Suppression of plasma insulin-like growth factor-1 levels in healthy, nulliparous, young women using low dose oral contraceptives.
Insulin-like growth factor-1 (IGF-1) levels were analyzed in 43 healthy, nulliparous women aged 19-25 years. Blood samples were drawn in a standardized way in follicular and luteal phases, for present users during cycle days 5-10 and 18-23, respectively. In each women, absolute levels and a difference in p-IGF-1 levels between the two menstrual cycle phases (delta IGF-1) were related to oral contraceptive (OC) use, height, weight, age, gonadotropin and serum sexual hormone binding globulin (s-SHBG) levels. In the follicular phase and cycle days 5-10, absolute values of p-IGF-1 did not significantly differ between present, former and never users of OCs, in contrast to a significant difference (p = 0.0013) in the luteal phase and cycle days 18-23 between present users and never users, after adjustment for age. delta IGF-1 was significantly negatively correlated to present OC use, compared with nonusers (p = 0.0002). delta IGF-1 did not significantly differ between former and never users. While height and weight were not significantly related to delta IGF-1, there was a significant negative correlation between age and delta IGF-1 (p = 0.05). Also, s-SHBG and p-IGF-1 were significantly negatively related in the luteal phase and cycle days 18-23 after adjustment for age (p = 0.006), although this relationship disappeared after adjustment for present OC use.
Department of Oncology, University Hospital, Lund, Sweden.
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Jernström
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Olsson
D000328:Adult; D003276:Contraceptives, Oral / Q000008:administration & dosage / Q000494:pharmacology*; D004958:Estradiol / Q000097:blood; D005260:Female; D005498:Follicular Phase / Q000097:blood*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008183:Luteal Phase / Q000097:blood*; D010298:Parity; D011374:Progesterone / Q000097:blood
D003276:Contraceptives, Oral; D011374:Progesterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I