Hot topic - Children's blood pressure is rising
6 May 2004 - written by Bupa's Health Information Team
In the May 5 2004 issue of The Journal of the American Medical Association, a US study has found the rise in childhood obesity may also be partly responsible for a rise in children's blood pressure. This may have a bearing on the children's future health as high blood pressure increases the risk of heart disease and stroke in later life.
Below we look at the issue in more depth:
What did the study find?
The US study looked at 3,496 US children aged 8 to 17 years in 1988-1994 and compared their blood pressure to 2,086 US children of the same age in 1999-2000.
The researchers measured the children's:
- systolic blood pressure - the pressure in the arteries when the heart is pumping blood
- diastolic blood pressure - the pressure in the arteries between heart beats when blood is not being pumped
The average systolic blood pressure for the children was 104.6mmHg in 1988-1994 and this rose to 106mmHg in 1999-2000.
The average diastolic blood pressure for children in 1988-1999 was 58.4mmHg and this rose to 61.7mmHg in 1999-2000.
In other words, children's systolic blood pressure had risen by an average of 1.4 mmHg and their diastolic blood pressures had risen by an average of 3.3mmHg.
Why is this seen as important?
Having high blood pressure in later life raises the risk of developing heart disease and stroke. High blood pressure is defined as having a systolic blood presure of 140 or more and/or a diastolic blood pressure of 90 or more.
The children's average blood pressure does not suggest that they will have high blood pressure soon. However, blood pressure rises with age and the fact that children have higher blood pressure than previous children means that they are at more at risk of developing the problem in the future. One of the study's researchers, Dr Jeffrey Cutler, said: "The increases found by the study in children's average blood pressures may seem small, but they can have serious consequences."
Dr Cutler claimed that previous research suggests that every 1-2mmHg rise in children's systolic blood pressure increases their risk of developing high blood pressure by 10 percent. Therefore, the children studied in 1999-2000 had an average increased risk of high blood pressure in later life of 14 percent when compared with those children studied in 1988-1994.
What is thought to be responsible for this rise in blood pressure?
The researchers believe that part of the rise in children's blood pressure is partly due to the rise in the numbers of children who are overweight or obese. In fact, the researchers have calculated that 29 percent of the rise in systolic blood pressure and 12 percent in the rise in diastolic blood pressure could be attributed to the increase in children's weights.
According to previous research, the percentage of boys who were overweight had risen from 11.3 percent in 1988-1994 to 15.5 percent in 1999-2000. While the percentage of girls who were overweight had risen even more dramatically from 9.7 percent in 1988-1994 to 15.5 percent in 1999-2000.
Apart from being overweight or obese, the other main lifestyle factors that contribute to increased blood pressure are not getting enough physical activity and eating too much salt in the diet.
Could UK children's blood pressure also be higher than previous generations?
The levels of childhood overweight and obesity are increasing in the UK, so it is more than likely that UK children's blood pressure are also higher than previous generations.
Both Professor Graham MacGregor, chairman of the Blood Pressure Association, and Belinda Linda, head of medical information at the British Heart Foundation agree that the rise in UK children's weights will mean that their blood pressure will be higher too. They are concerned that will lead to higher rates of high blood pressure in later life.
What can be done to reduce childhood obesity and children's blood pressures?
Reduce the amount of salt in the daily diet
Many children eat more than the recommended daily amount of salt in their diet (see table below). Two of the main contributors to this are the salt found in processed foods (for example ready meals and crisps) and salt that is added while cooking.
| D A I L Y S A L T L E V E L S | |
|---|---|
The UK Government's Scientific Advisory Committee on Nutrition (SACN) recommends the following daily salt intakes: |
|
Baby aged up to six months old |
less than 1g per day |
Baby aged 7-12 months |
1g per day |
Child aged 1-6 years |
2g per day |
Child aged 7-14 years |
5g per day |
Adult (aged 14+ years) |
a maximum of 6g per day |
Make sure children get at least 60 minutes of physical activity every day
The UK Government now recommends that all children (up to teenage) should be physically active for at least 60 minutes per day, every day of the week. This activity can be built up through the day in bouts of 10 minutes or more, which means that it is possible to incorporate this activity more easily into daily life. For example, the Government suggests children could build this up by:
- playing in break times at school
- walking or cycling to and from school
- taking part in organised activities such as PE, sports and swimming
- playing with friends near home
However, it is also important for children to develop strong bones, it is vital that children engage in activities that build healthy bones at least twice a week. Activities such as running, jumping, ball games and gymnastics are ideal for strengthening bones. In addition, muscle strength and flexibility can be developed through activities such as carrying, climbing and rough and tumble.
This level of activity will also help children to keep their weight under control.
Parents can encourage healthy lifestyles in their children
If parents set good role models for their children, by eating healthily, not cooking with salt or adding it at the dinner table, and by being physically active in their daily lives, their children are more likely to adopt these lifestyle habits as well.
Further information
Bupa resources:
- Bupa factsheet: Blood pressure
- Bupa factsheet: Healthy eating
- Bupa factsheet: Avoiding childhood obesity
- Bupa factsheet: Physical activity
- Children's health section
