Joint models reveal genetic architecture of pubertal stage transitions and their association with BMI in admixed Chilean population.

Early or late pubertal onset can lead to disease in adulthood, including cancer, obesity, type 2 diabetes, metabolic disorders, bone fractures, and psychopathologies. Thus, knowing the age at which puberty is attained is crucial as it can serve as a risk factor for future diseases. Pubertal development is divided into five stages of sexual maturation in boys and girls according to the standardized Tanner scale. We performed genome-wide association studies (GWAS) on the "Growth and Obesity Chilean Cohort Study" cohort composed of admixed children with mainly European and Native American ancestry. Using joint models that integrate time-to-event data with longitudinal trajectories of body mass index (BMI), we identified genetic variants associated with phenotypic transitions between pairs of Tanner stages. We identified $42$ novel significant associations, most of them in boys. The GWAS on Tanner $3\rightarrow 4$ transition in boys captured an association peak around the growth-related genes LARS2 and LIMD1 genes, the former of which causes ovarian dysfunction when mutated. The associated variants are expression and splicing Quantitative Trait Loci regulating gene expression and alternative splicing in multiple tissues. Further, higher individual Native American genetic ancestry proportions predicted a significantly earlier puberty onset in boys but not in girls. Finally, the joint models identified a longitudinal BMI parameter significantly associated with several Tanner stages' transitions, confirming the association of BMI with pubertal timing.

The p190 RhoGAPs, ARHGAP35, and ARHGAP5 are implicated in GnRH neuronal development: Evidence from patients with idiopathic hypogonadotropic hypogonadism, zebrafish, and in vitro GAP activity assay.

PURPOSE: The study aimed to identify novel genes for idiopathic hypogonadotropic hypogonadism (IHH). METHODS: A cohort of 1387 probands with IHH underwent exome sequencing and de novo, familial, and cohort-wide investigations. Functional studies were performed on 2 p190 Rho GTPase-activating proteins (p190 RhoGAP), ARHGAP35 and ARHGAP5, which involved in vivo modeling in larval zebrafish and an in vitro p190A-GAP activity assay. RESULTS: Rare protein-truncating variants (PTVs; n = 5) and missense variants in the RhoGAP domain (n = 7) in ARHGAP35 were identified in IHH cases (rare variant enrichment: PTV [unadjusted P = 3.1E-06] and missense [adjusted P = 4.9E-03] vs controls). Zebrafish modeling using gnrh3:egfp phenotype assessment showed that mutant larvae with deficient arhgap35a, the predominant ARHGAP35 paralog in the zebrafish brain, display decreased GnRH3-GFP+ neuronal area, a readout for IHH. In vitro GAP activity studies showed that 1 rare missense variant [ARHGAP35 p.(Arg1284Trp)] had decreased GAP activity. Rare PTVs (n = 2) also were discovered in ARHGAP5, a paralog of ARHGAP35; however, arhgap5 zebrafish mutants did not display significant GnRH3-GFP+ abnormalities. CONCLUSION: This study identified ARHGAP35 as a new autosomal dominant genetic driver for IHH and ARHGAP5 as a candidate gene for IHH. These observations suggest a novel role for the p190 RhoGAP proteins in GnRH neuronal development and integrity.

High DHEAS in girls and metabolic features throughout pubertal maturation.

CONTEXT: An association between premature adrenarche and metabolic syndrome at presentation has been described. Our aim was to assess whether the presence of high dehydroepiandrosterone sulphate (DHEAS [HD]) at the adrenarche determines the risk of metabolic syndrome during puberty, taking into account body mass index (BMI) and birth weight. DESIGN: Prospective observational. PATIENTS: Five hundred four girls from the Growth and Obesity Chilean Cohort Study were followed from birth through puberty. At age ~7, subjects were classified by DHEAS concentrations into the HD (>75th percentile) or normal DHEAS (ND, ≤75th percentile) subgroups. MEASUREMENTS: Anthropometrics, semiannual clinical pubertal staging and hormonal and metabolic levels. The relationships among DHEAS at age ~7, metabolic syndrome, and each of its components independently, were analyzed by linear and logistic regression models during puberty and 1-year postmenarche, adjusted by confounders. RESULTS: Girls with HD at 7 years exhibited higher BMI, more central fat and higher serum androgen and insulin like growth factor (IGF)-I levels throughout puberty. Also, girls with HD had a greater prevalence of hyperglycemia at B2 and B4 breast stages, and of low HDL at B4. At 1 year after menarche, HD girls had a higher prevalence of metabolic syndrome, and those with BMI > 1 SD score had a higher metabolic score and insulin levels than ND girls with similar BMI. CONCLUSIONS: Our observations suggest that girls with HD at the age of adrenarche may be at greater risk for metabolic syndrome at adolescence, especially in those who are overweight or obese. Our results emphasize the importance of lifestyle interventions for childhood overweight and obesity among girls with HD.

