New research suggests that high blood pressure during and after exercise is linked to an increased risk of cardiovascular issues later in life.
The study, appearing in the Journal of the American Heart Association, may help clinicians develop new prognostic tools for cardiovascular issues.
Blood pressure and disease
Cardiovascular illnesses relate to issues with a person’s heart or blood vessels. According to the American Heart Association (AHA), these can include heart disease, heart attacks, stroke, arrhythmia, and heart valve problems.
A key issue driving cardiovascular diseases is high blood pressure, also known as hypertension. According to the Centers for Disease Control and Prevention (CDC), high blood pressure is a risk factor for heart disease and stroke, two of the leading causes of death in the United States.
High blood pressure occurs when a person’s blood vessels become stiff and narrow. This may be due to lifestyle factors, such as too little physical activity or consuming too much salt, or health issues, such as diabetes or obesity. Sometimes, hypertension may be a combination of lifestyle factors and disease.
The relationship between blood pressure and cardiovascular disease is well known, and the relationship between blood pressure and exercise has been explored before.
However, fewer studies have explored the relationship between blood pressure following exercise in middle age and cardiovascular disease in later life.
The authors of the present study set out to fill this gap in the literature.
To do this, the authors drew on data from the Framingham Heart Study, a long-term study in the U.S. which the National Heart, Lung, and Blood Institute organize.
The team focused on data from 1,993 participants with an average age of 58 years.
The researchers looked at each participant’s blood pressure following submaximal exercise, that is, exercise slightly below the maximum intensity that each participant could manage.
The study observed two measurements of blood pressure: blood pressure during exercise, and how far blood pressure had returned towards normal 3 minutes after exercise.
The researchers noted systolic blood pressure, which is the pressure when a person’s heartbeats, and diastolic, the pressure when the heart is between beats.
Twelve years later, the authors checked whether the participants developed any cardiovascular diseases or whether they had died from cardiovascular illnesses.
They also gathered information about subclinical disease at 5 years. They did this by measuring the thickness of the lining of the carotid artery and the thickness of the heart muscle on the left side.
Researchers directly associate both of these measures with the risk of cardiovascular disease.
At the 5-year mark, the team associated high systolic blood pressure during exercise and recovery with both types of subclinical disease.
Diastolic blood pressure during exercise only had an association with thickening of the heart muscle, while poor diastolic recovery was only associated with thickening of the carotid artery.
Increased risk of illness and death
After adjusting for other risk factors of cardiovascular disease, the authors found that both systolic and diastolic measures of exercise blood pressure were risk factors for developing hypertension 12 years later.
They also found that better levels of blood pressure recovery were protective against hypertension.
In contrast, the authors found that neither systolic nor diastolic blood pressure during exercise predicted cardiovascular disease at 12 years, after adjusting for other risk factors for cardiovascular disease and excluding participants not receiving treatment for hypertension.
However, they found that good recovery of systolic blood pressure after exercise was protective, reducing risk of cardiovascular disease by 17%.
According to Dr. Vanessa Xanthakis, the corresponding author of the article and an investigator for the Framingham Heart Study:
“The way our blood pressure changes during and after exercise provides important information on whether we will develop disease in the future; this may help investigators evaluate whether this information can be used to better identify people who are at higher risk of developing hypertension and CVD [cardiovascular diseases], or dying later in life.”
— Dr. Vanessa Xanthakis
As well as helping clinicians develop new prognostic tools for cardiovascular illnesses, Dr. Xanthakis says the study’s findings suggest that a person should keep track of their blood pressure numbers during and after exercise, reporting any changes to their doctor.