Altered regulation of insulin-like growth factor binding protein-I in patients with polycystic ovary syndrome

Enrico Carmina, Frank Z. Stanczyk, Randy S. Morris, Phillip Lee, Gopal Savjani, Rogerio A. Lobo

Research output: Contribution to journalArticle

21 Scopus citations

Abstract

Objective:Insulin-like growth factor (IGF-I) action is influenced by circulating as well as tissue levels of its binding proteins. Because serum IGF binding protein-1 (IGFBP-1) levels have been found to be decreased in patients with polycystic ovary syndrome (PCOS), we tested the hypothesis that regulation of IGFBP-1 secretion may be different in patients with PCOS compared with normal women. Methods: We studied 15 normal ovulatory women and 15 women with PCOS of similar age (21 ± 1 and 22 ± 1 years, respectively). All subjects were studied after an overnight fast between days 5-8 after spontaneous or progestin-induced menses. Perturbations included the administration of insulin intravenously, maintenance of a euglycemic clamp, and, in a subsequent cycle, the administration of a long-acting somatostatin analogue (octreotide, 100 μg) given subcutaneously. Blood samples were collected before treatment, every 15 minutes for 6 hours after insulin, and every 30 minutes for 3 hours after octreotide administration. Serum levels of IGF-I, IGFBP-1, IGFBP-3, and insulin were measured by specific immunoassays. Results: Compared with the controls, patients with PCOS had significantly higher insulin levels, similar IGF-I and IGFBP-3 levels, and significantly lower IGFBP-1. Insulin did not change serum IGF-I levels in either group, although a significant decrease in IGFBP-1 levels occurred in normal women but not in patients with PCOS. Octreotide treatment also did not change serum IGF-I levels in either group, but serum insulin levels decreased significantly and IGFBP-1 levels increased significantly in both groups; this response was significantly greater in controls. Conclusion: Our data are compatible with the notion that regulation of IGFBP-1 is altered in women with PCOS and that several factors may be involved.

Original languageEnglish (US)
Pages (from-to)743-747
Number of pages5
JournalJournal of the Society for Gynecologic Investigation
Volume2
Issue number6
StatePublished - Nov 1995
Externally publishedYes

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Keywords

  • Insulin-like growth factor binding-protein 1
  • polycystic ovary syndrome

ASJC Scopus subject areas

  • Reproductive Medicine
  • Obstetrics and Gynecology
  • Developmental Biology

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