight (56.03%, n = 237), overweight (19.15%, n = 81) and obesity (24.82%, n = 105). The proportion of advanced BA in obesity group was significantly higher than those of normal weight and overweight groups (χ² = 18.088, p<0.001). In the subgroup with normal weight, higher serum IGF-1 SDS (p = 0.009) and DHEAS SDS (p = 0.003) affected BA advancement independent of BMI SDS.

Conclusions

Girls with IPT confirmed by GnRH stimulation test aged 4–8 years might have significantly advanced BA. Obesity was highly associated with advanced BA. Age-specific serum IGF-1 SDS and DHEAS SDS were risk factors for BA advancement independent of BMI.

MiR-664-2 impacts pubertal development in a precocious-puberty rat model through targeting the NMDA receptor-1†

Precocious puberty (PP) commonly results from premature activation of the hypothalamic-pituitary-gonadal axis (HPGA). Gonadotropin-releasing hormone (GnRH) is the initial trigger for HPGA activation and plays an important role in puberty onset. N-methyl-D-aspartate (NMDA) can promote pulsatile GnRH secretion and accelerates puberty onset. However, the mechanism of N-methyl-D-aspartate receptors (NMDARs) in PP pathogenesis remains obscure. We found that serum GnRH, luteinizing hormone (LH), follicle-stimulating hormone (FSH), estrogen (E2) levels, hypothalamic NMDAR1, and GnRH mRNA expression peaked at the vaginal opening (VO) day. Next, the hypothalamic NMDAR1 mRNA and protein levels in rats treated with danazol, a chemical commonly effecting on the reproductive system, were significantly increased at the VO day (postnatal day 24) compared to controls, accompanied by enhanced serum GnRH, LH, FSH, and E2 levels. Further, microRNA-664-2 (miR-664-2) was selected after bioinformatics analysis and approved in primary hypothalamic neurons, which binds to the 3'-untranslated regions of NMDAR1. Consistently, the miR-664-2 expression in hypothalamus of the Danazol group was decreased compared to Vehicle. Our results suggested that attenuated miR-664-2 might participate in PP pathogenesis through enhancing the NMDAR1 signaling.

Low prevalence of organic pathology in a predominantly black population with premature adrenarche: need to stratify definitions and screening protocols

Background

Premature adrenarche has been described as clinical and biochemical hyperandrogenism before the age of 8 years in girls and 9 years in boys and absence of signs of true puberty. Adrenal pathology such as adrenal tumors or non-classical congenital adrenal hyperplasia (NCCAH) and exogenous androgen exposure need to be excluded prior to diagnosing (idiopathic) premature adrenarche. Premature adrenarche is more common among black girls compared to white girls and other racial groups. Adrenal pathology such as NCCAH is less common as a cause for premature adrenarche compared with idiopathic premature adrenarche. The evaluation guidelines for premature adrenarche however are not individualized based on racial/ethnic differences. Few studies have been done to evaluate a largely black population with premature adrenarche to assess the incidence of adrenal pathology.

Methods

This cross-sectional retrospective study evaluated characteristics of prepubertal patients seen in an endocrine clinic for premature adrenarche.

Results

Two hundred and seventy three subjects had signs of early adrenarche. Three subjects were found to have CAH (2 with NCCAH and 1 with late diagnosis classical CAH). None were black. Exogenous androgen exposure was etiology in 4 additional subjects. These 7 patients were excluded from further analysis. The remaining subjects had idiopathic PA (n = 266); 76.7% were females. The mean age at initial visit was 6.42 +/− 1.97 years (with no racial difference) although black subjects were reported symptom onset at a significantly younger age compared to non-Hispanic white patients.

Conclusions

Our study showed organic pathology was very uncommon in a predominantly black population with premature adrenarche. Patient factors that influence the probability of an underlying organic pathology including race/ ethnicity should be considered to individualize evaluation.

Differential analysis of nutrient intake, insulin resistance and lipid profiles between healthy and premature thelarche Chinese girls

Background

Premature thelarche (PT) is a benevolent ailment affecting young girls. Multiple factors are reported to correlate with this condition, but the mechanisms responsible for the onset of PT have not yet been fully investigated. This study aimed to evaluate the relationship of nutrient intake, insulin resistance and lipid profile with PT.

