Chronic Diseases in Canada

Volume 31, no. 1, December 2010

Executive summary – Report from the Canadian Chronic Disease Surveillance System: Hypertension in Canada, 2010

S. Dai; C. Robitaille; C. Bancej; L. Loukine; C. Waters; O. Baclic

Author References

1. Centre for Chronic Disease Prevention and Control, Public Health Agency of Canada, Ottawa, Ontario

Correspondence: Sulan Dai, MD, PhD, Centre for Chronic Disease Prevention and Control, Public Health Agency of Canada, 785 Carling Ave., A/L 6806A, Ottawa, ON, K1A 0K9,
Tel.: 613-960-0558, Fax: 613-941-2057,
Email: sulan.dai@phac-aspc.gc.ca

Introduction

Hypertension is a common and serious health problem among Canadians, and tracking hypertension leads to understanding how the condition can be prevented and treated. The Report from the Canadian Chronic Disease Surveillance System: Hypertension in Canada, 2010 provides a current and comprehensive picture of hypertension in Canada. Written in collaboration with the provincial and territorial governments, it is the Public Health Agency of Canada's first national surveillance report on hypertension from the Canadian Chronic Disease Surveillance System (CCDSS), which was initially used to track diabetes.

The main purpose of the report is to provide governments and the public with new knowledge in order to help reduce the risk of developing hypertension and to improve its outcomes among Canadians.

The report shows that hypertension—defined by CCDSS as a minimum of one hospitalization or of two physician claims with a diagnosis of hypertension within a two-year period—is highly prevalent. The number of Canadian adults living with hypertension has increased between 1998/99 and 2006/07 and is projected to continue to increase, with a resultant major impact on Canada's health system. Moreover, a substantial number of Canadians are living with both hypertension and diabetes; for them, mortality rates from any causes are higher than among people with only one of these conditions.

Highlights

The Report from the Canadian Chronic Disease Surveillance System: Hypertension in Canada, 2010 features the most recent data available, from fiscal year 2006/07, as well as trend data from 1998/99 to 2006/07. Where data on both diagnosed hypertension and diabetes are presented, trend data are from 2000/01 onwards as data for diabetes were not available prior to this. The report also provides provincial/territorial comparisons. However, data for Nunavut and Quebec were unavailable, though these will likely be available in future reports. Data were reported for adults aged 20 years and older.

Prevalence

• Nearly 6 million Canadians—or more than one in five adults over the age of 20—were living with diagnosed hypertension in 2006/07 (24.0% of women and 21.3% of men, crude prevalence).
• The age-standardized prevalence of diagnosed hypertension increased from 12.9% in 1998/99 to 19.6% in 2006/07.
• Projections indicate that, if current age and sex trends continue, by 2011/12 about 7.3 million Canadians will have been diagnosed with hypertension—an estimated increase of 25.5% from 2006/07.

Incidence

• Age-standardized incidence rates of diagnosed hypertension remained stable throughout the study period with overall incidence rates (age-standardized to the 1991 Canadian population) of 26.2 per 1000 in 1998/99 and 25.8 per 1000 in 2006/07.
• Almost half a million (450 000) Canadians were newly diagnosed with hypertension in 2006/07 (22.1 per 1000 population aged 20 years and older, 21.6 per 1000 women and 22.7 per 1000 men, crude incidence).

Provincial and territorial comparisons

• The age-standardized prevalence of diagnosed hypertension was above the national average in the Atlantic provinces and below the national average in the west and north (Yukon, Northwest Territories and British Columbia).
• Yukon has the highest age- standardized incidence rate of diagnosed hypertension, closely followed by Newfoundland and Labrador. The lowest rates were observed in Ontario and the Northwest Territories.

Hypertension and diabetes

• In 2006/07, 5.1% of Canadians aged 20 years and older (1 million) were living with both diagnosed diabetes and hypertension.
• 22.7% of adults with diagnosed hypertension also had diagnosed diabetes, and 62.8% of adults with diagnosed diabetes also had diagnosed hypertension.
• Age-standardized prevalence of diagnosed diabetes among adults with diagnosed hypertension increased from 10.9% in 2000/01 to 14.3% in 2006/07.

Mortality

• Between 1998/99 and 2006/07, all-cause mortality rates for adults with diagnosed hypertension decreased from 7.3 per 1000 to 6.7 per 1000 among women and from 12.2 per 1000 to 10.2 per 1000 among men.
• In 2006/07, all-cause mortality rates were, respectively, 34% and 44% higher among women and men with diagnosed hypertension than among those without diagnosed hypertension.
• In 2006/07, age-standardized all-cause mortality rates were about 2 times higher for adults with both diagnosed hypertension and diabetes compared to adults with diagnosed hypertension only.

Summary

The Report from the Canadian Chronic Disease Surveillance System: Hypertension in Canada, 2010 provides an up-to-date picture of hypertension in Canada. Although the overall incidence rate has been stable, the prevalence has been increasing steadily over the last decade, meaning that the number of Canadians who are living with hypertension has increased.

Known as the "silent killer," hypertension is a leading modifiable risk factor for cardiovascular disease (CVD) and mortality in the world. In most cases, hypertension has no symptoms and can only be diagnosed through proper blood pressure measurement. If left untreated, hypertension can increase a person's risk of stroke, coronary heart disease, dementia, diabetes, heart and kidney failure and other chronic diseases.

Hypertension affects all age groups, but the risk of hypertension increases with age. The Canadian population is aging, and with increasing rates of obesity and diabetes, the risk of developing hypertension is projected to increase in Canada.

The risk of developing hypertension can be reduced through eating a healthy diet, limiting sodium intake, avoiding excessive alcohol consumption, losing excess weight and through regular physical activity.

Hypertension can be controlled with lifestyle modifications and/or use of blood pressure lowering medication. Moreover, it is important that individuals with hypertension have their cholesterol and blood sugar levels and kidney function checked regularly as the presence of these risk factors increases the risk of damage from hypertension. Improved management of hypertension can prevent heart disease, kidney disease and stroke in the population.

For more information, the Report from the Canadian Chronic Disease Surveillance System: Hypertension in Canada, 2010 is now available on the PHAC website at:
http://phac-aspc.gc.ca/cd-mc/cvd-mcv/ccdss-snsmc-2010/index-eng.php