Unfit Irish teenagers are showing evidence of heart disease, according to a new study.
The groundbreaking work being carried out in Dublin City University on male transition-year students has found teenagers with low fitness levels are showing worrying early signs of cardiovascular disease, which is Ireland’s biggest killer — accounting for a third of all deaths every year.
Tests in the ongoing study found 15-year-old boys with low fitness levels have less healthy blood vessels than high-fit students with some also showing signs of hypertension and high cholesterol.
Study author Sinead Sheridan said she has found a marked difference in the cardiovascular health profile of highly-fit and moderately-fit kids and the low-fitness kids.
“Heart disease begins in childhood due to exposure to risk factors such as inactivity, low fitness, and poor diet and we are now unfortunately seeing it in 15-year-old boys who have low levels of fitness,” said the PhD researcher at the school of health and human performance in DCU.
“What we’ve found so far is that the kids in the low-fit group have much higher LDL cholesterol, which is bad cholesterol, and they have much greater blood pressure and in some of the cases we’ve actually seen hypertension.”
As part of the study, 70 transition-year students visited the vascular research unit in the school of health where they had a blood sample taken, their percentage of body fat measured, and their fitness assessed during a VO2 max test on a treadmill.
“Along with risk factors for heart disease such as blood pressure, cholesterol and percentage body fat and cigarette smoking, we also measured the disease process itself,” said the DCU researcher.
“Using ultrasound, we measured how well the blood vessels could dilate and we found that in 15-year-old boys with poor fitness levels, the blood vessels could dilate only 50% as much as high-fit teens. Unfit boys also had greater thickening in the carotid arteries, clearly indicating these children had early onset of heart disease.”
According to the Irish Heart Foundation approximately 10,000 people die every year from cardiovascular disease — including coronary heart disease, stroke and other circulatory diseases.
The author pointed out that the study, Aerobic fitness, Cardiovascular Disease Risk Factors and Sub-clinical Cardiovascular Disease in Irish teenage boys found that unfit teenagers were not necessarily overweight.
She said: “In our low-fit group the majority of the guys were overweight but there were also guys in the group who were actually very lean.
“It is actually better to be overweight and fit than to be lean and unfit. Studies show that fitness trumps over all the other risk factors.”
Ms Sheridan, a graduate PE teacher from DCU, said the attitude towards fitness and physical exercise in schools needs to change.
She said: “The big thing is our children are not fit. There needs to be a shift in how PE is taught and on the importance of fitness and activity so kids leaving school can take this with them into adulthood.
“The real take-home message is that 15-year-old boys with low levels of fitness have risk factors for heart disease and sub-clinical heart disease.””
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