Urinary gonadotropin assay on 24-h collections as a tool to detect early central puberty onset in girls: determination of predictive thresholds.

STUDY QUESTION: Is the 24-h urinary gonadotropin assay an effective diagnostic tool in central precocious puberty (CPP) in girls? SUMMARY ANSWER: This study is the first to provide 24-h urinary gonadotropin assay data, using an electrochemiluminescent immunoassay (CMIA), and to report its usefulness as a tool for the diagnosis of CPP. WHAT IS KNOWN ALREADY: Data about the GnRH test in the diagnosis of CPP are variable and there is no consensus regarding its interpretation. The measurement of FSH and LH in urines was previously reported to be an alternative biological tool. STUDY DESIGN, SIZE, DURATION: This is a retrospective two-cohort study, involving a setting and a validation cohort. A total of 516 girls, included between October 2012 and July 2015, and 632 urinary collections were analyzed in the setting cohort. In the validation cohort, 39 girls were included between January 2021 and May 2023, and 49 urinary collections were analyzed. PARTICIPANTS/MATERIALS, SETTING, METHODS: This study included girls who consulted for an investigation of disturbed growth rate or a clinical suspicion of puberty onset in different medical centres across France (setting cohort). Girls with a suspicion of precocious puberty onset were addressed at the expert centre of paediatric endocrinology of the Groupement Hospitalier Lyon Est (validation cohort). Pelvic ultrasonography was performed and enabled their classification according to clinical and morphologic changes criteria (prepubertal or pubertal groups). The parents collected 24-h urine samples (u24) according to standardized instructions. FSH and LH (urinary or plasmatic) were measured using a current and automated CMIA. MAIN RESULTS AND THE ROLE OF CHANCE: The area under the ROC curves for CPP prediction was 0.709 for u24FSH (P < 0.001), 0.767 for u24LH (P < 0.001), and 0.753 for the u24LH/u24FSH ratio (P < 0.001). We retained all possible combinations of the four thresholds in the validation cohort (u24FSH = 1.1 or 2.0 IU/24 h; u24LH = 0.035 or 0.08 IU/24 h). The combination of u24FSH > 1.1 IU/24 h and u24LH > 0.08 IU/24 h had a positive PV of 85.7% and a negative PV of 94.3%, a sensitivity of 85.7% and a specificity of 94.3%, for classifying prepubertal and pubertal girls in this cohort. LIMITATIONS, REASONS FOR CAUTION: This is a retrospective study, in which a margin of error remains due to the inherent uncertainty regarding the clinical assessment of pubertal onset. It must be considered that the thresholds can only apply to the used reagents; measurements without extractions using other reagents are likely to show important heterogeneity. WIDER IMPLICATIONS OF THE FINDINGS: The assay performed herein is a simple, non-invasive, and analytically robust technique meeting the criteria for an alternative to the GnRH test which could be used to supplement its lack of sensitivity. STUDY FUNDING/COMPETING INTEREST(S): No specific funding was used. All authors declared no conflict of interest. TRIAL REGISTRATION NUMBER: In-house #23-5214 registered study.

The value of urinary gonadotropins in the diagnosis of central precocious puberty: a meta-analysis.

BACKGROUND: The gonadotropin-releasing hormone (GnRH) stimulation test is time-consuming, invasive, and costly. However, it is the diagnostic gold standard for central precocious puberty (CPP), which in girls is defined as the onset of secondary sexual characteristics before the age of 8 years accompanied by breast buds, accelerated growth, and advanced bone age. This meta-analysis was performed to compare the diagnostic value of urinary gonadotropins and the GnRH stimulation test for CPP. METHODS: We searched six databases for relevant literature. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we estimated the sensitivity, specificity, area under the summary receiver operating characteristic curve (AUC), and publication bias. RESULTS: Six eligible trials fulfilled the inclusion criteria. In the meta-analysis of urinary luteinizing hormone (ULH), after excluding the data of one study, we obtained an AUC of 0.90 (sensitivity = 0.81, specificity = 0.85). The meta-analysis of the ULH to urinary follicle-stimulating hormone (UFSH) ratio revealed an AUC of 0.8116 (sensitivity = 0.79, specificity = 0.84). CONCLUSION: Both the ULH level and ULH:UFSH ratio are effective and available approaches for CPP diagnosis. TRIAL REGISTRATION: INPLASY 2021120076 .

