Estradiol Levels and Secretory Dynamics in Normal Girls and Boys as Determined by an Ultrasensitive Bioassay: A 10 Year Experience

Janfaza, Mona; Sherman, Tami Irwin; Larmore, Kimberly A.; Brown-Dawson, Jacquelyn M.; Klein, Karen Oerter

doi:10.1515/jpem.2006.19.7.901

Cited by 57 publications

(46 citation statements)

References 27 publications

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“…. They are also consistent with the hypothesis that continued exposure to estrogen leads to epiphyseal fusion' (Klein et al 1996;Janfaza et al 2006). …”

Section: Discussionsupporting

confidence: 85%

Are Americans shorter (partly) because they are fatter? A comparison of US and Dutch children's height and BMI values

Komlos

Breitfelder²

2007

Annals of Human Biology

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Objective: The study compared the height and BMI values of US children and youth by gender in the most recent NHANES surveys (1999)(2000)(2001)(2002)(2003)(2004) to those of their Dutch counterparts in 1997 in order to gain insights into the different growth patterns. Results: US children and youth are both shorter and heavier than their Dutch counterparts. US adolescent girls tend to experience an earlier growth spurt than do the Dutch and the velocity of growth of US boys slows down faster after the adolescent growth spurt than does that of their Dutch counterparts. The latter end up being approximately 5.6 cm taller and their median BMI values are 1.9-2.0 less than that of US youth between the ages of 10 and 19. This implies that US boys of the same height at age 19 are 8.8 kg heavier than their Dutch counterparts, and girls of age 13 are 7.2 kg heavier. Discussion: Some studies link high BMI values in childhood to an earlier onset of adolescence, which in turn has been linked to less growth thereafter. Conclusion: The fast tempo of growth of the US children may be associated with high energy balance, which leads to higher BMI values and which in turn may be associated with less growth during adolescence.

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“…. They are also consistent with the hypothesis that continued exposure to estrogen leads to epiphyseal fusion' (Klein et al 1996;Janfaza et al 2006). …”

Section: Discussionsupporting

confidence: 85%

Are Americans shorter (partly) because they are fatter? A comparison of US and Dutch children's height and BMI values

Komlos

Breitfelder²

2007

Annals of Human Biology

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“…The extraction RIA corresponds well with RCBA for values down to the analytical limits (23). Furthermore, the 17b-estradiol values obtained in prepubertal girls with our extraction RIA are more or less identical to those obtained by RCBA (20,21). By compilation of all this data, we estimate that our modified commercial extraction RIA has similar clinical usefulness as RCBAs.…”

Section: Discussionsupporting

confidence: 71%

“…Klein and coworkers have developed a RCBA to measure estrogenic activity with a detection limit between 0.07 and 0.7 pmol/l 17b-estradiol equivalents. The sample volume used was 800 ml, the interassay CV was 13% at 7 pmol/l and increased to about 60% at 0.07 pmol/l (19,20). Another RCBA has been developed by Paris et al (21).…”

Section: Discussionmentioning

confidence: 99%

A purification step prior to commercial sensitive immunoassay is necessary to achieve clinical usefulness when quantifying serum 17β-estradiol in prepubertal children

