People whose parents divorced during their childhood may be at a greater risk of stroke later in life, according to a new study published January 22, 2025 in the open-access journal PLOS One by Esme Fuller-Thomson of University of Toronto, Canada, and colleagues.
Each year, approximately 795 000 individuals in the U.S. have a stroke. Previous work has established many sociodemographic risk factors for stroke, as well as connections between adverse childhood events and stroke. In the new study, researchers looked specifically at the impact of childhood parental divorce among adults with no history of childhood abuse. They used data on 13 205 adults aged 65 and over from the 2022 Behavioral Risk Factor Surveillance System.
The study found that people who had experienced parental divorce before they were 18 years old had 1.61 times higher odds of having a stroke when compared to respondents who did not experience parental divorce (AOR=1.61, 95% CI=1.15-2.24). The association did not vary by sex, and remained even after controlling for known risk factors such as diabetes, depression, and small social support networks.
The current study was not designed to analyse the potential mechanism of this association, nor to prove causation. The conclusions may not be generalisable to younger generations, who have experienced overall higher rates of parental divorce. In addition, several potential confounding factors – including blood pressure, cholesterol, contraceptive use, age at parents’ divorce, and types of strokes – were not available in the data.
However, the authors say that their data supports an association between parental divorce during childhood and increased stroke risk, even in the absence of childhood abuse and other trauma.
Senior author Esme Fuller-Thomson adds: “It is extremely concerning that older adults who grew up in divorced families had 60% higher odds of stroke, even after excluding those who had been physically or sexually abused as children. The magnitude of the association between parental divorce and stroke was comparable to well-established risk factors for stroke such as male gender and having diabetes.”
Image of an astrocyte, a subtype of glial cells. Glial cells are the most common cell in the brain. Credit: Pasca Lab, Stanford University NIH support from: NINDS, NIMH, NIGMS, NCATS
New research from the University of Rochester finds that microglia function may not be as similar across sex as once thought. This discovery could have broad implications for how diseases like Alzheimer’s and Parkinson’s are approached and studied, and points to the necessity of having gender-specific research. It is already known that more women are diagnosed with Alzheimer’s and more men are diagnosed with Parkinson’s, but it’s unclear why.
Microglia are the immune cells of the central nervous system, clearing toxins in the brain. But if they are overactive, they can damage neurons instead and, in some cases, have been found to promote the progression of neurodegenerative diseases like Alzheimer’s and Parkinson’s. Although there are known sex-related differences in how microglia function, it was thought to be less variation in how they behave in adulthood. The new study showied how microglia respond differently in adult male versus female mice when given an enzyme inhibitor to block its microglia survival receptor.
“It is a fortuitous finding that has repercussions for what people are doing in the field, but also helps us understand microglia biology in a way that people may not have been expecting,” said Ania Majewska, PhD, professor of Neuroscience and senior author of the study in Cell Reports. “This research has a lot of ramifications for microglia biology and as a result all these diseases where microglia are important in a sex-specific manner.”
Pexidartinib or PLX3397 is an enzyme inhibitor commonly used to remove microglia in the lab setting to help researchers better understand the role of these cells in brain health, function, and disease. PLX3397 is also used to treat the rare disease tenosynovial giant cells tumours (TGCT), a condition that causes benign tumours to grow rapidly in the joints.
Researchers in the Majewska Lab were using PLX3397 in male versus female experiments but continued to run into difficulties, so they decided to take a different approach with the inhibitor. Instead of using it to ask other questions, they decided to better understand how microglia were responding to the drug in males versus females.
First author Linh Le, PhD (‘24), currently a Research Scientist, SetPoint Medical Corp, was a graduate student in the Majewska Lab when she found the expected response from microglia to PLX3397 in male mice: it blocked the receptor that signals microglial survival and depleted the microglia. However, Le, et al, were surprised to find that female microglia responded with a different signalling strategy that resulted in increased microglial survival and less depletion.
