Couch potato children more likely to suffer premature heart damage

Children who spend a lot of time sitting down face a higher risk of heart enlargement, the study found – Fertnig/E+

Couch potato children are more likely to suffer premature heart damage, a new study warns.

An increase in time from childhood spent sitting down caused progressing heart enlargement, according to the findings.

However, light physical activity, such as walking a dog or cycling to the shops, can reverse the risk, scientists say.

Scientists from the Universities of Bristol and Exeter teamed up with colleagues from the University of Eastern Finland for the study, published in the European Journal of Preventive Cardiology.

Left ventricular hypertrophy refers to an excessive rise in heart mass and size. In adults, it is known to increase the risk of heart attack, stroke and premature death.

The study involved 1,682 children from the University of Bristol’s Children of the 90s group who were followed from the ages of 11 to 24.

Increased heart mass

The participants spent an average of six hours per day in sedentary activities at the start of the study, increasing to nine hours per day by young adulthood.

The increase in time spent seated was associated with progressing heart enlargement, contributing 40 per cent to the total increase in heart mass within a seven-year growth period from adolescence to young adulthood.

The more time spent sitting down increased heart mass, regardless of obesity or higher blood pressure, according to the findings.

But an average of three to four hours per day of light physical activity (LPA) reduced the increase in heart mass by 49 per cent, scientists say.

In addition, higher LPA was also associated with better cardiac function.

Light physical activity, such as walking a dog, was associated with better cardiac function – Paul Plews/Image Source

Participating in moderate-to-vigorous physical activity (MVPA) showed signs of slightly increasing the heart size – by 5 per cent – which is largely physiological, according to the research team.

Previous studies involving the same participants have linked excessive time spent seated to increased inflammation, high insulin, obesity, dyslipidemia and arterial stiffness.

But light exercise has emerged as an “effective” way of reducing the harmful effects of too much time spent sitting down as a youngster.

However, no previous study has examined whether long-term light exercise from childhood holds the potential to reverse the increase in cardiac mass.

Echocardiography measurements

The participants in the latest study wore accelerometer devices on their waists at the ages of 11, 15 and 24 and had echocardiography measurements of the heart structure and function at ages 17 and 24.

Their fasting blood samples were also repeatedly measured for “good” and “bad” cholesterol as well as glucose, insulin and other health indicators.

Blood pressure, heart rate and family history of cardiovascular disease, as well as dual-energy X-ray absorptiometry-measured fat mass and lean mass, were also accounted for.

Prof Andrew Agbaje, of the University of Eastern Finland, said: “There is growing evidence that childhood sedentariness is a health threat that needs to be taken seriously.

“There must be a paradigm shift in how we view childhood sedentariness, as the mounting evidence is pointing at a ticking time bomb.”

Effective antidote to sedentariness

Prof Agbaje added: “LPA is an effective antidote to sedentariness.

“It is easy to accumulate three to four hours of LPA daily.

“Examples of LPA are outdoor games, playing in the playground, walking a dog, running errands for parents, walking and biking to the shopping mall or to school, taking a stroll in the park, playing in the forest, gardening, casual basketball, soccer, floorball, golf, frisbee, et cetera.

“We can encourage children and adolescents to participate in LPA daily for better cardiovascular health.”

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