Hypertension on the rise in Canada

Canadian Medical Association JournalNov 22 2011

Higher rates in women older than 65 and in Atlantic provinces

Hypertension in Canada is increasing, and it is projected that more than one-quarter of Canadian adults will be diagnosed with hypertension by 2012/13, according to a study in CMAJ (Canadian Medical Association Journal) http://www.cmaj.ca/site/embargo/cmaj101863.pdf. Older women were more likely to be diagnosed with high blood pressure compared with men, and people in the Atlantic provinces had the highest rates of hypertension.

Canadian researchers looked at data on 26 million adults aged 20 years and over between 1998 and 2007/08 to determine how common hypertension was in the population (prevalence) and the number of new cases (incidence). They looked at the data by age group and by province/territory. The Canadian Chronic Disease Surveillance System (CCDSS), which includes all Canadians who have used the health care system, was the data source.

Approximately 6 million (23%) of Canadians were living with diagnosed hypertension in 2007/08, and slightly more women (24.3%) than men (21.7%) had the condition. This rate is higher than that reported in the 2007 Canadian Community Health Survey, which found a prevalence of 19.2%. In 2007/08, about 418,000 - almost half a million - new adult cases were diagnosed. Adjusting for age, rates of hypertension increased from 12.5% in 1998/99 to 19.6% in 2007/08, with an annual increase of 5%.

"If the 2007/08 age- and sex-specific incidence and mortality remain constant, we forecast that about 26.5% (7.4 million) of Canadian adults will be living with diagnosed hypertension by 2012/13," writes Ms. Cynthia Robitaille, Public Health Agency of Canada, with coauthors.

Over the last 10 years, hypertension became more prevalent as people aged and there were more new cases. In women over age 60, prevalence rates were higher (43.6%) than in men (40%). The rates of new cases increased in women older than 75 (8.6% compared with 8.2%). Hypertensive adults aged 20󈞝 years old were two to four times more likely to die compared to people without high blood pressure.

Elevated blood pressure is the number one risk factor for death and for reduced quality of life. It accounts for approximately 13% of all deaths and can increase the risk of stroke, dementia, heart and kidney failure, and other chronic diseases.

"Programs to improve the lifestyles of Canadians, such as the proposed initiative to reduce sodium consumption, will be critical to decrease the incidence and prevalence of diagnosed hypertension in Canada," conclude the authors.