A new study suggests that even slightly higher than normal blood pressure readings can increase the risk of strokes in the future. The study, which was recently published in the journal Neurology, helps to reinforce previous findings.

Prehypertension, a condition where blood pressure readings are over normal levels but are not high enough to be classified as hypertension, are linked to significantly increased risks of strokes.

The study involved reviewing and analyzing data from 760,000 study participants, who were followed for 36 years. Researchers concluded that people with prehypertension had a 66 percent greater chance of developing a stroke than individuals with normal blood pressure.

Experts say that hypertension is diagnosed at a reading of 140 over 90 millimeters of mercury, and that prehypertension numbers range from 120/80 to 139/89.

Of those involved in the study, 20 percent of all strokes happened in participants with hypertension. The risk remained elevated even after traditional risk factors for strokes, such as smoking, high cholesterol, and diabetes, were ruled out.

Dr. Ralph Sacco, chairman of neurology at the University of Miami Miller School of Medicine, said, “This meta-analysis confirms evidence from many studies, and I think it continues to warn physicians and the public that more vigorous control of blood pressure is important for reducing stroke risk. Sacco, who was not involved in the study, continued, “The findings confirm even mild to moderate levels of elevated blood pressure are important for determining stroke risk.”

Nearly one out of every three Americans has high blood pressure, leading to an increased risk for stroke and heart disease.

Study author Dr. Dingli Xu, blood pressure researcher at the Southern Medical University in Guangzhou, China, said, “Considering the high proportion of the population who have higher than normal blood pressure, successful treatment of this condition could prevent many strokes and make a major difference in public health.”

Diet and exercise remain the most effective ways to decrease stroke risk among those with hypertension, Xu concludes.