A billion people have high blood pressure

LONDON — The number of people with high blood pressure has almost doubled in 40 years to over 1.1 billion worldwide, scientists said on Wednesday, with the burden of the condition shifting from the rich to the poor.

In the largest study of its kind analysing blood pressure in every nation between 1975 and 2015, the scientists said that it has dropped sharply in wealthy countries — possibly due to healthier diets and lifestyles — but risen in poorer ones.

The increases are especially significant in Africa and South Asia, the researchers said, and could be partly due to poor nutrition in childhood.

High blood pressure, also known as hypertension, puts extra strain on the blood vessels and major organs such as the heart, brain and kidneys. It is the world’s top cause of cardiovascular disease, which leads to strokes and heart attacks, and is estimated to cause 7.5 million deaths a year worldwide.

Led by World Health Organisation researchers working with hundreds of scientists internationally, this study covered blood pressure measurements from nearly 20 million people and was published in The Lancet medical journal.

In Europe, Britain had the lowest proportion of people with high blood pressure in 2015. South Korea, the United States and Canada had the lowest hypertension rates in the world.

More than half the world’s adults with high blood pressure in 2015 lived in Asia, the study estimated. Some 226 million people in China have high blood pressure, it said, as do 200 million in India.

“High blood pressure is no longer related to affluence — as it was in 1975 — but is now a major health issue linked with poverty,” said Majid Ezzati, a professor at Imperial College London’s school of public health.