Childhood fitness a trump card in later heart health

Childhood fitness a trump card in later heart health

A new study from a group of international researchers, including those at the University of Tasmania's Menzies Institute for Medical Research, has found that aerobic exercise in childhood can help offset the long-term cardiovascular health risks associated with childhood obesity.

The study found that higher aerobic fitness in childhood, independent of abdominal fat, reduced the risk of developing metabolic syndrome in early adulthood by 36 percent compared to those with lower childhood fitness levels.

Metabolic syndrome is a clustering of key cardiovascular disease risk factors and is associated with an increased risk of subsequent coronary artery disease, stroke and Type 2 diabetes.

The study has been published in the online edition of the International Journal of Obesity and involves researchers from Menzies, the University of Georgia (USA) and the George Institute for Global Health at Oxford University. It used data collected for the Childhood Determinants of Adult Health Study (CDAH), which is based at Menzies.

Researchers conducted a 20-year follow-up of 1,792 Australians who had also participated in a national childhood health and fitness survey in 1985 when they were aged 7 to 15 years. Data collection in childhood included a 1.6 km run to assess cardio-respiratory fitness and waist circumference measures to assess abdominal fat. As adults, participants attended one of 34 clinics held across Australia, where they underwent a range of health and fitness assessments.

The senior author on the study is the Menzies' Director, Professor Alison Venn. Professor Venn said very few studies had looked at the influence of childhood fitness in combination with childhood obesity on adult cardiovascular risk.

She said the combination of a high waist circumference and low cardio-respiratory fitness in childhood was especially concerning. "These participants were over eight times more likely to have the metabolic syndrome in adulthood than those who had low waist circumference and high aerobic fitness levels."

While the long-term cardiovascular risks of childhood obesity were reduced among those with higher childhood fitness, children with higher levels of abdominal fat still had a three-fold increased risk of adult metabolic syndrome after adjusting for their fitness level.

The paper's lead author, Associate Professor Michael Schmidt, of the University of Georgia, said that a number of studies had found that higher levels of aerobic fitness could substantially reduce the cardiovascular disease risks associated with adult obesity, but few studies had looked to see whether this might also be true regarding childhood obesity.

Co-author Professor Terry Dwyer, of The George Institute for Global Health, said:  "These findings are the first from a follow-up of children for as long as 20 years.  What they show is that fitness in childhood is important not just because it reduces levels of body fat in childhood, but that fitness itself has benefits to health."

Data from the Childhood Determinants of Adult Health study is used in a number of Menzies research projects that are looking into cardiovascular disease through the life course.

M D Schmidt, C G Magnussen, E Rees, T Dwyer and A J Venn. Childhood fitness reduces the long-term cardiometabolic risks associated with childhood obesity, International Journal of Obesity.

Contact: Miranda Harman

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