For the first time in history, prevalence of high blood pressure is higher in low- and middle-income countries, according to new research.

In a 2010 data analysis involving more than 968,000 people from 90 countries, more than 30 percent of adults worldwide live with high blood pressure — and 75 percent of them live in low- and middle-income countries.

High blood pressure is a major risk factor for heart disease and stroke, and is the leading preventable cause of premature death and disability worldwide.

Using sex- and age-specific high blood pressure prevalence from 131 past reports, researchers found:

  • In 2010, 31.1 percent (1.39 billion) of the global adult population had high blood pressure — 28.5 percent (349 million) from high-income countries and 31.5 percent (1.04 billion) from low- and middle-income countries.
  • High blood pressure prevalence decreased by 2.6 percent in high-income countries while increasing 7.7 percent in low- and middle-income countries between 2000 and 2010.
  • In high-income countries, significant high blood pressure improvements occurred from 2000 to 2010: awareness increased from 58.2 percent to 67 percent, treatment rates improved from 44.5 percent to 55.6 percent and control increased from 17.9 percent to 28.4 percent.
  • In low- and middle-income countries, awareness slightly improved, from 32.3 percent to 37.9 percent, and treatment increased from 24.9 percent to 29 percent. But high blood pressure control worsened, from 8.4 percent to 7.7 percent.

“Aging populations and urbanization, which is often accompanied by unhealthy lifestyle factors such as high sodium, fat and calorie diets and lack of physical activity, may play an important role in the epidemic of hypertension in low- and middle-income countries,” said Jiang He, M.D., Ph.D., senior study author and a researcher at Tulane University School of Public Health and Tropical Medicine in New Orleans.

“Healthcare systems in many low- and middle-income countries are overburdened and do not have the resources to effectively treat and control hypertension,” he said. “In addition, because hypertension is symptomless and many people in low- and middle-income countries do not have access to screenings or regular preventative medical care, it is often underdiagnosed.”

Most of the world’s population is represented in the study, but more than half of the countries didn’t have data on hypertension prevalence. So some of the regional and global estimates of adults living with high blood pressure may be inaccurate, researchers said.

“Hypertension needs to be a public health priority in low- and middle-income countries to prevent future cardiovascular and kidney disease, and associated costs to society,” said Katherine T. Mills, Ph.D., the study’s lead author and a researcher at Tulane University. “Collaboration is needed from national and international stakeholders to develop innovative and cost-effective programs to prevent and control this condition.”

The study appears in the American Heart Association journal Circulation.