The Use of Morning Urinary Gonadotropins and Sex Hormones in the Management of Early Puberty in Chinese Girls.

CONTEXT: Although gonadotropin-releasing hormone stimulation test (GnRHST) is the gold standard in diagnosing central precocious puberty (CPP), it is invasive, expensive, and time-consuming, requiring multiple blood samples to measure gonadotropin levels. OBJECTIVE: We evaluated whether urinary hormones could be potential biomarkers for prepuberty or postpuberty, aiming to simplify the current diagnosis and prognosis procedure. METHODS: We performed a cross-sectional study of a total of 355 girls with CPP in National Clinical Research Center for Child Health in China, including 258 girls with positive and 97 girls with negative results from GnRHST. Twenty patients received GnRH analogue (GnRHa) treatment and completed a 6-month follow up. We measured luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, prolactin, progesterone, testosterone, and human chorionic gonadotropin in the first morning voided urine samples. RESULTS: Their urinary LH levels and the ratios of LH to FSH increased significantly with the advancement in Tanner stages. uLH levels were positively associated with basal and peak LH levels in the serum after GnRH stimulation. A cutoff value of 1.74 IU/L for uLH reached a sensitivity of 69.4% and a specificity of 75.3% in predicting a positive GnRHST result. For the combined threshold (uLH ≥ 1.74 + uLH-to-uFSH ratio > 0.4), the specificity reached 86.6%. After 3 months of GnRHa therapy, the uLH and uFSH levels decreased accordingly. CONCLUSION: uLH could be a reliable biomarker for initial CPP diagnosis and screening; uLH could also be an effective marker for evaluating the efficacy of clinical treatment.

Diagnostic value of urinary luteinizing hormone levels in the monitoring of precocious puberty treatment.

Objective To determine whether first-voided urinary LH (FV-ULH) - level measurement can adequately assess pubertal suppression as much as standard tests can. Subjects and methods The study group included patients with central precocious puberty and rapidly progressing early puberty who received up to 3 - 4 doses of GnRHa therapy monthly and did not have adequate hormonal suppression after GnRH stimulation (90-minute LH level > 4 IU/L). Design: All of the participants underwent an LHRH test just after admission to the study. According to the stimulated peak LH levels, the patients were divided into 2 groups and followed until the end of the first year of treatment. The concordance between FV-ULH and stimulated LH levels was assessed. Results The FV-ULH levels in patients with inadequate hormonal suppression were significantly high compared to patients with adequate hormonal suppression. FV-ULH levels were very strongly correlated with stimulated LH levels (r = 0.91). Its correlation with basal LH levels was significant (r = 0.65). However, this positive correlation was modestly weakened after the first year of treatment. The cutoff value for FV-ULH of 1.01 mIU/mL had the highest sensitivity (92.3%) and specificity (100%). Conclusion FV-ULH levels, using more reliable and sensitive assay methods, can be used to monitor the adequacy of GnRHa therapy.

Diagnostic value of urinary luteinizing hormone levels in the monitoring of precocious puberty treatment

ABSTRACT Objective To determine whether first-voided urinary LH (FV-ULH) - level measurement can adequately assess pubertal suppression as much as standard tests can. Subjects and methods The study group included patients with central precocious puberty and rapidly progressing early puberty who received up to 3 - 4 doses of GnRHa therapy monthly and did not have adequate hormonal suppression after GnRH stimulation (90-minute LH level > 4 IU/L). Design: All of the participants underwent an LHRH test just after admission to the study. According to the stimulated peak LH levels, the patients were divided into 2 groups and followed until the end of the first year of treatment. The concordance between FV-ULH and stimulated LH levels was assessed. Results The FV-ULH levels in patients with inadequate hormonal suppression were significantly high compared to patients with adequate hormonal suppression. FV-ULH levels were very strongly correlated with stimulated LH levels (r = 0.91). Its correlation with basal LH levels was significant (r = 0.65). However, this positive correlation was modestly weakened after the first year of treatment. The cutoff value for FV-ULH of 1.01 mIU/mL had the highest sensitivity (92.3%) and specificity (100%). Conclusion FV-ULH levels, using more reliable and sensitive assay methods, can be used to monitor the adequacy of GnRHa therapy.

