High BP Onsets Vary in East, South Asian UK Adults

Research Highlights:

• A data analysis projected that South Asian adults living in the United Kingdom may experience elevated blood pressure nine years earlier than East Asian adults on average.
• The largest blood pressure disparities between South Asian and East Asian adults were projected to be in 18-39-year-old men and 40–64-year-old women.
• The projected increase in systolic blood pressure in middle age East Asian adults was linked to a nearly 2.5 times higher risk for heart disease caused by blocked arteries and a nearly fourfold greater risk of stroke. Even at an older age, high systolic blood pressure predicted risk for all types of stroke.

DALLAS, Feb. 12, 2025 — South Asian and East Asian adults living in the United Kingdom may have distinct trajectories to develop high blood pressure over their life course, according to new research published today in Hypertension, an American Heart Association journal.

Researchers analyzed health records for more than 3,400 adults enrolled in the UK Biobank who self-identified as having South Asian or East Asian ethnicity. Previous research found that individuals with South Asian ancestry living in the United Kingdom had substantially higher risk of heart disease caused by blocked arteries, or atherosclerotic cardiovascular disease (ASCVD), compared with individuals with European ancestry, as well as that South Asian adults living in the United States had higher death rates from ASCVD compared with white adults. Here, researchers explored differences in long-term blood pressure patterns and their potential lifetime effects on cardiovascular disease of those differences between South Asian and East Asian adults.

"High blood pressure and its management varies widely across racial and ethnic populations, and the frequently used 'Asian' category hides those differences," said lead study author So Mi Jemma Cho, Ph.D., a postdoctoral fellow at Massachusetts General Hospital and the Broad Institute of MIT and Harvard. "This is crucial considering that high blood pressure at a young age is a major contributor to premature heart disease risk and given the emerging initiatives to study distinct cardiometabolic profile across different Asian subpopulations."

The study used data for South Asian and East Asian adults who had at least two blood pressure readings taken during primary care visits after age 18 years. Researchers tracked participants' heart disease events, including heart attacks, stroke and peripheral artery disease, using hospitalization and outpatient care records. Building on these baseline differences, as well as risk factors including current smoking status, dietary score and a metric of social determinants of health, the researchers estimated participants' blood pressure patterns at five-year increments and modeled their predicted relationships to cardiovascular disease risk.

The analysis found that:

• South Asian adults underwent earlier and faster increases in blood pressure compared to East Asian adults. At age 30 years, the average projected systolic blood pressure was 124.9 mmHg in South Asian men and 107.4 mmHg in South Asian women compared to 120.7 mmHg and 105.7 mmHg in East Asian men and women.
• On average, South Asian men were projected to reach a systolic (top number) blood pressure of 130 mmHg or higher, classified as high blood pressure by the 2017 ACC/AHA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults, 10 years sooner than East Asian men (at 36 vs. 46 years). For women, the gap was 7 years (45 vs. 52 years).
• The combined projection for South Asian men and women to reach a systolic blood pressure of 130 mmHg was age 40 years, compared to age 49 years for East Asian men and women—a 9-year difference.
• For South Asian adults, high blood pressure observed in early adulthood was associated with higher lifetime cardiovascular disease risks. For East Asian adults, higher blood pressure in midlife was associated with higher atherosclerotic cardiovascular disease risk; even at ages 65 and older, high blood pressure was associated with heightened risk of stroke.
• Each standard deviation increase in midlife systolic blood pressure in East Asian adults was linked to a nearly 2.5 times higher risk for ASCVD and a nearly fourfold greater risk of stroke. Systolic blood pressure in East Asian adults ages 65 years or older was significantly linked to all types of stroke risk.
• Young adulthood diastolic blood pressure was strongly linked to peripheral artery disease in South Asian adults (2.18 times higher risk per standard deviation increase).
• These findings were consistent when examining blood pressure trajectory based on genetic ancestry, rather than self-identified ethnicity.

"These findings demonstrate the need to tailor blood pressure screenings and treatment timing for different Asian subpopulations to advance personalized care and prevention strategies for historically understudied communities," said senior study author Pradeep Natarajan, M.D., M.M.Sc., an associate professor at Harvard Medical School. "Distinct age-related blood pressure patterns provide valuable insights to better manage cardiovascular risks and improve care for diverse populations."

