According to a new study published in JAMA, people who have escalating levels of high blood pressure over a 25-year period beginning in early adulthood are more likely to develop atherosclerosis and associated heart problems in later life.
Atherosclerosis is when plaque - made up of fat, cholesterol and calcium, among other things - builds up inside a person's arteries. These plaque build-ups can limit the flow of blood, leading to serious and potentially fatal problems, such as disease of the heart or arteries.
Because atherosclerosis does not usually cause symptoms until it blocks an artery, many people do not know they have this condition until it causes a medical emergency.
Experts know that high blood pressure is a risk factor for atherosclerosis and heart disease, though it is usually only taken into account by doctors in middle or older age. But recent studies have shown that the larger the changes in blood pressure in an individual over time, the greater the likelihood of that person developing heart disease.
Blood pressure 'trajectories'
The researchers behind this new study wanted to see if, based on people's blood pressure readings over time, they could plot a blood pressure "trajectory" that is associated with developing atherosclerosis and associated heart problems.
This trajectory could act as a warning sign, telling doctors that a person is likely to develop heart disease in later life.
To measure this likelihood of heart disease, the researchers examined how much "coronary artery calcification" (CAC) the patients had - this is the extent to which atherosclerosis had affected the arteries of the heart.
The study tracked the blood pressure readings of 4,681 people over a 25-year period, beginning in the mid-1980s, when the people in the study were aged between 18 and 30.
From this data, the researchers were able to detect five distinct blood pressure trajectories. These were:
- 22% of participants maintained low blood pressure throughout the period of the study
- 42% had moderate blood pressure levels throughout the study
- 19% had fairly high blood pressure throughout
- 5% started the study with high blood pressure, which increased over the study period.
The group that had the highest levels of CAC were the participants whose blood pressure increased over the study period - about 25% of these people had a high CAC score.
By contrast, in the group that maintained low blood pressure, only 4% had a high CAC score.
High blood pressure has been used to predict stroke risk and likelihood of fatal heart attack, so the authors of the study think that blood pressure patterns could also be used in this way to predict how atherosclerosis could cause heart-damaging calcification of the coronary arteries in later life.
"Although BP has been a well-known risk factor for cardiovascular disease for decades, these findings suggest that an individual's long-term patterns of change in blood pressure starting in early adulthood may provide additional information about his or her risk of development of coronary calcium," the authors say, adding:
"Additional research is needed to examine the utility of specific blood pressure trajectories in risk prediction for clinical cardiovascular disease events and to explore the effect of lifestyle modification, treatment and timing of intervention on lifetime trajectories in BP and outcomes."
In 2012, Medical News Today reported on a study finding that one of the main causes of atherosclerosis are disease-causing cells called "macrophages."