“These findings are crucial in the rapidly emerging field of developing disease-modifying therapies that target microglia,” said Majewska. “We do not yet know why the microglia are acting differently in the two sexes. I think we’d like to understand how the signaling through this receptor is regulated in different conditions, such as hormonal changes, basal state, inflammatory, or an anti-inflammatory state.”
Sleepiness at the wheel is a significant contributing factor to motor vehicle accidents. A new analysis published in Otolaryngology–Head and Neck Surgery reveals that for people with sleep apnoea, getting surgery for their condition may lessen their risk of such accidents compared with using a Continuous Positive Airway Pressure (CPAP) device at night or receiving no treatment.
In the analysis of data on 2 832 437 patients with obstructive sleep apnoea, 3.4% of patients who underwent surgery were in a car accident at any point following their diagnosis, compared with 6.1% of those using a CPAP and 4.7% of those not receiving any treatment.
Patients receiving no treatment had 21% higher odds of motor vehicle accidents compared with the surgery group. The surgery group had 45% lower odds compared with the CPAP group.
Patients with obstructive sleep apnoea who experienced accidents were more likely to have comorbidities such as hypertension, diabetes, and heart failure following the accident.
“Our findings underscore the profound impact that inadequately managed obstructive sleep apnoea can have on individual health and public safety,” said corresponding author Elliott M. Sina, BA, a medical student at the Sidney Kimmel Medical College at Thomas Jefferson University. “This work adds to the growing body of evidence supporting surgical interventions such as hypoglossal nerve stimulation as an effective alternative treatment for select patients with obstructive sleep apnoea.”
Calorie content drives food preference despite similar taste in individuals with and without obesity
Source: Pixabay CC0
Higher calorie foods were preferred among individuals with and without obesity despite similar taste and texture, according to a study published December 17th in the open-access journal PLOS Biologyby Albino Oliveira-Maia from the Champalimaud Foundation, Portugal, and colleagues.
Eating sends signals to the brain with information about a food’s energy content, which can influence food preferences irrespective of flavor. People with obesity often have impairments in areas of the brain where dopamine is released, which may drive reward-related eating and a preference for energy-dense foods rich in fat and sugars. Weight loss due to bariatric surgery has been associated to a normalization of reward-related eating with a shift of preferences toward healthier options, but the underlying mechanisms are not well understood.
In this study, after examining a large group of healthy volunteers, researchers compared food preferences in three groups: 11 individuals with obesity, 23 post-bariatric surgery patients, and 27 non-obese control subjects. They gave participants sweetened low-fat yogurt with and without maltodextrin (a carbohydrate that adds calories to the yogurt with no impact on taste or texture). Participants ate the yogurt at home, alternating between the maltodextrin-containing and -free yogurt. All three groups ate more of the maltodextrin-containing yogurt, despite rating both as equally pleasant. Somewhat unexpectedly, the effects of maltodextrin on yogurt consumption were similar in individuals with obesity relative to their non-obese counterparts.
The study also used radioactive iodine labelling and single photon emission computed tomography to visualise dopamine receptors in the brain. Consistent with previous studies, individuals with obesity had lower dopamine receptor availability than non-obese controls. Dopamine receptor availability was similar in the surgical and non-obese groups and was associated with more restrained eating. These results suggest that obesity-related brain changes can be reversed after bariatric surgery, potentially impacting the amount of food consumed but not necessarily the types of food preferred.
The authors add, “We were very intrigued that, while behaviour was guided towards eating yoghurts with higher energy-content, this did not seem to be a result of explicit choices, since consistent changes in pleasantness of flavours enriched with carbohydrates were not found. Importantly, this behaviour was maintained in patients with obesity and after weight-loss surgery, even though there were important differences in their brain dopaminergic system.”
