title: [Serum osteocalcin and bone alkaline phosphatase in healthy children in relation to age and gender].
abstract: Biochemical markers of bone formation are important in the study of growth and skeletal metabolism. However, interpretation of their values for children and adolescents is difficult because they depend on many factors such as age, gender, pubertal stage, race, nutritional and health status, specificity of assays and others. Therefore, age and sex specific reference ranges for bone formation markers must be established in a defined paediatric population. The purpose of this study was the investigation of normal serum concentration of osteocalcin (OC) and bone alkaline phosphatase (BALP) in Polish children aged 2-18 years. We studied 121 healthy children (56 girls, 65 boys) divided into 3 age groups of both genders: prepubertal, pubertal and postpubertal. The level of OC was determined by N-MID Osteocalcin One Step ELISA kit (Osteometer Bio Tech, Denmark) and the activity of BALP was measured using an enzyme immunoassay Alkphase-B kit (Metra Biosystems, USA). We observed, that both formation markers showed sigmoid regression curves with increasing age. The peak values of OC and BALP occurred during puberty in girls aged 9-13 years (115.6 +/- 21.3 ng/ml; 108.8 +/- 23.6 U/L) and in boys aged 10-15 years (117.8 +/- 22.3 ng/ml; 118.4 +/- 24.5 U/L). In all children after puberty, we observed a gradual lowering of both markers. However, girls showed decreased postpubertal values of OC and BALP 2-3 years earlier than boys, indicating the earlier completion of puberty in girls. The correlation between OC and BALP was statistically significant (r=0.612; p<0.001) in tested children. The results of this study may establish the reference values for bone turnover markers in Polish healthy children, which will be useful in the diagnosis and monitoring of therapy in bone diseases.
authors.affiliation: Zakład Biochemii i Diagnostyki Laboratoryjnej, Instytut Matki i Dziecka, 01-211Warszawa, ul. Kasprzaka 17a, Poland. biochem@imid.med.pl
authors.forename: Jadwiga
authors.initials: J
authors.lastname: Ambroszkiewicz
authors.forename: Joanna
authors.initials: J
authors.lastname: Gajewska
authors.forename: Teresa
authors.initials: T
authors.lastname: Laskowska-Klita
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000469:Alkaline Phosphatase / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001846:Bone Development / Q000502:physiology*; D016723:Bone Remodeling / Q000502:physiology*; D001842:Bone and Bones / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D015675:Osteocalcin / Q000097:blood*; D011627:Puberty / Q000378:metabolism; D012016:Reference Values; D012737:Sex Factors
chemical_list: D015415:Biomarkers; D015675:Osteocalcin; D000469:Alkaline Phosphatase