Blood Pressure. The Numbers.
December 22, 2015 MVP Blog comments
Q: What is the significance of elevated diastolic blood pressure if the systolic is normal?
A: Both elevated systolic blood pressure (the top number) and diastolic (the bottom number), together or alone, increase the risk for cardiovascular disease. The systolic reading indicates the pressure in the arteries produced when the heart beats; the diastolic is the arterial pressure between beats, when the heart is at rest. Readings below 120/80 are considered healthy.
(NYTimes.com, by Nicholas Bakalar)
Though high systolic and diastolic readings are both associated with increased risk, they may present different risks for different diseases. In 2014, researchers published a study of more than 1.25 million people 30 and older who were initially free of cardiovascular disease. They recorded their blood pressures, and followed them for an average of 5.2 years, during which 83,098 developed cardiovascular disease.
Over all, those with a reading above 140/90 had a higher risk for cardiovascular disease than those with lower blood pressure — an unsurprising finding.
But the researchers also found that the risk of some diseases could be predicted by a high systolic reading, and others by a high diastolic reading. For example, the risk for heart attack is more strongly associated with an elevated systolic pressure. But the risk for abdominal aortic aneurysm, a swelling or rupture in the large artery that goes from the heart to the chest and abdomen, is higher when the diastolic pressure is elevated.
“It’s reasonable to say that the systolic effect over all is slightly stronger than the diastolic,” said the senior author of the study, Dr. Harry Hemingway, a professor of clinical epidemiology at University College London and director of the Farr Institute.
“But if you have isolated diastolic hypertension,” he added, “you still have hypertension, and you should take measures to lower it.”