Abstract
Insulin-like growth factor (IGF) binding proteins are produced by ovarian follicular
cells and can oppose the effects of the IGFs and gonadotropins on these cells. Since
polycystic ovarian syndrome (PCOS) is characterized by disordered follicular development,
with the accumulation of antral follicles within the ovary which fail to respond appropriately
to endogenous FSH, it has been hypothesized that one or more IGFBPs, which can act
as FSH antagonists in vitro, could play a role in inhibiting follicular development
in this syndrome. Follicular fluid IGFBP levels, however, do not differ between PCOS
follicles and the androgenic, presumably atretic follicles of cycling women without
PCOS. Serum IGFBP-1 levels are lower in PCOS, likely because of hyperinsulinemia,
and serum free IGF-1 levels are raised. This alternation may drive the excess thecal
androgen production characteristic of PCOS follicles. Alterations in IGFBPs may sustain
the anovulatory steady state in PCOS but are unlikely to initiate development of the
syndrome.
Keywords:
Polycystic ovary syndrome - insulin-like growth factors - insulin-like growth factor
binding proteins
