A new meta-analysis concludes that up to 100 million Americans diagnosed with prehypertension do not actually face an increased risk of blood-pressure related health consequences. Published in The Journal of General Internal Medicine, the results were derived from two decades of blood pressure data on 13,792 people from the National Health and Nutrition Examination Survey. Current guidelines, which were last updated in 2003 by the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure, classify people with a blood pressure reading above 120/80 millimeters of mercury as prehypertensive and state that the risk of heart disease may begin to arise in those with readings as low as 115/75. As a result, tens of millions of people with these blood pressure levels are considered at risk for future diseases and are often encouraged to modify their lifestyles to prevent their readings from worsening.
In the latest study, researchers contest these recommendations and find that for people over 50, a systolic blood pressure reading (the first number) of 140 or higher is most predictive of mortality. For those under 50, a diastolic pressure reading (the second number) of 100 or more is the best predictor of poor health.
Dr. Brent Taylor, lead investigator for the Veterans Affairs Health Care System in Minneapolis and assistant professor of medicine at the University of Minnesota, believes the new research should “at least start a conversation about why normal is set where it is. If we make small changes to where we set normal blood pressure, it has huge implications in the numbers of people we identify as being at risk.”
While ACSH's Dr. Gilbert Ross acknowledges that the new study is counter to the most recent trend of lowering the cutoff for normal blood pressure, he says it may be important for those considered to be hypertensive or prehypertensive to get treated to improve their health and longevity. “Even though it encompassed a large number of subjects and extracted data from a relatively reliable database, this study is worthy of being paid attention to but bears repeating before the last decade’s worth of studies is discarded.”