In a paradigm shift in how we view mutations, researchers uncover forms of DNA damage in healthy cells – most particularly in blood stem cells – that can persist unrepaired for years.
While most known types of DNA damage are fixed by our cells’ in-house repair mechanisms, some forms of DNA damage evade repair and can persist for many years, new research shows. This means that the damage has multiple chances to generate harmful mutations, which can lead to cancer.
Scientists from the Wellcome Sanger Institute and their collaborators analysed family trees of hundreds of single cells from several individuals. The team pieced together these family trees from patterns of shared mutations between the cells, indicating common ancestors.
Researchers uncovered unexpected patterns of mutation inheritance in the trees, revealing that some DNA damage persists unrepaired. In the case of blood stem cells, this can be for two to three years.
The research, published in Nature, changes the way we think about mutations, and has implications for understanding the development of various cancers.
Throughout our life, all of the cells in our body accumulate genetic errors in the genome, known as somatic mutations. These can be caused by damaging environmental exposures, such as smoking, as well as the everyday chemistry occurring in our cells.
DNA damage is distinct from a mutation. While a mutation is one of the standard four DNA bases (A, G, T or C) in the wrong place, similar to a spelling mistake, DNA damage is chemical alteration of the DNA, like a smudged unrecognisable letter. DNA damage can result in the genetic sequence being misread and copied incorrectly during cell division, in a process known as DNA replication. This introduces permanent mutations that can contribute to the development of cancers. However, the DNA damage itself is usually recognised and mended quickly by repair mechanisms in our cells.
If researchers can better understand the causes and mechanisms of mutations, they may be able to intervene and slow or remove them.
In a new study, Sanger Institute scientists and their collaborators analysed data in the form of family trees of hundreds of single cells from individuals. The family trees are constructed from patterns of mutations across the genome that are shared between cells – for example, cells with many shared mutations have a recent common ancestor cell and are closely related.
The researchers collated seven published sets of these family trees, known as somatic phylogenies. The data set included 103 phylogenies from 89 individuals,1 spanning blood stem cells, bronchial epithelial cells and liver cells
The team found unexpected patterns of mutation inheritance in the family trees, revealing that some DNA damage can persist unrepaired through multiple rounds of cell division. This was particularly evident in blood stem cells, where between 15 to 20 per cent of the mutations resulted from a specific type of DNA damage that persists for two to three years on average, and in some cases longer.
This means that during cell division, each time the cell attempts to copy the damaged DNA it can make a different mistake, leading to multiple different mutations from a single source of DNA damage. Importantly, this creates multiple chances of harmful mutations that could contribute to cancer. Researchers suggest that although these types of DNA damage occur rarely, their persistence over years means they can cause as many mutations as more common DNA damage.
Overall, these findings change the way researchers think about mutations, and have implications for understanding the development of cancer.
When children with obesity undergo weight-loss treatment, the effects have repercussions later in life and the risk of serious health problems and premature death is lower as they reach young adulthood. However, this is not the case for depression and anxiety, a study from Karolinska Institutet published in JAMA Pediatrics reports.
The study shows that children and adolescents who respond well to obesity treatment are less likely to develop obesity-related diseases, such as type 2 diabetes, hypertension and dyslipidaemia as young adults.
The treatment studied involved support for children with obesity and their families designed to motivate healthy diets, exercise and sleep habits – what is known as “behavioural lifestyle therapy”.
“The results are very good news,” says the study’s last author Emilia Hagman, principal researcher at the Department of Clinical Science, Intervention and Technology, Karolinska Institutet. “Whether or not the treatment of obesity in childhood has long-term health benefits have been debated, since weight-loss is hard to maintain.”
Higher risk of dying as young adults
The study shows that children with obesity who respond to treatment also run a lower risk of premature death. A previous study, published in PLOS Medicine by the same research group, has shown that children with obesity have a much higher mortality risk in early adulthood, and were much more likely to die from suicide and somatic conditions. Just over a quarter of deaths were obesity-related.
