Premature thelarche: a follow up study of 40 girls. Natural history and endocrine findings

Diagnostic utility of the average peak LH levels measured during GnRH stimulation test

OBJECTIVES

Gonadotropin-releasing hormone (GnRH) test is the gold standard test to evaluate the hypothalamus-pituitary-gonadal (HPG) axis for the diagnosis of central precocious puberty (CPP). However, the diagnosis of cases with clinical features of CPP whilst have borderline peak luteinizing hormone (LH) remain challenges. We aimed to evaluate diagnostic performance of the average of LH levels measured during GnRH stimulation test.

METHODS

Cases with diagnosis of CPP and premature thelarche (PT) who had a GnRH stimulation test results were retrospectively reviewed. Anthropometric measurements (weight, height, and body mass index), age and sex-specific standard deviation scores, growth velocity, puberty stages, bone ages, serum FSH, LH, and estradiol levels were measured by electrochemiluminescence immunological method (ECLIA), and the GnRH stimulation test results, which performed by obtaining venous blood samples at basal, 20th, and 40th minutes for FSH and LH measurement, were recorded.

RESULTS

A total of 76 girls (38 CPP, 38 PT) were included. We detected an average peak LH cut-off value of 4.25 IU/L with 94.7 % sensitivity and 97.4 % specificity, a 97.3 % positive predictive value, and a 94.9 % negative predictive value in GnRH test to differentiate cases with CPP from PT.

CONCLUSIONS

This is the first study evaluating the diagnostic utility of the average of LH levels measured during GnRH stimulation test. We showed that the average of two LH measurements has a high diagnostic performance. Therefore, it can be used as a valid and reliable diagnostic tool for assessment of HPG axis activation, particularly for cases with a borderline peak LH level.

Etiological, Clinical and Biochemical Characteristics of 367 Children with Early Pubertal Development from Thrace Region of Turkey

Background: Appearance of menarche before nine years of age, secondary sex characteristics before 8 in girls and 9 in boys is defined as Precocious Puberty (PP). Objective: The aim of this study was to describe etiologies, clinical findings, and compare anthropometric properties and biochemical characteristics of children with PP. Methods: In this single-centre study, 367 patients of whom medical records were reviewed diagnosed as premature thelarche (PT), premature adrenarche (PA), Central PP (CPP), and peripheral PP (PPP). The diagnosis was based on clinical, laboratory, and radiologic investigations and their follow-up. Results: During six years, 349 girls (%95,1) and 18 boys (%4,9) diagnosed as PP. The most common etiologies were CPP;127 (%34,6), PT;117 (%31,9), PA;112(%30,5) and PPP 11(%3), respectively. CPP group had significantly higher levels of height, weight, body mass index (BMI) and obesity/overweight incidence, estradiol (E2), basal luteinizing hormone (LH), peak LH, and peak LH/ follicle-stimulating hormone (FSH) ratio and higher uterine dimensions compared to the PT group while the PT group had significantly higher levels of peak FSH compared to the CPP group (p

Disorders of Puberty in Girls

Puberty is the process through which reproductive competence is achieved and comprises gonadarche and adrenarche. Breast development is the initial physical finding of pubertal onset in girls and typically occurs between 8 and 13 years. Menarche normally occurs 2 to 3 years after the onset of breast development. Pubertal onset is controlled by the gonadotropin-releasing hormone pulse generator in the hypothalamus; however, environmental factors such as alterations in energy balance and exposure to endocrine-disrupting chemicals can alter the timing of pubertal onset. Improvement in nutritional and socioeconomic conditions over the past two centuries has been associated with a secular trend in earlier pubertal onset. Precocious puberty is defined as onset of breast development prior to 8 years and can be central or peripheral. Delayed puberty can be hypogonadotropic or hypergonadotropic and is defined as lack of breast development by 13 years or lack of menarche by 16 years. Both precocious and delayed puberty may have negative effects on self-esteem, potentially leading to psychosocial stress. Patients who present with pubertal differences require a comprehensive assessment to determine the underlying etiology and to devise an effective treatment plan.

