Reducing daily sitting time by one to two hours could have a significant and positive impact on future cardiovascular health, scientists, including one of Indian-origin suggest.
Researchers found that sedentary behaviour is associated with increased amounts of calcium deposits in heart arteries, which in turn is associated with a higher risk of heart attack.
“This is one of the first studies to show that sitting time is associated with early markers of atherosclerosis buildup in the heart,” said Amit Khera, from University of Texas in the US.
“Each additional hour of daily sedentary time is associated with a 12 per cent higher likelihood of coronary artery calcification,” said Khera.
Researchers found that reducing daily “sitting time” by even 1 to 2 hours per day could have a significant and positive impact on future cardiovascular health.
For individuals with a desk job that requires them to sit for large portions of the day, they suggested taking frequent breaks.
“Try a one to five minute break every hour. Stand up. Walk up a flight of stairs. All of this helps in a small way. Then get in your strenuous exercise in the evening as well,” said Julia Kozlitina from University of Texas.
In some individuals, cholesterol builds up inside the walls of the arteries supplying blood to the heart in mounds called cholesterol plaques. Over time, calcium accumulates in these plaques, researchers said.
The amount of coronary artery calcium can be measured through Computed Tomography (CT) scanning and directly correlates with the amount of cholesterol plaque, as well as with heart attack risk, they said.
For the study, researchers asked 2,000 participants to wear a device that measured their activity levels for a week.
Participants spent an average of 5.1 hours sitting per day and an average of 29 minutes in moderate to vigorous physical activity each day, researchers said.
“We observed a significant association between increased sedentary time and coronary artery calcium. These associations were independent of exercise, traditional cardiovascular disease risk factors such as diabetes and high blood pressure, and socioeconomic factors,” said Khera.
“This research suggests that increased subclinical atherosclerosis characterised by calcium deposition is one of the mechanisms through which sedentary behaviour increases cardiovascular risk and that this risk is distinct from the protective power of exercise,” he said.
The findings were published in the Journal of the American College of Cardiology: Cardiovascular Imaging.