1. < Message from the Chair

As a leading department of medicine, research represents an important pillar of our core missions. Despite many recent headwinds facing our research enterprise, we remain committed to ensuring that this mission — so critical to the health, well-being and vitality of our communities — continues to thrive. As such, for the first “Science Monday” of 2025, I highlight a handful of recent standout publications that demonstrate our scholastic excellence. This sample reflects a subset of the stellar efforts of our research faculty, who have been busy making groundbreaking discoveries that move the field of medicine forward. 

Li Lab Cinnamon Study Makes Top 10 ASN Articles of 2024

Research led by Zhaoping Li, MD, PhD, professor of medicine and chief of the division of clinical nutrition, received special recognition by the leading journal in the field. Dr. Li’s March 2024 publication in the American Journal of Clinical Nutrition on the anti-glycemic properties of cinnamon made the top 10 most viewed articles within the journals of the American Society of Nutrition for the year. This was based on the article’s Altmetric score, which measures how much attention an article receives across many platforms including downloads, mentions by news outlets, social media, policy documents and more.

“The single most important thing, was that we focused on continuous glucose levels. It’s not taken at just one time point,” Dr. Li explained. “We really considered variation and overall effects.” 

Eighteen participants were involved in the study, which took place across four weeks. Future experiments will include more subjects and be extended to assess whether people can replace sugar with cinnamon in their diets. 

“We want to see if the cinnamon not only has intrinsic benefits, but also has the added benefit of reducing sugar intake,” Dr. Li said.

Please join me on congratulating Dr. Li on her team’s recognition and outstanding work! I look forward to seeing the results of follow up studies that arise from these initial results.

Amy Vandiver, MD, PhD, Identifies Aging-Linked Mutations in Mitochondrial DNA

Mitochondrial DNA is an important yet still-mysterious contributor to the aging process. Thanks to the work of Amy Vandiver, MD, PhD, a dermatologist and STAR program alumni, we are one step closer to understanding how mutations in the mitochondrial genome influence skin aging.

In a study published Dec. 16 in Aging Cell, Dr. Vandiver and her team in the lab of Michael Teitell, MD, PhD developed an induced pluripotent stem cell (iPSC) model to demonstrate that changes in a phenomenon called heteroplasmy — genetic variation within the population of mitochondria in a cell —were associated with age-related growth and metabolic changes.

“Typically, stem cells are all about division, not a lot of growth — they’re one of the most rapidly-dividing cell types there are, so they don’t have a lot of time to sit and grow big before they divide,” Dr. Vandiver said. “But in our cells with high levels of deletion, we saw a shift of that, where they were dividing much more slowly and spending more time accumulating mass.” This persisted even after the team differentiated the cells into other types, a finding that Dr. Vandiver described as “striking.” 

“We were able to replicate some of the growth patterns we see in aging stem cells just by altering the level of mitochondrial mutation heteroplasmy,” she said. They also had metabolic changes that mirrored those seen in aging cells. 

“It was exciting to us to see that,” Dr. Vandiver said. 

Ultimately, while she cannot say definitively whether the mitochondrial genomic changes used in the models are the cause of age-related skin shifts in skin function, Dr. Vandiver views these findings as a crucial first step to developing therapies that could potentially treat or prevent them. By understanding how mitochondrial genome changes arise and what their downstream consequences are, it will be possible to come up with interventions that target them.

“We know that these mutations are present at high levels in older skin. By seeing that in the iPSC model those changes directly cause metabolic and growth changes, that gives us more impetus to try to use them as targets for intervention in aging skin,” she said. “This study gave us a lot of insight into the metabolic changes that are downstream of having high levels of bad mitochondrial DNA.”

Very nice work Amy — kudos to you and your team!