Neurobiology of puberty and its disorders

Puberty, which in humans is considered to include both gonadarche and adrenarche, is the period of becoming capable of reproducing sexually and is recognized by maturation of the gonads and development of secondary sex characteristics. Gonadarche referring to growth and maturation of the gonads is fundamental to puberty since it encompasses increased gonadal steroid secretion and initiation of gametogenesis resulting from enhanced pituitary gonadotropin secretion, triggered in turn by robust pulsatile GnRH release from the hypothalamus. This chapter reviews the development of GnRH pulsatility from before birth until the onset of puberty. In humans, GnRH pulse generation is restrained during childhood and juvenile development. This prepubertal hiatus in hypothalamic activity is considered to result from a neurobiological brake imposed upon the GnRH pulse generator resident in the infundibular nucleus. Reactivation of the GnRH pulse generator initiates pubertal development. Current understanding of the genetics and physiology of the brake will be discussed, as will hypotheses proposed to account for timing the resurgence in pulsatile GnRH and initiation of puberty. The chapter ends with a discussion of disorders associated with precocious or delayed puberty with a focus on those with etiologies attributed to aberrant GnRH neuron anatomy or function. A pediatric approach to patients with pubertal disorders is provided and contemporary treatments for both precocious and delayed puberty outlined.

Adequacy of basal luteinizing hormone levels in the diagnosis of central precocious puberty

AIM

To determine the clinical, anthropometric, and laboratory parameters that could be used for differentiating central precocious puberty from premature thelarche in girls who had breast development between the ages of 3 and 8 years.

MATERIAL AND METHODS

The study included 344 girls (196 girls with idiopathic central precocious puberty, 148 girls with premature thelarche) who underwent gonadotropin- releasing hormone stimulation tests for breast development. Age at diagnosis, bone age, anthropometric measurements, basal/stimulated hormone levels were recorded. Univariate regression analysis was performed to determine the parameters that could be used for differentiating precocious puberty from premature thelarche. Significant parameters in univariate analyses were grouped according to the thresholds determined using receiver operating characteristic curves and reevaluated through multivariate analysis.

RESULTS

The bone age, height-standard deviation score, body mass index-standard deviation score, and growth velocity-standard deviation score at diagnosis were found to be higher; pubertal stages were found to be more advanced; uterus and ovary volumes were found to be larger; and the basal/peak luteinizing hormone, follicle-stimulating hormone, luteinizing hormone/follicle-stimulating hormone levels were found to be higher in the subjects with precocious puberty. There was no difference between estradiol levels between the two groups. The best thresholds to differentiate the two groups were found as 0.65 IU/L (78% sensitivity, 100% specificity), 1.9 IU/L (100% sensitivity, 72% specificity), 0.25 (67% sensitivity, 100% specificity) and 1.1 (69% sensitivity, 71% specificity), respectively, for basal luteinizing hormone, follicle-stimulating hormone, luteinizing hormone/follicle-stimulating hormone ratio, and the growth velocity-standard deviation score.

CONCLUSION

In girls presenting with early breast development, a basal luteinizing hormone level of ≥0.65 IU/L and a luteinizing hormone/follicle-stimulating hormone ratio of ≥0.25 are sensitive ways to demonstrate activation of the hypothalamo-pituitary-gonadal axis. Among these, the variable that gives the best sensitivity and specificity is the measurement of basal luteinizing hormone levels (≥0.65 IU/L), which can be used as a screening test in the diagnosis of central precocious puberty.

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.

Serum Levels of Polybrominated Diphenyl Ethers in Girls with Premature Thelarche

BACKGROUND/AIMS

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants and have shown endocrine disruption properties in experimental studies. The aim of this study was to investigate the association between the exposure to PBDEs and alterations of puberty in girls referred for idiopathic central precocious puberty (ICPP) and premature thelarche (PT).

METHODS

A case-control study was conducted in 124 girls: 37 girls with ICPP (mean age 7.4 ± 0.9 years), 56 with PT (mean age 5.7 ± 2.1 years) and 31 controls (mean age 5.4 ± 1.9 years). PBDE serum concentrations, hormone levels and anthropometry were assessed. PBDE concentrations were corrected for total serum lipid content. Individual exposure to PBDEs was evaluated through ad hoc questionnaires.

RESULTS

PBDE serum concentrations corrected for total lipid content were significantly higher in girls with PT (mean 1.49 ± 0.63 log ng/g) than in controls (mean 1.23 ± 0.54 log ng/g; p < 0.05). PT girls showed higher levels of PBDE than ICPP girls (1.49 ± 0.63 vs. 1.37 ± 0.49 log ng/g), though this was not significant. An analysis of the questionnaires revealed no significant differences in exposure between the three groups.

CONCLUSION

Our findings suggest that higher concentrations of serum PBDEs are associated with PT in girls.

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.

