Insulin-like growth factor-1 in relation to adult weight and birth weight in healthy nulliparous women

Objective: To study the relationships between plasma insulin-like growth factor-1 (IGF-1) concentrations and birth weight, current weight and other constitutional factors among healthy, nulliparous women aged 19-25 years. Design and methods: Forty healthy female university students aged 19-25 years volunteered for this study. They had never been pregnant and were not using oral contraceptives (OCs). Blood samples were drawn both in the follicular and luteal cycle phases (08:00-10:00 h) and weight, height, and waist-hip ratio were measured at the same time by one person (H.J). Information regarding age, birth weight, OC use, etc. was obtained from a questionnaire filled out by the women. Plasma IGF-1 concentrations were analyzed by radio immunoassay. Results: In a multivariate model including birth weight, current weight and age, IGF-1 was significantly inversely associated with birth weight in both cycle phases, while current weight was positively associated with IGF-1 in both cycle phases although only significantly so in the follicular phase. IGF-1 concentrations in both cycle phases showed a non-significant decrease with age. Conclusion: In this group of 19-25-year-old healthy nulliparous women IGF-1 displayed a significant inverse association with birth weight in both cycle phases given that the current weight was adjusted for, while current weight was positively related to IGF-1 concentrations. (C) 1998 International Federation of Gynecology and Obstetrics.