International Study Refines Definition of High Blood Pressure in Youth
New data helps experts better identify children at increased risk for heart disease later in life.
Experts can better identify children likely to have heart disease as adults, thanks to study findings that help refine blood pressure guidelines in children.
Published in the American Heart Association journal Circulation, this study analyzed childhood blood pressure levels in seven countries across the globe. While many countries have national data on blood pressure in adolescents, there is no universal definition of high blood pressure that can be used worldwide. By combining data, experts hoped to create a single, unified definition for elevated blood pressure in children that could be applied internationally, particularly in countries where local data is sparse.
In total, researchers analyzed blood pressure data from more than 52,600 non-overweight children across seven countries, including China, India, Iran, Korea, Tunisia and the United States. Children were between 6 and 19 years old and considered healthy, with no existing diseases or serious medical conditions.
After analysis, researchers found that the cutoff for elevated blood pressure may be lower in children than previously recognized.
Blood pressure is typically recorded as two numbers, which are written as a ratio. Systolic blood pressure is the top number, which measures the pressure in the arteries when the heart beats. Diastolic blood pressure is the bottom number, which measures pressure in the arteries between beats.
In the recent study, while the range for diastolic blood pressure was similar to national U.S. data, the range for systolic blood pressure was different. According to findings, children at the higher end of the blood pressure range (90th and 95th percentile based on sex, age and height) had a systolic blood pressure that was 1-5 mmHg lower than current U.S. guidelines. Therefore, many children with a “normal” blood pressure based on U.S. guidelines would actually have elevated blood pressure levels, based on recent data.
As experts explain, these new references will serve as a useful tool in assessing blood pressure in children. Since the data was averaged among seven different countries, findings are more universal than country-specific data and guidelines.
For example, current U.S. guidelines were released in 2004 by the National Institutes of Health. This report was based on U.S data from 1973–2000 and included overweight and obese children. Although these guidelines are used by experts in Europe and other countries, they’re based on country-specific data and may not be applicable to other countries. Experts also point out that including of overweight children in previous studies may have skewed blood pressure ranges.
Of course, there’s no question that existing guidelines remain useful. National data has helped create a benchmark for evaluating blood pressure in children and teens. However, recent international data can help refine our understanding of high blood pressure in children and better identify children at increased cardiovascular risk.
Questions for You to Consider
- Who is at risk for high blood pressure?
- Risk for hypertension increases with age, and most adults will eventually be affected by this condition at some time in their lives. However, diabetes, obesity, stress, high sodium intake, tobacco use and excessive alcohol use can greatly increase risk for high blood pressure.