The response to gonadotropin releasing hormone (GnRH) stimulation test does not predict the progression to true precocious puberty in girls with onset of premature thelarche in the first three years of life

CONTEXT

Premature thelarche in early childhood may evolve into true precocious puberty. The individuation of cases progressing to precocious puberty is challenging.

OBJECTIVE

We analyzed the parameters predictive for progression in girls younger than 3 years.

DESIGN AND SETTING

We conducted a retrospective longitudinal study.

PATIENTS AND METHODS

A total of 450 girls referred for premature thelarche were initially evaluated, 353 were clinically monitored at 3-month intervals, and 97 underwent endocrine and imaging assessment. Central precocious puberty (CPP) was diagnosed in girls showing LH peak response to GnRH testing >5 mU/mL with tuber cinereum hamartoma at magnetic resonance imaging, or with normal magnetic resonance imaging but progression of puberty during follow-up.

MAIN OUTCOME MEASURE

We measured the progression to precocious puberty.

RESULTS

Idiopathic premature thelarche (IPT) was diagnosed in 85 of the 97 girls who underwent extensive evaluation, CPP in nine girls, and peripheral precocious puberty in three girls. The uterus was >34 mm in six (7%) IPT girls and six (66.6%) CPP girls. Basal LH was >0.2 mU/mL in one (1.17%) IPT girl and eight (88.8%) CPP girls. LH peak was >5 mU/mL in 31 (36.4%) IPT girls and nine (100%) CPP girls. LH peak/FSH peak ratio was >1 in six (66.6%) CPP girls.

CONCLUSIONS

None of the available tests alone allows identification of girls who will progress to precocious puberty. Elevated LH responses to GnRH are common but are not related to progression toward puberty. The combined measurement of basal LH and longitudinal diameter of the uterus represents a reliable screening approach to identify subjects who should undergo GnRH testing.

Premature thelarche in infants and toddlers: prevalence, natural history and environmental determinants

STUDY OBJECTIVE

The aim of this study was to measure the prevalence of premature thelarche in infant and toddler girls and to determine if environmental sources of estrogen were associated with early breast development.

DESIGN

Observational with mixed methods: Retrospective chart review, cross-sectional component involving an interview survey, along with longitudinal follow-up of girls with thelarche up to six months.

SETTING

A general pediatric clinic within a teaching hospital located in a large Midwestern city.

PARTICIPANTS

Girls, between the ages of 12 and 48 months, and their mothers, presenting for well-child care.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Prevalence of premature thelarche; association of premature thelarche with selected environmental exposures.

RESULTS

Among the 318 subjects, the overall prevalence of premature thelarche was measured at 4.7% (n = 15). The prevalence by race/ethnicity was 4.2% among White Non-Hispanics, 4.6% among Blacks and 6.5% among White Hispanics. The peak prevalence occurred between 12-17 months of age. All thelarche cases were Tanner stage 2. No statistically significant relationship was found between premature thelarche and environmental exposures. Upon follow-up, 44% of the cases of premature thelarche had persistent breast development.

CONCLUSIONS

Our study demonstrated a higher prevalence of premature thelarche than has been previously reported. This study lacked power because of the small number of premature thelarche cases, the ubiquitous presence of environmental exposure as well as the potentially small effect of each environmental factor. Future studies need to employ a very large sample in order to accurately analyze the relationship between environmental toxicants and premature thelarche.

Premature thelarche in Taiwanese girls

This study was conducted to understand the clinical features and natural course of Taiwanese girls with premature thelarche (PT). The medical records of 91 Taiwanese girls with PT who were diagnosed younger than six and have been regularly followed up for more than two years were reviewed. For comparison, GnRH test was also done in 25 girls with central precocious puberty (CPP) and 10 normal prepubertal girls. The age of onset of these patients was 1.5 +/- 1.6 years and 79% of them developed PT before the age of two. Girls with PT had intermediate degree of hypothalamic-pituitary-ovarian activity between prepuberty and CPP with FSH-predominant response to GnRH stimulation. 87% of patients have complete regression of breast development during 3.8 +/- 2.5 years' follow-up but 19% of them have progressed to CPP during follow-up. We conclude that Taiwanese girls with PT more often developed within the first two years of life. Activation of hypothalamic-pituitary-gonadal axis with predominant FSH activity during infancy may contribute to its development. In addition, PT is not always a benign self-limited condition, and clinicians should be cautious about pubertal development of these patients.

Premature thelarche: age at presentation affects clinical course but not clinical characteristics or risk to progress to precocious puberty

OBJECTIVES

To determine whether age at premature thelarche (PT) onset affects the clinical characteristics, course, and risk of progression to precocious puberty (PP).

