A new study finds that the risk of high blood pressure in American teens has increased by 27 percent in the past 13 years, as the waist gets thicker and children consume more salt in their diets.
“High blood pressure is a predominant risk factor for stroke and stroke rates have increased in children in the United States in recent years,” said Dr. David Katz, director of the Center for Cancer Research. Prevention of Yale University (Yale University Prevention Research Center). He was not involved in the study.
The Harvard researchers collected data on more than 3,200 children between the ages of 8 and 17 years, who took part in the National Health and Nutrition Examination survey from 1988 to 1994, comparing them with more than 8,300 children from the same survey from 1999 to 2008.
The researchers indicated that although the children in the study had high blood pressure, they could not be classified as hypertensive since the results must be high three times in a row to have that diagnosis.
As the obesity epidemic continues, doctors see more and more children with high blood pressure, an expert said.
“Today only, I’m going to see 10 to 15 [patients], mostly teenagers, who are overweight and suffer from hypertension,” said Dr. Ana Paredes, a pediatric nephrologist at Children’s Hospital of Miami.
The first step in treating these children is to change their diets and increase the amount of exercise they do, Paredes said. “I give them a plan they can follow,” she said. “I tell them to try to lose a pound a week.”
Paredes also advises his patients to reduce salt in their diets. Much of the salt that children consume comes from processed foods and beverages such as sodas, she said. “If you are taking Gatorade when you are watching TV or working on the computer, you are intoxicating yourself with salt,” she commented.
Katz said the new study adds weight to the evidence that sodium intake affects blood pressure in children, as well as adults.
“The path of high sodium intake to high blood pressure and an increase in stroke cases is cause for concern and corrective action,” Katz said.
Americans eat an average of 3,400 milligrams (mg) of salt each day – that’s more than double the recommendation of 1, 500 mg or less from the American Heart Association. Two thirds of the salt are processed foods and restaurant meals.
The association between body mass index – a measure of body fat – and blood pressure is even stronger than the association with sodium, Katz said. “As obesity rates increase in our children, blood pressure also increases,” Katz said.
The high salt content in processed foods is correctable as is the influence that makes children obese, he said. “If we need another reason to take action, this study offers us a reason, just as our children’s blood pressure increases, so does the pressure to do whatever it takes to put a stop to these trends.”
The researchers indicated that for adults, normal blood pressure is considered to be less than 120/80 mm Hg. However, blood pressure among children varies according to age, sex and height.
When calculating the risk of high blood pressure, the differences between the two groups of children were taken into consideration in terms of age, sex, race / ethnicity, body mass, waist size and salt intake.
The most outstanding of the study was published online (online) on July 15 and in the August print edition of the journal Hypertension , and included the following:
Although children were more likely to have high blood pressure, the rate increased rapidly in girls.
Over time, more children were overweight and a larger waist – especially girls.
Children with larger waists were almost twice as likely to have high blood pressure, compared with children with a thin waist.
Black children had a 28 percent higher risk of having high blood pressure than white children.
Children who consumed the most salt were 36 percent more likely to have high blood pressure, compared with children who consumed less salt.
In both studies, more than 80 percent of the children had a daily salt intake of more than 2,300 mg. However, few children in the next study had a salt intake above 3,450 mg.
“We all hope that sodium consumption will continue to rise,” said lead researcher Bernard Rosner, a professor of medicine at Harvard Medical School, in a statement. “It seems that there has been a bit of attention to diet recommendations but not much attention.”
“High blood pressure is dangerous in part because many people do not know they have it,” he added. “It’s kind of deceptive, you have to measure your blood pressure regularly to keep up.”
The researchers noted that high blood pressure has been the cause of 350,000 cases of deaths that have been prevented each year in the United States.
Maggie McClure is a freelance writer based in Winnipeg. She has written for the Calgary Sun, Reader’s Digest, CBC Online,, Rogers Media and others. When Maggie isn’t busy writing, she’s working as a PSW in an aging care facility. Maggie mostly covers stories concerning vulnerable Canadians. There are several ways to contact Maggie here.