Novel loci and Mapuche genetic ancestry are associated with pubertal growth traits in Chilean boys.

Puberty is a complex developmental process that varies considerably among individuals and populations. Genetic factors explain a large proportion of the variability of several pubertal traits. Recent genome-wide association studies (GWAS) have identified hundreds of variants involved in traits that result from body growth, like adult height. However, they do not capture many genetic loci involved in growth changes over distinct growth phases. Further, such GWAS have been mostly performed in Europeans, but it is unknown how these findings relate to other continental populations. In this study, we analyzed the genetic basis of three pubertal traits; namely, peak height velocity (PV), age at PV (APV) and height at APV (HAPV). We analyzed a cohort of 904 admixed Chilean children and adolescents with European and Mapuche Native American ancestries. Height was measured on roughly a [Formula: see text]month basis from childhood to adolescence between 2006 and 2019. We predict that, in average, HAPV is 4.3 cm higher in European than in Mapuche adolescents (P = 0.042), and APV is 0.73 years later in European compared with Mapuche adolescents (P = 0.023). Further, by performing a GWAS on 774, 433 single-nucleotide polymorphisms, we identified a genetic signal harboring 3 linked variants significantly associated with PV in boys (P [Formula: see text]). This signal has never been associated with growth-related traits.

Phenotypic continuum between Waardenburg syndrome and idiopathic hypogonadotropic hypogonadism in humans with SOX10 variants.

PURPOSE: SOX10 variants previously implicated in Waardenburg syndrome (WS) have now been linked to Kallmann syndrome (KS), the anosmic form of idiopathic hypogonadotropic hypogonadism (IHH). We investigated whether SOX10-associated WS and IHH represent elements of a phenotypic continuum within a unifying disorder or if they represent phenotypically distinct allelic disorders. METHODS: Exome sequencing from 1,309 IHH subjects (KS: 632; normosmic idiopathic hypogonadotropic hypogonadism [nIIHH]: 677) were reviewed for SOX10 rare sequence variants (RSVs). The genotypic and phenotypic spectrum of SOX10-related IHH (this study and literature) and SOX10-related WS cases (literature) were reviewed and compared with SOX10-RSV spectrum in gnomAD population. RESULTS: Thirty-seven SOX10-associated IHH cases were identified as follows: current study: 16 KS; 4 nIHH; literature: 16 KS; 1 nIHH. Twenty-three IHH cases (62%; all KS), had ≥1 known WS-associated feature(s). Moreover, five previously reported SOX10-associated WS cases showed IHH-related features. Four SOX10 missense RSVs showed allelic overlap between IHH-ascertained and WS-ascertained cases. The SOX10-HMG domain showed an enrichment of RSVs in disease states versus gnomAD. CONCLUSION: SOX10 variants contribute to both anosmic (KS) and normosmic (nIHH) forms of IHH. IHH and WS represent SOX10-associated developmental defects that lie along a unifying phenotypic continuum. The SOX10-HMG domain is critical for the pathogenesis of SOX10-related human disorders.

Reproductive hormones during pubertal transition in girls with transient Thelarche.

