[Reference values for IGF-I, IGFBP-1, IGFBP-3 and osteocalcin in healthy children in Zaragoza]

Area of Science:

• Pediatric endocrinology
• Biochemical markers
• Growth and development

Background:

• Accurate reference values for key growth biomarkers are essential for pediatric health assessment.
• Insulin-like growth factor (IGF)-I, IGF binding protein (IGFBP)-1, IGFBP-3, and osteocalcin are critical indicators of growth and metabolic status.
• Existing reference ranges may not be universally applicable across diverse populations.

Purpose of the Study:

• To determine age-, sex-, and pubertal stage-specific reference values for basal serum concentrations of IGF-I, IGFBP-1, IGFBP-3, and osteocalcin.
• To provide updated reference data for healthy children in Zaragoza, Spain.
• To highlight the importance of population-specific reference ranges for accurate clinical interpretation.

Main Methods:

• Cross-sectional study of healthy children aged 0-14 years in Zaragoza.
• Measurement of basal serum concentrations using immunoradiometric assays.
• Estimation of reference values and ranges following International Federation of Clinical Chemistry guidelines.

Main Results:

• Reference values for IGF-I, IGFBP-1, IGFBP-3, and osteocalcin were established and stratified by age, sex, and pubertal stage.
• Significant variations in concentrations were observed during puberty, with differences noted between prepuberty and puberty.
• While sex did not impact IGF-I or IGFBP-1, minor differences in IGFBP-3 and osteocalcin levels were found between boys and girls.

Conclusions:

• Basal serum concentrations of IGF-I, IGFBP-1, IGFBP-3, and osteocalcin exhibit significant variability based on age, sex, and pubertal development.
• The findings underscore the necessity of establishing and utilizing population-specific reference values for these biomarkers.
• Accurate interpretation of these growth factors requires laboratory- and population-specific reference data.