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The number of adults living with hypertension has doubled since the 90s. Eddie Pearson/Stocksy
  • An international study investigated changes in the prevalence and treatment of hypertension (high blood pressure) between the years 1990 and 2019 in 184 countries.
  • Worldwide, the number of people living with the condition more than doubled over this period to almost 1.3 billion.
  • The researchers say that smoking and poor diets, which lead to obesity, are partly responsible for the increase.
  • More than half of all people with hypertension in 2019, or 720 million individuals, were receiving no treatment for the condition because many of them were unaware that they had it.

In 2015, hypertension was responsible for about 8.5 million deaths worldwide. It is a risk factor for a range of health conditions, including kidney disease and cardiovascular conditions such as stroke and heart disease.

Despite being relatively easy to diagnose and treat with inexpensive drugs, the medical community refers to high blood pressure as a “silent killer” because most people with it show no symptoms.

New research by an international team of scientists has discovered that in 2019, close to 41% of women and 51% of men with high blood pressure were unaware that they had the condition.

The same study found that, in total, about 53% of women and 62% of men with hypertension were not receiving appropriate treatment, as most of them were not aware that they had the condition.

“Nearly half a century after we started treating hypertension, which is easy to diagnose and treat with low cost medicines, it is a public health failure that so many of the people with high blood pressure in the world are still not getting the treatment they need,” says Prof. Majid Ezzati, Ph.D., senior author of the study and professor of global environmental health at Imperial College London in the United Kingdom.

The new analysis appears in The Lancet.

The Non-Communicable Disease Risk Factor Collaboration (NCD-RisC) analyzed data from 1,201 studies that were representative of the populations of 184 countries.

The studies used blood pressure measurements and information about treatment for a total of 104 million people.

Modeling by the researchers suggested that the number of people aged 30–79 years with hypertension increased globally from about 650 million in 1990 to almost 1.3 billion in 2019.

Most of the increase occurred in low and middle income countries.

There were improvements in treatment and control in high income countries such as Germany, the United States, and Portugal.

The improvements were particularly impressive in Canada, Iceland, and South Korea.

However, there was also major progress in the treatment and control of hypertension in some middle income countries, including Costa Rica, Kazakhstan, South Africa, Brazil, Turkey, and Iran.

The researchers attribute this progress to the expansion of universal health coverage and the strengthening of primary care in these countries.

“Our analysis has revealed good practice in diagnosing and treating hypertension not just in high income countries but also in middle-income countries,” says Prof. Ezzati.

“These successes show that preventing high blood pressure and improving its detection, treatment, and control are feasible across low and middle income settings if international donors and national governments commit to addressing this major cause of disease and death,” he adds.

However, the study found little improvement in the treatment and control of hypertension in Nepal, Indonesia, and most countries in sub-Saharan Africa and Oceania.

In these countries, less than a quarter of women and a fifth of men with hypertension received treatment for the condition in 2019. Overall, fewer than 10% had well-controlled blood pressure.

“Low detection and treatment rates that persist in the world’s poorest nations, coupled with the rising number of people who have hypertension, will shift an increasing share of the burden of vascular and kidney diseases to sub-Saharan Africa, Oceania, and South Asia,” warns co-author Leanne Riley, M.Sc., from the World Health Organization (WHO) in Switzerland.

“Improving the capacity of these countries to detect and treat hypertension as part of primary healthcare and universal health coverage must be accelerated.”

Medical News Today asked Prof. Ezzati why the prevalence of hypertension has increased in many low and middle income countries since 1990.

“[T]he likely causes are changes in diet — more processed carbohydrates acting partly through obesity [and] more packaged foods that may have salt — and smoking,” he replied.

“Prevention is crucial — making fruits and vegetables accessible and affordable, lowering salt, [and] tobacco control,” he added.

But he emphasized that treatment was just as important as prevention, stressing the importance of “doing what it takes for people to avoid the adverse consequences of hypertension.”

In an accompanying comment article, Tu Nguyen, M.D., Ph.D., and Clara Chow, M.D., Ph.D., both from the University of Sydney in Australia, write:

“The analysis highlights the stark differences in hypertension prevalence, treatment, and control, with some regions seeing substantial increases over time and others substantial decreases in prevalence.”

They note that whereas global control rates are stable at about 20%, they are less than 10% in sub-Saharan Africa and even lower in Indonesia (5%), Vanuatu (6%), and the Solomon Islands (7%).

They conclude:

“We need better strategies to increase diagnosis and management, leveraging primary care or existing systems or identifying new methods to engage consumers in blood pressure management.”

The authors of the new analysis mention some limitations of their study.

For example, fewer data were available for analysis from some countries, especially in Oceania and sub-Saharan Africa.

In addition, the team was unable to compare the type of drugs that different countries used to treat hypertension because the surveys did not consistently collect these data.