The analysis of endocrine disruptors in patients with central precocious puberty.

BACKGROUND: A few studies have reported a positive association between phthalate exposure and pubertal timing, but several conflicting reports exist. The main objective of the study was to determine whether phthalate exposure was associated with central precocious puberty in girls. METHODS: This was a multicenter case-control study wherein 47 girls with central precocious puberty (CPP) and 47 controls (26 pre-pubertal girls and 21 pubertal girls) were enrolled. No obese girls were included. Five phthalate metabolites (creatinine adjusted) and bisphenol A (BPA) were measured in the first spot urine samples of these 94 girls in the early morning. RESULTS: The median values of monobenzyl phthalate (MBzP), mono-2-ethyl-5-carboxypentyl phthalate (MECPP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP), and mono-n-butyl phthalate (MnBP) were 3.1, 29.3, 18.0, 15.4, and 25.2 µg/g creatinine in the CPP group, 4.3, 53.7, 35.7, 29.1, and 66.0 µg/g creatinine in the pre-pubertal control group, and 1.7, 28.7, 21.4, 12.1, and 33.3 µg/g creatinine in the pubertal control group, respectively. The urinary concentration of the five phthalates was significantly lower in the CPP group than in the pre-pubertal control group (P < 0.001). Conversely, there was no significant difference in the urinary concentration of the five phthalates between the CPP and pubertal control groups (P values: 0.077 for MBzP, 0.733 for MECPP, 0.762 for MEHHP, 0.405 for MEOHP, and 0.981 for MnBP). In addition, the BPA level was not significantly different between the CPP and pubertal control groups (BPA median values: 0.63 µg/g creatinine, the CPP group; 1.7 µg/g creatinine, the pubertal control group; P value = 0.092). CONCLUSIONS: Our study showed that there was no significant difference in the urinary phthalate levels between the CPP and pubertal control groups. Moreover, phthalate metabolites were significantly lower in the CPP group than in the pre-pubertal control group. Further investigation about endocrine disruptors and pubertal progression is needed.

Random urinary gonadotropins as a useful initial test for girls with central precocious puberty.

Recent evidence indicates that urinary gonadotropins may be an alternative method for detecting pubertal disorders. The aim of this study was to evaluate the associations of first morning voided (FMV) and random urinary gonadotropins with the pubertal response to a gonadotropin-releasing hormone (GnRH) stimulation test to determine whether random urinary gonadotropins can be used as an alternative method for evaluating central precocious puberty (CPP). In total, 100 girls aged 6.0-8.9 years were enrolled. The subjects were divided into two groups according to their pubertal response to the GnRH stimulation test: a positive group (n = 68) and a negative group (n = 32). Random urinary luteinizing hormone (LH), follicle-stimulating hormone (FSH), and the LH:FSH ratio were significantly positively correlated with FMV urinary LH (r = 0.411, p < 0.001), FMV urinary FSH (r = 0.494, p < 0.001), and the FMV urinary LH:FSH ratio (r = 0.519, p < 0.001). The optimal cutoff values from receiver operating characteristic (ROC) curve analyses were determined to be 0.20 IU/L for random urinary LH (area under the curve (AUC) of 0.812, p < 0.001), 3.03 IU/L for random urinary FSH (AUC of 0.670, p = 0.004) and 0.08 for the random urinary LH:FSH ratio (AUC of 0.784, p < 0.001). No differences were observed between FMV and random urinary LH (p = 0.827), between FMV and random urinary FSH (p = 0.650), or between the FMV and random urinary LH:FSH ratio (p = 0.688) in ROC curve analyses with DeLong's test. Based on our findings, random urinary gonadotropins may be applicable in clinical practice as a useful initial test for girls with CPP.

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 ±â€¯6.88 µg/g creatinine) were found to be significantly higher compared to control group (11.54 ±â€¯1.39 µg/g creatinine, p = 0.002). In PT group, %MEHP was also markedly higher vs. control (17.84 ±â€¯3.31 vs. 6.44 ±â€¯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.

Association between bisphenol a exposure and idiopathic central precocious puberty (ICPP) among school-aged girls in Shanghai, China.

