Bone metabolism and circulating IGF-I and IGFBPs in dexamethasone-treated preterm infants

Early Hum Dev. 1999 Dec;56(2-3):127-41. doi: 10.1016/s0378-3782(99)00039-0.


Aim: To characterize the ontogeny of circulating IGF-I, the IGF binding proteins (IGFBPs) and biochemical markers of bone turnover in dexamethasone (DEX)-treated preterm infants with chronic lung disease.

Methods: Plasma and urine samples from 17 infants were obtained prior to DEX, after 9-12 days of DEX and 10 days after the completion of DEX to assess plasma IGF-I, IGFBPs, osteocalcin and urinary N-telopeptide. Nutrient intakes and growth were monitored from birth until term corrected age at which time body composition was evaluated by dual energy X-ray absorptiometry.

Results: Although nutrient intakes did not differ during or after DEX, weight gain (115 vs. 174 g/week) and length gain (0.7 vs. 1.0 cm/week) were higher after DEX treatment. Plasma IGF-I, IGFBP-3 and osteocalcin increased over time. N-telopeptide was the only biochemical parameter which appeared to be suppressed during DEX (1342 nM bone collagen equivalents/mM creatinine vs. 2486 (pre-DEX) and 2292 (post-DEX)). At term corrected age, bone mineral content was lower in dexamethasone-treated infants compared to preterm and term reference infants.

Conclusion: Changes in circulating IGFBP-2 and IGFBP-3 paralleled the changes reported in non-steroid-treated infants; however, it remains uncertain whether the natural rise in IGF-I was suppressed by DEX treatment. Assessment of these circulating components provided limited insight into the mechanisms by which DEX alters growth and bone turnover.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon
  • Body Composition
  • Bone Density
  • Bone and Bones / metabolism*
  • Collagen / urine
  • Collagen Type I
  • Dexamethasone / therapeutic use*
  • Female
  • Gestational Age
  • Glucocorticoids / therapeutic use*
  • Humans
  • Infant, Newborn
  • Infant, Premature / metabolism*
  • Insulin-Like Growth Factor Binding Protein 2 / blood
  • Insulin-Like Growth Factor Binding Protein 3 / blood
  • Insulin-Like Growth Factor Binding Proteins / blood*
  • Insulin-Like Growth Factor I / metabolism*
  • Male
  • Milk, Human
  • Osteocalcin / blood
  • Peptides / urine


  • Collagen Type I
  • Glucocorticoids
  • Insulin-Like Growth Factor Binding Protein 2
  • Insulin-Like Growth Factor Binding Protein 3
  • Insulin-Like Growth Factor Binding Proteins
  • Peptides
  • collagen type I trimeric cross-linked peptide
  • Osteocalcin
  • Insulin-Like Growth Factor I
  • Dexamethasone
  • Collagen