Distortion occurring in the blood vessels of the eyes in overweight and obese young children could be an indication of greater risk of cardiovascular disease as they grow into adulthood, a new study reveals.
Previously, these changes - widening of veins and narrowing of arteries - were only observed in the retinas of heavy teenagers and adults, and this is the first time such disturbing indicators have been seen in children as young as six years old.
The research comes from a study involving 1,740 six year olds from 34 schools in Sydney, Australia, and was published yesterday in the International Journal of Obesity.
After accounting for differences such as sex, ethnicity, eyeball length, birth weight and average blood pressure, the researchers found unique changes in minute blood vessels in the retinas of children who were over the average weight.
Dr Edna Roche, a consultant paediatrician who runs a weight management clinic for children at Tallaght Hospital, Dublin, said the study added to the work undertaken by other researchers which demonstrate changes in the coronary arteries of young children.
She said the Bogalusa heart study in the US showed, for example, that 65 per cent of obese five- 10-year-olds had a minimum of one cardiovascular risk factor and 25 per cent had two or more risk factors.
Children were also presenting with high blood pressure and high cholesterol levels in the Republic, she revealed.
"In our clinic we see children as young as eight with cardiovascular risk factors such as high blood pressure and abnormal blood lipids," she said.
"In a recent study of children aged eight-17 [ attending the weight-management clinic at Tallaght hospital], we found almost two-thirds of patients had one additional cardiovascular risk factor."
The latest Australian study reinforced the importance of considering cardiovascular health in childhood, Dr Roche said.
"It is important that we promote active healthy lifestyles to prevent childhood obesity and maintain cardiovascular health."
Dr Donal O'Shea, a consultant physician with a special interest in obesity at Loughlinstown and St Vincent's hospitals in Dublin, said it was already known that blood pressure and cholesterol were raised in obese children.
However, he added that the new study indicated that these changes were already affecting blood vessels in children as young as six years.
"At the end of the day, heart attack and stroke are caused by narrowing blood vessels and this study is showing that already in six-year-olds, that narrowing is likely to happen if you are obese at that age," he said.
The Republic had reduced its cardiovascular death rate over the past 20 years but Dr O'Shea warned that "we could lose the effect of all those gains as a result of obesity".
The findings of the Australian study were "definitely an extension of what we already know and a worrying extension of what we already know", he said.
Furthermore, Dr O'Shea noted that there was no way of treating blood pressure and high cholesterol levels in children at present as drugs used to treat these conditions were only licensed for use on adults.
"There is no way of treating it that is, other than by weight loss," he said.