Diabetes Forecast

Many U.S. Adults Have Masked Hypertension

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What to Know

Approximately four out of five people with diabetes have high blood pressure, or hypertension, which increases your chances for a heart attack, stroke, kidney disease, and diabetes-related eye disease. Diagnosing high blood pressure, though, can be tricky. Some people have what’s called “white coat hypertension,” in which blood pressure spikes in the doctor’s office, possibly due to stress. Other people experience the opposite. Their blood pressure appears normal when measured at the clinic but is high at other times. This study sought to determine how many American adults have this latter condition, known as masked hypertension.

The Study

Researchers first examined data from 811 participants in a 2016 study on masked hypertension, conducted in the New York City metropolitan area. In that study, the participants had their blood pressure measured during three doctor visits. Then, for 24 hours, each participant wore a portable device that recorded their blood pressure every 28 minutes. The researchers used the results of this study to predict masked hypertension in 9,316 participants in a much larger national study conducted between 2005 and 2010. Together, the two studies allowed them to estimate the total number of U.S. adults with masked hypertension.

The Results

As many as 17.1 million U.S. adults have masked hypertension, the study authors concluded. That’s nearly 1 in 8 of the 139 million adults whose blood pressure readings are normal when taken in the doctor’s office. Men were more than twice as likely as women to have masked hypertension, as were people over the age of 45. The rates of masked hypertension were also higher in people with type 2 diabetes and in those whose blood pressure was above normal but not considered high (140/90 mmHg and above), when measured by a doctor.


People with an elevated risk of masked hypertension, such as older men, people with type 2 diabetes, and those with elevated blood pressure, should be screened for masked hypertension, which increases the risk of potentially fatal heart problems, the study authors say. They also recommend that such screening should include the use of a type of blood pressure monitor that takes continuous readings over a 24-hour period. More research is needed to be sure that the masked hypertension estimates in this study are accurate.

Prevalence of Masked Hypertension Among U.S. Adults With Nonelevated Clinic Blood Pressure.” Y. Claire Wang, Daichi Shimbo, Paul Muntner, Andrew E. Moran, Lawrence R. Krakoff, and Joseph E. Schwartz. American Journal of Epidemiology, 2017;185(3):194–202.

The information on this screen does not take the place of care from your doctor or other health care provider. If you have general questions about diabetes or diabetes-related research, e-mail askada@diabetes.org or call 1-800-DIABETES (800-342-2382).



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