Risk factors for hypertension start young

Dec 22, 2006

By age 10, some black children already have high nighttime blood pressure, an early signal of impending cardiovascular disease, a new study shows.

As they grow up, black children also show greater increases in nighttime blood pressure, according to a study that followed children's blood pressures over 15 years.

Blacks experience less of a dip in nighttime blood pressure than whites. The gap between the pressure measurements of whites and blacks also widens as children get older.

At night, blood pressure should drop because the body is resting, says Dr. Gregory Harshfield, director of MCG's Georgia Prevention Institute and a co-author on the study published in the Dec. 19 edition of Circulation, the journal of the American Heart Association.

One reason for the higher nighttime pressure is some blacks retain more sodium, which increases fluid volume in their bodies and their blood pressure, according to researchers.

To determine pressure differences between black and white children and at what age those differences occur, Dr. Frank Treiber, vice president for research and study co-author measured the ambulatory blood pressures of almost 700 children 12 times during 15 years.

"Most previous studies have looked at a cross section of people and this 15-year study allows us to look at one population over an extended period of time," says Dr. Xiaoling Wang, genetic epidemiologist and the study's lead author. "This helps us identify the age that these problems begin to occur – as early as age 10."

Ethnic differences were still measurable in study subjects even after researchers controlled for factors such as height, body mass index, socioeconomic status and stress-related coping strategies.

Interestingly, she says, tests of people of African descent who live outside the United States have shown normal nighttime blood pressure.

"That most likely means that the problem is not purely genetic and also is likely caused by environmental factors like salt intake and stress," Dr. Wang says. "It has already been proven that stress causes sodium retention, but there could be also other factors. This study further supports existing research and warrants further study of the causes for racial differences in blood pressure at an early age."

Source: Medical College of Georgia

Explore further: CDC investigating error that caused live anthrax shipments

Related Stories

How do you feel? Video of your face may tell all

Apr 06, 2015

Rice University researchers are developing a highly accurate, touch-free system that uses a video camera to monitor patients' vital signs just by looking at their faces. The technique isn't new, but engineering ...

Progeny of old parents have fewer offspring

Mar 09, 2015

Reproduction at old age involves risks that may impact one's own life and may impose reduced biological fitness on the offspring. Such evidence, previously obtained in humans and other taxa under laboratory ...

Fluid-filled pores separate materials with precision

Mar 06, 2015

In nature, pores can continuously control how a living organism absorbs or excretes fluids, vapors and solids in response to its environment; for example, tiny holes invisible to the naked eye called stomata ...

Recommended for you

S. Korea reports two additional MERS cases

1 hour ago

South Korea confirmed two more MERS cases Friday, bringing the total number of patients infected with the potentially deadly virus to nine, though none are in critical condition, health officials said.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.