The effect of oral contraceptive different patterns of use on circulating IGF-1 and bone mineral density in healthy premenopausal women

Abstract

Both insulin-like growth factor-1(IGF-1) and oral contraceptive (OC) use have been linked to premenopausal breast and colorectal cancers, osteoporosis and cardiovascular disease. Understanding the effects of different patterns of use of OC on IGF-1 levels and bone mineral density (BMD) may offer insight into its influence on osteoporosis. We conducted a cross-sectional study, which included 135 women, who were then divided into three groups: Group A who were OC current users, 41 women; Group B who never use OC, 51 women; and Group C who were past users of OC, 41 women. Each patient completed a questionnaire on demographic parameters, marital state history and contraception history including duration of use and type of contraceptive pills or used method. Lower-end radius, proximal femur and lumbar spine BMD were measured by dual-energy X-ray absorptiometry. IGF-1 was assessed with chemiluminescent immunometric assay. The three groups were similar in total body T value of BMD (with slight better results in past users than the other two groups but it was statistically insignificant difference), and past users showed significantly higher BMD values compared to current users at spine, femur and forearm. Nonusers also had better BMD values compared to current users (spine and forearm BMD). Among past users, the mean level of circulating IGF-1 was higher than the other two groups and that difference was statistically significant. Past OC use and/or nonuse has a more favorable impact on BMD compared to current use and that this relationship is in part mediated by IGF-1. Hence, it appears that OC use is beneficial to BMD if used in the past and then discontinued or if never used at all compared to current use.