Study by Andrea Shin, MD, MSCR Finds That Race and Gender Influence Spending on IBS Care

It is well known that people with irritable bowel syndrome (IBS) have greater healthcare spending than those who do not. However, until recently, it was unclear whether factors like race and gender influence spending amounts, or whether IBS patients from certain demographics have different experiences with the healthcare system. To address this question, UCLA gastroenterologist Andrea Shin, MD, MSCR led a wide-ranging study involving data from more than 95,300 adults with IBS. An article about their findings was published Dec. 9 in Clinical Gastroenterology and Hepatology. 

The researchers also observed that overall healthcare spending — not IBS-specific spending — was greater for women than for men. More research will be required to understand why women with IBS spend more on healthcare overall. However, it could be that they have additional comorbidities that coexist with IBS, which translates into additional healthcare spending.

The results point to different avenues for research, such as exploring why some treatments, like endoscopies, might be costlier for men than for women even as healthcare spending overall was higher. The high cost of emergency department visits among some demographics will be fertile ground to explore as well.

“The next question to answer is why these differences are occurring,” Dr. Shin said. “Why is spending on care different between these different groups?”

Please join me in congratulating Dr. Shin and her team on this important study!

Joanna Schaenman, MD, PhD Characterizes Immune Response to COVID-19 in Organ Transplant Patients

COVID-19 is particularly dangerous for solid organ transplant (SOT) recipients, who must take lifelong, powerful immune-suppressive drugs to prevent their bodies from rejecting the transplanted organ. Joanna Schaenman, MD, PhD, an infectious diseases physician at UCLA, and a team of researchers from UCLA, UCSF, the University of Texas at Austin, Emory School of Medicine and more recently published a study that illuminates major differences in how the immune response of SOT patients differs from that of non-SOT patients with COVID-19, with implications for treatment.

These results present some major implications for treatment approaches and a need for additional studies on immune-modulating treatments in transplant recipients.

Given the early observations that severe COVID-19 was accompanied by a ‘cytokine storm’ immune response in previously healthy individuals, standard treatments for hospitalized adults with severe COVID-19 targets the immune system with steroids and Janus kinase inhibitors. The finding that immune response in SOT patients differs significantly from normal hosts calls this routine practice into question and suggests that additional studies for immune modulation-related therapies in transplant recipients should be performed to identify best treatment practices.

Dr. Schaeman noted that although the study applies to all SOT patients, it is most relevant for those who have had lung transplants. Furthermore, it has implications for future pandemics, as COVID-19 offered a unique opportunity to see how the immune responds to a pathogen it has never encountered before. Additionally, the study “also underlines the fact that as most initial therapy and vaccination studies exclude immunocompromised patients, this patient population would benefit from directed studies to identify optimal therapies,” she said.

Thank you Dr. Schaeman and team for this exceptional work!

For Open Heart Surgery, Referral Networks May Keep Black Patients Out of Top Hospitals, Study Led by Ioana Popescu, MD, MPH Finds

After accounting for distance from home to available hospitals, Black patients are less likely than their white peers to undergo elective coronary artery bypass grafting (CABG) surgery at top-quality hospitals, possibly due to subpar referral networks, a recent study led by associate professor of medicine and internist Ioana Popescu, MD, MPH shows. The research was published Dec. 27 in Circulation: Cardiovascular Quality and Outcomes.

“The main finding was that there are clear and significant effects of referral networks,” Dr. Popescu said. “This is the first time, to my knowledge, that the effects of referral networks on hospital admission have been quantified and shown to vary by race.”

Dr. Popescu’s research is part of a larger NHLBI R01 grant to understand how physician referral networks influence differences in outcomes for Black and white patients with coronary heart disease. Early in her career, Dr. Popescu and her team showed that proximity to high-quality hospitals was less influential than non-geographic factors in determining whether a Black patient’s CABG took place at a hospital with low mortality rates. Her earlier work also revealed that of physicians treating Black and white patients, and in the structure of physician networks caring for Black and white patients, it seemed that physician referral networks for CABG might contribute to the observed differences in high quality hospital use between the two populations.