STUDY DESIGN

Data regarding course of growth and puberty were retrieved from the medical files of 139 girls with PT followed up from 1995 to 2005. Analysis was based on age at PT appearance (birth, 1-24 months, and 2-8 years); course was categorized as regressive, persistent, progressive, or cyclic.

RESULTS

At diagnosis, height standard deviation score, bone age-chronological age ratio, and hormonal values were comparable in the 3 age groups. PT regressed in 50.8%, persisted in 36.3%, progressed in 3.2% and had a cyclic course in 9.7%. A progressive or cyclic course was significantly more prevalent among girls presenting after 2 years (52.6%) compared with girls presenting at birth (13.0%) or at 1 to 24 months (3.8%) (P < .001). PP occurred in 13% irrespective of age at PT presentation or clinical course.

CONCLUSIONS

Clinical and anthropometric characteristics at admission and risk of PP were similar in all girls with PT, regardless of age at onset. There are currently no clinical or laboratory tests that can predict the risk of progression to PP at presentation.

Premature thelarche: clinical and laboratorial assessment by immunochemiluminescent assay

In order to establish cut-off limits and to distinguish isolated premature thelarche (IPT) from precocious puberty (PP), we evaluated data from 79 girls with premature thelarche, comparing basal and stimulated LH and FSH serum concentrations with those from 91 healthy girls. A GnRH stimulation test was performed in 10 normal girls and in 42 with premature thelarche. Comparison among groups was performed by Kruskal-Wallis and Dunns tests. LH values were significantly greater in girls with IPT than in control groups. Basal gonadotropin concentrations were higher in patients with PP than in controls, but not different from patients with IPT. Peak LH levels after GnRH stimulation distinguished those two groups, with a cut-off value of 4.0 IU/L, but still with minimal overlap. In conclusion, a girl with premature thelarche and LH peak value above 4.5 IU/L has, indeed, PP, but values between 3.5 and 4.5 IU/L point to careful follow-up.

Isolated premature thelarche and thelarche variant: clinical and auxological follow-up of 119 girls

Age of thelarche presentation, breast evolution, growth and puberty patterns were retrospectively evaluated in 119 girls with premature thelarche (PT). Thelarche spontaneously presented before 2 yr of chronological age in 80% of girls and completely regressed in 60% of them. Breast regression was significantly more frequent in the patients with more precocious thelarche presentation. In 40% of the girls breast size did not significantly change during a follow-up period ranging from 12 to 134 months (40.6 +/- 32.5). Among the 38 girls who were followed up to an age greater than 8 yr, seven (18.4%) developed central precocious puberty (PP). These 7 patients who progressed into true PP were indistinguishable from girls with normal puberty for age of thelarche presentation, breast size, evolution and auxological features. On the contrary, a subgroup of patients (28.5%) with accelerated height velocity and/or bone age at diagnosis of PT showed an auxological pattern different from normally growing girls during a 3-yr follow-up, but they did not seem to have higher risk of progressing into precocious puberty. In conclusion, PT encompasses different clinical, and perhaps hormonal situations, therefore requiring careful clinical follow-up.

Progression of premature thelarche to central precocious puberty

To evaluate whether girls with premature thelarche progress to central precocious puberty (CPP) and to analyze their clinical and hormonal characteristics, we retrospectively examined 100 girls with premature thelarche who were followed for several years. Fourteen of the patients with characteristics diagnostic of premature thelarche (isolated breast development before age 8 years, bone age advancement within 2 SD of normal, normal growth velocity, follicle-stimulating hormone-predominant response to luteinizing hormone-releasing hormone) progressed during follow-up to precocious or early central puberty (progressive breast size increase, bone age acceleration, and significant decrease in predicted adult height). The chronologic age of this group of 14 girls was 5.1 +/- 2.0 years at the onset of premature thelarche and 7.8 +/- 0.6 years (mean +/- SD) after progression to central early or precocious puberty. Pelvic ultrasonography showed significant differences in measurements between the time of diagnosis of premature thelarche and progression to CPP. Nine of these patients required treatment, three with cyproterone acetate and six with luteinizing hormone-releasing hormone analogs, and all responded as expected for classic CPP. At baseline evaluation, no clinical or hormonal characteristics could be established that separated the 14 children who progressed to precocious or early puberty from the 86 girls who did not. We conclude that premature thelarche is not always a self-limited condition and may sometimes accelerate the timing of puberty.