Anxiety Underlies White Coat Hypertension
A new study suggests that spikes of anxiety can cause the blood pressure of some people to rise when a doctor is examining them, a phenomenon known as the “white coat effect.”
Nine percent of patients studied showed signs of white coat hypertension, which could prompt doctors to prescribe unneeded medication and potentially lower blood pressure to dangerous levels.
“Doctors should not be taking a blood-pressure reading,” said study lead author Gbenga Ogedegbe, M.D., an associate professor at New York University School of Medicine. “Automated devices should be doing it.”
According to Ogedegbe, several studies have revealed the existence of the white-coat effect, but its cause has not been clear.
Research has suggested that the effect is not harmless. People who show it have a slightly elevated risk of having a heart attack six to nine years later, said Ogedegbe, who completed the research while at Columbia University. “We need to find out why it is there to understand why people have this effect,” he said.
In the study, researchers examined 238 patients ages 18 to 80 in a hypertension clinic. The patients went to several doctor appointments and wore portable blood-pressure measuring devices at home.
The study results appear in the December 8 issue of the journal Archives of Internal Medicine.
Nine percent of participating patients showed signs of higher blood pressure when doctors measured it. The readings coincided with higher anxiety levels.
Visiting the doctor may trigger bad memories about previous experiences in the world of medicine and cause anxiety to spike, Ogedegbe said.
Matthew Lucks, M.D., a cardiologist at Scripps Memorial Hospital La Jolla in San Diego, said it’s best for patients to get blood-pressure readings at home. His office has given monitors to patients that measure their blood pressure at set intervals and provide printouts.
The new study does leave one mystery: the so-called “reverse white-coat effect.”
Blood pressure levels actually dipped in 19 percent of the patients when doctors measured it. Researchers have been mulling over this phenomenon, also known as “masked hypertension,” for the past 10 years, Ogedegbe said.
“We don’t know what to do with these people,” he said.
Patients can also buy blood-pressure monitors at the drugstore, but it’s wise to check their readings against a monitor in the doctor’s office to make sure they’re accurate, Lucks said.