Brief roundup of research done by experts at UCLA Health

Below is a brief roundup of news and story ideas from the experts at UCLA Health. For more information on these stories or for help on other stories, please contact us at [email protected].

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The link between obesity, the brain, and stroke Obesity, a growing global problem, increases the risk for stroke and vascular brain injury with long-term consequences including the development of cognitive impairment and dementia. A new UCLA study focused on identifying molecular pathways induced by diet-induced obesity in the brain of mice and humans found that overweight mice had strokes in the deep brain white matter that were 30% larger than normal weight mice. The researchers, led by Dr. Jason D. Hinman, Associate Professor and Vice Chair of Research in Neurology and Stroke Program Director of the West Los Angeles VA Medical Center, also found that obesity induced a specific inflammatory pathway in brain blood vessels that limits the ability of the brain to repair after stroke. They also showed that because obesity damages brain blood vessels, this specific pathway can be measured in patients' bloodstream and may be a new biomarker to identify patients with silent brain vascular injury at risk for stroke, especially in those with obesity. Read the study in Cell Reports and watch Dr. Hinman discuss the research in this UCLA Health video.

Reducing low value treatments in Alzheimer's Disease and related dementias Physicians routinely prescribe antipsychotic medications to patients with dementia to control their behavioral disturbances, despite the fact that these low-value drugs are not considered first-line therapy and can even increase the risk for death. To help curb this trend, a UCLA-led team has designed a clinical trial aimed at steering physicians away from prescribing these drugs, or to reduce the dosages and number of pills in the bottle. Under the one-year controlled randomized trial, participating physicians would either receive an electronic health record clinical decision support intervention or no intervention at all. The intervention will do three things: alert the physician that the drug can increase mortality risk, offer non-drug behavioral resources for caregivers, and default the prescription to the lowest dosage and number of pills and not include refills. The researchers believe that this would be the first such clinical trial to combine two behavioral economic principles – a desire for non-malfeasance (do no harm), and auto-defaulting to the lowest supply of the medications as possible. Read the full details about the clinical trial at the peer-reviewed journal PLOS ONE.

Opioids frequently prescribed in cirrhosis Using weighted data representing 12.3 million ambulatory visits in the US, researchers found that opioids were frequently prescribed to patients with cirrhosis, often without a documented pain diagnosis, raising concerns about appropriateness. Encounters involving older, male, Black patients and primary care physicians were associated with prescription risk. The authors say de-escalation efforts should be individualized towards these patient communities and prescribers, who may be less familiar with the patient population and should be educated on risks of their opioid use. Read the study in Clinical Gastroenterology and Hepatology.

Masks for COVID also prevented whooping cough A new analysis by researchers at UCLA Health finds public health prevention measures taken during the COVID pandemic led to a dramatic drop in whooping cough cases in their health system. Whooping cough, or pertussis, spreads rapidly through droplet transmission, impacting individuals of all ages. Whooping cough is vaccine preventable, however immunity wanes over time. When patients seek care, the risk of transmission to other patients and health care workers can be high. The researchers sought to evaluate the impact of COVID-19 mitigation measures, like masking and school closures, on the number of primary pertussis cases in patients and secondary cases in staff members at ambulatory clinics at their institution before and after the COVID-19 pandemic. Pertussis cases for 2019, 2020, and 2021 were 1,008, 87, and 0 respectively. There were no reported health care worker exposures after March 2020. The authors say their findings demonstrate that masking can impact respiratory disease transmission outside of COVID-19, and that the results are of clinical importance in health care as they show how wearing a mask with symptomatic respiratory patients can be beneficial in reducing exposure to health care workers. Read the study in the American Journal of Infection Control

Microbiome approaches to food allergies The prevalence of food allergies continues to rise, and with limited existing therapeutic options there is a growing need for new and innovative treatments. Food allergies are, in a large part, related to environmental influences on immune tolerance in early life, and represent a significant treatment challenge. This review, led by Dr. Diana Chernikova, pediatric allergy and immunology fellow at the David Geffen School of Medicine at UCLA, discusses the intersection between the gut microbiome and the development of food allergies, with particular focus on microbiome therapeutic strategies. These emerging microbiome approaches to food allergies are subject to continued investigation and include dietary interventions, pre- and probiotics, microbiota metabolism-based interventions, and targeted live biotherapeutics. Read about the findings in the Dec. 3, 2022 issue of Nutrients.

Medicaid expansion, increased access may reduce HIV infections Enacting Medicaid expansion and increasing the use of preventive and antiviral medications could result in a decline of new HIV infections among young Black gay, bisexual, and other men who have sex with men (MSM), reports a study co-authored by Dr. Nina Harawa, professor of Medicine and Epidemiology at the UCLA David Geffen School of Medicine and the Fielding School of Public Health. Led by Francis Lee, PhD, of the University of Chicago, the study used a technique called "agent-based network modeling" to simulate the effects of alternative Medicaid expansion strategies on HIV transmission among young Black gay, bisexual, and other MSM in Houston. Simulations projected the effects of Medicaid expansion alone and with the addition of two further strategies that have shown promise in increasing engagement with ART and PrEP. In the study models, all three scenarios were projected to lead to considerable declines in HIV transmission among young Black gay, bisexual, and other MSM. With Medicaid expansion alone, the HIV incidence rate (new cases per 100 uninfected) was projected to decrease by 17.5% by the tenth year, while the number of new infections would decrease by 14.9%. The most aggressive scenario modeled would nearly halve rates of new infections. Read the study in the journal Medical Care..