CONTEXT: Transient thelarche (TT), that is, the appearance, regression and subsequent reappearance of breast buds, is a frequent phenomenon, but little is known about pubertal transition in these girls. OBJECTIVE: To describe pubertal progression, growth, genotypes, reproductive hormones and growth factors in girls with TT compared to those who do not present TT (non-TT). DESIGN: Retrospective analysis of a longitudinal population-based study. PATIENTS OR OTHER PARTICIPANTS: Girls (n = 508) of the Chilean Growth and Obesity cohort. MEASUREMENTS: Pubertal progression, reproductive hormones, follicle stimulating hormone (FSH) beta subunit/FSH receptor gene single nucleotide polymorphisms and growth. RESULTS: Thirty-seven girls (7.3%) were presented TT. These girls entered puberty by pubarche more frequently (51%) than girls with normal progression (non-TT; n = 471; 23%, P = .005). Girls with TT who were under 8 years old had lower androgens, anti-Müllerian hormone (AMH), luteinizing hormone (LH) and oestradiol (all P < .05) than older girls with TT. At the time of Tanner breast stage 2 (B2), girls with TT had higher androgens, LH, FSH, IGF1, LH, insulin and oestradiol (P < .01) than at the time of TT. TT girls were older at B2 (10.3 ± 1.1 vs. 9.2 ± 1.2 years, P < .001) and menarche (12.3 ± 0.8 vs. 12.0 ± 1.0 years, P = .040) than their counterparts (non-TT). No differences in anthropometric variables or FSHB/FSHR genotypes were detected. CONCLUSION: Transient thelarche is a frequent phenomenon that does not appear to be mediated by hypothalamic-pituitary-gonadal axis activation or by adiposity. Hormonal differences between earlier TT and later TT suggest that their mechanisms are different.

Neonatal diabetes due to potassium channel mutation: Response to sulfonylurea according to the genotype.

OBJECTIVE: A precision medicine approach is used to improve treatment of patients with monogenic diabetes. Herein, we searched SU efficiency according to the genotype-phenotype correlation, dosage used, and side effects. RESEARCH DESIGN AND METHODS: Systematic review conducted according the PRISMA control criteria identifying relevant studies evaluating the in vivo and in vitro sensitivity of ATP-dependent potassium channels according to the characteristics of genetic mutation. RESULTS: Hundred and three selected articles with complete data in 502 cases in whom 413 (82.3%) had mutations in KCNJ11 (#64) and 89 in ABCC8 (# 56). Successful transfer from insulin to SU was achieved in 91% and 86.5% patients, respectively, at a mean age of 36.5 months (0-63 years). Among patients with KCNJ11 and ABCC8 mutations 64 and 46 were associated with constant success, 5 and 5 to constant failure, and 10 and 4 to variable degrees of reported success rate, respectively. The glibenclamide dosage required for each genotype ranged from 0.017 to 2.8 mg/kg/day. Comparing both the in vivo and in vitro susceptibility results, some mutations appear more sensitive than others to sulfonylurea treatment. Side effects were reported in 17/103 of the included articles: mild gastrointestinal symptoms and hypoglycaemia were the most common. One premature patient had an ulcerative necrotizing enterocolitis which association with SU is difficult to ascertain. CONCLUSIONS: Sulfonylureas are an effective treatment for monogenic diabetes due to KCNJ11 and ABCC8 genes mutations. The success of the treatment is conditioned by differences in pharmacogenetics, younger age, pharmacokinetics, compliance, and maximal dose used.

Early Obesity: Risk Factor for Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD), defined as fat accumulation greater than 5% in hepatocytes, may progress to fibrosis or cirrhosis later in life. NAFLD prevalence in adolescents has increased significantly in direct relation with obesity prevalence. Fatty liver has become the most frequent indication for liver transplantation in adults. OBJECTIVE: The aim of the study was to identify anthropometric variables during the first 10 years of life associated to the risk of developing NAFLD in adolescence. METHODS: Longitudinal cohort study 'Growth and Obesity Chilean Cohort Study' (GOCS) consisting of 513 children born in 2002 to 2003, with yearly anthropometric data collected over a 10-year period. The presence of intrahepatic fat in the livers of subjects 14 to 16 years of age was determined using abdominal ultrasound. In addition, elastography was performed on all participants with ultrasound evidence of NAFLD. RESULTS: 9.7% of the participants presented findings compatible with NAFLD. After 2 years of age, obesity significantly and progressively increased the probability of NAFLD occurrence in adolescence. Obesity at 5 years of age was associated with the highest OR for NAFLD, reaching values of 8.91 (95% CI 3.03-16.11). Among participants with NAFLD, those with altered liver elasticity (≥7 kPa) had greater weight, BMI z-score, waist and hip circumference, and altered liver enzymes (P < 0.05). CONCLUSION: The risk of developing NAFLD in adolescence increases progressively with early obesity starting at age 2 years.

