%0 Journal Article
%T A cross-sectional study of different patterns of oral contraceptive use among premenopausal women and circulating IGF-1: implications for disease risk
%A Kristina M Blackmore
%A Jody Wong
%A Julia A Knight
%J BMC Women's Health
%D 2011
%I BioMed Central
%R 10.1186/1472-6874-11-15
%X In a cross-sectional study of 328 premenopausal women ages 18 to 21 and 31 to 40 we examined the relationship between different patterns of OC use and circulating IGF-1 using adjusted linear regression analysis. Information on OC use was obtained through an interviewer administered questionnaire. Plasma IGF-1 was assessed with enzyme linked immunosorbent assay (ELISA).Among women aged 18 to 21, ever OC use was significantly associated with decreased IGF-1 levels compared to never use (¦Â = -57.2 ng/ml, 95% confidence interval (CI): -88.7, -25.8). Among women aged 31 to 40, past users who first used OC at 25 years of age or older (¦Â = 43.8 ng/ml, 95% CI: 8.8, 78.8), in the last 15 years (¦Â = 35.1 ng/ml, 95% CI: 9.3, 61.0) or after 1995 (¦Â = 46.6 ng/ml, 95% CI: 13.4, 79.8) had significantly higher IGF-1 levels compared to never users.This is the first study to highlight the long term effects of OC use after cessation on IGF-1 levels among premenopausal women, which previously were thought to be transitory. Future studies of past use and IGF-1 levels are required and must consider age/timing of use and type/generation of OC used. Additional studies are needed to confirm the potential mediation of IGF-1 levels in the links between OC use and health outcomes.Insulin-like growth factor-I (IGF-I) is a growth hormone (GH) dependent peptide produced primarily in the liver, but it is also produced locally by many other tissues and can act in an autocrine and paracrine manner as well as through endocrine pathways [1]. IGF-1 plays an important role in physiological growth, development and homeostasis. Circulating IGF-1 concentrations have been used as an indicator of the total pool of IGF-1 available to cells and as a reflection of inter-individual differences in IGF-1 tissue bioactivity [2].The relationship between circulating IGF-1 levels and disease risk among women is complex as studies have shown that IGF-1 can be either positively (e.g. cancer) or negatively (i.e. osteopor
%U http://www.biomedcentral.com/1472-6874/11/15