BPA may increase heartbeat irregularities

CINCINNATI, June 11 (UPI) -- Bisphenol A, found in many plastic household items, has been linked in animals to an increased frequency of heartbeat irregularities, U.S. researchers say.

Study co-author Scott Belcher of the University of Cincinnati finds low-dose BPA and estrogen can act alone or in combination to increase harmful arrhythmias in female rats and mice.

Because BPA has properties similar to those of the main female hormone estrogen, it is considered an "environmental estrogen," Belcher says.

Mice and rats in the study had normal heart rhythms at baseline, before administration of BPA or estrogen, Belcher says.

The investigators studied heart rhythms in both the working heart and in cultured heart muscle cells. In both models, exposure to BPA increased the frequency of arrhythmias, compared to baseline, in females but not in male animals, the authors say.

Administration of estrogen alone also increased the frequency of arrhythmias in females.

Arrhythmias were most frequent in the female rats and mice when they received both BPA and estrogen, at levels normally found in female humans, the researchers say.

BPA is found in polycarbonate-plastic baby bottles, refillable water bottles and food containers as well as the linings of metal food cans.

The findings are scheduled to be presented at The Endocrine Society's 91st annual meeting in Washington.