This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
People who spent more time on moderate to vigorous exercise, and less time sitting, had a lower risk of heart disease, regardless of their genetic makeup. Research found that people with the highest genetic risk benefitted most. In this group, switching sitting for physical activity (brisk walking or cycling, for example) was associated with a greater reduction in the risk of developing heart disease (compared with those with the lowest genetic risk).
The study included 77,500 people. Their genetic risk of coronary heart disease was assessed, and they wore a wrist device for 1 week to measure their activity level. Researchers found that 60 minutes per day spent in moderate to vigorous activity (for example, exercise, active commuting, intense housework or gardening), instead of sitting, was linked to a 9% lower risk of coronary heart disease over the following 8 years, regardless of people’s genetic risk.
The findings provide reassurance to clinicians and the public that more exercise, and less sitting, could lower anyone’s risk of coronary heart disease, even those with an inherited risk of heart disease.
For more information on coronary heart disease, visit the NHS website.
The issue: does exercise protect against heart disease in people with high genetic risk?
In coronary heart disease, fatty deposits block the blood vessels that supply the heart muscles. It is a common condition that can cause heart attacks and stroke; 66,000 people in the UK die from it each year. People can reduce their risk by adopting a healthy lifestyle including exercise, healthy eating, quitting smoking, and so on. However, some people are genetically prone to the disease, and cannot change this component of their risk.
Little research has investigated whether exercise reduces the risk of coronary heart disease among those genetically prone to the condition. This study addressed that question.
What’s new?
Researchers analysed data from 77,500 White British people from the UK Biobank. More than half (57%) were women, and their average age was 56. Participants had not had coronary heart disease or a stroke before the study. The researchers analysed participants’ genetic data to calculate their risk of coronary heart disease.
All participants wore a wrist device for a week to measure their physical activity. The researchers used hospital admission data and death records to assess how many developed coronary heart disease over the next 8 years. They controlled for sex, smoking status, diet, and other factors.
The researchers found that:
- replacing 60 minutes of sitting time with the same amount of moderate to vigorous physical activity per day was linked with a 9% lower risk of coronary heart disease, regardless of people’s genetic makeup
- people with the highest genetic risk of coronary heart disease gained most from moderate to vigorous physical activity; they had larger reductions in their future likelihood of developing coronary heart disease than people with low genetic risk.
Why is this important?
Replacing time spent sitting with moderate to vigorous exercise was associated with a lower risk of coronary heart disease, even among people genetically prone to the condition. This should reassure clinicians and the public that anyone can reduce their risk of coronary heart disease through moderate to vigorous physical activity, regardless of their genetic risk. Light physical activity (such as a gentle walk) did not have the same effect in this study.
The study showed the link between exercise and reduced risk of coronary heart disease, but could not conclude that exercise caused the reduction. The data from this study is from people in the UK Biobank who tend to be wealthier and in better health than the rest of the population; participants were all White British. The findings may therefore not be fully generalisable to the whole population or to people of other ethnicities.
What’s next?
The researchers plan to explore whether exchanging sitting for physical activity can reduce risk of other diseases such as type 2 diabetes, cancer, and dementia, regardless of people’s genetic risk. Previous work has typically explored whether exercise can reduce the risk of coronary heart disease. The study team are planning a trial to see whether, in addition, exercise can improve cardiovascular health (including coronary heart disease) in groups of people with higher or lower genetic risk.
You may be interested to read
This is a summary of: Kim Y, and others. Replacing device-measured sedentary time with physical activity is associated with lower risk of coronary heart disease regardless of genetic risk. Journal of Internal Medicine 2023. DOI: 10.1111/joim.13715.
Information on coronary heart disease from the British Heart Foundation.
Guidelines on physical activity and sedentary behaviour from the World Health Organisation.
A study showing how less time spent watching TV could benefit the prevention of coronary heart disease: Kim Y, and others. Genetic susceptibility, screen-based sedentary activities and incidence of coronary heart disease. BMC Medicine 2022; 20: 1 – 11.
Information on taking part in NIHR studies regarding coronary heart disease.
Funding: this study was supported by the NIHR Cambridge Biomedical Research Centre.
Conflicts of Interest: none declared.
Disclaimer: Summaries on NIHR Evidence are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that the views expressed are those of the author(s) and reviewer(s) at the time of publication. They do not necessarily reflect the views of the NHS, the NIHR or the Department of Health and Social Care.