BACKGROUND: Bisphenol A (BPA) is a well-known and widely used endocrine disrupter, but data on its association with childhood reproductive development are limited. OBJECTIVES: We investigated the possible relationship between exposure to BPA and idiopathic central precocious puberty (ICPP) in school-aged girls. METHODS: We conducted a 1:1 matched case-control study in Shanghai, China, between July 2011 and September 2012. This study included 136 school-aged (6 to 9 years old) girls diagnosed with ICPP and 136 controls matched for age and body mass index (BMI). We measured the urinary BPA concentrations of all the girls and examined the association with odds of having ICPP. Laboratory examinations including serum estradiol (E2) levels, basal and gonadotropin-releasing hormone (GnRH)-stimulated luteinizing hormone (LH), and follicle-stimulating hormone (FSH) levels, bone ages (BA), and uterine and ovarian sizes were conducted in the ICPP girls. RESULTS: Median concentrations of urinary BPA in the ICPP and control groups were 6.35 and 1.17 µg/g creatinine (Cr), respectively (p < 0.001). After adjustment for confounders, compared to those with the lowest concentrations of BPA, the highest concentrations were associated with a 9.08-fold increased odds of having ICPP [odds ratio (OR) = 9.08, (95% confidence interval (CI): 2.83-29.15)]. In the ICPP group, modest negative correlation was present between urinary BPA concentrations (µg/g Cr) and peak FSH levels [ß = -0.090 (95% CI: -0.178, -0.003), p = 0.044]. CONCLUSIONS: Our findings suggest that BPA exposure is associated with increased odds of having ICPP in school-aged girls, and the potential mechanism may be attributable to the relatively low FSH levels.

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.

Higher phthalate concentrations are associated with precocious puberty in normal weight Thai girls.

BACKGROUND: The cause of precocious puberty may be associated with genetics and other conditions such as central nervous system (CNS) insults, or the exposure to endocrine disrupting chemicals (EDCs). Phthalates is known to be one of the EDCs and have estrogenic and antiandrogenic activities, and may be associated with advanced puberty. The objective of the study was to determine the association between urinary phthalate metabolites and advanced puberty. METHODS: A cross-sectional study was conducted in patients with precocious puberty (breast onset <8 years, n=42) and early puberty (breast onset 8-9 years, n=17), compared to age-matched controls (n=77). Anthropometric measurements, estradiol, basal and gonadotropin releasing hormone (GnRH)-stimulated follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels, uterine sizes, ovarian diameters and bone ages (BA) were obtained. Urine samples were collected and mono-methyl phthalate (MMP) and mono-ethyl phthalate (MEP) were analyzed by high performance liquid chromatography (HPLC) and adjusted with urine creatinine. RESULTS: The median adjusted-MEP concentration in girls with precocious puberty, was greater than in normal girls (6105.09 vs. 4633.98 µg/g Cr: p<0.05), and had the same trend among early puberty and normal puberty (5141.41 vs. 4633.98 µg/g Cr: p=0.4), but was not statistically significant. CONCLUSIONS: Precocious puberty girls had an association with increased MEP concentration. This is the first report of the association between urinary phthalate levels and precocious puberty in Thai girls.

Nocturnal Urinary Excretion of FSH and LH in Children and Adolescents With Normal and Early Puberty.

Context: Clinical use of single serum gonadotropin measurements in children is limited by the pulsatile secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). However, first morning voided (FMV) urine may integrate the fluctuating gonadotropin serum levels. Objective: We aimed to evaluate urinary and serum gonadotropin levels according to age, sex, and pubertal stage in healthy children and to assess the clinical use of FMV urinary gonadotropins in children with disordered puberty. Design: Cross-sectional part of the COPENHAGEN Puberty Study and longitudinal study of patients. Setting: Population-based and outpatient clinic. Patients or Other Participants: Eight hundred forty-three healthy children from the COPENHAGEN Puberty Study and 25 girls evaluated for central precocious puberty (CPP). Main Outcome Measures: Clinical pubertal staging, including serum and urinary gonadotropin levels. Results: Urinary gonadotropins increased with advancing age and pubertal development and were detectable in FMV urine before physical signs of puberty. FMV urinary LH correlated strongly with basal (r = 0.871, P < 0.001) and gonadotropin-releasing hormone (GnRH)-stimulated serum LH (r = 0.82, P < 0.001). Urinary LH was superior to urinary FSH in differentiating the pubertal stage. Receiver operating curve analysis revealed that a cut-off standard deviation (SD) score of 2 for urinary LH (IU/L) gave a sensitivity of 75% and a specificity of 92% in predicting a positive GnRH stimulation test (LHmax > 5 IU/L). Urinary concentrations of LH decreased after 3 months of GnRH treatment to levels below +2 SDs. Conclusions: Urinary gonadotropin levels increased before the onset of puberty and were elevated in girls with CPP. We suggest urinary LH as an alternative noninvasive method to improve diagnosing and therapeutic management of children with disordered puberty.

