Researchers suggest that the female hormone oestrogen could have a protective effect in the kidneys.

In previous studies, it has been shown that female mice and rats are less likely to develop renal damage compared to their male counterparts. However, female mice lost this advantage when their ovaries were surgically removed. It was noted that oestrogen could possibly be the key to this advantage. This hormone is also present in men, but is less pronounced.

To test whether the female sex hormones play a role in protecting the normal renal tissues from being damaged, the research team led by Dr. Judith Lechner of the Medical University of Innsbruck, Austria, recruited 11 healthy, unmedicated and naturally ovulating women ages 25 to 44, and 6 postmenopausal women aged 57 to 64. They also involved a control group which consisted of men aged 24 to 73.

Daily urine samples were collected from the participants and these were analysed for the presence of enzymes excreted when there is renal damage. Results of the analysis showed that there is an increase in these enzymes during the phases of ovulation and menstruation, while lower levels were observed in postmenopausal women and in men.

This was a unique study design as daily samples over multiple menstrual cycles were collected, as compared to other studies wherein typically, single samples from menstrual phases of high and low hormone exposure were compared.

Dr. Lechner said, “This result suggests that cyclical changes of female hormones might affect renal cell homeostasis, potentially providing women with an increased resistance against kidney damages.” She also adds that, “Thus, recurring changes of sex hormone levels, as brought about by the natural menstrual cycle, might be involved in periodic tissue remodeling not only in reproductive organs, but to a certain extent in the kidneys as well.”

Dr. Lechner’s hypothesis was that oestrogen could be helping in the replacement of damaged cells. Kidney cells might be induced to grow during the phases when there is high oestrogen exposure. On the other hand, damaged or older cells might be discarded during phases when there is decreased oestrogen.

However, researchers noted that age could also play a role in protecting the kidneys from damage.

Further investigation may be needed for a clearer understanding of women’s resistance to kidney failure. Dr. Lechner hopes that their study can contribute to develop new strategies beneficial for both men and women. MIMS