research

Duke University Researcher Calls For A ‘His & Hers’ Approach To Tackling Hypertension

Durham, NC – As we leave behind the season for eating, drinking and being merry, a researcher says this is also a good time to keep a watchful eye on your blood pressure.

RESEARCH
Professor Anita Layton

Anita Layton, Duke University Research Professor in Mathematics and the Canada 150 Research Chair at the University of Waterloo, reveals studies showing heart-related deaths increase by as much as five percent during December and January. She highlights that traditional holidays such Christmas and New Years are associated with increased risk of heart attack, with contributing factors to include emotional distress, anger, anxiety, sadness, grief, and stress; as well as excessive food intake, alcohol and long-distance travel increasing the odds of a heart attack. The good news is that high blood pressure can be treated as a preventive measure, and now for the first time, a research team is suggesting a more fine-tuned approach to prescribing medications.

Professor Layton and her team focus on a “his and hers approach” to tackling high blood pressure and share how men and women react differently to blood pressure medication. Working on aspects of personalized medicine for 4-5 years, Layton says they utilize what they consider “the new microscope” to illustrate this theory. The new microscope they are referring to is mathematical models of blood pressure regulation. Layton confirms that “these models are sex-specific [and] with the appropriate inputs these models can represent hypertensive men and women.

Then by further changing some of these inputs, the models can represent different anti-hypertensive treatments [and] predict how effective a given treatment is for men and women.” She goes on to note that “the invention of the microscope allows us to see microscopic things that we weren’t able to see before. Like a microscope, mathematical models offer a variety of ‘magnification levels’ that focus on different aspects of a person. For example, ‘macroscopic’ models may focus on whole-organ function and metabolism, whereas ‘microscopic’ models may simulate membrane transport kinetics.” 

As an advocate for ending gender bias in medicine, Layton proclaims “the traditional one-size-fits-all model to prescribing high blood pressure medication is problematic. When you look at men and women who are being treated for high blood pressure, you find that men achieve control [of their hypertension] at a slightly higher rate than women, putting women at a disadvantage.” She goes on to explain that “the advantage of men is even more striking considering that women actually have a higher rate of medication compliance, being more likely to seek treatment and follow their medication regimens. Studies show that only 45 percent [of women] successfully get their blood pressure under control compared to 51 percent of treated men.”

Anita LaytonWhen asked exactly how her team are using formulas to simulate how men and women function differently and how blood pressure medication is formulated to react in the body, Layton confirms that “a number of physiological processes work together to regulate our blood pressure: a (non-sex) hormone system, a nervous system, etc. These systems react to changes in blood pressure and their sensitivity differs between men and women. For instance, let’s say both men and women go on a high-salt diet which raises their blood pressure. Their blood pressure elevations would kick the nervous system into action to counteract that blood pressure increase. That response is stronger in women. This difference is represented in the mathematical equations.

When blood pressure medications are administered to men and women, the models represent the effects of those meds by changing some of the inputs to each of the previously mentioned blood pressure regulatory systems (nervous system, hormone system, etc.). Because these systems are configured somewhat differently between men and women, they are also affected differently by blood pressure medications.”  Layton goes on to emphasize when “simply put, some drugs will work better for women. It depends on which part of the blood pressure regulatory system you target. If you target one aspect where men are more sensitive, it’s likely the drug will be more effective for men and vice versa.”

Following publication of the team’s first set of sex-specific computational models for blood pressure regulation, collaborators — including Alicia McDonough of the University of South California, Jennifer Sullivan of Augusta University and David Cherney of the University Health Network, Toronto — are using the models to gain a better understanding of which drugs will be more effective in lowering blood pressure in female patients. The models can also be used by drug companies to screen new potential blood pressure therapies to determine which are most likely to succeed should they start the regulatory approval process.

In addition, they can be utilized to identify patients who are most likely to be susceptible to triple whammy, the term used for drug-induced renal failure that occurs in some hypertensive patients when they take certain painkillers. Layton provides an important example regarding the effect of a triple whammy. She shares that “hypertensive patients who are on a diuretic (water pill) and ACEI or ARB [classifications of blood pressure medications] if they take a type of painkiller like an NSAID (e.g. aspirin), there is a good chance that they may suffer acute kidney injury.”

Layton explains that her overall goal is to cure diseases, stop aging and eliminate human suffering. She aims to remove gender bias that often leads to misdiagnosis or inappropriate treatment in women in particular. After watching both of her parents and many other family members struggle to control high blood pressure and diabetes despite being in general good health, Layton is keen to see the medical community apply her team’s findings to offer sex-based therapies that highlight gender differences.

She believes math is the new microscope, as it allows you to see the human biological system in a new light and gain a better understanding of what’s really going on, in a very cost-effective and precise way. Her team’s hope is to raise awareness about the importance of considering gender when prescribing blood pressure medications, not just among clinicians, but among patients and caregivers as well.

Layton, who sits on the Editorial Board of SIAM Journal on Dynamical Systems and SIAM Review, will be presenting some of her recent work at the 2020 SIAM Annual Meeting, which takes place in Toronto, Canada in July. To find out more about Professor Anita Layton’s research, her findings are published in SIAM News, a publication of Society for Industrial and Applied Mathematics (SIAM).

About Society for Industrial and Applied Mathematics (www.siam.org)
The Society for Industrial and Applied Mathematics (SIAM), headquartered in Philadelphia, Pennsylvania, is an international society of more than 14,000 individual, academic and corporate members from 85 countries. SIAM helps build cooperation between mathematics and the worlds of science and technology to solve real-world problems through publications, conferences, and communities like chapters, sections and activity groups. Learn more at
siam.org.