title: Serum and urine insulin-like growth factor-1 as biochemical growth maturity indicators.
abstract: BACKGROUND
  Biochemical markers are agents directly involved in bone growth and remodeling and can be quantitatively evaluated from various biologic fluids. The aim of this study was to assess the changes in the levels of insulin-like growth factor-1 (IGF-1) in serum and urine as a growth maturity indicator and to compare them with the cervical vertebral maturation radiographic stages.
  
  
  METHODS
  The study was conducted with 72 female subjects aged 8 to 20 years. Cervical vertebral maturation stages, and serum and urine IGF-1 levels were recorded for all subjects, and the subjects were equally divided into the 6 cervical vertebral maturation groups. Median values of IGF-1 for each stage of cervical vertebral maturation were calculated and statistically compared with those of the other stages.
  
  
  RESULTS
  The levels of serum and urine IGF-1 at stage 4 of cervical vertebral maturation were significantly higher than those from the other stages (P <0.01). Stage 4 corresponded to a mean age of 13.67 years. A significant correlation was observed between serum and urine IGF-1 (P <0.001).
  
  
  CONCLUSIONS
  Urine IGF-1 follows the growth curve similar to serum IGF-1. Thus, urine IGF-1 may be regarded as a promising noninvasive tool for growth assessment. Further research is necessary to validate these results in a different population and with a larger sample.
authors.affiliation: Postgraduate student, Department of Orthodontics and Dentofacial Orthopaedics, Maulana Azad Institute of Dental Sciences, New Delhi, India. Electronic address: sinha_m7@yahoo.co.in.
authors.forename: Mohita
authors.initials: M
authors.lastname: Sinha
authors.affiliation: Professor and head, Department of Orthodontics and Dentofacial Orthopaedics, Maulana Azad Institute of Dental Sciences, New Delhi, India.
authors.forename: Tulika
authors.initials: T
authors.lastname: Tripathi
authors.affiliation: Professor, Department of Orthodontics and Dentofacial Orthopaedics, Maulana Azad Institute of Dental Sciences, New Delhi, India.
authors.forename: Priyank
authors.initials: P
authors.lastname: Rai
authors.affiliation: Director and professor, Department of Biochemistry, Maulana Azad Medical College, New Delhi, India.
authors.forename: Santosh Kumar
authors.initials: SK
authors.lastname: Gupta
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood / Q000652:urine; D001846:Bone Development / Q000502:physiology; D001842:Bone and Bones / Q000033:anatomy & histology; D002574:Cervical Vertebrae / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000254:growth & development; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis* / Q000652:urine; D011627:Puberty / Q000097:blood / Q000652:urine; D011859:Radiography; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007334:Insulin-Like Growth Factor I