It is increasingly clear that men and women differ in their baseline physiology, ranging from the cardiovascular system, the liver, the adipose tissues to the kidney. Recent findings on sex differences in physiology are starting to uncover how these differences could potentially explain the long-standing sexual dimorphism in disease susceptibility, progression, and response to drugs. At BPS2023, I had the opportunity to discuss with leading scientists on this topic, to learn about cutting-edge research that are underway to tackle the unmet need in improving women’s health.
Dr. Charlotte Smith, a postdoctoral scholar working with Drs. Crystal M. Ripplinger and Eleonora Grandi at UC Davis Department of Pharmacology, told me that sex differences are prevalent in cardiovascular conditions, including hypertension, heart failure, and cardiac arrythmias. In general, women are more resilient to arrythmia than men, but they respond poorly to existing treatment regimens and face poor prognosis. Therefore, it is crucial to study how the female heart functions differently from the male counterpart in normal conditions and in time of arrythmia.
On Feb 21 (Tuesday), Dr. Charlotte Smith presented a poster on “sex differences in electrophysiology of the intact atria”, delineating how rabbit hearts react to arrythmia-inducing stimuli between the sexes. This work reminds me of their recent publication in Science Advances, where whole-heart imaging revealed how female and male hearts respond differently to the stress hormone noradrenaline in mice (Caldwell et al., 2023). Additional posters were presented by her colleagues in the same session, who also study sex differences in cardiac physiology. Earlier, on Feb 19 (Sunday), Dr. Kim T. Hellgren from the Grandi Lab presented a study on “quantitative male-to-female translation of cardiac electrophysiological response to drugs”, providing strategies to approach sex-specific susceptibility to the arrhythmia called Torsade de Pointes (Fogli Iseppe et al., 2021).
Besides Drs. Crystal M. Ripplinger and Eleonora Grandi, other groups at UC Davis are also actively studying sexual dimorphism in cardiac arrythmias. In particular, Drs. Colleen E. Clancy and Igor Vorobyov in the same department have been leading the research on female sex risk in arousal-induced arrythmias (Vorobyov and Clancy, 2018). On Feb 20 (Monday) and 21 (Tuesday), multiple posters were presented by students and postdoctoral fellows to showcase their ongoing work.
As we understand more about how the susceptibility to cardiac arrhythmias differ between the sexes, we will one day understand the overall mechanisms that are at play in cardiac arrhythmias like Torsades.