The increase in blood pressure has been linked to the stress of being a mother, a new study finds.
But a new analysis of data from over 6,000 adults suggests that some of the rising numbers are driven by more mundane factors.
It also suggests that more and more people are taking heart-healthy, lifestyle-enhancing measures to control their blood pressure, the researchers said.
“It’s an extremely interesting study and I think it adds to our understanding of how the stress response works in the context of our health,” said Daniel Noguchi, a senior researcher at the National Institute of Diabetes and Digestive and Kidney Diseases, or NIDDK, who led the research.
The study, published online in the journal Circulation, is the first to analyze blood pressure over time for more than 200,000 U.S. adults.
Researchers compared the blood pressure of the adults over time to a baseline, using the U.N. Centers for Disease Control and Prevention’s National Health Interview Survey.
In the two years since then, the average blood pressure increased by 3.6 millimeters (1.3 inches) for women and by 3 millimeters for men, but stayed about the same for both men and women.
The difference was small and the researchers say they are not sure why.
But the finding has a caveat: People with a lot of stress may have more of a need to avoid stress.
The researchers compared the average daily stress levels of adults in the two study periods to their blood pressures over time, then used the data to calculate how much stress a person in that group was exposed to over that period.
They found that the average person in the study was exposed more than three times the daily stress level of the average adult in the general population.
The increase in stress is driven by an increase in the risk of hypertension, a condition in which blood pressure rises more rapidly than normal.
The new study does not identify the underlying mechanism for the increased risk, but the researchers think it may be related to more stress, more work and other factors.
In addition to the impact on blood pressure from a greater risk of having high blood pressure during pregnancy, the study also suggests some other reasons for the rise in blood pressures, including increased exposure to air pollution, smoking, obesity and sedentary lifestyles.
“There’s a lot that we don’t know yet,” said Dr. Michael W. Weidenbach, the lead author of the study and director of the NIDDM’s Division of Cardiovascular and Hematology at the University of Michigan Health System.
“This study suggests that if we want to reduce blood pressure we need to take these things into account.”
Dr. Weenbach noted that the study does show that people are more likely to take a stress-reducing measure when they are in their early twenties, but it doesn’t seem to have any effect on blood pressures in later life.
“In other words, the risk is still the same,” he said.
“There are a lot more confounding factors.”
Researchers are also trying to understand how blood pressure might change over time in older adults.
The National Heart, Lung, and Blood Institute, which runs the National Institutes of Health, and NIDDK supported the research, which was funded by the National Center for Complementary and Alternative Medicine, the National Heart Association and the American Heart Association.