Methods

Two hundred sixty-three girls with PT, and 222 healthy girls of similar age were enrolled into this study. Their demographics, Tanner stage of breast development, nutrient intake, insulin resistance and lipid profiles were compared.

Results

Daily protein and fat intakes, insulin resistance parameters including serum insulin-like growth factor 1, fasting glucose to insulin ratio, quantitative insulin check index and homeostasis model of assessment of insulin resistance, as well as serum levels of triacylglycerol, total cholesterol and low-density lipoprotein, were all significantly altered in PT patients. Daily intake of energy and carbohydrate, and serum level of high-density lipoprotein protein were statistically indistinguishable between PT patients and healthy controls.

Conclusion

Chinese girls with PT are potentially insulin resistant, which warrants more clinical attention and further investigation to address the underlying etiology.

Clinical, biochemical and gender characteristics of 97 prepubertal children with premature adrenarche

Background Premature adrenarche (PA) is defined as the appearance of clinical signs of androgen action associated with levels of dehydroepiandrosterone sulfate (DHEAS) ≥40 μg/dL, before age 8 years in girls and 9 years in boys, without breast or testicular enlargement. The aim of this study was to characterize a population of prepubertal Caucasian children with PA and to compare them with regard to gender and body mass index (BMI) (normal BMI vs. overweight/obesity). Methods We performed a cross-sectional study of Portuguese Caucasian prepubertal children followed, due to PA, in pediatric endocrinology clinics of a university hospital. Results Eighty-two girls and 15 boys were included (mean age at evaluation: 7.4 ± 1.3 years). The mean birth weight was 2990 ± 689 g; only two children were small for gestational age. Girls presented premature pubarche at a younger age (median [interquartile range (IQR)] 6 (5-6) years vs. 7 (7-8) years in boys; p < 0.001). No gender differences were found for gestational age, birth weight, maternal age at menarche, anthropometry, bone age advancement or androgen levels. The majority of the subjects were overweight or obese (59%). Overweight/obese PA children were taller and had a more advanced bone age than normal-BMI PA children. Overweight/obese children presented higher levels of DHEAS and androstenedione. Bone age advancement and DHEAS were correlated (r = 0.449; p = 0.05). Conclusions We found no evidence of reduced fetal growth. Girls presented premature pubarche at a younger age. No major gender differences in androgen levels were found in prepuberty. Obese and overweight PA children tend to be taller, have a more advanced bone age and higher levels of androgens than normal-BMI PA children.

The prevalence of premature thelarche in girls and gynecomastia in boys and the associated factors in children in Southern China

Background

To investigate the prevalence and risk factors of premature thelarche (PT) in girls and gynecomastia (GM) in boys in Southern China.

Methods

We conducted a cross-sectional study of preschool children across 9 cities in Zhejiang province. A total of 6273 children in the age-group of 2–7 years were recruited from January 2014 to March 2015. Relevant information was collected from mothers through face-to-face interviews. Logistic regression models were used to examine the correlates of PT and GM. Odds ratios (ORs) with 95% confidence intervals (CIs) are reported.

Results

The prevalence of PT among girls was 4.8% and that of GM among boys was 0.8%. One hundred girls were diagnosed with PT before the age of 2 years; 69 (69.0%) of these girls experienced spontaneous resolution of PT. Twenty-four boys were diagnosed with GM before the age of 2 years; 10 (41.7%) of these experienced spontaneous resolution of GM. Children borne of mothers with early onset of menarche and those belonging to high-income families were at a higher risk of premature breast development. Greater consumption of eggs was associated with premature breast development in early childhood.

Conclusions

Socioeconomic status of family, early onset of menarche in mother, and consumption of eggs were strongly associated with premature breast development in early childhood.

Visceral fat thickness and its associations with pubertal and metabolic parameters among girls with precocious puberty

PURPOSE

This study aimed to investigate associations of central obesity with sexual maturation and metabolic parameters in Korean girls with precocious puberty.

METHODS

This retrospective study evaluated data from 72 girls under 8 years of age with a chief complaint of early breast development. The patients were categorized as central precocious puberty (CPP) subjects or non-CPP subjects based on their gonadotropin-releasing hormone stimulation test results. Visceral fat thickness (VFT) was measured using ultrasonography and defined as the distance from the linea alba to the aorta. Patient anthropometric, metabolic, and hormonal parameters were also evaluated.

