When High Blood Pressure Isn't Obvious

Masked hypertension in patients with kidney disease increased health risks


What happens when your blood pressure wears a mask?

Masked hypertension occurs when patients show normal blood pressure readings in the doctor's office, even though their blood pressure is normally much higher. A new study found that in patients with chronic kidney disease (CKD), masked hypertension can cause heart, kidney and blood vessel damage.

Taking a patient's blood pressure at a doctor's visit can be problematic. It's a single reading at one point in time. Outside the office, many patients have very different readings, as your blood pressure reading can vary considerably based on factors like time of day and stress levels.

Lead study author Paul Drawz, MD, MHS, MS, and colleagues studied 1,492 men and women with CKD. Study participants were enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study.

Study participants wore a special blood pressure monitoring device 24 hours a day outside the doctor's office.

Dr. Drawz and team found that almost 28 percent of patients had masked hypertension. This is particularly important in patients with CKD because they already have an increased risk of kidney damage.

One of the more common problems is “white coat hypertension,” in which blood pressure readings are higher than normal in the doctor's office. Masked hypertension is the opposite -- normal readings in the doctor's office, high blood pressure out of the doctor's office.

For people who have CKD, masked hypertension can lead to heart and blood vessel damage, and make their kidney problems worse.

Previous research has shown that healthy people may have masked hypertension. This study looked specifically at people with chronic kidney disease.

"Our findings support the recommendations that patients check their blood pressure outside the usual doctor's office setting, either by 24-hour blood pressure monitoring as done in our study, or by monitoring blood pressure at home,” Dr. Drawz commented in a press release, Dr. Drawz is a nephrologist (a doctor who specializes in kidney problems) and assistant professor of medicine at the University of Minnesota.

The study was published in the February Clinical Journal of the American Society of Nephrology.

Information on study funding was not available.

None of the authors reported a conflict of interest.