Rachel
05-24-2010, 08:56 PM
Expect the unexpected: Cdn kids' blood pressure not up, despite obesity rates
19/05/2010 5:23:00 PM
Helen Branswell, Medical Reporter, The Canadian Press
TORONTO - There's a little bit of good news on the childhood obesity front.
A new Canadian study has found that rates of high blood pressure among Canadian kids are "remarkably low." That's despite the fact that there are record levels of obese and overweight children and teens, and obesity and high blood pressure are generally thought to go hand in hand.
The findings, from Statistics Canada's Canadian Health Measures Survey, showed that just under one per cent of kids had elevated blood pressure levels and another two per cent had blood pressure readings that were borderline high.
"To find so few youth with elevated blood pressure was surprising," said Dr. Gilles Paradis, a professor of public health at McGill University in Montreal and lead author of the study.
"We found that the average blood pressure of youth was lower than we expected and that the proportion of youth who had elevated blood pressure was not as high as we expected."
The study found that among the children studied, those who were overweight or obese had a statistically higher chance of having elevated systolic blood pressure rates than those who were of a healthy weight. The systolic blood pressure is the first number given in a blood pressure reading.
Paradis also suggested it's not clear how quickly these kids might develop high blood pressure and the cardiovascular problems that go along with it as they become adults. Still, he said the better-than-expected numbers may indicate there's a window of opportunity in which prevention efforts could make a difference.
"From a prevention point of view, it suggests that we have time to intervene to prevent the sort of negative consequences of obesity levels in our population," Paradis said.
"That means that you're not condemned as soon as you develop overweight or obesity of developing elevated blood pressure, for example. You have time to intervene to prevent those negative consequences. That's a good thing."
The findings were based on blood pressure readings from nearly 2,100 children and teens aged six to 19 from across the country.
This is the first time in decades there have been national estimates of rates of elevated blood pressure based on readings from Canadian children.
However, a study Paradis and others published in 1999 reported that between 12 and 23 per cent of Quebec children aged nine, 13 and 16 had high-normal or elevated blood pressure readings.
He said the difference may in part relate to the instruments used to take the blood pressure readings. Some are known to overestimate blood pressure while some give more conservative readings.
Another partial explanation may be the way the readings were taken. In the current study, the children were isolated in an environment designed to be calming in order to reduce the effect of what's known as "white coat hypertension." That's when blood pressure goes up just by virtue of the fact a medical professional is taking a blood pressure reading.
Had the readings been taken in a context more similar to normal circumstances, the readings could have been higher, Paradis said.
But those factors can't account for the entire difference between the rates in the national study and the rates in the earlier Quebec research. Paradis suggested it may just be true that Canadian kids aren't yet having as much of a blood pressure problem as experts would expect, given the rates of obesity and overweight.
That doesn't mean those problems aren't on the horizon if overweight kids and teens don't modify their lifestyles, he said.
"We should not rest on our laurels," Paradis said.
"We need to be proactive and vigorously combat the obesity epidemic. Because if we don't, ultimately many of these kids will become obese adults and will develop the negative effects of obesity including elevated blood pressure and ultimately diabetes, heart attacks and so on."
19/05/2010 5:23:00 PM
Helen Branswell, Medical Reporter, The Canadian Press
TORONTO - There's a little bit of good news on the childhood obesity front.
A new Canadian study has found that rates of high blood pressure among Canadian kids are "remarkably low." That's despite the fact that there are record levels of obese and overweight children and teens, and obesity and high blood pressure are generally thought to go hand in hand.
The findings, from Statistics Canada's Canadian Health Measures Survey, showed that just under one per cent of kids had elevated blood pressure levels and another two per cent had blood pressure readings that were borderline high.
"To find so few youth with elevated blood pressure was surprising," said Dr. Gilles Paradis, a professor of public health at McGill University in Montreal and lead author of the study.
"We found that the average blood pressure of youth was lower than we expected and that the proportion of youth who had elevated blood pressure was not as high as we expected."
The study found that among the children studied, those who were overweight or obese had a statistically higher chance of having elevated systolic blood pressure rates than those who were of a healthy weight. The systolic blood pressure is the first number given in a blood pressure reading.
Paradis also suggested it's not clear how quickly these kids might develop high blood pressure and the cardiovascular problems that go along with it as they become adults. Still, he said the better-than-expected numbers may indicate there's a window of opportunity in which prevention efforts could make a difference.
"From a prevention point of view, it suggests that we have time to intervene to prevent the sort of negative consequences of obesity levels in our population," Paradis said.
"That means that you're not condemned as soon as you develop overweight or obesity of developing elevated blood pressure, for example. You have time to intervene to prevent those negative consequences. That's a good thing."
The findings were based on blood pressure readings from nearly 2,100 children and teens aged six to 19 from across the country.
This is the first time in decades there have been national estimates of rates of elevated blood pressure based on readings from Canadian children.
However, a study Paradis and others published in 1999 reported that between 12 and 23 per cent of Quebec children aged nine, 13 and 16 had high-normal or elevated blood pressure readings.
He said the difference may in part relate to the instruments used to take the blood pressure readings. Some are known to overestimate blood pressure while some give more conservative readings.
Another partial explanation may be the way the readings were taken. In the current study, the children were isolated in an environment designed to be calming in order to reduce the effect of what's known as "white coat hypertension." That's when blood pressure goes up just by virtue of the fact a medical professional is taking a blood pressure reading.
Had the readings been taken in a context more similar to normal circumstances, the readings could have been higher, Paradis said.
But those factors can't account for the entire difference between the rates in the national study and the rates in the earlier Quebec research. Paradis suggested it may just be true that Canadian kids aren't yet having as much of a blood pressure problem as experts would expect, given the rates of obesity and overweight.
That doesn't mean those problems aren't on the horizon if overweight kids and teens don't modify their lifestyles, he said.
"We should not rest on our laurels," Paradis said.
"We need to be proactive and vigorously combat the obesity epidemic. Because if we don't, ultimately many of these kids will become obese adults and will develop the negative effects of obesity including elevated blood pressure and ultimately diabetes, heart attacks and so on."