RESULTS

Increased VFT was correlated with an earlier onset of thelarche among all study subjects (r=-0.307, P=0.034). Overweight CPP subjects showed higher insulin resistance than normal weight CPP subjects. Insulin resistance was not significantly different between overweight and normal weight non-CPP subjects. VFT was not significantly different between CPP and non-CPP subjects (2.22±0.79 cm vs. 2.74±1.47 cm, P=0.169). However, overweight and obese CPP subjects (body mass index percentile&gt;85%) had lower VFT than non-CPP obese subjects.

CONCLUSION

Central obesity, defined using ultrasonography-measured VFT, might be associated with early pubertal development in Korean girls. However, VFT was not higher in CPP than non-CPP patients and was not significantly correlated with insulin resistance. Further longitudinal studies with a larger cohort are needed.

Associations Between Maternal Prepregnancy Body Mass Index and Gestational Weight Gain and Daughter's Age at Menarche: The Avon Longitudinal Study of Parents and Children

Earlier puberty and menarche are associated with adverse health outcomes. Reported associations of maternal adiposity with daughter’s age at menarche are inconsistent. We examined associations between maternal prepregnancy body mass index (BMI; weight (kg)/height (m)²) and gestational weight gain (GWG) and daughter’s ages at menarche (n = 3,935 mother-offspring pairs), pubarche (Tanner stage 2 for pubic hair) (n = 2,942 pairs), and thelarche (Tanner stage 2 for breast development) (n = 2,942 pairs) in the Avon Longitudinal Study of Parents and Children, a prospective United Kingdom pregnancy cohort study (baseline 1991–1992). During a follow-up period of up to 17 years (1991–2008), mean menarcheal age was 12.6 (standard deviation, 1.2) years. Both maternal prepregnancy BMI and GWG were inversely associated with daughter’s age at menarche after adjustment for maternal age, parity, socioeconomic status, smoking, maternal menarcheal age, and ethnicity (mean differences were −0.34 months (95% confidence interval: −0.45, −0.22) per BMI unit and −0.17 months (95% confidence interval: −0.26, −0.07) per kg, respectively). Associations remained unchanged after adjustment for birth weight and gestational age but were attenuated to the null when results were adjusted for daughter’s prepubertal BMI. Similar results were found for ages at pubarche and thelarche. These findings indicate that greater prepregnancy BMI and GWG are associated with earlier puberty in daughters and that these associations are mediated by daughters’ prepubertal BMIs.

Urinary phthalate metabolite concentrations in girls with premature thelarche

In girls, breast development before eight years of age is called "premature thelarche (PT)". There are few studies in literature that show the interaction between PT and phthalate exposure. The aim of this study was to determine the urinary levels of di-(2-ethylhexyl) phthalate (DEHP) metabolites and other phthalate metabolites in girls with PT. PT group consisted of 29 newly diagnosed subjects. Control group comprised of healthy age-matched girls (n = 25). Urinary phthalate metabolite concentrations were measured by liquid chromatography/tandem mass spectroscopy (LC-MS/MS). The urinary concentrations of mono-(2-ethyl-hexyl)phthalate (MEHP) in the PT group (33.96 ± 6.88 μg/g creatinine) were found to be significantly higher compared to control group (11.54 ± 1.39 μg/g creatinine, p = 0.002). In PT group, %MEHP was also markedly higher vs. control (17.84 ± 3.31 vs. 6.44 ± 1.13, p = 0.001). Our results suggest that DEHP is more efficiently converted to MEHP in girls with PT, the importance of which needs to be further elucidated.

Clinical follow-up data and the rate of development of precocious and rapidly progressive puberty in patients with premature thelarche

BACKGROUND

We aimed to evaluate the clinical follow-up data of patients with premature thelarche and determine the rate of development of precocious and early puberty in these patients.

METHODS

The charts of 158 girls with premature thelarche who were followed-up in our pediatric endocrinology polyclinic were reviewed. The patients were divided into three groups according to the age at onset: group 1 (0-1 month) (n=12), group 2 (1-24 months) (n=40) and group 3 (2-8 years) (n=106).

