In fact, people with the highest average blood pressure levels no longer live in high-income Western and Asian-Pacific countries, such as Germany, France, Norway and Japan, the study found. They live instead in low- and mid-income countries, particularly in south Asia and sub-Saharan Africa, such as Bangladesh, Nepal, Ethiopia and Malawi.
High blood pressure also remains persistently high in central and eastern European countries, such as in Slovenia and Lithuania.
This globalization of high blood pressure is a disturbing trend. That’s because long-term exposure to high blood pressure (or hypertension) — defined as a systolic pressure of 140 mmHG or higher and a diastolic pressure of 90 mmHG or higher — substantially raises the risk of developing heart disease, stroke, kidney disease, dementia and other serious medical conditions.
It also raises the risk of early death. The World Health Organization (WHO) estimates that high blood pressure kills an estimated 7.5 million people prematurely each year — almost 13 percent of all deaths.
Most of those deaths are now occurring in the developing world.
Target unlikely to be met
There have been some favorable trends regarding high blood pressure in recent years — all occurring, however, in high-income countries. Australia, Canada, Germany, Sweden and Japan, for example, have made significant progress in reducing high blood pressure among their populations.
“Taken globally, high blood pressure is no longer a problem of the Western world or wealthy countries. It is a problem of the world’s poorest countries and people,” said the study’s lead author, Majid Ezzati of the Imperial College London, in a released statement.
“Our results show substantial reductions in blood pressure and prevalence are possible, as seen in high-income countries over the past 40 years,” he added. “They also reveal that WHO’s target of reducing the prevalence of high blood pressure by 25 percent by 2025 is unlikely to be achieved without effective policies that allow the poorest countries and people to have healthier diets — particularly reducing salt intake and making fruit and vegetables affordable — as well as improving detection and treatment with blood pressure lowering drugs.”
Four decades of data
For the study, Ezzati and his colleagues analyzed data collected between 1975 and 2015 from population-based surveys involving more than 19 million adults in 200 countries.
They found that the number of adults with high blood pressured increased from 594 million in 1975 to 1.13 billion in 2015, with the increase occurring primarily in low- and middle-income countries.
More than half (590 million) of adults with high blood pressure live in east, southeast and south Asia — including 199 million in India and 226 million in China.
And those numbers are likely to keep rising, say the researchers, due to population growth and aging trends.
Here are some other key findings from the study:
- During the past four decades, the average blood pressure across all countries (and adjusted for age) has remained mostly stagnant in men, and has dropped by about 2.5 mmHG in women. Almost all that change in women, however, occurred before 2000.
- Some countries have astonishingly high percentages of people with the condition. One third of men living in several central and eastern European countries, such as Croatia, Latvia, Lithuania, Hungary and Slovenia, have high blood pressure, for example. The same is true for one third of women living in most west-African countries, such as Niger, Chad and Mali.
- In 2015, the United States, Canada, the United Kingdom, Peru, South Korea and Singapore had the lowest proportion of adults living with high blood pressure — about 1 in 8 women and 1 in 5 men.
The cost of inaction
As a commentary that accompanies the study notes, the lower rates in high-income countries are primarily due to population-wide public health interventions. Those efforts include educating people about dietary and lifestyle changes, of course, but they also involve lesser-known actions that the public doesn’t usually associate with lowering blood pressure, such as reducing air and noise pollution and expanding access to indoor heating and air conditioning.
Improved medical care and broader use of medications with proven effectiveness at lowering blood pressure have also been important.
“However, these treatments remain heavily underused in both rich and poor countries, calling for alternative models of health-care delivery that are less dependent on healthcare professionals and instead make evidence more directly accessible to end-consumers,” writes Dr. Kazem Rahim, a cardiologist at the University of Oxford, in the commentary that accompanies the study.
“The failure to tackle this issue more decisively will come at a high cost, particularly to disadvantaged individuals and societies,” he adds.
FMI: You can read the study and the commentary at The Lancet’s website.