“This emphasises the importance of providing early treatment, as we know that timely intervention increases the likelihood of success and helps mitigate the long-term health risks associated with obesity,” says Dr Hagman.
Depression and anxiety are not affected
However, the risk of depression and anxiety was not affected by the treatment outcomes in childhood, the JAMA Pediatrics paper shows. No matter the outcome of obesity treatment in childhood, the risk of anxiety and depression was unchanged in young adulthood.
“It has been believed that weight loss could decrease symptoms of depression and anxiety, but we can now show that it’s not the case,” says Dr Hagman. “Even though there’s a link between the two comorbidities, they must be treated in parallel.”
The study included over 6700 individuals who had received treatment for obesity during childhood identified via the BORIS register (the Swedish Childhood Obesity Treatment Register) and who were then followed up as young adults in the Swedish Patient Register, the Prescribed Drugs Register and the Cause of Death Register. A control group from the general population was also used, matched by age, sex and place of residence.
GLP1 analogues, which have become popular obesity drugs in recent years, were not part of the study as they were yet approved when the study participants were being treated for obesity. As Dr Hagman points out, it is still uncommon for this type of drug to be administered to children.
“I’m in favour of their use as these drugs eases feelings of hunger, which is something that some children struggle with” she says. “That said, lifestyle therapy is still the foundation of all treatments for childhood obesity.”
The research group will now be trying to identify therapy options that are most effective for different individuals and the health/risk markers that are significant for future health.
One of the first acts President Trump took on assuming office again on January 20, 2025, was to unilaterally withdraw the United States from the World Health Organization (WHO). Trump complained of the WHO’s “mishandling” of the COVID pandemic, influence by other countries, and the US financial support was excessive compared to China, which “has 300 percent of the population of the United States, yet contributes nearly 90 percent less to the WHO.”
The WHO released a statement, expressing its regret at the decision and pointing out its importance: “WHO plays a crucial role in protecting the health and security of the world’s people, including Americans, by addressing the root causes of disease, building stronger health systems, and detecting, preventing and responding to health emergencies, including disease outbreaks, often in dangerous places where others cannot go.”
The organisation also took aim at Trump’s criticism of its lack of reforms: “With the participation of the United States and other Member States, WHO has over the past 7 years implemented the largest set of reforms in its history, to transform our accountability, cost-effectiveness, and impact in countries. This work continues.”
Critics say that the move would only hand China the opportunity to effectively take control of global health if it chooses to becomes the WHO’s main contributor: though the US is the single largest contributor, it contributed only $1.3 billion in the 2022-23 biennium. An affordable amount compared to the vast sums both countries spend on their militaries. While the WHO did lavish praise on China, many experts saw it as undue and perhaps concerning – but China’s contribution, while currently small, is rising: $86 million in the 2018-19 biennium. After the US, the next largest contributors are Germany ($856 million) and the Bill and Melinda Gates Foundation ($830 million).
The Society for Healthcare Epidemiology of America (SHEA) stressed the importance of global health cooperation. In a statement, the organisation wrote: “It is essential that the United States continues our connection with the WHO to coordinate surveillance, monitoring, detection, prevention, research, and response to public health threats including outbreaks, antimicrobial resistance and high consequence pathogens such as viral haemorrhagic fevers (Ebola, Marburg), Mpox, and highly pathogenic avian influenza (eg, H5N1).”
Indeed, Trump may not simply be able to withdraw by presidential decree; since the US joined the WHO by an act of Congress, it would likely take congressional approval to leave it and Trump may face a lawsuit over this.
Trump previously announced his intention to withdraw the US from the WHO in 2020, something which Gostin et al. warned in The Lancet would not work out well for the US and the world. “Withdrawal from WHO would have dire consequences for US security, diplomacy, and influence. WHO has unmatched global reach and legitimacy.” Additionally, they warned of the sheer difficulty of such a messy divorce: “The US administration would be hard pressed to disentangle the country from WHO governance and programmes.”
