The Relationship between the Premenstrual Syndrome and Resting Cardiac Vagal Tone in Young Healthy Females: Role of Hormonal Contraception

Evolutionary-based predictions imply that the premenstrual syndrome (PMS) affects women who failed to conceive while in biosocial conditions that allow immediate reproduction. We investigated how the PMS is related to the heart rate variability (HRV), a marker of general fitness and well-being. The HRV indices (SDNN and rMSSD) were calculated using resting ECGs of 113 physiologically fertile women and 64 women using hormonal contraception (HC users, HCu). The intensity of PMS symptoms was self-assessed (Shortened Premenstrual Assessment Form). Analyses were conducted using parametric and nonparametric tests and general linear modelling (GLM). In HC non-users (HCnu), a greater intensity of PMS symptoms was significantly associated with higher values of HRV. Similar relations were not present in HCu. Post-hoc GLM confirmed that the relation between the PMS intensity and HRV indices varies as a function of the HCu status. A positive association between the PMS intensity and high HRV indices in women who did not use HC may confirm that the PMS affects fertile women who did not conceive, despite being in conditions favorable to pregnancy. The absence of a similar link in HCu women implies that synthetic steroids may disturb the link between the PMS and functioning of the autonomic nervous system.