High blood pressure, also known as hypertension, is common around the world and the leading cause of heart disease, but many people are unaware that they have it, a new study shows.
The international team of researchers noted that this is true for wealthy, developed nations as well as low-income countries. And despite the availability of drugs to control high blood pressure, many people who do know they have the condition are not being properly treated.
"Blood pressure-lowering drugs are generally inexpensive and commonly available treatments," senior study author Dr Salim Yusuf, a professor of medicine at McMaster University's Michael G. DeGroote School of Medicine in Hamilton, Ontario, Canada, said in a university news release. "However, only a third of patients commenced on treatment are on enough treatment to control their blood pressure. This is worst in low-income countries, but significant in high- and middle-income countries, too."
The researchers led by the Population Health Research Institute (PHRI) of McMaster University and Hamilton Health Sciences examined data on 154 000 adults aged between 35 and 70. The participants, who did not have a history of heart disease or stroke, were from 17 different countries of varying economic strength.
All participants had their blood pressure and medication use monitored. The researchers also collected information on their age, gender, level of education and other risk factors, including whether participants knew they had high blood pressure.
"Our study indicates over half of people with hypertension are unaware of their condition and, amongst those identified, very few are taking enough treatment to control their blood pressure," study author Dr Clara Chow, a member of PHRI and an associate professor of medicine of Sydney University and the George Institute for Global Health in Australia, said in the news release.
The study, published on 3 September in the Journal of the American Medical Association, found only 46.5% of those with high blood pressure were aware of their condition. Just 32.5% of patients who were aware of the fact that they had high blood pressure were effectively keeping their condition under control.
Improvements are needed around the world in the diagnosis and treatment of high blood pressure, the researchers concluded.
"The findings are disturbing and indicate a need for systematic efforts to better detect those with high blood pressure," Yusuf said. "Early use of combination therapies, that is, two or more types of blood pressure-lowering treatments taken together, may be required."
The study was partially funded by unrestricted grants from several pharmaceutical companies.
Visit the American Heart Association to learn more about hypertension.