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Context: The increase in bone mineral content (BMC) and density (BMD) measured by dual-energy x-ray absorptiometry (DXA) in obese children may not sustain the mechanical load associated with weight, and the factors influencing bone mineralization are not well known., Objective: We described bone mineralization in boys with overweight/obesity and leanness in relation to body composition., Methods: Cross-sectional study in the Pediatric Endocrinology Unit of Angers University Hospital with 249 overweight/obese boys aged 8-18 who underwent DXA and insulin, testosterone, and IGF-1 measurements. Bone mineralization was compared with data from 301 lean boys of similar age and height from NHANES 2011-2015, using the same DXA model. Path analyses were performed to evaluate factors associated with total body less head (TBLH) BMC., Results: The mean age- and height-adjusted difference in TBLH BMC between obese and lean boys was 241 ± 20 g/cm2. Each 1 kg/m2 increase in BMI was associated with +39 ± 6 g of TBLH BMC in lean subjects vs + 25 ± 3 g in obese subjects (P < .05). Each 1 kg/m2 increase in lean BMI (LBMI) was associated with +78 ± 5 g of TBLH BMC in lean and obese boys, and each 1 kg/m2 increase in fat mass index (FMI) was associated with a decrease of 9 ± 3 g of TBLH BMC. The TBLH BMC was directly positively influenced by LBMI and indirectly and positively influenced by IGF-1, testosterone, and insulin (mediated through height and LBMI). FMI indirectly influenced TBLH BMC, both positively through LBMI and negatively through its negative impact on IGF-1 and testosterone., Conclusion: The increase in bone mineralization in obese children does not adapt to the increase in body mass., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)

Introduction: Serum calcium is frequently measured during the neonatal period, and is known to be influenced by the vitamin D status. We hypothesized that the 25OHD concentration may influence the lower limit of the serum calcium normal range in neonates., Methods: We included in our prospective cohort study 1002 mother-newborn pair recruited from April 2012 to July 2014, in two centers located in the neighborhoods of Paris, France, whose serum calcium was measured at 3 days of life. We established, after exclusion of outliers, a 95% confidence interval (CI) for serum calcium 1) in our whole population of 1002 neonates, 2) in neonates with a cord blood 25OHD concentration ≥ 30 nmol/L, and 3) in those with a 25OHD ≥ 50 nmol/L., Results: The mean serum total calcium was 2.46 ± 0.13 nmol/L [95% CI: 2.19-2.72 mmol/L], 2.47 ± 0.25 mmol/L [95% CI: 2.22-2.72 mmol/L], and 2.50 ± 0.25 mmol/L [95% CI: 2.25-2.75 mmol/L] in the whole group, in the 514 neonates with 25OHD ≥ 30 nmol/L, and in the 202 neonates with 25OHD ≥ 50 nmol/L respectively. The lower limit of the 95% range was significantly higher in neonates with 25 OHD ≥ 30 nmol/L (p<0.05) and ≥ 50 nmol/L (p<0.001) than in the entire cohort., Conclusion: We show that the lower limit of the normal serum calcium range is higher in groups with a higher 25OHD than in unselected subjects. We propose that the reference range for serum calcium in neonates is 2.25 to 2.75 mmol/L., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Introduction: Congenital hypothyroidism with gland-in-situ (CH-GIS) is usually attributed to mutations in the genes involved in thyroid hormone production. The diagnostic yield of targeted next-generation sequencing (NGS) varied widely between studies. We hypothesized that the molecular yield of targeted NGS would depend on the severity of CH., Methods: Targeted NGS was performed in 103 CH-GIS patients from the French national screening program referred to the Reference Center for Rare Thyroid Diseases of Angers University Hospital. The custom targeted NGS panel contained 48 genes. Cases were classified as solved or probably solved depending on the known inheritance of the gene, the classification of the variants according to the American College of Medical Genetics and Genomics, the familial segregation, and published functional studies. Thyroid-stimulating hormone at CH screening and at diagnosis (TSHsc and TSHdg) and free T4 at diagnosis (FT4dg) were recorded., Results: NGS identified 95 variants in 10 genes in 73 of the 103 patients, resulting in 25 solved cases and 18 probably solved cases. They were mainly due to mutations in the TG (n = 20) and TPO (n = 15) genes. The molecular yield was, respectively, 73% and 25% if TSHsc was ≥ and < 80 mUI/L, 60% and 30% if TSHdg was ≥ and < 100 mUI/L, and 69% and 29% if FT4dg was ≤ and > 5 pmol/L., Conclusion: NGS in patients with CH-GIS in France found a molecular explanation in 42% of the cases, increasing to 70% when TSHsc was ≥ 80 mUI/L or FT4dg was ≤ 5 pmol/L., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Endocrine Society.)

Context: Alterations in semen characteristics and circulating Sertoli and Leydig cell hormones have been described in obese male adults. Whether hormonal alterations occur before adulthood has not been fully evaluated., Objective: We describe circulating Sertoli and Leydig cell hormone levels in overweight-obese (ow/ob) boys through childhood and adolescence in a cross-sectional study., Methods: Monocentric study in the Pediatric Endocrinology Unit of Angers University Hospital. Three hundred and fifty-one obese and overweight boys aged 5-19 years underwent physical examination, dual-energy X-ray absorptiometry for body composition, oral glucose tolerance test on insulin and glucose, and measurements of follicle-stimulating hormone, luteinizing hormone, anti-Müllerian hormone (AMH), inhibin B, testosterone, and estradiol. Hormonal levels were compared with normative data obtained from 652 healthy nonoverweight nonobese boys of similar age or Tanner stage., Results: Median inhibin B and testosterone levels during puberty were significantly lower in ow/ob than in healthy boys (1) from age >12 years and thereafter for inhibin B, and (2) from age >14 years and thereafter for testosterone. At Tanner stages 4 and 5, 26%, 31%, and 18% of inhibin B, testosterone, and AMH values were below the 5th percentile in ow/ob subjects (P < .01). In multiple regression analyses, estradiol and total bone mineral density Z-score were negative predictors of inhibin B, fat mass percentage was a negative predictor of testosterone, and insulin was a negative predictor of AMH., Conclusion: Lower Sertoli and Leydig cell hormone levels during puberty were observed in the ow/ob boys., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)