Almost one out of five Canadians has high blood pressure without knowing it, finds a new study, making them vulnerable to what doctors call the silent killer.
Statistics Canada released a study on hypertension (high blood pressure) in adults this week. The study is part of the Canadian Health Measures Survey, the most comprehensive national health survey in decades, and tracked the blood pressure of about 3,500 people aged 20 to 79.
About 19 per cent, or 4.6 million, Canadians have hypertension, the study found. About 17 per cent of those did not know they had it and were not receiving treatment. ("Normal" blood pressure is less than 120 units; "hypertense" is more than 140.)
High blood pressure is the world's leading risk factor for death, notes report co-author Michel Joffres, killing about 7.5 million people a year. "It's not infectious disease. It's not malnutrition. It's high blood pressure."
But awareness of the problem has skyrocketed, Joffres says — about 83 per cent of Canadians now know they have high blood pressure, the study found, compared to about 57 per cent two decades ago. "It's a huge improvement."
Heart aware
Hypertension rates appeared to drop about three per cent compared to the last major blood pressure study done 20 years ago, says Statistics Canada analyst Kathryn Wilkins, but this was likely due to different testing methods. (The last study used real doctors to test pressure, which could have made patients nervous — the "white coat" effect while this one used auto-testers.) Rising rates of obesity and diabetes would likely mean more hypertension in the future.
Gender was not a factor in hypertension, the study found, with men and women having about the same rates of it. Age, however, was — just two per cent of adults aged 20 to 39 had high blood pressure, compared to more than half of those 60 to 79.
Major public education efforts by doctors and groups like the Heart and Stroke Foundation have helped make more people aware of hypertension over the last two decades, Wilkins says. Many now test their pressure on their own at home or at stores. "The problem is still there … but more people are having it treated."
Hypertension is called the silent killer, says the Sturgeon Hospital's chief of cardiology, Zaheer Lakhani, as it has few outward symptoms. "Most people who have it don't know they have it," he says. He recommended getting tested for it at least once a year. Many doctors test their patients whenever they come in for a visit.
There's usually no specific cause for high blood pressure, Lakhani says, but there are risk factors such as obesity, alcohol and salt consumption. "You have to be careful of your fast-food intake."
Canadians could cut hypertension rates significantly by eating less salt, Joffres says. Canadians eat about 3,500 milligrams of salt a day, his research suggests; cutting this by about half would eliminate about 30 per cent of all hypertension, save the country $400 million and prevent about 17,000 cases of stroke and heart disease.
Statistics Canada will keep monitoring blood pressure rates every two years to track changes in hypertension, Wilkins says. A study on blood pressure in children should come out later this spring.
The study, Blood Pressure in Canadian Adults, is available at www.statcan.gc.ca.