Obesity and Related Metabolic Biomarkers and Its Association with Serum Levels of Estrogen in Pre-pubertal Chilean Girls.

Purpose: Recent reports show that girls with higher body mass index (BMI) have an earlier puberty onset (thelarche). It has been suggested that earlier puberty is a consequence of higher levels of estrogen due to increased aromatization of androgens in adipose tissue. Thus, we aimed to assess the relation between serum levels of estrogen and excess weight (BMI ≥1SD) and central adiposity (>75th percentile for waist circumference) in prepubertal girls at age 7.Materials and Methods: We conducted a cross-sectional study within the Growth and Obesity Cohort Study of 1190 low-middle income children from Santiago, Chile. We selected a random sample of 107 prepubertal girls at age 7. A trained dietitian measured weight, height and waist circumference. Additionally, a fasting blood sample was collected to measure serum levels of estradiol equivalents (via ultrasensitive recombinant cell bioassay), dehydroepiandrosterone sulfate (DHEAS), insulin, insulin-like growth factor 1 (IGF-1), and leptin.Results: Excess weight was observed in 40% of our sample; 11.2% had high central adiposity, and the mean level of estradiol equivalents was 3.6 ± 2.3 pg/ml. In the univariate and multivariate analyzes, we did not observe an association between excess weight, central adiposity and estradiol equivalent levels; however, insulin was inversely associated with the serum level of estradiol equivalents.Conclusions: Our participants had a mean level of estradiol equivalents of 3.6 pg/ml (±2.3 pg/ml) at the pre-pubertal stage. However, with the exception of insulin, we did not observe an association between estradiol equivalents and markers of adiposity and metabolic and hormonal factors.

Impact of route of administration on genotoxic oestrogens concentrations using oral vs transdermal oestradiol in girls with Turner syndrome.

OBJECTIVE: The established link between oestrogen and breast cancer occurs via both oestrogen receptor (ER)-mediated and non ER-mediated mechanisms. The term genotoxic estrogens describes mutagenic metabolites, including oestrogen catechols and quinones, which have been linked to breast carcinogenesis in post-menopausal women. We aimed to assess whether the route of administration of 17ß oestradiol (E2 ) affects the accumulation of genotoxic oestrogen metabolites in a model of ovarian failure in young girls with Turner syndrome. METHODS: Stored plasma samples obtained at 0 and 12 months were used from 40 adolescents with Turner syndrome who participated in a 12 months randomized controlled trial of the metabolic impact of E2 orally (2 mg/d) vs transdermally (100 µg/d); dose escalation allowed matching of unconjugated E2 levels in the parent study. We measured 12 oestrogen metabolites (total concentrations = conjugated and unconjugated) using a highly sensitive LCMSMS assay. Results from 48 normally menstruating adolescents were used for comparison. RESULTS: After treatment, least square mean (SE) total E2 concentrations were higher in the oral vs transdermal group (6784 pmol/L vs 1123 [1614], P < 0.0001), as was oestrone (E1 ) (91 060 pmol/L vs 19 278 [16 534], P < 0.0001). Also, higher after oral treatment were catechol-oestrogens 4-hydroxy-E2 (149 vs 28 [±49] pmol/L), 2-hydroxy-E2 (300 vs 76 [±52]), 4-hydroxy-E1 (450 vs 105 [±113]), 2-hydroxy-E1 (3094 vs 740 [±684]) and 16α-hydroxy-E1 (3,007 vs 157 [±534]) (<0.001 between groups). Levels were much closer to controls in the transdermal group. CONCLUSIONS: Common feminizing doses of oral oestradiol for 12 months result in substantial accumulation of unphysiologic, genotoxic oestrogens compared to transdermal oestradiol, expanding concerns about oral oestrogens' first hepatic passage. Further studies assessing long-term risks of these metabolites in women taking different forms of oestrogen are needed.

Childhood and adolescent phenol and phthalate exposure and the age of menarche in Latina girls.

