People who have a surge in their blood pressure during the morning are more likely to have a stroke.

Researchers in Japan studied a group of 519 people with high blood pressure. They measured ambulatory blood pressure - that is, blood pressure over a 24 hour period. At the same time, brain scans were done to see if there were lesions indicating the person had suffered a 'mini stroke' - a brief interruption of blood to the brain.

They found that those who had a morning surge in their systolic (upper figure) blood pressure were more likely to have had multiple mini strokes. They were also more likely to have a 'real' stroke. In fact, the morning surge was linked to a three times greater risk of stroke compared to those whose blood pressure varied in a less dramatic way. The goal of blood pressure medication should be to damp down this morning surge and so reduce stroke risk, the researchers say.

Source

Circulation 3rd March 2003