Study details, background and design:

• Health data was from the UK Biobank, a study of 503,325 adults living in the United Kingdom who were 40 to 69 years of age at enrollment between 2006 and 2010. The in-depth health and biomedical information was collected for participants registered in the United National Health Service with a U.K. general practitioner (similar to a primary care physician in the U.S.).

• This analysis included 3,453 participants. 3,077 of the participants self-identified as originating from South Asia and 376 of participants self-identified as being from East Asia. 47% of the South Asian participants self-identified as women and 53% as men; 64.9% of East Asian participants self-identified as women and 35.1% as men.

• The 2017 ACC/AHA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults classifies high blood pressure as having top or bottom blood pressure measures greater than or equal to 130/80 mm Hg.

• Within the UK Biobank, participants who self-identified as originating from India, Pakistan, Bangladesh, Bhutan, Maldives, Nepal or Sri Lanka are defined as South Asian. Participants who self-identified as originating from China are defined as East Asian.

• Participants' characteristics at UK Biobank enrollment included that:
  • South Asian adults had higher blood pressure readings and were at least three times more likely to be on antihypertensive medications compared to East Asian adults.
  • South Asian adults had higher body weight on average, measured by body mass index, with an average of 27.6 kg/m² compared to 24.2 mg/m² in East Asian adults.
  • South Asian adults had slightly lower levels of "bad" LDL cholesterol (128.1 vs. 133.4 mg/dL), likely because they were more frequently prescribed cholesterol-lowering medications (27.5% vs. 10.6%).

• Outcomes and health records collected after enrollment found that:
  • High blood pressure affected nearly twice as many South Asian adults as East Asian adults by age 40 years.
  • South Asian adults were more likely to begin taking medication for high blood pressure three years sooner (age 53.7 vs. 56.9 years, and at an average SBP of 143 mmHg and 141 mmHg, respectively).
  • South Asian adults had four times the lifetime incidence of heart disease caused by blocked arteries than East Asian adults (3.5 vs. 0.9 per 1,000 person-years).

• Key risk factors included in projections were: current smoking status, defined as lifetime smoking of at least 100 cigarettes and without indication of cessation at enrollment; dietary score was quantified based on self-recalled average intake of fruit, vegetable, whole grains, fish, dairy and vegetable oils, refined grains, meats, and sugar-sweetened beverages by the U.K. National Health Service's Eatwell Guide; and socioeconomic status was determined using the Townsend Deprivation Index, which is based on occupation, car ownership, home ownership and household overcrowding.

The study's limitations include that its findings may not apply to Asian people living outside the U.K., as differences in health care systems, living environments and cultural adaption could influence the results.

"The authors provide important evidence supporting that cardiovascular risk factors like hypertension are not uniformly experienced among the diverse communities that are frequently but inappropriately aggregated under the race label 'Asian,'" said Nilay S. Shah, M.D., M.P.H., FAHA, chair of the Association's 2024 scientific statement "Social Determinants of Cardiovascular Health in Asian Americans." Shah, who was not involved in the study, is an assistant professor of cardiology and preventive medicine at Northwestern University Feinberg School of Medicine and a general and preventive cardiologist in the Bluhm Cardiovascular Institute of Northwestern, both in Chicago.

"It's increasingly recognized that ethnicity is distinct from biological exposures like genetics. Given the authors' ability to evaluate both, these findings showing that hypertension epidemiology varies by both self-identified Asian group ethnicity and genetic Asian ancestry should prompt greater exploration of differences in social risk factors that may explain the differences in hypertension and CVD outcomes among self-reported Asian ethnicity groups; simultaneously, the genetic composition leading to differences in hypertension epidemiology among Asian genetic ancestry groups remain to be more thoroughly understood," Shah said.

"Ultimately, these findings from a U.K. population of Asian adults suggest a complex interplay of social factors and genetics resulting in varying experiences of hypertension in Asian populations. There is much, much more work to be done to understand cardiovascular risk factors and outcomes experienced by Asian populations."

Co-authors, disclosures and funding sources are listed in the manuscript.