Self-monitoring blood pressure levels in the morning might be a more effective way to assess stroke and heart disease risk, a new Japanese study is reporting.

For this study, the researchers headed by Kazuomi Kario, a professor and chairman of the division of cardiovascular medicine at Jichi Medical University School of Medicine in Tochigi, set out to examine if at-home blood pressure monitoring could be an effective predictor of cardiovascular artery disease (CAD) events.

"In clinical practice, morning home blood pressure may predict heart disease and stroke better than office blood pressure, and be more effective in managing high blood pressure," Kario explained. "Few reports have investigated the predictive ability of home blood pressure for heart disease and stroke. This largest home blood pressure study is the first to demonstrate that morning home blood pressure may be superior to clinic pressure."

The researchers analyzed data on 21,591 patients with high blood pressure (hypertension) taken from the Home blood pressure measurement with Olmesartan Naive patients to Establish Standard Target blood pressure (HONEST) study. The mean age of the participants was 65. At the study's follow-up, 127 patients suffered from a stroke and 121 had cardiovascular problems.

The researchers looked at the blood pressure readings that were taken in the morning to assess risk of stroke and heart disease and found that people who had a systolic blood pressure reading at around 145 mm Hg or higher in the mornings, were more likely to have a stroke and more likely to develop heart problems in comparison to people who had a morning reading of 125 mm Hg. Systolic blood pressure is the top number.

The researchers noted that if stroke risk was assessed based on systolic blood pressure levels taken at the doctor's office, the levels would be 150 mm Hg versus 130 mm Hg. For heart disease, the systolic blood pressure readings would be 160 mm Hg compared to 130 mm Hg.

The discrepancy between the readings taken at-home and in the office can affect the type of care that at-risk patients receive. For example, doctors might not stress the importance of adopting healthier lifestyle habits in patients who have an in-office systolic reading of around 145 mm Hg as strongly as they would in patients who have a reading that is around 160 mm Hg even though this study's findings suggest that patients with the 145 mm Hg reading also have a similar increased risk of heart disease.

"There is increasing interest and guideline recommendations toward using blood pressure readings taken at home to assess risk and guide treatment of hypertension [high blood pressure]," said Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles, who was not a part of the study. "The lower the morning home blood pressure reading, the better the outcomes."

Controlling blood pressure levels is important in general because blood pressure is one of the leading causes of stroke, cardiovascular events and premature deaths.

The study was published in the Journal of the American College of Cardiology.