Cold exposure can cause blood pressure spike

 
By HSC Staff Writer • Published: January 15th, 2007
Category: Health in a Heartbeat
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Kids often hear the refrain, “Don’t forget your hat and gloves!” before they venture outside in the winter. As we age, that advice may do more than keep us warm. It also might prevent a cold-weather-induced spike in blood pressure that could cause a heart attack.

Americans generally have more heart attacks during the winter than any other season of the year. But blood pressure changes as one possible culprit haven’t been widely studied.

University of Florida researchers have identified a gene that triggers cold-induced hypertension in mice. The scientists studied normal lab mice and mice that lacked a gene called A-T-one. The blood pressure of the normal mice soared fifty points after nearly five weeks living in forty-one-degree Fahrenheit temperatures. The mice that didn’t have the A-T-one gene had no increase in blood pressure.

More studies are necessary to see whether the gene plays a similar role in people. But doctors emphasize that bundling up when the mercury drops isn’t just for tundra dwellers. In fact, the U-F study demonstrated elevated blood pressure began when temperatures dropped only into the mid-forties. This indicates that even Sunbelt residents who occasionally brave chilly morning or night temperatures also need to cover up.

Cold temperatures also are a special risk for patients with hypertension and heart disease, because cold-induced high blood pressure tends to remain elevated long after coming in from the cold. So all heart patients should take proper precautions and bundle up when venturing into the winter chill.