The sex hormone estrogen may be the reason why more women than men suffer from irregular heartbeats or arrhythmia, a recent study in Sweden reveals.
Although women generally have better protection against cardiovascular disease than men, this no longer holds true when it comes to hereditary diseases that cause abnormal heart rhythms, they write Science Daily.
Researchers at Sweden’s Linköping University looked at the condition known as long QT syndrome (SQTL), in which the heart takes longer than normal to complete each beat.
This syndrome is most often caused by congenital hereditary changes or a mutation affecting one of the heart’s ion channels.
The condition is relatively rare, affecting about one in 2,500 people.
Ion channels are small pores that pass through cell membranes and regulate the flow of electrically charged ions into and out of the cell. Some ion channels act as an accelerator and others as a brake. Together, they regulate each of the 2.5 billion heartbeats most of us have in our lifetime.
“We’re trying to understand which substances in the body have an impact on ion channel function. If we could figure out how this regulation works, maybe we could understand why some individuals are more protected and others are more affected,” he says. Sara Liin, Associate Professor in the Department of Biomedical and Clinical Sciences at LiU.
Using frog eggs, the team inserted the human version of the ion channel into eggs that lack this channel. The scientists added the most active form of the sex hormone estrogen, called estradiol, and measured ion channel function.
Estrogen, the main female sex hormone, but found in smaller amounts in men’s bodies, has been shown to inhibit ion channel function, indicating that this hormone may increase the risk of certain types of arrhythmia. Other sex hormones had no effect.
The researchers point out that estrogen has many positive effects, but for women with an increased hereditary risk of SQTL, this hormone could be a risk factor.
