Simple new interventions — using existing drugs and supplements in different ways — may one day help stop or slow the decline of cardiovascular function in patients with chronic kidney disease.
Vienna Brunt, PhD, an assistant professor in the Division of Renal Diseases and Hypertension at the University of Colorado Anschutz Department of Medicine, is leading research supported by the National Institutes of Health (NIH) to uncover links between the gut microbiome and arterial dysfunction in aging patients. She is also investigating what exactly causes cardiovascular complications in patients with kidney disease.
“Cardiovascular disease is so prevalent in kidney disease, and I do think it’s underappreciated,” Brunt says. “There’s really not enough work that's done that looks at both combined.”
Recently, a new concept has emerged to emphasize that the connection exists. Cardiovascular-kidney metabolic syndrome (CKM) is a newly recognized health condition that encompasses various health issues including chronic kidney disease, heart disease, and obesity or diabetes. Recognizing the diseases under one syndrome is meant to help the public better understand just how those diseases are connected.
Aiming to improve knowledge about the interconnections between these conditions, Brunt is leading innovative research that has gained national attention. In 2021, she earned a highly competitive Pathway to Independence Career Development Award from the National Heart, Lung, and Blood Institute, one of the largest institutes within the NIH, to advance her studies.
According to the Centers for Disease Control and Prevention, about one in seven adults in the U.S. may have chronic kidney disease, and it is becoming more common. For many patients with chronic kidney disease, cardiovascular complications can be fatal. Discovering ways to prevent or slow these complications has the potential to reduce morbidity and improve quality of life for many patients, emphasizing the importance of Brunt’s work.
A supplement’s potential for one type of patient
At the start of her career, Brunt’s research mostly focused on young adults who were at risk for cardiovascular problems and later shifted to older adults. Now she is studying patients with chronic kidney disease, including polycystic kidney disease, which is a genetic condition in which the kidneys develop fluid-filled cysts that cause damage.
She came to CU Anschutz in 2022 to work more closely with physicians and patients, in addition to other researchers, with the aim of better guiding her research to help people who are impacted by cardiovascular disease. The pioneering nature of her work has earned Brunt several recognitions and awards over the years.
In the research focusing on polycystic kidney disease, Brunt was interested in running a pilot study that looked at using an available supplement that has been considered for kidney patients in previous research: MitoQ. The supplement is marketed in sales to support energy and healthy aging. But in Brunt’s work, instead of focusing on the supplement’s possible impact on the kidney alone, she examined how the supplement would impact the decline of cardiovascular function.
The pilot study showed the supplement may help to slow or reverse those cardiovascular complications. Now, she’s conducting research to learn more about the timeframe where it may be most effective. Many patients with polycystic kidney disease aren’t diagnosed until they are in their 30s or 40s.
"In terms of the magnitude of this, it’s not curing the disease, there is no drug available for that, but this has the potential to work alongside other medications,” Brunt says. “I personally find there to be really good potential.”
The link to the gut
The five-year career development award that Brunt earned from the NIH has supported her investigations into another potentially important connection — the interactions between the gut microbiome and the cardiovascular system.
Brunt has found that as adults age, bacteria in the gut microbiome that help transform fiber into short-chain fatty acids decline significantly. Those short-chain fatty acids, particularly one called acetate, help guard against systemic inflammation that can contribute to cardiovascular problems.
Brunt’s research has considered what might happen if that short-chain fatty acid was supplemented back into the body when the levels drop off in older adults. One existing prescription drug, calcium acetate, provides a source of acetate.
Recently, Brunt helped conduct a blinded trial that recruited 32 older adults and offered them the prescription drug for 12 weeks, testing them before and after to see if their cardiovascular function was impacted. The trial was completed in April. Brunt and her team are still analyzing the data and expect to have more complete results next year, but Brunt is hopeful based on prior research findings.
“It’s something that we can get and that can have a big impact,” Brunt says.
In upcoming studies, Brunt would like to research if this same approach would be effective for adults with chronic kidney disease, who, even when younger, can have even lower levels of that bacteria that helps produce the acetate.
Many times, Brunt likes to consider alternative interventions that don’t involve drugs, such as supplements or targeted diets, but in this case she considered that prescription drug after having looked at the effects of increasing fiber in people’s diets as a way to help them increase their acetate short-chain fatty acid levels. Research showed that without high levels of the bacteria in the microbiome to convert the fiber, the effects were limited. Additionally, Brunt says, high-fiber diets are difficult for most Americans to adhere to long-term.
Still, Brunt approaches research looking at exercise and healthy diets first, and she believes those interventions should always be a top recommendation for patients. When research can help find drugs that can safely help, she says it is a plus.
That’s why having a team to help guide research so it has the best impact on patients is always important, she says.
“You need to do it in a way that actually matters to patients,” Brunt says about her approach to research. “It helps you go in the right direction.”
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