The measurement of urinary gonadotropins for assessment and management of pubertal disorder.

OBJECTIVE: Measurement of urinary LH (uLH) and FSH (uFSH) may facilitate non-invasive pubertal assessment but there is a need for further validation by studying children and adolescents with disorders of puberty. DESIGN: 65 cases (Male: 25) with a median age of 12 years (2.9-18.1) supplied at least one non-timed urine sample for uLH and uFSH measurement by immunoassay and corrected for creatinine excretion. 25 cases were receiving GnRH-agonist (GnRH-a) at the time of sample collection. In 41 cases, urine samples were collected prior to a LHRH test and in 12 cases matched serum samples for basal LH (sLH) and FSH (sFSH) were also available. RESULTS: There was a significant correlation between sLH and uLH:uCr (r=0.82; p-value <0.001) and sFSH and uFSH:uCr (r=0.93; p-value <0.001). Based on receiver operator characteristics analysis, a uLH:uCr value of 0.05 IU/mmol as a cut-off would detect a LH peak >5U I/L with a sensitivity of 86% and a specificity of 72% with a positive predictive value of 93%. In pubertal boys (6) and girls (22) with a sLH peak >5UI/L, median uLH:uCr was 0.27 IU/mmol (0.27-0.28) and 0.17 IU/mmol (0.09-0.43), respectively. The median uFSH:uCr was 0.51 IU/mmol (0.41-0.60) for boys and 1.1 IU/mmol (0.21-2.44) for girls. In the 25 cases on GnRH-a, the median uLH:uCr for boys and girls was 0.02 IU/mmol (0.01-0.02) and 0.02 IU/mmol (0.004-0.07), respectively, and the median uFSH:uCr was 0.07 IU/mmol (0.05-0.09) and 0.27 IU/mmol (0.09-0.54), respectively. CONCLUSION: Urinary gonadotrophins reflect serum gonadotrophin concentration and may represent a reliable non-invasive method of assessing pubertal progress.

The evaluation of possible role of endocrine disruptors in central and peripheral precocious puberty.

Exposure to environmental chemicals can affect genetic and epigenetic molecular pathways and may cause altered growth and development. Among those exposures, endocrine-disrupting chemicals (EDCs) are of particular concern as humans are abundantly exposed to these chemicals by various means in every period of life. Several well-known environmental chemicals, including phthalates and bisphenol A (BPA), are classified as EDCs. These EDCs are suggested to play roles in early onset of puberty in girls. The aim of this study is to determine plasma phthalate (di(2-ethylhexyl)phthalate [DEHP] and its main metabolite mono(2-ethylhexyl)phthalate [MEHP]) and urinary BPA levels in girls with idiopathic central precocious puberty (CPP) and peripheral precocious puberty (PPP). This study was performed on newly diagnosed idiopathic central precocious puberty (CPP) patients (n = 42) and peripheral precocious puberty (PPP) (n = 42) patients, who were admitted to Keçiören Training and Research Hospital, Clinic of Pediatric Endocrinology between August 2012 and -July 2013. Nonobese healthy girls (n = 50) were used as the control group. Urinary BPA levels were not statistically different in control, PPP and CPP groups (medians 10.91, 10.63 and 10.15 µg/g creatinine, respectively; p > 0.05). Plasma DEHP levels were significantly higher in PPP group when compared to control. Plasma MEHP levels were not significantly different in control and PPP groups (p > 0.05). However, in CPP group, both plasma DEHP and MEHP levels were significantly higher than control and PPP groups. This study showed that phthalates might play a role in the occurence of CPP in girls.

