As many as 1.13 billion people in the world have high blood pressure, says a new study published in the journal The Lancet.
The study reveals the number of people with high blood pressure has nearly doubled in four decades. Image credit: Gerald Oswald.
Researchers from an international consortium called NCD Risk Factor Collaboration studied changes in blood pressure in every country in the world between 1975 and 2015. They analyzed blood pressure measurements from 19.1 million people.
“We estimated worldwide trends in mean systolic and mean diastolic blood pressure, and the prevalence of, and number of people with, raised blood pressure, defined as systolic blood pressure of 140 mm Hg or higher or diastolic blood pressure of 90 mm Hg or higher,” the scientists explained.
The number of adults with raised blood pressure increased from 594 million in 1975 to 1.13 billion in 2015, with the increase largely in low-income and middle-income countries, according to the study.
In 2015, 258 million (23%) of the 1.13 billion adults with high blood pressure lived in South Asia (200 million in India) and another 235 million (21%) lived in East Asia (226 million in China).
The UK was found to be the European country with the lowest proportion of people with high blood pressure in 2015, while South Korea, the United States and Canada were lowest in the world.
“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 Imperial College London professor of global environmental health Majid Ezzati, senior author on the study.
“The reason for this finding is unclear, but it may be linked to overall better health and increased consumption of fruits and vegetables.”
The condition is also caught more frequently, and earlier, and managed with medication in high-income countries. These factors may have helped counteract rising obesity, which is a risk factor for high blood pressure.
“Increasing evidence suggests poor nutrition in early life years increases risk of the high blood pressure in later life, which may explain the growing problem in poor countries,” Prof. Ezzati said.
“Poor nutrition in childhood in low income countries may also play a role in the study findings.”
The study revealed men had higher blood pressure than women in most countries in the world in 2015. Globally, 597 million men had raised blood pressure, compared to 529 million women.
The research also showed that much of the rise in the number of people with high blood pressure over the last 40 years is also due to a larger, and older, world population.
“The condition is caused by a number of factors including dietary influences, such as eating too much salt and not enough fruit and vegetables, obesity, insufficient exercise and some environmental factors such as lead exposure and air pollution. The condition is more common in older ages,” the authors explained.
The country with the highest age-corrected proportion of men with high blood pressure in 2015 was Croatia (38% of the population), while Niger had the highest proportion of women with high blood pressure (36%).
In the United States, the age-corrected proportion of people with high blood pressure was 15% for men and 11% for women in 2015, placing them 2nd lowest in the world. In 2015, men’s average blood pressure in the country was 124/74 mm Hg, while women in 2015 had an average blood pressure of 117/71 mm Hg.
“Tackling the epidemic of high blood pressure in low and middle-income countries is one of the most pressing global health challenges,” Prof. Ezzati said.
“We need economic means and regulation to improve access to high quality food, especially fruits and vegetables, and reduce excessive salt in food.”
“We also need a stronger healthcare system, to identify people with high blood pressure earlier, and improve access to treatment and medication.”
“Without these measures, the world is unlikely to achieve the World Health Organization’s target of reducing the proportion of people with high blood pressure by 25% by 2025.”
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NCD Risk Factor Collaboration. Worldwide trends in blood pressure from 1975 to 2015: a pooled analysis of 1479 population-based measurement studies with 19.1 million participants. The Lancet, published online November 15, 2016; doi: 10.1016/S0140-6736(16)31919-5
This article is based on a press-release issued by Imperial College London.