RESULTS

At admission, the mean height standard deviation score (SDS), body weight (BW)-SDS, body mass index (BMI) and BMI-SDS were significantly higher in group 3 than in group 1 and group 2. At admission, 8.8% of the patients were obese and 24% of the patients were overweight. The majority of patients who were obese and overweight were in group 3. At the end of the follow-up, thelarche regressed in 24.7%, persisted in 32.9%, progressed in 25.9% and had a cyclic pattern in 16.5% of the patients. Precocious or rapidly progressive puberty developed in 47 of the 158 patients (29.7%). The mean age at progression to early or rapidly progressive puberty was 98.1±17.6 months. A total of 89.3% of the patients who progressed to early or rapidly progressive puberty were in group 3.

CONCLUSIONS

Precocious or rapidly progressive puberty developed in 29.7% of subjects with premature thelarche. As patients who developed rapidly progressive puberty had a higher BW-SDS and BMI-SDS than those who did not, it is suggested that the increase in weight could stimulate rapidly progressive puberty in cases with premature thelarche.

Urinary bisphenol A levels in Turkish girls with premature thelarche

There is a growing concern over the timing of pubertal breast development and its possible association with exposure to endocrine disrupting chemicals (EDCs), such as bisphenol A (BPA). BPA is abundantly used to harden plastics. The aim of this study was to investigate the relation between premature thelarche (PT) and BPA by comparing the urinary BPA levels of PT girls with those of healthy subjects. Twenty-five newly diagnosed nonobese PT subjects (aged 4-8 years) who were admitted to the Pediatric Endocrinology Department at Akdeniz University were recruited. The control group composed of 25 age-matched girls without PT and other endocrine disorders. Urinary BPA levels were measured by high pressure liquid chromatography. The median urinary concentrations of BPA were found to be significantly higher in the PT group compared to the healthy control group (3.2 vs. 1.62 μg/g creatinine, p < 0.05). We observed a weak positive correlation between uterus volume and urinary BPA levels. There was a weak correlation between estradiol and urinary BPA levels ( r = 0.166; p = 0.37); and luteinizing hormone and urinary BPA levels ( r = 0.291; p = 0.08) of PT girls. Our results suggest that exposure to BPA might be one of the underlying factors of early breast development in prepubertal girls and EDCs may be considered as one of the etiological factors in the development of PT.

Investigating the relationship between precocious puberty and obesity: a cross-sectional study in Shanghai, China

OBJECTIVES

Obesity is reported to be closely relevant to early sexual development but the relationship between sexual precocity and obesity or central obesity is still inconsistent, especially in boys. We aimed to investigate the relationship between precocious puberty and obesity as well as central obesity.

DESIGN

A large population-based cross-sectional study using multistage, stratified cluster random sampling.

SETTING

Data from the Shanghai Children's Health, Education and Lifestyle Evaluation (SCHEDULE) study in June 2014.

PARTICIPANTS

17 620 Chinese children aged 6-12 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

Obesity was defined by WHO Child Growth Standards. Central obesity was defined by sex-specific waist-to-height ratio (WHtR) cut-offs (WHtR ≥0.48 for boys, WHtR ≥0.46 for girls). Precocious puberty was identified by Tanner stage of breast, pubic hair and testicle development. A χ² test was performed to compare rates. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the association between precocious puberty and general obesity and central obesity. Probit analysis was used for estimating the median age at entry into Tanner stage 2 or greater for breast, pubic hair and testicle development. Linear regression was utilised to compare the effects of WHtR and body mass index (BMI) on sex development indicators.

RESULTS

25.98% and 38.58% of boys with precocious puberty were respectively accompanied by obesity (OR=2.15, 95% CI=1.31 to 3.50) or central obesity (OR=2.10, 95% CI=1.46 to 3.03); meanwhile, 13.86% and 29.42% of girls with precocious puberty were respectively accompanied by obesity (OR=9.00, 95% CI=5.60 to 14.46) or central obesity (OR=5.40, 95% CI=4.10 to 7.12). The median ages of breast, pubic hair and testicle development decreased with BMI increase and median ages of thelarche and testicular development rather than pubarche were earlier in children with central obesity.

CONCLUSIONS

Earlier pubertal development was positively associated with obesity and central obesity in Chinese children.

