Menopause, Menstrual Cycle, and Skin Barrier Function.

Background: There are a limited number of studies describing the impact of the menstrual cycle and postmenopause on the skin barrier function, and existing research data are conflicting. The aim of our research was to investigate the impact of the menstrual cycle and postmenopause on the epidermal barrier function and its main biophysical parameters-transepidermal water loss (TEWL) and skin hydration (SH).

Materials and methods: Eighty-one female participants were included in the study, aged 18-65 years, of which 36 in the reproductive period (average age 27.06 ± 5.60 years) and 45 in postmenopause (average age 56.56 ± 4.37 years). TEWL and SH were measured during the ovulatory and mid-luteal phases in participants in the reproductive period, and on two occasions, 7 days apart, in posmenopausal participants.

Results: The mean TEWL value was significantly higher in the mid-luteal phase (TEWL 2; 9.92 ± 1.37) compared to the ovulatory phase (TEWL 1; 8.87 ± 1.59). However, no significant difference in TEWL was observed between the two groups of participants. The mean SH value was significantly higher in the ovulatory phase (SH 1; 40.55 ± 7.80) compared to the mid-luteal phase (SH 2; 36.27 ± 7.42). Moreover, SH in the ovulatory phase was significantly higher in comparison to the postmenopausal group (40.55:36.27; p = 0.009).

Conclusion: Our study indicates a more functional epidermal barrier during the ovulatory phase, as evidenced by higher TEWL values and lower SH values compared to the mid-luteal phase. However, the differences between the two participant groups remain intriguing, as no significant difference in TEWL was observed between them, despite significantly higher SH values in the ovulatory phase compared to the postmenopausal group.