Popular media often portrays heart disease as a man's problem, but new research suggests that women's blood vessels actually age faster than men's do.
The new study found that blood pressure started increasing in women as early as the third decade of life, and it continued to rise higher than blood pressure in men throughout their life span.
The researchers said that this early change in blood pressure sets the stage for different types of cardiovascular disease later in life.
"Women actually start out with a lower blood pressure," explained study senior author Dr Susan Cheng, director of public health research at the Smidt Heart Institute at Cedars-Sinai Medical Center, in Los Angeles.
Women should aim lower
"If you think of it like a race, women start behind the starting line. So, when they get to the finish line, women have gotten there by running faster and harder, [which] causes more stress to their systems," Cheng said.
Based on these findings, she said, it's possible that women should be aiming for lower blood pressure numbers.
The study was published online in JAMA Cardiology.
During the past 20 years, research has begun to challenge the notion that women and men have the same types of heart disease, but that women just have it later in life and may have unusual symptoms.
Recent studies have found big differences in the types of heart disease each sex often has. Men are more likely to have the typical Hollywood heart attack, with searing chest pain. On the other hand, women are more likely to have what's called small vessel disease, according to background information in the study.
Both are types of ischemic heart disease – that means that blood flow to the heart is blocked. But the underlying cause is different. A heart attack usually happens if an artery is narrowed from cholesterol build-up and a blood clot blocks the artery, cutting off blood flow to the heart. In small vessel disease, the heart's smaller blood vessels don't have a lot of build-up on them, but they don't function properly, according to the US National Heart, Lung, and Blood Institute.
At the root of a heart attack
"When you think of traditional heart disease, women do have that later in life. But it's probably not that straightforward. Small vessel disease is much more subtle and it's harder to recognise," Cheng said.
The researchers also noted that heart failure may occur differently in women and men.
The study included more than 32 000 people ranging in age from five to 98. Over four decades, the researchers gathered almost 145 000 blood pressure measurements.
Since high blood pressure is often at the root of heart attack, heart failure and stroke, the researchers sifted through the data to figure out when blood pressure starts to rise.
The investigators found that women showed signs of higher blood pressure much earlier in life than men.
Cheng said this study wasn't designed to figure out the cause of the accelerating blood vessel ageing in women. But she said women's blood vessels are smaller than men's to start with, and that's true even if you account for the difference in size between men and women. So, she said, risk factors for heart disease like smoking or a poor diet might take more of a toll on women's blood vessels.
Cheng said there's a lot more research to be done. Her team would like to better understand how sex differences might affect how well a blood pressure medicine works. Also, does the threshold where high blood pressure is diagnosed need to be changed for women?
Gender equity required
The author of an accompanying editorial, Dr Nanette Wenger, said, "What this study says is that blood pressure may be really important for women. The higher trajectory starts early and is a continuous rise. Women should know their blood pressure, and they should know when it changes."
Wenger, a professor of medicine at Emory University School of Medicine in Atlanta, said it's possible that heart disease risk calculators may need to be adjusted. Women may also need to be assessed earlier in life, she suggested.
"We need gender equity in research and prevention, and in access to care and treatment," Wenger said.
If blood pressure is above 120/80, it's time to start implementing lifestyle changes such as cutting back on sodium, losing weight, quitting smoking, eating healthy and getting physically active, Wenger advised.
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