HealthDay News — More than half of all patients with hypertension worldwide are unaware of their condition, researchers found.
Among the 46.5% of patients who knew they had hypertension, the majority were receiving a drug treatment for the condition (87.5%), but only about one third taking medication had their hypertension under control (32.5%), Salim Yusuf, MD, DPhil, of Hamilton General Hospital in Hamilton, Ontario, and colleagues reported in the Journal of the American Medical Association.
Although a number of effective BP-lowering treatments exist, hypertension remains one of the leading causes of cardiovascular disease and mortality worldwide.
Yusuf and colleagues examined hypertension prevalence, awareness, treatment and control in 142,042 adults from 17 countries grouped by income in the Prospective Urban Rural Epidemiology (PURE) study.
High-income countries included Canada, Sweden and the United Arab Emirates. Upper-middle-income countries included Argentina, Brazil, Chile, Poland, Turkey, Malaysia and South Africa. Lower-middle-income countries included China, Colombia and Iran. Low-income-countries included Bangladesh, India, Pakistan and Zimbabwe. Data from U.S. patients were not included in the study.
Participants were aged 35 to 70 years at baseline and were followed for 10 years. Researchers analyzed cardiovascular disease risk factors, such as smoking, hypertension history, psychosocial factors and physical measures, as well as sitting blood pressure.
Hypertension status was determined through self-report and receipt of BP-lowering medications, and was defined as 140 mm/Hg systolic and 90 mg/Hg diastolic. Stage 2 hypertension was defined 160 mm/Hg systolic and 100 mm/Hg diastolic. BP control was defined as achieving a BP measurements below 140 mm/Hg systolic and 90 mm/Hg diastolic.
Primary outcomes were awareness of hypertension status, use of BP-lowering treatments and hypertension control.
Overall, 40.8% of the study population had hypertension with an average BP of 131/82 mm/Hg. Participants aged 50 years and older had consistently higher prevalence of hypertension compared with younger patients, but had greater rates of awareness, treatment and control (P<0.001 for all), the researchers found.
Low-income countries had the lowest number of patients aware and treated, at 40.8% and 31.7%, respectively (P<0.001 for both). Among low-income countries, hypertension awareness, treatment and control were significantly higher in urban compared with rural areas. Low education was associated with lower awareness, treatment and control only in low-income countries.
Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers were the most common drugs taken (13.6%) among those receiving BP-lowering medication, followed by beta blockers (8.2%), calcium antagonists (8.2%), and diuretics (7%). Less than half of patients were taking two or more medications (30.8%).
“These findings suggest substantial room for improvement in hypertension diagnosis and treatment,” the researchers concluded.
Study limitations included low response rates in low-income countries and reliance on a single measure of hypertension among participants.