Contributions of CAG repeat length in the androgen receptor gene and androgen profiles to premature pubarche in Korean girls

The CAG repeat length of the androgen receptor (AR) gene, which exhibits an inverse relationship to AR sensitivity, might influence the development of the pubarche along with hyperandrogenemia. There are ethnic differences in the AR CAG repeat length, however, no Asian studies on premature pubarche (PP) have been reported, including Korea. Our objectives were to examine the hormone levels and AR CAG repeat length, and to assess their contributions to PP in Korean girls. Subjects with PP (n=16) and normal pubarche (NP, n=16), and normal controls (NC, n=16) were enrolled. The levels of dehydroepiandrosterone (DHEA), dehydroepiandrosterone-sulfate (DHEAS), 17-hydroxyprogesterone (17-OHP), and free testosterone (FT) were checked. The methylation-weighted (MW) average CAG repeat lengths were analyzed. The median ages at pubarche were 7.4 and 8.9 years in the PP and NP groups, respectively, and the levels of 17-OHP, DHEAS, and FT were similar in both groups. The PP group exhibited a higher DHEAS:DHEA ratio than the NP group (P=0.014). The medians of the MW average CAG repeat length of the AR gene were 22.4 for all subjects and did not differ among the PP (22.3), NP (22.4), and NC (22.2) groups. The AR CAG repeat lengths in the PP and NP groups did not correlate with DHEAS or FT levels. These results suggest that the AR CAG repeat length was not involved in the development of PP in Korean girls. However, excessive adrenal androgen levels, particularly those caused by increased sulfotransferase activity, might be important in the pathogenesis of PP.

Increasing incidence of premature thelarche in the Central Region of Denmark - Challenges in differentiating girls less than 7 years of age with premature thelarche from girls with precocious puberty in real-life practice

Background

Premature thelarche (PT) seems to be increasing and it is difficult to differentiate its early stages from precocious puberty (PP). Clinical and biochemical parameters are warranted to differentiate the two diagnoses.

Methods

One hundred ninety-one girls aged 0.5–7 years were included. Diagnoses were validated and the girls were categorized to the groups PP (n = 27) and PT (n = 164). Anthropometry, Tanner stages, ethnicity, bone age, and biochemistry, were recorded. Conventional variables for diagnosing PP were compared between the groups at time of referral to identify parameters predictive for the diagnosis.

Results

The referral rate of PT increased from 1998–2013. Girls with PT and PP differed with regards to age at referral, body mass index standard deviation scores (BMISDS), ethnicity, bone age advancement, basal luteinizing hormone (LH), gonadotropin releasing hormone (GnRH) stimulated LH and follicle stimulating hormone (FSH), basal and stimulated LH/FSH ratio, and sex-hormone binding globulin (SHBG). Apart from SHBG there was considerable overlap of the variables between the PT and the PP groups.

Conclusions

First, the incidence of PT appears to increase. Second, SHBG was the variable which best discriminated PT from PP. Third, stimulated LH in 1–3 years old girls with PT is similar to stimulated LH in 5–7 years old girls with PP. Age, BMISDS, ethnicity, bone age, stimulated gonadotropins and LH/FSH and SHBG are all useful variables for differentiating PP from PT. However normative data for stimulated LH and FSH in the age group 0.5–7 years are warranted.

Reference values for serum dehydroepiandrosterone-sulphate in healthy children and adolescents with emphasis on the age of adrenarche and pubarche

OBJECTIVE

Adrenarche is a component of normal pubertal development. Recent decades have witnessed changes in the timing and tempo of puberty in different populations. We aimed to obtain normative data on dehydroepiandrosterone-sulphate (DHEA-S) secretion in healthy children and to evaluate the age of adrenarche, pubarche and the DHEA-S levels at which pubarche starts in both sexes.

METHODS

Serum DHEA-S concentrations were measured in 531 healthy (291 female) Turkish children aged 1 month-18 years by an automated chemiluminescence method. Pubic hair development was evaluated. DHEA-S concentrations >108·4 nmol/l (40 μg/dl) were regarded as adrenarche. Age-related normative data were constructed. Age at adrenarche and pubarche and the DHEA-S levels at pubarche were estimated using ROC analyses.

