Menstrual dysfunction in Norwegian top athletes

Of 301 Norwegian female top athletes, all members of the national team in 27 different sports, who were approached with a questionnaire about menstrual function, 278 (92.4%) responded. Ninety-nine of the respondents who used oral contraceptives were excluded. Of the remaining 179, 18 (10.1%) reported secondary amenorrhea (greater than 4 months since the last period) and were chosen for further studies. Blood samples were drawn for hormonal analyses between 10 and 12 a.m. and at least 12 hours after the last training session. Their mean age was 20.8 years (range 18-27), mean height 169.8 cm (160-180), mean weight 58.5 kg (51-67), and their mean age at menarche 14.6 years (13-16.5), significantly older than that of the other top athletes: 13.5 years (p less than 0.05). Their mean number of training hours per week was 16.1 (12-24). Hormonal changes were consistent with simple normoprolactinemic hypothalamic suppression, characterized by low values of FSH, estradiol-17 beta and prolactin. The androgen hormones demonstrated high levels of dihydrotestosterone. Testosterone levels were within normal limits, but in the upper part of the range, whereas sex hormone-binding globulin was in the lower normal range.