Prenatal irisin is inversely related to the term placental telomere length.

Irisin is a myokine mainly produced by skeletal muscle that impacts the body's systemic metabolism. It is connected to aging, telomere length, and oxidative stress markers in human adults and in vitro. The serum irisin concentration increases during pregnancy and has been linked to some birth outcomes like macrosomia. On the other hand, its inverse relation with the chance of pregnancy disorders like preeclampsia and gestational diabetes suggests a protective role for this myokine in pregnancy. It is suggested that irisin may exert its impact on pregnancy by affecting the placenta, which has not been studied yet. Here, we questioned whether prenatal serum irisin is related to placental markers, including telomere length and antioxidant activity. Research has shown that the status of these markers at birth can predict the predisposition to some chronic diseases later in life. We included 80 pregnant mothers (17-41 years old) and newborn dyads randomly selected from the enrolled participants of the Rafsanjan Birth Cohort Study (one of the five district areas of the PERSIAN birth cohort studies), who delivered at the Nik-Nafs Maternity Hospital in Rafsanjan in 2022. Irisin levels were measured in the mother's blood serum in pregnancy using ELISA. The relative telomere length and the GPX and SOD enzyme activities were measured in the term placenta using real-time PCR and colorimetric assays, respectively. We found an inverse relationship between the serum irisin levels during pregnancy and relative telomere length in the term placenta. Irisin level was not significantly associated with the activity of SOD and GPX enzymes. Therefore, our data does not support the protective role of prenatal irisin on the placental telomere shortening and oxidative stress. Future studies are warranted to assess more placental markers in relation to pregnancy irisin levels.