Obesity in childhood raises risk of stroke

OBESE CHILDREN face a higher risk of heart disease and stroke than was previously thought, according to a new study.

Researchers at the University of Oxford have shown that obese children and adolescents have several risk factors for heart disease including raised blood pressure, cholesterol and blood-sugar levels, and a thickening of the heart muscle, compared with normal weight children.

If these risk factors are allowed to progress into adulthood, obese children could already be at a 30-40 per cent higher risk of future stroke and heart disease than their normal-weight counterparts, the study published today in the British Medical Journal says.

Ireland has the second-highest rate of obesity in Europe, and one in four three-year-olds is overweight. Minister for Health James Reilly is considering proposals for a tax on sugary drinks as a means of tackling obesity in Ireland. He is due to receive a report on the possible impact next month.

In New York, a ban on large-size sugary drinks has been passed while, in the UK, MPs are calling for similar legislation. Scientists already know that being overweight in adulthood increases the risk of cardiovascular disease. The effect of obesity on children is less well understood, but evidence suggests a similar association.

In the latest study, a team of researchers based at the University of Oxford set out to examine the scale of the association between weight and risk factors for heart disease in children.

They analysed the results of 63 studies involving 49,220 healthy children aged between five and 15. The studies measured weight and one or more known cardiovascular disease risk factors, such as high blood pressure, high cholesterol and blood glucose levels.

Overweight was defined as a body mass index (BMI) of 25-30 and obesity was defined as BMI of 30 or more.

Compared with normal weight children, obese children had significantly higher blood pressure and cholesterol levels. Overweight children also had raised blood pressure, but to a lesser degree than obese children. Fasting insulin levels and insulin resistance, known markers for diabetes, were significantly higher in the obese but not the overweight children.

The authors say the exact ages at which changes in a child’s risk factors begin need to be established to help build a more accurate picture of the cardiovascular risk likely to be faced as adults.

“Weight, and especially obesity, has a significant effect on the risk parameters for cardiovascular disease that are present in children from age five years,” they conclude. “This effect could give them a head start on their normal and even overweight classmates for future cardiovascular disease, diabetes and stroke.”