title: Age-related changes in serum levels of insulin-like growth factor-II and its binding proteins correlate with calcaneal bone mineral density among post-menopausal South-Indian women.
abstract: BACKGROUND
  Insulin-like growth factor (IGF) system components are important regulators of bone metabolism, which have a predominant role in determining bone mineral density (BMD). While the serum levels of IGF-I are regulated by various systemic hormones and growth factors, IGF-II levels reflect the skeletal production relative to physical activity, mechanical loading, aging, race etc. Though various studies have been carried out among women of different ethnic groups to understand the relationship between serum levels of IGF-II and BMD, the results seem to be quite inconclusive.
  
  
  METHODS
  We evaluated the same, recruiting South-Indian women who engage themselves in a wide variety of physical activities pertaining to their profession and life style.
  
  
  RESULTS
  Serum levels of IGF-II and IGF binding protein (IGFBP)-3 showed positive correlation with calcaneal BMD, whereas IGFBP-4 showed negative correlation. These IGF system components exhibited similar correlations with serum bone formation markers and opposite trend with bone resorption marker. While both IGF-II and IGFBP-3 levels were observed to be decreased with aging and menopause, IGFBP-4 levels increased.
  
  
  CONCLUSIONS
  The alterations in serum levels of IGF-II and its binding proteins due to aging and menopause could be some of the major contributors of decreased calcaneal BMD observed among elderly women.
authors.affiliation: Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27101, United States.
authors.forename: Sivanandane
authors.initials: S
authors.lastname: Sittadjody
authors.forename: Ramachandran
authors.initials: R
authors.lastname: Ilangovan
authors.forename: Thilakavathy
authors.initials: T
authors.lastname: Thangasamy
authors.forename: Ramamoorthy C
authors.initials: RC
authors.lastname: Vignesh
authors.forename: Subramanyam
authors.initials: S
authors.lastname: Veni
authors.forename: Alain G
authors.initials: AG
authors.lastname: Bertoni
authors.forename: Subramanian
authors.initials: S
authors.lastname: Srinivasan
authors.forename: Chinappa
authors.initials: C
authors.lastname: Subramanian
authors.forename: Narasimhan
authors.initials: N
authors.lastname: Srinivasan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood*; D015519:Bone Density; D002111:Calcaneus / Q000737:chemistry*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007194:India; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D018974:Insulin-Like Growth Factor Binding Protein 4 / Q000097:blood; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood*; D007335:Insulin-Like Growth Factor II / Q000032:analysis*; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood*; D012016:Reference Values; D055815:Young Adult
chemical_list: C515497:IGFBP3 protein, human; D018972:Insulin-Like Growth Factor Binding Protein 3; D018974:Insulin-Like Growth Factor Binding Protein 4; D018969:Insulin-Like Growth Factor Binding Proteins; D007335:Insulin-Like Growth Factor II