Increased levels of bisphenol A (BPA) in Thai girls with precocious puberty.

BACKGROUND: Reports on the secular trend of pubertal onset indicate a recent earlier start especially in girls. Bisphenol A (BPA), which posses estrogenic activity, might be a cause of advanced puberty. The objective of the study was to determine the association between BPA and advanced puberty. METHODS: A cross-sectional study was conducted in patients with advanced puberty (n=41) compared to age-matched controls (n=47). Anthropometric measurements, estradiol, basal and gonadotropin releasing hormone (GnRH)-stimulated follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels, uterine sizes, ovarian diameters and bone ages were obtained. Urinary BPA concentrations were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC/MSMS) with the lower limit of quantification (LLOQ) of 0.05 ng/mL. RESULTS: The median adjust-BPA concentration in advanced puberty group was higher than in control groups [1.44 vs. 0.59 µg/g creatinine (Cr): p<0.05]. We also found that the median adjust-BPA concentration in girls with advanced puberty who were overweight/obese, was greater than in the normal pubertal overweight/obese girls (1.74 vs. 0.59 µg/g Cr: p<0.05), and was in the same trend among normal weight girls with advanced and normal puberty (0.83 vs. 0.49 µg/g Cr: p=0.09), but not statistically significant. CONCLUSIONS: The present findings suggest that BPA exposure appears to be related to an earlier age at onset of puberty especially in obese girls.

The relation of urinary bisphenol A with kisspeptin in girls diagnosed with central precocious puberty and premature thelarche.

BACKGROUND: Bisphenol A (BPA) is known as an endocrine disruptor and it is supposed to have a role on the development of central precocious puberty (CPP). Kisspeptin, a hypothalamic peptide, is a neuromodulator of gonadotropin releasing hormone and it has an important role on regulation of the onset of puberty. The BPA levels in girls with CPP and premature thelarche (PT) and its relation with kisspeptin levels were investigated. METHODS: Twenty-eight girls with CPP, 28 girls with PT and 22 prepubertal girls as a control group were enrolled to the study. Urinary BPA and serum kisspeptin levels were compared in the groups. Bivariate correlations were performed to evaluate the relations of BPA with kisspeptin and estradiol. RESULTS: There was no statistical difference between groups regarding BPA levels. Serum kisspeptin levels were higher in CPP group than controls [306.56 (interquartile range (IQR), 175.63-504.66) vs. 157.62 (IQR, 55.61-285.00) p: 0.008]. There were no correlations between BPA and kisspeptin levels (r: 0.088, p: 0.391) and between BPA and estradiol (r: -0.171, p: 0.144). CONCLUSIONS: The BPA levels did not differentiate between groups and it seems that the exposed amount of BPA in daily life did not affect kisspeptin levels in girls with CPP and PT.

Urinary zearalenone levels in girls with premature thelarche and idiopathic central precocious puberty.

AIM: Recently, it was reported that the development of breast tissue and secondary sex characteristics in girls occurred at much younger age and the incidences of premature thelarce (PT) and central idiopathic precocious puberty (ICPP) are increasing. In this context, we wanted to evaluate the mycoestrogen exposure as triggering factor for premature sexual development. METHODS: The girls living in Mediterranean region of Turkey were divided in to three groups: control (N.=25; mean age: 6.45 ± 1), PT (N.=28; mean age: 6.86 ± 0.95) and ICPP (N.=25; mean age: 6.97 ± 0.87). Urinary ZEN levels were measured by using ELISA technique and were normalized by urinary creatinine levels. Body Mass Index (BMI) was evaluated and sex hormone levels were also measured. RESULTS: We found that urinary ZEN was detectable in ~81% of all samples and observed an increase of ~2-fold in PT and a significant increase ~2.8-fold in ICPP group vs. control. We did not find any significant correlations between urinary ZEN levels and BMI and sex hormones in any of the groups. CONCLUSION: To our knowledge, this is the first study evaluating urinary ZEN levels in PT and ICPP Turkish patients. We can postulate that ZEN exposure can contribute to the etiology of PT and PP; however further studies on large number of subjects are needed to confirm the present data.

Urinary bisphenol a levels in girls with idiopathic central precocious puberty.