BACKGROUND: The age of menarche has been associated with metabolic and cardiovascular disease, as well as cancer risk. The decline in menarcheal age over the past century may be partially attributable to increased exposure to endocrine disrupting chemicals (EDCs). METHODS: We assessed the influence of 26 phenol and phthalate biomarkers on the timing of menarche in a longitudinal cohort of Chilean girls. These EDCs were quantified in urine collected prior to the onset of breast development (Tanner 1; B1), and during adolescence (Tanner 4; B4). Multivariable accelerated failure time (AFT) models were used to analyze associations between biomarker concentrations and the age of menarche adjusting for body mass index (BMI) Z-score and maternal education, accounting for within-subject correlation. RESULTS: Several biomarkers were significantly associated with the age at menarche; however, these associations were dependent on the timing of biomarker assessment. A log(ng/ml) increase in B1 concentrations of di(2-ethylhexyl) phthalate biomarkers was associated with later menarche (hazard ratio (HR): 0.77; 95% CI: 0.60, 0.98), whereas higher B1 concentrations of 2,5-dichlorophenol and benzophenone-3 were associated with earlier menarche (HR: 1.13; 95% CI: 1.01, 1.27; HR: 1.17; 95% CI: 1.06, 1.29, respectively). Elevated B4 concentrations of monomethyl phthalate were similarly associated with earlier menarche (HR: 1.30; 95% CI: 1.10, 1.53). The impact of monoethyl phthalate and triclosan concentrations on pubertal timing were significantly modified by BMI Z-score. Higher monoethyl phthalate and triclosan concentrations were associated with earlier menarche among overweight or obese girls, but not among those that were normal weight. CONCLUSIONS: This study identifies modulation of sexual maturation by specific EDC biomarkers in Latina girls.

Is There a Difference between Ultrasonographic (US) Uterine Changes of Oral Versus Transdermal (TD) 17ß Estradiol (17ß E2) in Girls with Turner Syndrome (TS)? Own Experience and Literature Review.

BACKGROUND: Among patients with Turner Syndrome (TS), premature ovarian failure is a main feature. Recently published consensus guidelines recommend that transdermal (TD) estradiol is the preferred route for estrogen replacement. Studies related to ultrasound (US) measurements during estrogen replacement in TS patients using estradiol (17ß E2) and correlating uterine growth with estrogen metabolites are limited. OBJECTIVES: To compare uterine morphology and hormonal changes depending on route of administration of 17ß E2 (oral vs. TD) in a small population of girls with TS. SUBJECTS: 11 hypogonadal girls with TS (mean (SE) age 14.5 ± 1.4 years; BMI -0.98 ± -1.0 SDS) who participated in a larger study on the effects of oral versus TD 17ß E2 agreed to do a sub-study on the effect of the form of 17ß E2 treatment on uterine size. METHODS: 17ß E2 was given orally or TD for 12 months, titrated to doses up to 2 mg orally or 100 µg TD to achieve normal estradiol levels. Subjects received monthly progesterone for 1 week for withdrawal bleeding. At baseline, 6 and 12 months, a pelvic ultrasound was performed while on estradiol only. RESULTS: Uterine morphology and endometrial thickness increased comparably in both groups. E2 concentrations were comparable at 12 months between both groups but E1 and E1S were lower in TD group at 12 months. CONCLUSIONS: According to our experience, in a group of TS patients randomized to oral vs TD 17ß E2 and monitored with trans-abdominal US, both groups achieved similar increases in uterine size comparable to normal women. To confirm our observation a larger sample and a longer evaluation period is needed.

Functionally compromised CHD7 alleles in patients with isolated GnRH deficiency.

Inactivating mutations in chromodomain helicase DNA binding protein 7 (CHD7) cause CHARGE syndrome, a severe multiorgan system disorder of which Isolated gonadotropin-releasing hormone (GnRH) deficiency (IGD) is a minor feature. Recent reports have described predominantly missense CHD7 alleles in IGD patients, but it is unclear if these alleles are relevant to causality or overall genetic burden of Kallmann syndrome (KS) and normosmic form of IGD. To address this question, we sequenced CHD7 in 783 well-phenotyped IGD patients lacking full CHARGE features; we identified nonsynonymous rare sequence variants in 5.2% of the IGD cohort (73% missense and 27% splice variants). Functional analyses in zebrafish using a surrogate otolith assay of a representative set of these CHD7 alleles showed that rare sequence variants observed in controls showed no altered function. In contrast, 75% of the IGD-associated alleles were deleterious and resulted in both KS and normosmic IGD. In two families, pathogenic mutations in CHD7 coexisted with mutations in other known IGD genes. Taken together, our data suggest that rare deleterious CHD7 alleles contribute to the mutational burden of patients with both KS and normosmic forms of IGD in the absence of full CHARGE syndrome. These findings (i) implicate a unique role or preferential sensitivity for CHD7 in the ontogeny of GnRH neurons, (ii) reiterate the emerging genetic complexity of this family of IGD disorders, and (iii) demonstrate how the coordinated use of well-phenotyped cohorts, families, and functional studies can inform genetic architecture and provide insights into the developmental biology of cellular systems.

