Blood pressure of Canadian children and youth, 2009 to 2011

Among Canadian children and youth, 96% have a measured blood pressure that is considered normal, while the remaining 4% have a measured blood pressure that is considered borderline or elevated. Blood pressure is generally higher among overweight and obese children and youth.

The average resting blood pressure is 94/61 mmHg for Canadian children aged 6 to 11 years and 98/62 mmHg for Canadian youth aged 12 to 19 years based on directly measured blood pressure results from the 2009 to 2011 Canadian Health Measures Survey (CHMS).

Overall, 96% of children and youth have a blood pressure that is considered normal, while the remaining 4% have a measured blood pressure that is considered borderline or elevated (Chart 1) according to the criteria of the National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents and the Joint National Committee on Prevention, Detection and Treatment of High Blood Pressure.Note 1, Note 2 Boys were no more likely than girls to have borderline or elevated blood pressure.

Chart 1
Distribution of household population aged 6 to 19, by blood pressure classification, sex and age group, Canada, 2009 to 2011

Description for Chart 1

Chart 1 Distribution of household population aged 6 to 19, by blood pressure classification, sex and age group, Canada, 2009 to 2011

Blood pressure and body composition

Children and adolescents with higher body mass index tend to have higher systolic blood pressure (SBP) (Chart 2). Average SBP was significantly higher in overweight and obese children aged 6 to 11, and in obese adolescents aged 12 to 19, when compared to their normal weight counterparts. Differences in diastolic blood pressure (DBP) were not as strong; only overweight boys aged 6 to 11 had a significantly higher DBP compared to those of normal weight.

Chart 2
Average systolic blood pressure, by body mass index classification, age group and sex, household population aged 6 to 19, Canada, 2009 to 2011

Description for Chart 2

Chart 2 Average systolic blood pressure, by body mass index classification, age group and sex, household population aged 6 to 19, Canada, 2009 to 2011

About blood pressure

Blood pressure (BP) is a measure of the force of blood against the artery walls, and is expressed as systolic pressure (SBP)/diastolic pressure (DBP) in millimetres of mercury (e.g., 120/80 mmHg). The systolic pressure (top number) is the pressure when the heart contracts and pushes the blood out and the diastolic pressure (bottom number) is the lowest pressure when the heart relaxes between beats.

Blood pressure has many implications for health. High systolic blood pressure and/or high diastolic blood pressure can cause damage to the blood vessels and can result in heart attack or stroke, which are leading causes of hospitalization and death in Canada. Elevated blood pressure in childhood is a risk factor for the development of hypertension in adulthood, and is more likely in those with elevated body mass index.

Table
Blood pressure classifications in children and adolescents
Table summary
This table displays the results of blood pressure classifications in children and adolescents ages 6 to 17 and ages 18 and 19 (appearing as column headers).
  Ages 6 to 17Note 1 Ages 18 and 19Note 2
Normal SBP and DBP < 90th percentile Mean SBP/DBP < 120/80 mmHg
Borderline SBP or DBP ≥ to the 90th percentile, but < the 95th percentile OR
Measured mean SBP/DBP > 120/80 mmHg
Mean SBP of 120-139 mmHg and mean DBP of 80-89 mmHg OR
Mean SBP of 120-139 mmHg and mean DBP < 80 mmHg OR
Mean SBP < 120 mmHg and mean DBP of 80-89 mmHg
Elevated SBP or DBP ≥ 95th percentile OR
Respondent reported using BP medication within the past month
Mean SBP/DBP of ≥ 140/90 mmHg OR
Respondent reported using BP medication within the past month

References

  1. National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. The fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents. Pediatrics. 2004;114(2 Suppl. 4th report):555-76.
  2. Chobanian AV, Bakris GL, Black HR, et al. Seventh report on the Joint National Comittee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension. 2003;42(6):1206-52.
  3. de Onis M, Onyango AW, Borghi E, Siyam A, Nishida C, Siekmann J. Development of a WHO growth reference for school-aged children and adolescents. Bulletin of the World Health Organization. 2007;85(9):660-7.

For more information on the Canadian Health Measures Survey, please contact Statistics Canada's National Contact Centre (toll-free 1-800-263-1136; 613-951-8116; infostats@statcan.gc.ca).