It happens to Bonnie Church every time she eats pizza or meatballs or anything with a lot of hidden sodium in it.
“I can eat salt and just balloon and have fluid retention and increased blood pressure at the same time,” she said, while her husband who ate the same thing is fine.
And like many women with hypertension, Church has been struggling to keep her blood pressure under control with medications.
“My doctor and I are working on that,” she said, after trying three different medications.
Those two issues might be related, an Augusta University researcher believes. Women might process sodium differently than men and blood pressure medications might work differently in them as well, said Dr. Jennifer Sullivan, a cardiovascular physiologist. However, there has been very little research done in women as opposed to men on these fronts, something that she is working to change.
Sullivan recently received an Established Investigator Award from the American Heart Association to explore her research into sex differences in how hypertension affects men and women. Up until 2004, when the group established its Go Red for Women campaign, there was very little awareness even among doctors that heart disease affected women as well as men, Sullivan said.
“Heart disease, cardiovascular disease were thought of as a man’s disease,” she said. “It was just kind of ignored (in women). The clinician was less aware of it, the basic scientist was less aware of it. The data was all male-centric.”
That includes the clinical research and the drugs prescribed to treat it, Sullivan said.
“Basic science research was focused almost entirely on males,” she said. “So really the entire paradigm we have for treatment is a male paradigm.”
But it has been an interest of Sullivan since she was in graduate school in the 1990s.
“We’ve already studied a lot of this in the male. We know how this works in the male,” she said. “We have absolutely no idea if it works the same in the female.”
Those differences could help explain the dissimilarities in treatment and reaction to sodium. Women make up more than half of the patients with hypertension but more than 50 percent of those women, like Church, cannot adequately control their blood pressure with medication. Women also seem to be more sensitive to salt – which increases blood pressure in more than half of them with hypertension.
“Women are more likely to know they have hypertension, they are more likely to go to their doctor, they are more likely to be treated but they are less likely to have controlled blood pressure on medications because we don’t know what causes hypertension in women,” Sullivan said.
The same is true in how the body handles sodium, she said.
“So little has been done to characterize sodium transporters and how sodium is handled in the female,” Sullivan said. “We know so much more in the male.”
Part of the gender difference may have to do with the immune system and its interaction with organ systems important for blood pressure, such as the kidneys and the vasculature. In early research in animals, Sullivan has shown that females are more likely to have a certain type of suppressing immune cells known as T regulatory cells that can help lower blood pressure.
The inability to create and promote these cells in women may be leading to the lack of blood pressure regulation, Sullivan said. Some of that might be affected by salt. Part of the ability to handle salt in the body depends on the chemical nitric oxide, which is also a powerful dilator of blood vessels and important for these particular immune cells.
“We think it is nitric oxide that is important in being able to provide an environment that promotes differentiation and development of these T regulatory cells,” Sullivan said. T regulatory cells, unlike broad-acting immune suppressing drugs, can be carefully targeted, which is already being studied in clinical trials, she said.
“It’s an intriguing target for me,” Sullivan said.
As part of her doctor’s visit Friday morning to talk about changes in her blood pressure medication, Church also talked to her doctor about sodium. That her body might handle salt differently, as well as those medications, makes perfect sense to her.
“I would believe that 100 percent,” Church said.
Reach Tom Corwin at (706) 823-3213 or firstname.lastname@example.org