Reference values of bone stiffness index and C-terminal telopeptide in healthy European children.
OBJECTIVE
Quantitative ultrasound measurements and bone metabolic markers can help to monitor bone health and to detect impaired skeletal development. Population-based reference values for children may serve as a basis for preventive measures to reduce the risk of osteoporosis and osteoporotic fractures in later life. This is the first paper providing age-, sex- and height-specific reference values for bone stiffness index (SI) and serum carboxy-terminal cross-linking telopeptide of type I collagen (CTX) in healthy, apparently prepubertal children.


METHODS
In the population-based IDEFICS baseline survey (2007-2008) and follow-up (2009-2010), 18,745 children from eight European countries were newly recruited. A total of 10,791 2-10.9-year-old and 1646 3-8.9-year-old healthy children provided data on SI of the right and left calcaneus and serum CTX, respectively. Furthermore, height and weight were measured. Percentile curves were calculated using the General Additive Model for Location Scale and Shape (GAMLSS) to model the distribution of SI and CTX depending on multiple covariates while accounting for dispersion, skewness, and the kurtosis of this distribution.


RESULTS
SI was negatively associated with age and height in children aged 2-5 years, whereas a positive association was observed in children aged 6-10 years. The dip in SI occurred at older age for higher SI percentiles and was observed earlier in taller children than in smaller children. The CTX reference curves showed a linear-positive association with age and height. No major sex differences were observed for the SI and CTX reference values.


CONCLUSIONS
These reference data lay the ground to evaluate bone growth and metabolism in prepubertal children in epidemiological and clinical settings. They may also inform clinical practice to monitor skeletal development and to assess adverse drug reactions during medical treatments.
Leibniz Institute for Prevention Research and Epidemiology-BIPS, Bremen, Germany.
D
D
Herrmann
Leibniz Institute for Prevention Research and Epidemiology-BIPS, Bremen, Germany.
T
T
Intemann
Unit of Epidemiology and Population Genetics, Institute of Food Sciences, Consiglio Nazionale delle Ricerche, Avellino, Italy.
F
F
Lauria
Department of Pediatrics, Institute of Clinical Sciences, The Queen Silvia Children's Hospital, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
S
S
Mårild
Department of Pediatrics, University of Pécs, Pécs, Hungary.
D
D
Molnár
GENUD (Growth, Exercise, Nutrition and Development) Research Group, University of Zaragoza, Zaragoza, Spain.
L A
LA
Moreno
Department of Public Health, Ghent University, Ghent, Belgium.
I
I
Sioen
Research and Education Institute of Child Health, Strovolos, Cyprus.
M
M
Tornaritis
Department of Chronic Diseases, National Institute for Health Development, Estonian Centre of Behavioral and Health Sciences, Tallinn, Estonia.
T
T
Veidebaum
1] Leibniz Institute for Prevention Research and Epidemiology-BIPS, Bremen, Germany [2] Institute of Statistics, Faculty of Mathematics and Computer Science, Bremen University, Bremen, Germany.
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I
Pigeot
1] Leibniz Institute for Prevention Research and Epidemiology-BIPS, Bremen, Germany [2] Institute of Statistics, Faculty of Mathematics and Computer Science, Bremen University, Bremen, Germany.
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Ahrens
D015415:Biomarkers / Q000097:blood; D001835:Body Weight; D001846:Bone Development / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D024042:Collagen Type I / Q000097:blood*; D004032:Diet; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control*; D006306:Health Surveys; D006801:Humans; D008019:Life Style; D008297:Male; D010024:Osteoporosis / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control*; D010446:Peptide Fragments; D010455:Peptides / Q000097:blood*; D011237:Predictive Value of Tests; D012016:Reference Values; D044465:White People
D015415:Biomarkers; D024042:Collagen Type I; D010446:Peptide Fragments; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide