Effect of oestrogen status on serum levels of growth hormone-binding protein and insulin-like growth factor-I in non-pregnant and pregnant women

Clin Endocrinol (Oxf). 1993 Nov;39(5):569-75. doi: 10.1111/j.1365-2265.1993.tb02411.x.


Objective: Since there appears to be a relationship between circulating oestrogens and growth hormone, we have investigated the effect of the oestrogen status of adult women on serum levels of GHBP and IGF-I.

Design and patients: The investigation was performed on serum samples of 14 spontaneously menstruating women, 10 women taking oral contraceptives containing 20-50 micrograms ethinyloestradiol, and 30 pregnant women at different stages of pregnancy.

Measurements: Serum levels of GHBP were measured by HPLC gel filtration and IGF-I levels were measured by RIA after acid-ethanol extraction.

Results: In the spontaneously menstruating women the mean +/- SD serum level of GHBP was 34.6 +/- 6.7% and of IGF-I 30 +/- 7 nmol/l. Serum GHBP levels were negatively (r = -0.67; P < 0.01) and IGF-I levels were positively related (r = 0.69; P < 0.01) to serum oestradiol concentrations. In the women taking oral contraceptives serum levels of GHBP were 47.0 +/- 7.4%. This was significantly (P < 0.001) higher than in spontaneously menstruating women. In contrast, IGF-I levels were not different from those obtained in spontaneously menstruating women. In the pregnant women, the mean +/- SD serum level of GHBP was not different from that observed in non-pregnant spontaneously menstruating women. Polynomial regression analysis, however, showed a significant (P = 0.01) second-order relationship between the duration of pregnancy and serum GHBP levels, with increasing levels during the first half of pregnancy and decreasing levels thereafter. Serum concentrations of IGF-I increased during the second half of pregnancy and were significantly (P < 0.005) elevated in the third trimester.

Conclusions: In non-pregnant women the endogenous oestrogen status seems to modulate negatively GHBP levels and positively IGF-I levels, whereas oral oestrogen administration, in contrast, increases serum levels of GHBP without modification of IGF-I levels. During pregnancy serum GHBP levels increase slightly during the first half of pregnancy and decrease thereafter, whereas IGF-I concentrations increase during the second part of pregnancy. The oestrogen status of women has a complex effect on serum concentrations of GHBP and IGF-I and has therefore to be taken into account when evaluating serum levels of GHBP and IGF-I.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Carrier Proteins / blood*
  • Estradiol / blood
  • Estrogens / blood*
  • Ethinyl Estradiol / administration & dosage
  • Female
  • Growth Hormone / blood*
  • Humans
  • Insulin-Like Growth Factor I / analysis*
  • Menstruation / blood
  • Pregnancy / blood*


  • Carrier Proteins
  • Estrogens
  • Ethinyl Estradiol
  • Estradiol
  • Insulin-Like Growth Factor I
  • Growth Hormone
  • somatotropin-binding protein