Medical Bulletin 18/ October/ 2024 - Video

In a new study evaluating meditation for chronic lower back pain, researchers at University of California San Diego School of Medicine have discovered that men and women utilize different biological systems to relieve pain. While men relieve pain by releasing endogenous opioids, the body’s natural painkillers, women rely instead on other, non-opioid based pathways.

Synthetic opioid drugs, such as morphine and fentanyl, are the most powerful class of painkilling drugs available. Women are known to respond poorly to opioid therapies, which use synthetic opioid molecules to bind to the same receptors as naturally-occurring endogenous opioids. This aspect of opioid drugs helps explain why they are so powerful as painkillers, but also why they carry a significant risk of dependence and addiction.

“Dependence develops because people start taking more opioids when their original dosage stops working,” said Fadel Zeidan, Ph.D., professor of anesthesiology and Endowed Professor in Empathy and Compassion Research at UC San Diego Sanford Institute for Empathy and Compassion. “Although speculative, our findings suggest that maybe one reason that females are more likely to become addicted to opioids is that they’re biologically less responsive to them and need to take more to experience any pain relief.”

The study combined data from two clinical trials involving a total of 98 participants, including both healthy individuals and those diagnosed with chronic lower back pain. Participants underwent a meditation training program, then practiced meditation while receiving either placebo or a high-dose of naloxone, a drug that stops both synthetic and endogenous opioids from working. At the same time, they experienced a very painful but harmless heat stimulus to the back of the leg. The researchers measured and compared how much pain relief was experienced from meditation when the opioid system was blocked versus when it was intact.

The study found:

Blocking the opioid system with naloxone inhibited meditation-based pain relief in men, suggesting that men rely on endogenous opioids to reduce pain.

Naloxone increased meditation-based pain relief in women, suggesting that women rely on non-opioid mechanisms to reduce pain.

In both men and women, people with chronic pain experienced more pain relief from meditation than healthy participants.

"These results underscore the need for more sex-specific pain therapies, because many of the treatments we use don’t work nearly as well for women as they do for men,” said Zeidan.

Reference: Jon G Dean, Mikaila Reyes, Valeria Oliva, Lora Khatib, Gabriel Riegner, Nailea Gonzalez, Grace Posey, Jason Collier, Julia Birenbaum, Krishnan Chakravarthy, Rebecca E Wells, Burel Goodin, Roger Fillingim, Fadel Zeidan, Self-regulated analgesia in males but not females is mediated by endogenous opioids, PNAS Nexus, 2024;, pgae453, https://doi.org/10.1093/pnasnexus/pgae453

Despite having no greater chance of developing problems after high risk cardiovascular surgery, women are more likely than men to die from postoperative complications, a University of Michigan-led study suggests.

Men and women had a similar rate of complications after an operation, around 15%. However, women died of those complications at a significantly higher rate: Surgical teams failed to rescue female patients 10.7% of the time, compared to 8.6% for male patients. The results are published in JAMA Surgery.

Researchers found a similar pattern in the failure to rescue rate for each individual procedure. The most common complications for men and women were kidney failure, pneumonia and lung failure.

In fact, women in the study were more likely to receive surgery at hospitals that, traditionally, take on a higher volume of high risk surgeries.

“These high risk procedures are inhexpected to have higher complirently ecation rates, but patients are still expected to have a positive outcome if the complication is managed quickly,” said co-author Gorav Ailawadi, M.D, M.B.A., chair of cardiac surgery at U-M Health and a director of the University of Michigan Health Frankel Cardiovascular Center “In our study, female patients had a lower rate of reoperation than males,” he added, using a term to mean a second operation within days of the first. “This may not be due to a lower need for reoperation; it could instead be a signal that their complications were not appropriately addressed.”

The explanation, so far, has largely centered around that fact that women are older when they receive surgery and have more comorbidities than men. Women also have smaller anatomy and vessel size, which can make surgery more technically difficult. This disparity is in addition to previous studies that have found that signs and symptoms of common disease, such as heart attack and stroke, are more often either missed or not taken seriously for female patients.

“After accounting for patient comorbidities and patient risk, we found that men and women had similar rates and types of complications; however, women remained more likely to die from those complications,” said co-author Andrew Ibrahim, M.D., M.Sc., associate professor of surgery at U-M Medical School and co-director of the Michigan Medicine Center for Healthcare Outcomes and Policy.