To find out, Dr. Popescu and her team analyzed claims data on 76,376 Black and white Medicare patients who underwent elective CABG procedures between 2017 and 2019. The researchers’ statistical framework was predicated on hospital choice models, which assume that patients and their physicians select one hospital over another based on location, hospital characteristics and an array of patient and physician factors. They ranked the relative quality of the hospitals in their assessment according to Medicare-published 30-day CABG mortality data and measured the strength of ties between primary care physicians and hospitals by how many CABG patients they shared in the 12 months prior to a subject’s surgery. 

Their results suggested that, on average, Black and white CABG patients are treated at hospitals with similar levels of mortality — an encouraging finding that differs from past research, the study authors noted. However, Black patients used low-mortality hospitals less often than expected given their geographic proximity to these hospitals. The researchers’ analysis found that this was partly explained by differences in physician-hospital referral networks.

In other words, “geography was more favorable to Black patients, but referral networks were more favorable to white patients,” Dr. Popescu said. “Black patients are in better geographical proximity to high-quality hospitals, but having a good hospital near you doesn’t necessarily mean you can have your open-heart surgery there.”

Dr. Popescu stressed that the results do not indicate outright bias on the part of the referring physicians. She and her team also conducted qualitative research during which they spoke with physicians about how they make referral decisions and found that they consider multiple factors in making referrals, including language preference, care concordance, means of transportation, follow-up and out of pocket costs among many other factors when deciding where to refer a patient. 

“Decisions are very complicated, and all we observe is the end result,” she said. “I think these studies are an interesting starting point to begin to understand referrals, which are a central part of healthcare in the US.” 

Thank you to Dr. Popescu and her team for all their great work on this important topic!

Jasmine Marcelin, MD and Renee Williams, MD, MHPE Share Expertise on Pharmacoequity and Colorectal Cancer Screening at Grand Rounds 

You will notice that two of the papers summarized above address the importance of scholarship in the area of health equity and the importance of understanding the impact of demographics, including race and socio-economic status — which are often linked — to health care access and outcomes. As such, it is important to recognize that two of our Grand Rounds during Black History Month focused on issues that pertain to equity and inclusion in medicine. 

On Feb. 13, Jasmine Marcelin, MD, vice chair for belonging and community engagement in the department of internal medicine at the University of Nebraska Medical Center was our Grand Rounds speaker. Her talk focused on disparities in antimicrobial prescribing between white patients and patients from communities of color, sharing data that showed how Hispanic and Black patients had higher rates of hospital-acquired infections than white patients, as well as greater rates of infections that are resistant to antibiotics. Additionally, she shared evidence that efforts to curb antibiotic use were disproportionately leading to Black and rural patients not getting the medicines they need to treat their infections. 

She noted that these findings had nothing to do with any individual’s race or ethnicity but instead were a manifestation of structural racism. As a solution, she proposed ways to use pharmacoequity (a term coined by UCLA physician-scientist Utibe Essian, MD, MPH) to solve these challenges. Some ideas included reminding patients of their role in decision making around antibiotic prescribing, improving representation of patients from rural areas and communities of color in clinical trials, and advocating on behalf of underserved populations to elected officials. 

Grand Rounds on February 6 was given by gastroenterologist Renee Williams, MD, MHPE, associate chair for health equity and professor of medicine in the department of medicine at NYU Langone. Dr. Williams presented an update on non-invasive colorectal cancer (CRC) screening techniques, an essential topic given increasing rates of early-onset CRC among young people and high rates of mortality from the disease among Black men and Native American women. She reviewed the various non-invasive techniques used to screen for CRC, including new blood-based tests that are coming to market, and offered suggestions for reoffering tests to patients who had previously declined colonoscopies.

Thank you to Dr. Marcelin and Dr. Williams for visiting us and delivering excellent talks!

Dale

P.S.

Last week our leadership team attended the Association of Professors of Medicine Meeting in Palm Springs. There were many insightful presentations and discussions on the many challenges currently facing departments of medicine. One presentation showed the following slide, which encouraged us to frame these challenges, some of which could be described as crises in perspective. While remaining cognizant of potential danger, I am standing in the opportunity lane.

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