High blood pressure found in 19% of Canadians

Nearly one in five Canadians adults about 4.6 million people between the ages of 20 and 79 has high blood pressure,Statistics Canada reported Wednesday.

The study was based on automated measurements of blood pressure and self-reported use of blood pressure medication, thedepartment said in its publication HealthReports.

When blood pressure is too high, it puts stress on the body's entire vascular system, forcing the heart to work harder, and increasing the risk of death from a variety of causes including heart disease and stroke.

As part of the broader Canadian Health Measures Survey,researcherssurveyed and tested 5,600Canadians agedsixto79years between March 2007 and February 2009 at mobile examination centres.

Participants were classified as having hypertension or high blood pressure if theirsystolic pressure, the top number,was140 or higher, their diastolic pressure, or bottom number,was90 or higher, or theyreported they had used medication for high blood pressure in the past month.

Uncontrolled blood pressure

Another 20 per centof participants 20 to 79years old werein the pre-hypertension range, and 61 per cent had normal blood pressure.

The pre-hypertension range was defined according to internationally recognized standards:systolic blood pressure of120to139 or diastolic blood pressure of80to89. Pre-hypertension is linked to anincreased risk of cardiovascular disease and is strongly predictive of hypertension.

About 80 per cent of the 4.6 million adults with hypertension were being treated with drugs, the report's authors found.

In two-thirds of those with hypertension, blood pressure was controlled with medication.

Age factor

Butin about 6.6 per cent of the adultpopulation,the condition was uncontrolled, meaning that their blood pressure stayedin the hypertensive range.

The prevalence of hypertension went up with age:

• Ages20 to 39: two per cent.
• Ages 40 to 59: 19 per cent.
• Ages 60 to 79: 53 per cent.

"Twenty years ago, we did a survey involving measured blood pressure, and at that time only 13 per centof people with hypertension had their blood pressure in the range we call controlled," said Kathryn Wilkins, a senior analyst at Statistics Canada in Ottawa who led the study. "This compares with 66 per centtoday. So that's encouraging."

It's difficult to say why, Wilkins said, butcampaigns to promote awareness of the importance of hypertension as a risk factor for heart disease and stroke may be paying off. Machines to measure blood pressure aremore common in pharmacies, and awareness by physicians has also improved, she said.

"The awareness levels have really come up," agreed Laura Weyland, a pharmacist and owner of a Shoppers Drug Mart in Toronto. "I think a lot of doctors' offices are recommending to go to the drug store and check your blood pressure.Or if [people]realize that their parents have high blood pressure, theycome in and they can check it, and make sure it is within the normal range."

Healthier lifestyles

Overall, the prevalence of hypertension was nearly the same in both sexes, at19.7 per cent in men and 19 per cent in women.

But inolder Canadians, there was a gap in blood control between men and women. For example, of those aged60to 69 using anti-hypertensive drugs, 19 per cent of women had uncontrolled blood pressure compared withseven per cent of men.

"Women are more likely to be aware of their hypertension, they're more likely to be on medication than men with hypertension. But somehow the success, or the efficacy, of the medication seems to be lower in women than in men," Wilkins said.

"And this has been observed in other countries as well, and the reasons really are not understood at this point."

Nearly 67 per cent ofCanadians over age 60 needed medication to control their hypertension.

"The sad reflection is that this could've been achieved by other mechanisms [than medication], such as reducing the amount of salt we eat, eating a healthierdiet, staying physically active, and stayinga good body weight," said study co-author Dr. Norman Campbell of the University of Calgary.

Canadians who don't have high blood pressure yet probably will in the future, Campbell said, citing research thatshows that nine out of ten people who live a normal life span will eventually end up with hypertension.

The Canadian Health Measures Survey also used direct measurements offitness and activity levels, nutritional status, exposure to environmental contaminants, infectious disease status, oral health, lung capacity andheart rate.

Blood pressure in children was not measured.