“In addition to reducing complications overall, we must focus on what happens after a complication occurs. Similarly, we have an opportunity after surgery to improve early recognition when a female patient is having a complication before it cascades to a point where we cannot rescue them. Improving the recognition and response to postoperative complications, especially for women, is needed to reduce longstanding disparities on outcomes after high-risk surgery.”

Reference: Wagner CM, Joynt Maddox KE, Ailawadi G, Ibrahim AM. Failure to Rescue Female Patients Undergoing High-Risk Surgery. JAMA Surg. Published online October 16, 2024. doi:10.1001/jamasurg.2024.4574

New research gives another reason to take folic acid supplements while pregnant.

A new study by Simon Fraser University researchers has found that folate may weaken the link between blood-lead levels in pregnant women and autistic-like behaviours in their children.

Researchers from SFU’s Faculty of Health Sciences, led by PhD candidate Joshua Alampi, published the study in the journal Environmental Health Perspectives.

“Folic acid supplementation during pregnancy has numerous benefits to child health, especially brain development,” says Alampi. “Our study suggests that adequate folic acid supplementation mitigates the neurotoxic effects of lead.”

The SFU-led study is the first to observe that adequate folic acid supplementation may reduce the risk between gestational lead exposure and autism. It found that associations between blood lead levels and autistic-like behaviours in toddlers were stronger among pregnant women with less than 0.4 milligrams per day of folic acid supplementation.

The team used data collected during 2008-2011 from 2,000 Canadian women enrolled in the Mother-Infant Research on Environmental Chemicals study. The Mother-Infant Research on Environmental Chemicals team measured blood-lead levels collected during first and third trimesters and surveyed participants to quantify their folic acid supplementation. Children born in this cohort study were assessed at ages three or four using the Social Responsiveness Scale (SRS), a common caregiver-reported tool that documents autistic-like behaviours in toddlers.

However, researchers also found that high folic acid supplementation > 1.0 milligram per day+ did not appear to have any extra benefit for mitigating the neurotoxic effects of lead exposure.

“The study’s finding aligns with Health Canada’s recommendation that all people who are pregnant, lactating, or could become pregnant, should take a daily multivitamin containing 0.4 milligrams of folic acid.”

Reference: Joshua D. Alampi, Bruce P. Lanphear, Amanda J. MacFarlane, Youssef Oulhote, Joseph M. Braun, Gina Muckle, Tye E. Arbuckle, Jillian Ashley-Martin, Janice M.Y. Hu, Aimin Chen, Lawrence C. McCandless, Combined Exposure to Folate and Lead during Pregnancy and Autistic-Like Behaviors among Canadian Children from the MIREC Pregnancy and Birth Cohort, 2024, Environmental Health Perspectives, 107003, 132, 10

doi:10.1289/EHP14479

https://ehp.niehs.nih.gov/doi/abs/10.1289/EHP14479

With heart attacks, every second counts. A new blood test diagnoses them in minutes rather than hours and could be adapted as a tool for first responders and people at home. The proof-of-concept work, which can be modified to detect infectious diseases and cancer biomarkers, is newly published in Advanced Science.

"Heart attacks require immediate medical intervention in order to improve patient outcomes, but while early diagnosis is critical, it can also be very challenging -- and near impossible outside of a clinical setting," said lead author Peng Zheng, an assistant research scientist at Johns Hopkins University.

"We were able to invent a new technology that can quickly and accurately establish if someone is having a heart attack."

Zheng and senior author Ishan Barman develop diagnostic tools through biophotonics, using laser light to detect biomarkers, which are bodily responses to conditions including disease. Here they used the technology to find the earliest signs in the blood that someone was having a heart attack.

The stand-alone blood test the team created provides results in five to seven minutes. It's also more accurate and more affordable than current methods, the researchers say.

Though created for speedy diagnostic work in a clinical setting, the test could be adapted as a hand-held tool that first responders could use in the field, or that people might even be able to use themselves at home.

The heart of the invention is a tiny chip with a groundbreaking nanostructured surface on which blood is tested. The chip's "metasurface" enhances electric and magnetic signals during Raman spectroscopy analysis, making heart attack biomarkers visible in seconds, even in ultra-low concentrations. The tool is sensitive enough to flag heart attack biomarkers that might not be detected at all with current tests, or not detected until much later in an attack.

Though designed to diagnose heart attacks, the tool could be adapted to detect cancer and infectious diseases, the researchers say.