Heterozygous mutations in natriuretic peptide receptor-B (NPR2) gene as a cause of short stature.

Based on the observation of reduced stature in relatives of patients with acromesomelic dysplasia, Maroteaux type (AMDM), caused by homozygous or compound heterozygous mutations in natriuretic peptide receptor-B gene (NPR2), it has been suggested that heterozygous mutations in this gene could be responsible for the growth impairment observed in some cases of idiopathic short stature (ISS). We enrolled 192 unrelated patients with short stature and 192 controls of normal height and identified seven heterozygous NPR2 missense or splice site mutations all in the short stature patients, including one de novo splice site variant. Three of the six inherited variants segregated with short stature in the family. Nine additional rare nonsynonymous NPR2 variants were found in three additional cohorts. Functional studies identified eight loss-of-function mutations in short individuals and one gain-of-function mutation in tall individuals. With these data, we were able to rigorously verify that NPR2 functional haploinsufficiency contributes to short stature. We estimate a prevalence of NPR2 haploinsufficiency of between 0 and 1/26 in people with ISS. We suggest that NPR2 gain of function may be a more common cause of tall stature than previously recognized.

Leuprolide acetate-stimulated androgen response during female puberty.

BACKGROUND: A physiological increase in androgen levels occurs during adolescence. Measuring androgen concentrations is the best method to distinguish normal evolution processes from hyperandrogenic disorders. HYPOTHESIS: The increase in circulating androgens during puberty is inversely associated with insulin sensitivity in normal weight girls. OBJECTIVE: To assess circulating levels of ovarian androgens and anti-Müllerian hormone (AMH) at baseline and after GnRH analogue (GnRH-a) stimulation in normal pubertal girls across different Tanner stages. We also studied the association between this response and insulin sensitivity. DESIGN: Prospective study of healthy girls (6-12 years) from the local community (n = 63). METHODS: Tanner I (n = 23) subjects were assessed cross-sectionally, and Tanner II girls (n = 40) were evaluated every 6 months until they reached Tanner V. Early morning dehydroepiandrosterone sulphate (DHEA-S), AMH, sex hormone-binding globulin (SHBG), androstenedione, glucose and insulin levels were measured. A GnRH-a test (500 µg/m(2) ; sc) and oral glucose intolerance test (OGTT) were performed. Differences throughout puberty were evaluated. RESULTS: Basal and/or stimulated Testosterone DHEA-S and 17-hydroxyprogesterone (17OHP) were inversely associated with insulin sensitivity (WIBSI) from the beginning of puberty, whereas androstenedione was directly associated with gonadotrophins. AMH was inversely associated with basal and stimulated gonadotrophins and directly with insulin area under the curve (AUC) only in the early stages of puberty. 17OHP and testosterone responsiveness increased significantly during puberty in all subjects, whereas testosterone levels changed less consistently. This pattern of ovarian-steroidogenic response was most evident during mid- and late puberty. Moreover, during late puberty only, basal 17OHP, testosterone and DHEA-S were positively associated with gonadotrophins. CONCLUSION: In normal nonobese girls born appropriate for gestational age, androgen synthesis was associated with insulin sensitivity in early puberty and with LH only in late puberty.

Breast bud detection: a validation study in the Chilean growth obesity cohort study.

