Relationship between bone mineral content and bone turnover markers, sex hormones and calciotropic hormones in pre- and early pubertal children
We investigated associations between bone mineral content (BMC) and bone-related biomarkers (BM) in pre-and early pubertal children of both sexes. In this population, we found that bone turnover markers explain a small part of BMC variance.
It is still debated whether BM including bone turnover markers (BTM), sex hormones and calciotropic (including cortisol) hormones provide information on BMC changes during growth.
Three hundred fifty-seven girls and boys aged 6 to 13 years were included in this study. BM was measured at baseline and BMC twice at 9 months and 4 years using DXA. Relationship between BMs was assessed using principal component analysis (PCA). BM was tested in its ability to explain BMC variation by using structural equation modelling (SEM) on cross-sectional data. Longitudinal data were used to further assess the association between BM and BMC variables.
BMC and all BMs, except calciotropic hormones, increased with age. PCA in BM revealed a three-factor solution (BTM, sex hormones and calciotropic hormones). In the SEM, age accounted for 61% and BTM for 1.2% of variance in BMC (cross-sectional). Neither sex nor calciotropic hormones were BMC explanatory variables. In the longitudinal models (with single BM as explanatory variables), BMC, age and sex at baseline accounted for 79–81% and 70–75% in BMC variance at 9 months and 4 years later, respectively. P1NP was consistently associated with BMC.
BMC strongly tracks in pre- and early pubertal children. In this study, only a small part of BMC variance was explained by single BTM at the beginning of pubertal growth.
KeywordsBone mineral content Bone remodelling Bone turnover marker Calciotropic hormones Gonadal steroid hormones Puberty
Biomarkers (including all markers measured in the blood)
Bone turnover marker
Dual-energy X-ray absorptiometry
25-Hydroxy vitamin D/calcifediol
Principal component analysis
Intact parathyroid hormone
Structural equation modelling
Sex hormone-binding globulin
We sincerely thank all children, teachers and parents for taking part in the study. We greatly appreciate the help of Giulio Conicella, Chantal Genet and Claude Kränzlin for their competent help in the bone measurements. We thank the foundation AETAS, Switzerland, for the use of their DXA-bus, the Swiss Heart Foundation for financial support of the current study and the funders of the initial study (KISS) including the Federal Council of Sports, Magglingen, Switzerland (grant number SWI05-013), and the Swiss National Foundation (grant number PMPDB-114401). And finally, also thanks to Erin Ashley West for proof-reading the manuscript.
This study was funded by the Swiss Heart Foundation. Funding for the initial trial (Effect of a general school-based physical activity intervention on bone mineral content and density) was provided by Swiss Federal Office of Sports and the Swiss National Science Foundation.
Compliance with ethical standards
Conflicts of interest
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