Effect of replacement estrogen on insulin-like growth factor-I in postmenopausal women: the Rancho Bernardo Study

J Clin Endocrinol Metab. 1996 Dec;81(12):4268-71. doi: 10.1210/jcem.81.12.8954026.


Insulin-like growth factor-I (IGF-I) is associated with protein, carbohydrate, and bone metabolism. Results of previous studies examining the effect of exogenous estrogen on levels of IGF-I have been inconsistent. We examined the cross-sectional association between serum IGF-I levels and hormone replacement therapy (HRT) use in 672 postmenopausal women aged 50 yr and older. The mean age-adjusted IGF-I level was highest in the 415 women who reported never or past HRT use (126.8 micrograms/L), lowest in the 128 women who reported using estrogen alone (99.3 micrograms/L), and intermediate in the 115 women who reported using combination estrogen and progesterone (112.4 micrograms/L). A significant linear decline in mean age-adjusted IGF-I levels by duration of HRT use among all current users was seen. The decrease in serum IGF-I with current use of HRT is not consistent with the fact that both HRT and increased levels of IGF-I have been associated with improved glucose and bone metabolism and lipid profile. Further research is needed to evaluate the effect of the addition of a progestin to oral HRT on IGF-I-induced changes in GH levels.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Cross-Sectional Studies
  • Estrogen Replacement Therapy*
  • Female
  • Growth Hormone / biosynthesis
  • Humans
  • Insulin-Like Growth Factor I / analysis*
  • Middle Aged
  • Postmenopause / blood*


  • Insulin-Like Growth Factor I
  • Growth Hormone