Effects of Menstrual Cycle on Skin Temperature
Have you ever wondered if the menstrual cycle affects the skin temperature in women? Scientific studies show that gender factors may influence the skin temperature (Tsk) (Fernández-Cuevas et al., 2015). In women, we find three main reasons that affect Tsk such as: menstrual cycle, subcutaneous fat, and metabolic rate.
“It’s important to know that hormonal changes in progesterone, estradiol or luteinizing hormone across the menstrual cycle do not only directly control reproductive events in women, but also exert an effect on other physiological systems, including thermoregulation”Baker and collaborators (2001)
Some studies showed that women have higher tympanic and upper body Tsk compared to men, similar to what Chudecka & Lubkowska (2015) find out searching for the differences in Tsk between women and men. Van Ooijen and collaborators (2001) described in their study that women have higher intestinal, rectal, and pectoralis temperature compared to men, which appear to be in agreement with the findings of Kim and collaborators (1998). These authors showed the results of measuring intestinal and rectal temperature in female subjects during post-ovulation state or using an oral contraceptive. The results are higher compared to men due to higher levels of (natural or synthetic) progestins (Kim et al., 1998).
Kim and collaborators (1998) also pointed out that postmenstrual women (older than 50 years) had significantly lower hand and core temperatures than premenstrual women (below the age of 13). On the other hand, women in their first 14 days of their cycle were more likely to have lower core temperature than women in the last 14 days.
It seems that the daily average core body temperature increases between 0,3ºC to 0,7º C in the early morning when waking up before any activity in the luteal phase of women with normal ovulatory menstrual cycles compared with the pre-ovulatory follicular phase due to the rise of progesterone in the post-ovulatory luteal phase (figure 1) (Baker et al., 2020).
There also seems that women with lower core temperature were more likely to have lower hand temperatures and not in men. (Kim et al., 1998).
Core temperature monitoring has been used to differentiate the follicular or luteal phases of the menstrual cycle enabling work on temperature regulation, fluid volume regulation, metabolism, and exercises responses.
In a pilot study that we performed, we observed no significant variations in abdominal skin temperature during the menstrual cycle on a young women (see figure 2) when compared with the core temperature variations described in other studies (Baker et al., 2020). If your main interest is absolute temperatures (or metrics as coefficient of variation), this is something to take into account (as all the influence factors). But as you might know, for prevention and injury monitoring we mainly use thermal asymmetries -comparing right to left Tsk-. We do so to avoid most of influence factors (menstrual cycle and hormones are some of them) since at it seems, they affect symmetrically both sides of the body.
The researches done till now show that factors as hormonal changes (i.e. progesterone during the menstrual cycle) the age, the moment of the day, and the use of oral contraceptives affect the core (intestinal and rectal) temperature and the hands and upper body skin temperature. However, the amount of publications focusing on skin temperature and menstrual cycle is reduced, therefore is further research needed to better understand how progesterone and estrogen interact in the brain to modify central thermoregulation as well as their effects in the periphery and skin temperature.
Baker, F. C., Waner, J. I., Vieira, E. F., Taylor, S. R., Driver, H. S., & Mitchell, D. (2001). Sleep and 24 hour body temperatures: a comparison in young men, naturally cycling women and women taking hormonal contraceptives. The Journal of physiology, 530(3), 565-574.
Baker, F. C., Siboza, F., & Fuller, A. (2020). Temperature regulation in women: Effects of the menstrual cycle. Temperature, 7(3), 226-262.
Chudecka, M., & Lubkowska, A. (2015). Thermal maps of young women and men. Infrared Physics & Technology, 69, 81-87.
Fernández-Cuevas, I., Marins, J. C. B., Lastras, J. A., Carmona, P. M. G., Cano, S. P., García-Concepción, M. Á., & Sillero-Quintana, M. (2015). Classification of factors influencing the use of infrared thermography in humans: A review. Infrared Physics & Technology, 71, 28-55.
Kim, H., Richardson, C., Roberts, J., Gren, L., & Lyon, J. L. (1998). Cold hands, warm heart. The Lancet, 351(9114), 1492.
Van Ooijen, A. M. J., van Marken Lichtenbelt, W. D., & Westerterp, K. R. (2001). Individual differences in body temperature and the relation to energy expenditure: the influence of mild cold. Journal of Thermal Biology, 26(4-5), 455-459.