Unmasking Masked Hypertension

You could still have high blood pressure even if your readings are ‘normal’ at the doctor’s surgery

DOCTORS ARE shedding light on what’s called ‘masked hypertension’ – when a patient’s blood pressure readings are normal at the doctor’s surgery but increase at other times of the day. It’s the reverse of ‘whitecoat hypertension’, which is when patients experience a spike in their blood pressure when they’re nervous at the doctor’s.

A new study published in the American Heart Association’s journal Circulation found alarming rates of masked, or undetected, high blood pressure in healthy adults who had normal readings at the surgery. The researchers monitored the blood pressure of 888 participants around the clock during daily activity.

When monitored, patients wore

a cuff on their arm attached to a small device that recorded their blood pressure. Participants had three blood pressure readings taken during three clinic visits, and finished with one 24-hour ambulatory blood pressure recording, where readings are taken every 30 minutes. None of the participants – more than half of them women, aged 45 on average, were taking blood pressure medication to lower their numbers.

The study revealed that 15.7 per cent of participants with normal clinic blood pressure had masked hypertension, and younger, normal weight participants had higher ambulatory blood pressure readings than older, overweight participants.

“These findings debunk the widely held belief that ambulatory blood pressure is usually lower than clinic blood pressure,” said lead investigator Dr Joseph Schwartz. “It is important for health-care providers to know that there is a systematic tendency for ambulatory blood pressure to exceed clinic blood pressure in healthy, untreated individuals evaluated for hypertension during well-patient visits.”

Masked hypertension can be difficult to catch, and it’s not completely clear what causes the condition, but it is known to be more common in men, tobacco users, those who drink alcohol excessively and people with diabetes. It may also be stress-induced, and because people have so much stress at work, or even at home, they find a bit of solace in their doctor’s office, causing them to chill out and provide false blood pressure results.

High blood pressure can contribute to stroke, heart failure, vision loss and kidney failure, heightening concerns over the condition.

Dr Gerald Fletcher, a spokesman for the American Heart Association, isn’t surprised by the findings. “It’s a major problem in our population,” he told Reader’s Digest. “People aren’t doing enough to keep their numbers low.” And it’s simply not possible to monitor everyone around the clock. Fletcher suggested starting with preventative measures such as reducing sodium intake, exercising more and getting regular medical checks.

Around-theclock monitoring revealed undetected high blood pressure among otherwise healthy adults