A new Australian study found that blood pressure measurements were significantly different between arms.
Blood pressure should be taken from both arms in children and adolescents. This is the key conclusion of a study led by the Murdoch Children’s Research Institute (MCRI) and published in the Journal of Hypertension.
The study, led by PhD candidate Melanie Clarke, found that the differences in blood pressure between arms were significant enough that could lead to different diagnosis.
“Misdiagnosis could occur when the blood pressure difference is greater than about 5 mmHg, but one in seven healthy children had a difference greater than 10 mmHg, which could lead to a failure to identify stage one or two hypertension,” Ms Clarke said in a press release.
In adults, interarm differences in blood pressure of 10 mmHg or more is established as a potential cardiovascular risk factor, due to its association with cardiovascular events/mortality. In a recent review from 24 studies (53 827 participants), for example, it was reported that systolic interarm difference was associated with an increase in cardiovascular events and death from all causes.
Among children and adolescents, it is estimated that a significant proportion suffer from high blood pressure, especially among those who are over their ideal weight. In fact, an obese child has a three-fold increased risk of developing hypertension, compared to a normal-weight child, according to a study. But being overweight is just one of the factors affecting high blood pressure. A recent study that measured the blood pressure of 4096 American students aged 6 to 17 year, found that over 26% of these children had at least one elevated blood pressure measurement, and about 60% of these children were not obese.
About the new study
In the study, researchers recruited 95 children and adolescents aged 7-18 years who attended a cardiology day clinic in Melbourne. After measuring their blood pressure in both arms, researchers found that one in four children, who were apparently healthy, had an inter-arm difference that could lead to misdiagnosis.
The results suggest that GPs and other health care providers should take blood pressure measurements from both arms. “Given blood pressure measured in a child’s right and left arm are often different, it’s important to take measurements in both arms to make a correct diagnosis. Accurate blood pressure assessment in kids is critical for identifying the potential risk for damage to the heart and blood vessels, which can lead to early-onset cardiovascular disease,” Ms Clarke said in the press release.
High blood pressure is a primary risk factor associated with heart disease and stroke, both leading causes of death worldwide. In children, it is important to accurately assess levels of high blood pressure, to start management of their condition early on.
“Children with high blood pressure, many of whom appear to be healthy, have a greater risk of developing hypertension in adulthood, a major risk factor for cardiovascular disease,” said Associate Prof Jonathan Mynard, senior author of the study.
According to international guidelines, blood pressure in children and adolescents should be measured at least once a year. However, Associate Professor Mynard said in Australia it wasn’t common practice for GPs to measure blood pressure in children or in both arms.
“We know high blood pressure is common in adults but many people don’t realise how common it is in kids too,” he said. Parents can help by encouraging their kids to eat a healthy diet that is low in salt and sugary drinks, and high in fruit, vegetables, and whole grains, and to engage in lots of physical activity,” he said in the press release.
“More work needs to be done to draw attention to the problem of childhood hypertension and its long-term consequences. Australia would benefit from having its own set of clinical guidelines addressing high blood pressure in children, including how to obtain accurate measurements and avoid misclassification,” he added.