Shift in High Blood Pressure Trend from High- to Low- and Middle-Income Countries
An estimated 597 million men and 529 million women had elevated blood pressure in 2015.
As blood pressure trends have shifted throughout the last 4 decades, blood pressure levels in low- and middle-income countries have increased, while blood pressure levels have decreased in high-income nations, according to research published in the Lancet.1
In a pooled analysis of national, subnational, and community population-based studies, researchers from the Non-Communicable Disease Risk Factor Collaboration (NCD-RisC) identified trends in both systolic and diastolic blood pressure (SBP, DBP) from 1975 to 2015. The prevalence of elevated blood pressure in 200 countries was also assessed.
The analysis identified 1479 studies measuring the blood pressure of 19.1 million adults. At least 1 data source was available for 87% (174) of 200 countries, which included 97.5% of the 2015 world population; 61% (122) countries had at least 2 data sources available. Of all sources identified, 35% were national samples; 17% were from 1 or more subnational regions; and 48% were from 1 or a small number of communities. Sixty-three percent of sources were from 1995 or later.
Between 1975 and 2015, the global, age-standardized mean SBP was “virtually unchanged” among men (126.6 mm Hg; 95% credible interval [CrI], 124-129.3 vs 127 mm Hg; 95% CrI, 125.7-128.3), with an increase of 0.07 mm Hg per decade. Over the same time period, slight decreases in mean SBP were noted in women (123.9 mm Hg; 95% CrI, 121.3-126.6 vs 122.3 mm Hg; 95% CrI: 121-123.6), with a decrease of 0.47 mm Hg per decade. Age-standardized mean DBP trends were similar (78.7 mm Hg; 95% CrI, 77.9-79.5 for men and 76.7 mm Hg; 95% CrI, 75.9-77.6 for women).
On a national level, the greatest decrease in mean SBP was found in Asia Pacific; the decrease was 3.2 mm Hg (95% CrI, 2.4-3.9) for women, and 2.4 mm Hg (95% CrI, 1.6-3.1) for men (posterior probability [PP] >.9999) per decade. The greatest decrease in mean DBP was found in the western super-region—including high-income English-speaking countries and countries from North and South Western Europe—with a decrease of 1.8 mm Hg (95% CrI, 1.4-2.3) for women and 1.5 mm Hg (95% CrI, 1.0-1.9) for men (PP >.9999) per decade.
Conversely, mean SBP and mean DBP increases were identified in both men and women living in east and southeast Asia, south Asia, Oceania, and sub-Saharan Africa; the highest mean blood pressures in 2015 were identified in central and eastern Europe, sub-Saharan Africa, and south Asia.
Overall, the estimated number of adults with elevated blood pressure increased from 594 million in 1975 to 1.13 billion in 2015 (597 million men and 529 million women), likely as a result of population growth and aging.
“Blood pressure is a multifaceted trait,” the authors noted, “affected by nutrition, environment, and behavior throughout the life course. Changes in risk factors and improvements in detection and treatment of raised blood pressure have, at least partly, resulted in the decrease of blood pressure in high-income countries.”
Majid Ezzati, PhD, professor at the School of Public Health at the Imperial College London and lead study author stated in a press release that while “substantial reductions” in both SBP and DBP are possible, “[data] reveal that the [World Health Organization's] target of reducing the prevalence of high blood pressure by 25% by 2025 is unlikely to be achieved” unless substantial policy efforts are made to bring improved detection and treatment to the poorest countries around the world.2
“If governments…are to address the large and inequitable burden of cardiovascular disease…associated with high blood pressure, they need to take a multifaceted approach using both population-based strategies throughout the life course and individual lifestyle management and treatment through primary care systems,” the authors concluded.
- Some countries—particularly those in sub-Saharan Africa and the Caribbean—had no or few data sources.
- Fewer data sources existed for many regions pre-1990.
- Only 53% of available sources included data for people older than 70 years of age; data were used to infer an age pattern and make estimates in older ages.
- Although the researchers' model accounted for and adjusted for systematic and random errors in data, the adjustments are not country-specific.
- Individual participant data could not be accessed for 20% of available data sources.
- Measurement device and protocol from different devices—standard mercury sphygmomanometers vs random-zero sphygmomanometers vs digital oscillometric devices—are not fully comparable, which may have affected estimated trends.
Disclosures: Dr Ezzati reports receiving a charitable grant from the Youth Health Program of AstraZeneca. Dr Smeeth reports receiving personal fees from GlaxoSmithKline and AstraZeneca, and is a trustee of the British Heart Foundation. Dr Sundstrom reports receiving personal fees from Iterim, and Dr Woodward reports receiving personal fees from Amgen.
- The NCD Risk Factor Collaboration (NCD-RisC). Worldwide trends in blood pressure from 1975 to 2015: a pooled analysis of 1479 population-based measurement studies with 19.1 million participants. Lancet. 2016. doi: 10.1016/S0140-6736(16)31919-5 [Epub ahead of print].
- High blood pressure affects 1.13 billion people, says new study [news release]. London, UK: Imperial College London; November 15, 2016.