OBJECTIVE: Bisphenol A (BPA) is an industrial chemical, particularly used to harden plastics. BPA is thought to have negative health effects on both laboratory animals and humans. Consider ing the decline in age of onset of puberty noted in recent years, particularly among girls, the importance of BPA as an estrogenic endocrine disruptor has increased. In this study, we aimed to determine urinary BPA levels in girls with idiopathic central precocious puberty (ICPP). METHODS: Non-obese girls newly diagnosed with ICPP (n=28, age 4-8 years) constituted the study group. The control group consisted of 25 healthy age-matched girls with no history of ICPP or any other endocrine disorder. Urinary BPA levels were measured by using high-performance liquid chromatography. RESULTS: In the ICPP group, urinary BPA levels were significantly higher compared to the control group [median 8.34 (0.84-67.35) µg/g creatinine and 1.62 (0.3-25.79) µg/g creatinine, respectively (OR=8.68, 95% CI:2.03-32.72, p=0.001)]. There was no marked correlation between urinary BPA levels and body mass index in either group. In the ICPP group, no significant correlations were found between urinary BPA levels and serum luteinizing hormone, follicle-stimulating hormone and estradiol levels. CONCLUSIONS: To our knowledge, this is the first study evaluating the urinary BPA levels in Turkish girls with ICPP. Our results indicate that the estrogenic effects of BPA may be an etiologic factor in ICPP.

The diagnostic value of first-voided urinary LH compared with GNRH-stimulated gonadotropins in differentiating slowly progressive from rapidly progressive precocious puberty in girls.

OBJECTIVE: Characterization of pubertal progression is required to prevent unnecessary intervention in unsustained or slowly progressive (SP) precocious puberty (PP), while delivering hormonal suppression in rapidly progressive (RP) PP. We aimed to assess the diagnostic value of first-voided urinary LH (ULH) compared with GNRH-stimulated gonadotropins in differentiating these forms of PP. METHODS: A total of 62 girls with PP underwent both GNRH stimulation and ULH assay. Fifteen girls with peak LH ≥ 10 IU/L started treatment immediately, whereas the other 47 girls were evaluated after 6 months for pubertal advancement, height acceleration, and bone-age maturation. Based on these criteria, the participants were assigned to five subgroups: pubertal regression, no progression or progression by one, two or three criteria. The first three subgroups were defined as SP-PP (n=29), while the other two subgroups were defined as RP-PP (n=18). An additional 23 prepubertal girls were evaluated for ULH. RESULTS: ULH but not serum gonadotropins could distinguish girls with two and three criteria from less progressive subgroups. By comparison with SP-PP (i.e. regression group and groups 0 and 1), those with RP-PP (group 2+3) had lower peak FSH (9.28±2.51 vs 12.57±4.30; P=0.007) and higher peak LH:FSH ratio (0.42±0.30 vs 0.22±0.12; P=0.022) and ULH (1.63±0.65 vs 1.05±0.26 IU/l; P<0.001). Based on receiver operating characteristics analysis, a ULH cutoff of 1.16 IU/l had a better sensitivity (83%) and positive and negative predictive values (65 and 88% respectively) than the other two parameters, with a specificity of 72%. CONCLUSIONS: ULH assay is a noninvasive, reliable method that can assist in the distinction between SP- and RP-PP.

Changes in steroid metabolism among girls with precocious puberty may not be associated with urinary levels of bisphenol A.

Precocious puberty (PP) refers to the appearance of physical and hormonal signs of pubertal development at an abnormally early age. Urinary steroid signatures obtained from 42 patients with central PP and 40 patients with peripheral PP were assessed to compare metabolic changes. Levels of androgens such as testosterone, androstenedione, androstenediol, 16α-hydroxy-dehydroepiandrosterone, and 5α-androstenedione tended to be high in both PP groups, and the level of 17ß-estradiol was higher in the central-PP group (P<0.01) than in the peripheral-PP and 32 age-matched healthy girls. Altered steroid metabolism was also associated with urinary BPA levels, and levels of testosterone, 17ß-estradiol, and pregnenolone were significantly increased among individuals with high BPA levels. In particular, a correlation was observed between estrogen metabolism and BPA levels irrespective of the type of PP. These findings suggest that in girls, BPA exposure causes metabolic changes in steroidogenesis, but not the early onset of PP.