Mild elevations in blood pressure but still within the normal range in young adults can increase the risk of heart damage by middle age, say researchers at the John Hopkins University.
The study suggests that high normal pressure begins to fuel heart damage in people, as young as 20, and can lead to changes in heart muscle function in as little as 25 years.
Investigators say their findings of abnormalities in the heart's capacity to contract and relax are especially troubling because they stemmed from a group of patients, the vast majority of whom had no hypertension.
Such abnormalities, the researchers say, are forerunners of two forms of heart failure, a condition marked by the progressive weakening heart muscle and the organ's gradual loss of blood-pumping ability.
Principal investigator Joao Lima said that their results suggest the heart muscle may be more exquisitely sensitive to the effects of even subtle elevations in blood pressure than we thought.
The study is published online in the Journal of the American College of Cardiology.