In the past 40 years, there has been a large increase in the number of people living with high blood pressure worldwide because of population growth and ageing--rising from 594 million in 1975 to over 1.1 billion in 2015.
The largest rise in the prevalence of adults with high blood pressure has been in low- and middle-income countries (LMICs) in south Asia (eg, Bangladesh and Nepal) and sub-Saharan Africa (eg, Ethiopia and Malawi). But high-income countries (eg, Australia, Canada, Germany, Sweden, and Japan) have made impressive reductions in the prevalence of adults with high blood pressure, according to the most comprehensive analysis of worldwide trends in blood pressure to date, published in The Lancet.
Both elevated systolic (higher than 140 mmHg; first number in blood pressure reading) and diastolic (higher than 90mmHg) blood pressure can be used to make a diagnosis of high blood pressure. Recent research suggests that the risk of death from ischemic heart disease and stroke doubles with every 20 mmHg systolic or 10 mmHg diastolic increase in middle and older ages.
Over the past four decades, the highest average blood pressure levels have shifted from high-income western countries (eg, Norway, Germany, Belgium, France) and Asia-Pacific countries (eg, Japan) to LMICs in sub-Saharan Africa, South Asia, and some Pacific island countries. High blood pressure remains a serious health problem in central and eastern Europe (eg, Slovenia, Lithuania).
"High blood pressure is the leading risk factor for stroke and heart disease, and kills around 7.5 million people worldwide every year. Most of these deaths are experienced in the developing world", explains lead author Professor Majid Ezzati from Imperial College London, London, UK.
"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. Our results show that substantial reductions in blood pressure and prevalence are possible, as seen in high-income countries over the past 40 years. They also reveal that WHO's target of reducing the prevalence of high blood pressure by 25% 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."
The findings come from a comprehensive new analysis of global, regional, and national trends in adult (aged 18 and older) blood pressure between 1975 and 2015. This includes trends in average systolic (the maximum pressure the heart exerts while beating) and diastolic blood pressure (amount of pressure in the arteries between beats), as well as prevalence of high blood pressure. The Non-Communicable Disease (NCD) Risk Factor Collaboration pooled data from 1479 population-based studies totalling 19.1 million men and women aged 18 years or older from 200 countries (covering more than 97% of the world's adult population in 2015).
The authors note that the findings are based on available data, estimates, and modelling and point out that some countries had few or no data sources, particularly those in sub-Saharan Africa and the Caribbean.
Key findings include:
- Canada, the UK, Australia, the USA, Peru, South Korea, and Singapore had the lowest proportion of adults living with high blood pressure in 2015 at below or around 1 in 8 women and 1 in 5 men (figure 4).
- At the other extreme, more than a third of men have high blood pressure in several central and eastern European countries including Croatia, Latvia, Lithuania, Hungary, and Slovenia; whilst around a third of women living in most countries in west Africa (eg, Niger, Chad, and Mali) have high blood pressure.
- In 2015, over half (590 million) of adults with high blood pressure lived in east, southeast and south Asia--of whom 199 million lived in India and 226 million in China.
- In 2015, systolic blood pressure levels were lowest in South Korea and Canada, at about 118 mmHg for men and 111 mmHg for women.
- Average age-corrected systolic blood pressure levels are highest in central and eastern Europe (eg, Slovenia, Lithuania, Croatia), sub-Saharan Africa (eg, Niger, Malawi, Mozambique), central Asia (eg, Georgia, Mongolia, Armenia), and Oceania (eg, Palau, Vanuatu), reaching 138 mmHg for Slovenian men and 133 mmHg for Nigerien women in 2015 (figure 4).
- Men had higher blood pressure than women in most world regions in 2015.
**Data visualisations and country by country data available**
NOTES TO EDITORS:
This study was funded by the Wellcome Trust
 Quotes direct from author and cannot be found in text of Article.
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