The average blood pressure of American youths is declining, a new CDC report suggests, even as updated guidelines classify almost 800,000 more of them as hypertensive.
Using National Health and Nutrition Examination Surveys (NHANES) data from 2001 through 2016, Sandra L. Jackson, PhD, and colleagues estimated the changes over time in the nationwide prevalence of obesity and hypertension among adolescents age 12-19. They also analyzed the results through the lenses of both the 2004 hypertension guidelines and the 2017 update released by the American Academy of Pediatrics.
The new guideline used updated percentile tables excluding individuals who were overweight or obese, which lowered the bar for hypertension given that heavier children are more likely to have high blood pressures. Under both guidelines, children age 12 to 17 were considered hypertensive if their BP was above the 95th percentile for their age. The 2017 update also classified hypertension as above 130/80 mm Hg for individuals 18 and 19 years old, whereas the old guidelines used a 140/90 cutoff.
Using the new criteria and the latest NHANES data sets, an additional 2.6 percent of U.S. youths would be classified as having hypertension, which translates to approximately 795,000 people nationwide. Jackson et al. said earlier screening and intervention would be recommended for these patients, which is crucial considering they could reduce their risk of cardiovascular disease by normalizing their blood pressures by adulthood.
“Youths who were older, male, and those with obesity accounted for a disproportionate share of persons reclassified as having hypertension,” Jackson et al. wrote. “Clinicians and public health professionals might expect to see a higher prevalence of hypertension with application of the new guideline and can use these data to inform actions to address hypertension among youths.”
Even though the updated guidelines paint a bleaker picture of the state of adolescent hypertension in the U.S., Jackson and coauthors found average blood pressures have actually declined since 2001. From then until 2016, the proportion of hypertensive children dropped from 7.7 percent to 4.2 percent using the updated criteria and from 3.2 percent to 1.5 percent using the 2004 guidelines.
“Despite significant increases in the prevalence of obesity and severe obesity from 2001–2004 to 2013–2016, the prevalence of hypertension declined significantly (3.5 percentage points) across this time,” the authors noted. “This decline in adolescent hypertension is consistent with other reports, and might be related to improved diet quality or improved screening and earlier lifestyle or pharmacologic intervention.”
Preferred lifestyle modifications include increasing physical activity and adhering to healthy nutritional habits such as the Dietary Approaches to Stop Hypertension (DASH) diet, the researchers said.
Although there appeared to be an increase in the use of blood pressure medications as the study progressed, the authors said the complete causes of the decline in adolescent hypertension remain uncertain. They also acknowledged the study data may be biased by participants’ self-reports and said blood pressure was measured multiple times on a single day rather than spread out over multiple visits, which is the recommended practice.
Daniel joined TriMed’s Chicago editorial team in 2017 as a Cardiovascular Business writer. He previously worked as a writer for daily newspapers in North Dakota and Indiana.