Middle-aged and older heterosexual men and women may be more likely to have high blood pressure if their spouse or partner has it, too, according to a large international study.
The study, published Wednesday in the Journal of the American Heart Association, showed that in up to nearly half of older couples in the United States, England, China and India both had high blood pressure, also known as hypertension. The findings highlight the potential for couples-based approaches to hypertension screening and management, researchers said.
"Many people know that high blood pressure is common in middle-aged and older adults, yet we were surprised to find that among many older couples, both husband and wife had high blood pressure," the study's senior author, Dr. Chihua Li, said in a news release. Li is a postdoctoral fellow at the University of Michigan. "For instance, in the U.S., among more than 35% of couples who were ages 50 or older, both had high blood pressure."
Nearly half of all adults in the U.S. have high blood pressure, according to American Heart Association statistics.
Prior studies conducted in small, regional or single-country settings have shown couples may mirror each other's blood pressure status and other diseases. But the new study is the first to look at couples in multiple high- and middle-income countries, co-author Dr. Jithin Sam Varghese said in the release. Varghese is an assistant research professor at the Emory Global Diabetes Research Center at Emory University in Atlanta.
"We wanted to find out if many married couples who often have the same interests, living environment, lifestyle habits and health outcomes may also share high blood pressure," he said.
In the study, researchers analyzed blood pressure measurements for 3,989 couples in the U.S., 1,086 English couples, 6,514 Chinese couples and 22,389 Indian couples. Couples were married or described themselves as partnered and living in the same household. Blood pressure measurements were taken at a single point in time.
Among English couples, the prevalence of both partners having high blood pressure was 47%, compared to nearly 38% of U.S. couples, 21% of Chinese couples and 20% of Indian couples.
But although high blood pressure is more common in the U.S. and England than in China and India, the connection between couples' blood pressure status was stronger in China and India. Compared to women married to men without high blood pressure, women whose husbands had high blood pressure were 9% more likely to have it themselves in the U.S. and England, yet they were 19% more likely in India and 26% more likely in China. The findings were similar for men married to women with and without high blood pressure.
Cultural factors could play a role in the mirrored blood pressure results, study co-author Dr. Peiyi Lu said in the release. Lu is a postdoctoral fellow in epidemiology at Columbia University Mailman School of Public Health in New York City. "In China and India, there's a strong belief in sticking together as a family, so couples might influence each other's health more," Lu said. "In collectivist societies in China and India, couples are expected to depend (on) and support each other, emotionally and instrumentally, so health may be more closely entwined."
Dr. Bethany Barone Gibbs, chair of the department of epidemiology and biostatistics at the School of Public Health at West Virginia University in Morgantown, said the findings suggest that current approaches for controlling hypertension on an individual level may not be adequate. Barone Gibbs, who was not involved with the new research, led the writing panel for a 2021 AHA scientific statement about physical activity's role in managing blood pressure and cholesterol.
Making lifestyle changes, such as increasing physical activity, reducing stress or eating healthier, "may be difficult to achieve and, more importantly, sustain if your spouse or partner are not making changes with you," she said in the release.