title: Relationship among insulinlike growth factor I concentrations, bone mineral density, and biochemical markers of bone turnover in postmenopausal women: a population-based study.
abstract: OBJECTIVE
  : To assess the association among serum insulinlike growth factor I (IGF-I) concentrations, bone mineral density (BMD), and biochemical markers of bone turnover in a large group of postmenopausal women from the general population.
  
  
  METHODS
  : As an extension of a larger epidemiological study, the Iranian Multicentral Osteoporosis Study, a total of 406 healthy postmenopausal women (age, 59.0 +/- 7.6 years) were randomly selected from 13 clusters in Bushehr Port. IGF-I, serum CrossLaps, degradation products of C-terminal telopeptides of type I collagen, and osteocalcin were measured by highly specific enzyme-linked immunosorbent assay. BMD was determined for the lumbar spine (L2-4) and proximal femur using dual-energy x-ray absorptiometry.
  
  
  RESULTS
  : The mean (+/- SD) serum IGF-I concentration for all postmenopausal women was 183.35 +/- 65.60 ng/mL. In age-adjusted analyses, there was no correlation between IGF-I and BMD at the lumbar spine and femoral neck. Compared with women in the lowest quartile of IGF-I, women in the highest quartile had a significantly greater means of osteocalcin (P = 0.04) and alkaline phosphatase (P = 0.01). Analysis by quartiles of IGF-I did not reveal an association with serum CrossLaps.
  
  
  CONCLUSIONS
  : Circulating IGF-I is associated with biochemical markers of bone formation, but there is no relationship among IGF-I, degradation products of C-terminal telopeptides of type I collagen, and BMD in postmenopausal women. Clearly more work will be needed before serum IGF-I can be used in clinical practice as a risk predictor for postmenopause-associated loss of bone mass.
authors.affiliation: Department of Endocrine and Metabolic Diseases, The Persian Gulf Tropical Medicine Research Center, Bushehr University of Medical Sciences, Bushehr, IR Iran. inabim@yahoo.com
authors.forename: Iraj
authors.initials: I
authors.lastname: Nabipour
authors.forename: Bagher
authors.initials: B
authors.lastname: Larijani
authors.forename: Saeideh
authors.initials: S
authors.lastname: Beigi
authors.forename: Seyed Mojtaba
authors.initials: SM
authors.lastname: Jafari
authors.forename: Mohammad
authors.initials: M
authors.lastname: Amiri
authors.forename: Majid
authors.initials: M
authors.lastname: Assadi
authors.forename: Raha
authors.initials: R
authors.lastname: Pazoki
authors.forename: Zahra
authors.initials: Z
authors.lastname: Amiri
authors.forename: Zahra
authors.initials: Z
authors.lastname: Sanjdideh
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D015519:Bone Density / Q000502:physiology*; D016723:Bone Remodeling; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D007492:Iran; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood*; D012307:Risk Factors; D016387:Women's Health
chemical_list: D015415:Biomarkers; D007334:Insulin-Like Growth Factor I