The association between insulin-like growth factor I and bone turnover markers in the general adult population

Bone. 2013 Sep;56(1):184-90. doi: 10.1016/j.bone.2013.06.013. Epub 2013 Jun 20.

Abstract

Objectives: Growth hormone (GH) and its main mediator, insulin-like growth factor I (IGF-I), play a fundamental role in human metabolism. Previous epidemiological studies investigating the association of IGF-I and bone turnover markers (BTMs) yielded conflicting results and were limited by study design or sample size. Therefore, we aimed to investigate the associations between serum levels of IGF-I or the IGF-I/IGF binging protein 3 (IGFBP-3) ratio and levels of BTMs including procollagen type 1 N-terminal propeptide (PINP), C-terminal telopeptides of type 1 collagen (CTX), and bone-specific alkaline phosphatase (BAP).

Methods: Data from 1463 men and 1481 women who participated in the first follow-up of the Study of Health in Pomerania were used. IGF-I and IGFBP-3 levels were measured using chemiluminescent immunometric assays on an Immulite 2500 analyzer. BTM levels were measured on the IDS-iSYS Multi-Discipline Automated Analyser. Analyses of variance (ANOVA) and quantile regression models were calculated.

Results: In men <55 years and premenopausal women ANOVA and quantile regression analyses revealed positive associations between IGF-I or even stronger the IGF-I/IGFBP-3 ratio and PINP [per unit increase in IGF-I/IGFBP-3 ratio in men: beta (95%-CI) 2.33 ng/ml (0.91; 3.75), p < 0.01; women: 3.63 ng/ml (2.31; 4.95), p < 0.01] or CTX [men: 20.8 ng/l (3.5; 38.0), p = 0.02; women: 12.0 ng/l (-1.2; 25.2), p = 0.07]. Furthermore in postmenopausal women, IGF-I and the IGF-I/IGFBP-3 ratio were inversely related with CTX levels, whereas an inverse U-shaped relation between IGF-I/IGFBP-3 ratio and PINP was found. Regarding BAP, we observed borderline significant associations with IGF-I or the IGF-I/IGFBP-3 ratio in older subjects only.

Conclusion: IGF-I levels and particularly free IGF-I, estimated by the IGF-I/IGFBP-3 ratio, are positively related with PINP as a bone formation marker and CTX as a bone resorption marker in healthy adult men younger than 55 years and premenopausal women. In older subjects the found positive as well as negative relations with BTMs have to be further investigated.

Keywords: BAP; Bone turnover markers; CTX; Insulin-like growth factor I; PINP; Study of Health in Pomerania.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Alkaline Phosphatase / blood
  • Biomarkers / blood*
  • Bone Remodeling*
  • Collagen Type I / blood
  • Female
  • Humans
  • Insulin-Like Growth Factor Binding Protein 3 / blood
  • Insulin-Like Growth Factor I / metabolism*
  • Male
  • Middle Aged
  • Peptide Fragments / blood
  • Peptides / blood
  • Procollagen / blood
  • Young Adult

Substances

  • Biomarkers
  • Collagen Type I
  • Insulin-Like Growth Factor Binding Protein 3
  • Peptide Fragments
  • Peptides
  • Procollagen
  • collagen type I trimeric cross-linked peptide
  • procollagen Type I N-terminal peptide
  • Insulin-Like Growth Factor I
  • Alkaline Phosphatase