RESULTS

Serum DHEA-S levels were high in the first 6 months of life then declined below 108·4 nmol/l (40 μg/dl) with a cut-off age of 0·46 years for girls and 0·61 years for boys with 98% and 96% statistical sensitivity. Stable minimum levels were observed for the following 5 years. The cut-off age for DHEA-S levels rising above 108·4 nmol/l (40 μg/dl) was 8·0 and 7·0 years for girls for boys, respectively. DHEA-S levels at transition from Tanner stage P1 to P2 was 90·5 nmol/l (33·4 μg/dl) in girls and 118 nmol/l (43·6 μg/dl) in boys. Median (CI) DHEA-S levels were 170·7(94·8-336) and 244(119·2-357·7) nmo/l [63(35-124) and 90(44-132) μg/dl] in girls and boys, respectively, with Tanner stage P2 pubic hair.

CONCLUSIONS

We established reference data of serum DHEA-S levels in a large group of children. Currently, adrenarche (DHEA-S>108·4 nmol/l) starts 1 year earlier in boys but higher DHEA-S levels are needed for transition from P1 to P2 in boys.

Nongenetic determinants of age at menarche: a systematic review

BACKGROUND

The acceleration of pubertal development is an important medical and social problem, as it may result in increased morbidity and mortality in later life. This systematic review summarizes relevant data about nongenetic factors, which contribute to age at menarche (AAM), and suggests those which may be the most important.

METHODS

The available literature from 1980 till July 2013 was searched using PubMed and Google Scholar databases. Finally, 154 papers were selected for the analysis.

RESULTS

Environmental factors, which may affect AAM, vary in populations of different ethnicity. The prenatal, infancy, and early childhood periods are the most susceptible to these factors. Body weight, high animal protein intake, family stressors (e.g., single parenting), and physical activity seem to influence AAM in most populations.

CONCLUSIONS

The data about influence of nongenetic factors on AAM are still inconsistent. The factors affecting prenatal and early childhood growth seem to have a larger effect on further sexual maturation. Further studies are needed in order to validate the association between other environmental determinants and AAM in different ethnical groups.

Clinical and laboratory characteristics of children referred for early puberty: preponderance in 7-8 years of age

OBJECTIVE

The aim of this study was to evaluate the girls referred to the pediatric outpatient clinic with a presumptive diagnosis of early puberty due to early onset of breast development or pubarche.

METHODS

Within the study period, we evaluated 289 subjects referred for concerns about early onset of puberty. History, anthropometric data, bone age (BA), hormones including luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, and dehydroepiandrosterone sulfate, as well as pelvic ultrasonography (USG)-derived ovarian and uterine volumes were analyzed.

RESULTS

Of the 289 girls referred for early onset of pubertal development, 64 (22.1%) had false alarms for puberty. Of the remaining 225 girls, 41 (18.2%) were diagnosed as premature pubarche, 56 (24.9%) as premature thelarche (PT), and 128 (56.9%) as precocious puberty (PP). Girls with early-onset puberty had more advanced BA, greater uterine and ovarian volumes, and also higher LH values than subjects with PP and PT. Nearly half of these girls were 7-8 years of age. Body mass index (BMI) standard deviation score was significantly higher in the PP cases.

CONCLUSIONS

There is a need for primary care physicians to be more knowledgeable on puberty and on puberty problems. There seems to be a preponderance of PP in 7-8-year-old children . Increased BMI may have a role in the trend towards earlier onset of puberty.

Is premature thelarche in the first two years of life transient?

OBJECTIVE

Premature thelarche (PT) refers to isolated onset of thelarche in girls younger than 8 years of age. Most cases have an onset under 2 years of age. We aimed to establish whether the onset of thelarche under 2 years of age certifies a transient clinical course, as suggested by several authors.

METHODS

Sixty-seven girls with an onset of PT under 2 years of age were classified as having early puberty (EP) or classical PT after one year of follow-up. Progression of pubertal findings or absolute growth velocity (GV) standard deviation score (SDS) above 1 SDS constituted the criteria for a diagnosis of EP.

RESULTS

Twenty (29.1%) girls were classified as having EP and 47 (70.1%) girls as having classical PT. Basal serum luteinizing hormone (LH; ICMA) values at a cut-off level of 0.3 IU/L were found to be a significant risk factor for having an atypical course [OR=7.8; CI (95%): 2.04-30.4, p=0.003].

CONCLUSIONS

Onset of thelarche under 2 years of age does not assure a transient course in a remarkable proportion of girls with PT. An absolute GV value of >1 SDS or a basal LH level ≥0.3 IU/L are suggested as indicators for close follow-up.