BACKGROUND: Early puberty onset has been related to future chronic disease; however breast bud assessment in large scale population studies is difficult because it requires trained personnel. Thus our aim is to assess the validity of self and maternal breast bud detection, considering girl's body mass index (BMI) and maternal education. METHODS: In 2010, 481 girls (mean age = 7.8) from the Growth and Obesity Chilean Cohort Study were evaluated by a nutritionist trained in breast bud detection. In addition, the girl(n = 481) and her mother(n = 341) classified the girl's breast development after viewing photographs of Tanner stages. Concordance between diagnostics was estimated (kappa, Spearman correlation) considering girls' BMI and mother's educational level. RESULTS: 14% of the girls presented breast buds and 43% had excess weight (BMI z-score > 1, World Health Organization 2007). Self-assessment showed low concordance with the evaluator (K < 0.1) and girls with excess weight over-diagnosed more than girls of normal weight (44% vs. 24%, p-value < 0.05). Instead, mothers showed good concordance with the evaluator (K = 0.7, 95% confidence interval (CI) = 0.6-0.9), even in overweight girls and/or in mothers with low education (K = 0.7, 95% CI = 0.6-0.8). CONCLUSIONS: Mothers were able to adequately evaluate the appearance of breast bud despite low educational level and girls' excess weight. Mother could be a useful resource for defining puberty onset in epidemiological studies, particularly developing countries.

Post menarcheal growth patterns in a contemporary cohort of Latino girls.

INTRODUCTION: Menarche is the last stage of pubertal development, which coincides with the completion of longitudinal growth. As a consequence of the lack of national and up-to-date data related to post-menarcheal (PM) growth, the aim of our work was to evaluate post menarcheal growth in a group of contemporary healthy Chilean girls followed, prospectively, until 4 years post-menarche. METHODS: This study was nested within the GOCS cohort, in a prospective fashion. The girls were followed yearly after menarche for at least four years. We modeled each girl growth using a Super Imposition by Translation and Rotation (SITAR) model. RESULTS: A total of 534 girls were evaluated prospectively, 399 girls had height measured two years after menarche, 421 after three years, and 364 of 534 had height measured at four year post menarche. Expected height gained PM, in the complete study group was 6.6 ± 2.5 cm. We observed that the largest gain in height occurred after the first year PM (3.8 1.5 cm). According to the age of menarche, the group with earlier menarche (< 11 years old ) had a greater height gain in cm after four years PM ( 8.2± 3.2 cm ) and the smallest gain was among girls with menarche at an age older than 13 yr (4.4±1.6) ( p<0.001). Age at menarche was significantly associated with all post menarche growth patterns (size, timing and intensity), indicating that girls with older age at menarche grew taller, later and slower than girls with younger age at menarche. Adjusting PM growth pattern by BMI maintained all these association. Applying the SITAR model specifically , girls experiencing menarche after the age of 13 years exhibited slower growth , occurring slightly earlier and with less intensity when adjusted by BMI at menarche . CONCLUSION: In a national and updated dataset we observed that girls grew until 4 years post menarche an average of 6.6 ± 2.5 cm., with greatest gain occurring in the first year PM , (3.8 ± 1.5 cm). Age at menarche was associated with menarche growth patterns.

Association between plasma leptin/adiponectin ratio and insulin resistance indexes in prepubertal children.

Objective: To assess the association between leptin/adiponectin ratio (LAR) and insulin resistance surrogates in prepubertal children. Materials and methods: Study based on data from the Growth and Obesity Chilean Cohort Study (GOCS) involving 968 Chilean prepubertal children. Plasma insulin, leptin, and adiponectin were determined by immunoassays. Several common insulin resistance surrogates were calculated, including the homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride/HDL cholesterol index, triglyceride-glucose (TyG) index, and the TyG index corrected for body mass index (BMI; TyG-BMI) and waist circumference (WC; TyG-WC). Associations among variables were assessed using multiple linear and logistic regression analysis. Results: There was a significant direct association between plasma leptin and LAR with BMI z-score but no association between plasma adiponectin and adiposity. After adjustments for sex and age, LAR was significantly associated with all insulin resistance surrogates (which were categorized using the 75th percentile as the cutoff point), with the TyG-WC index emerging as the surrogate with the highest magnitude of association (odds ratio [OR] 2.44, 95% confidence interval [CI] 2.05-2.9). After additional adjustment for BMI z-score, only the association between LAR and TyG-WC remained significant (OR 1.64, 95% CI 1.27-2.12). Conclusion: Plasma leptin and LAR were strongly associated with several common insulin resistance surrogates in prepubertal children, most notably with the TyG-WC index. Associations between LAR and insulin resistance indexes were mainly driven by the effect of plasma leptin, which is also directly associated with increased adiposity.