Changes in copper and zinc plasma concentrations during the normal menstrual cycle in women

Abstract

Objective. To investigate whether there is a fluctuation of the copper and zinc plasma levels during the menstrual cycle and if this correlates to the physiological fluctuations of estradiol and progesterone plasma concentrations in eumenorrhoic women.

Methods. We studied 14 eumenorrhoic women. Copper (Cu), zinc (Zn), estradiol (E2) and progesterone (Prg) plasma concentrations, during time of menstruation (time 1), midfollicular phase (time 2), time of ovulation (time 3) and midluteal phase (time 4) were determined.

Results. We observed significant changes in both copper plasma concentrations and zinc plasma concentrations during the four times studied (p < 0.05). The changes of Cu during the various phases correlated negatively with the changes in E2 (r > 0.5, p < 0.05), whereas the changes of Zn correlated positively with those of E2 (r > 0.8, p < 0.05). We were unable to demonstrate any statistically significant correlation between Cu and Prg or Zn and Prg.

Conclusions. This study indicates that there is a cyclic fluctuation of Cu and Zn concentrations in plasma during the menstrual cycle, in healthy eumenorrhoic women. This cyclic fluctuation might be due to the cyclic fluctuation of plasma levels of E2.

Keywords:

• Estradiol
• zinc
• copper
• sex hormones
• menstrual cycle

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.