Ankarberg‐Lindgren

Norjavaara

2008

European Journal of Endocrinology

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A purification step prior to commercial sensitive immunoassay is necessary to achieve clinical usefulness when quantifying serum 17b-estradiol in prepubertal children Carina Ankarberg-Lindgren and Ensio Norjavaara Department of Paediatrics, Institute of Clinical Sciences, The Sahlgrenska Academy at Göteborg University, S-416 85, Göteborg, Sweden (Correspondence should be addressed to C Ankarberg-Lindgren; Email: carina.ankarberg-lindgren@vgregion.se) AbstractObjective: To test the clinical usefulness of sensitive commercial immunoassays for determination of low 17b-estradiol concentrations in children. Methods: The lower limit of detection and clinical usefulness (functional sensitivity) of three commercial estradiol immunoassays were validated by use of 500 sera from prepubertal and pubertal children and 55 pooled sera. The three immunoassays consisted of two modified direct immunoassays; one RIA (Spectria Estradiol RIA) and one time-resolved fluoroimmunoassay (AutoDELFIA Estradiol), both with increased serum volume in relation to antibody concentration and extended incubation time. In the third method, serum was purified and concentrated using diethyl ether extraction prior to measurement by the modified Spectria Estradiol RIA. Results: The lower limits of detection and clinical usefulness were 9 and 30 pmol/l for the direct RIA, 11 and 50 pmol/l for the AutoDELFIA, and 4 and 6 pmol/l for serum determined by extraction RIA. When measuring the serum pool originating from girls at breast stages 1-2, the direct RIA and AutoDELFIA resulted in significantly higher 17b-estradiol concentrations when compared with the extraction RIA (C58 and C267%, P!0.001). We found a significant difference in 17b-estradiol concentrations between girls at breast stages 1 (median 6 pmol/l) and 2 (median 16 pmol/l), when quantified by the extraction RIA (P!0.0001) but no difference when quantified with the direct RIA (median values 12 and 14 pmol/l respectively). Conclusion: For determination of low serum 17b-estradiol concentrations in children, an extraction step prior to commercial immunoassay is needed to achieve clinically useful results.

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“…One plasmid contains the human estrogen receptor complementary DNA and the other plasmid includes an estrogen response element upstream from the structural gene for b-galactosidase (23). The sensitivity of the bioassay is 0.02-0.2 pg/ml (0.07-0.7 pmol/l); the intra-assay and interassay coefficients of variation (CV) at 0.2 pg/ml (0.7 pmol/l) ranged from 10% to 50% (24).…”

Section: Data Collection and Assaysmentioning

confidence: 99%

Ultrasensitive estrogen levels at 7 years of age predict earlier thelarche: evidence from girls of the growth and obesity Chilean cohort

Pereira

Uauy

Klein

et al. 2015

European Journal of Endocrinology

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Objective: Prepubertal estradiol equivalents have been inconsistently linked to age at thelarche; elucidating this relationship becomes relevant given the worldwide decline in the age of puberty onset. Thus, our aim is to assess whether prepubertal girls with higher serum levels of estradiol equivalents at age 7 have a greater risk of presenting early thelarche (ET). Design: Nested case-control study within the Growth and Obesity Cohort Study of 1196 low-middle income children (w50% girls) from Santiago, Chile. Girls were defined as cases (ET; nZ61) if breast bud appeared prior to 8 years of age; controls (nZ91) had thelarche O8 years. Methods: At 6.7 years, weight, height and waist circumference were measured and a fasting blood sample was obtained for measuring estrogen equivalent (ultrasensitive recombinant cell bioassay), DHEAS, leptin, insulin and IGF1. Beginning at 7 years old, Tanner staging was assessed prospectively twice a year and the appearance of breast bud was assessed by palpation. Results: Mean serum estradiol-equivalent at 6.7 years was 3.9G3.6 pg/ml for cases and 3.6G2.3 pg/ml for controls. Girls with ET had a higher risk of presenting elevated estradiol-equivalent (R5 pg/ml) at 7 years (ORZ2.05, 95% CI: 0.96-4.36) than controls that was borderline significant. However, after adjusting by BMI, insulin and IGF1 at age 7, the association between estradiol-equivalent and ET was significant (ORZ2.29 (95% CI: 1.05-5.01)). Conclusions: Chilean girls from low to middle socioeconomic status with ET exhibited double the risk of having high levels of estradiol-equivalent at 7 years than girls with a later age of thelarche. Whole-body adiposity and increased adrenal activity did not explain the observed prepubertal estrogen increase.

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Estradiol Levels and Secretory Dynamics in Normal Girls and Boys as Determined by an Ultrasensitive Bioassay: A 10 Year Experience

Cited by 57 publications

References 27 publications

Are Americans shorter (partly) because they are fatter? A comparison of US and Dutch children's height and BMI values

Are Americans shorter (partly) because they are fatter? A comparison of US and Dutch children's height and BMI values

A purification step prior to commercial sensitive immunoassay is necessary to achieve clinical usefulness when quantifying serum 17β-estradiol in prepubertal children

Ultrasensitive estrogen levels at 7 years of age predict earlier thelarche: evidence from girls of the growth and obesity Chilean cohort

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