Capping ten years of work to stem the tide of myopia, David Berntsen, Professor of Optometry at the University of Houston, is reporting that his team’s method to slow myopia not only works – but lasts.
The original Bifocal Lenses In Nearsighted Kids (BLINK) Study showed that having children with myopia wear high-add power multifocal contact lenses slows its progression. Now, new results from the BLINK2 Study, that continued following these children, found that the benefits continue even after the lenses are no longer used.
“We found that one year after discontinuing treatment with high-add power soft multifocal contact lenses in older teenagers, myopia progression returns to normal with no loss of treatment benefit,” reports Berntsen in JAMA Ophthalmology.
The study was funded by the National Institutes of Health’s National Eye Institute with collaborators from the Ohio State University College of Optometry.
In Focus: A Major Issue
Leading the team at the University of Houston, Berntsen takes on a significant challenge. By 2050 almost 50% of the world (5 billion people) will be myopic. Myopia is associated with an increased risk of long-term eye health problems that affect vision and can even lead to blindness.
From the initial study, high-add multifocal contact lenses were found to be effective at slowing the rate of eye growth, decreasing how myopic children became. Because higher amounts of myopia are associated with vision-threatening eye diseases later in life, like retinal detachment and glaucoma, controlling its progression during childhood potentially offers an additional future benefit.
“There has been concern that the eye might grow faster than normal when myopia control contact lenses are discontinued. Our findings show that when older teenagers stop wearing these myopia control lenses, the eye returns to the age-expected rate of growth,” said Berntsen.
“These follow-on results from the BLINK2 Study show that the treatment benefit with myopia control contact lenses have a durable benefit when they are discontinued at an older age,” said BLINK2 study chair, Jeffrey J. Walline, associate dean for research at the Ohio State University College of Optometry.
Eye Science
Myopia occurs when a child’s developing eyes grow too long from front to back. Instead of focusing images directly on the retina, they are focused at a point in front of the retina.
Single vision prescription glasses and contact lenses can correct myopic vision, but they fail to treat the underlying problem, which is the eye continuing to grow longer than normal. By contrast, soft multifocal contact lenses correct myopic vision in children while simultaneously slowing myopia progression by slowing eye growth.
Designed like a bullseye, multifocal contact lenses focus light in two basic ways. The centre portion of the lens corrects nearsightedness so that distance vision is clear, and it focuses light directly on the retina. The outer portion of the lens adds focusing power to bring the peripheral light into focus in front of the retina. Animal studies show that bringing light to focus in front of the retina may slow growth. The higher the reading power, the further in front of the retina it focuses peripheral light.
BLINK Once…Then Twice
In the original BLINK study, 294 myopic children, ages 7 to 11 years, were randomly assigned to wear single vision contact lenses or multifocal lenses with either high-add power (+2.50 diopters) or medium-add power (+1.50 diopters). They wore the lenses during the day as often as they could comfortably do so for three years. All participants were seen at clinics at the Ohio State University, Columbus, or at the University of Houston.
After three years in the original BLINK study, children in the high-add multifocal contact lens group had shorter eyes compared to the medium-add power and single-vision groups, and they also had the slowest rate of myopia progression and eye growth.
Of the original BLINK participants, 248 continued in BLINK2, during which all participants wore high-add (+2.50 diopters) lenses for two years, followed by single-vision contact lenses for the third year of the study to see if the benefit remained after discontinuing treatment.
At the end of BLINK2, axial eye growth returned to age-expected rates. While there was a small increase in eye growth of 0.03 mm/year across all age groups after discontinuing multifocal lenses, it is important to note that the overall rate of eye growth was no different than the age-expected rate. There was no evidence of faster than normal eye growth.
Participants who had been in the original BLINK high-add multifocal treatment group continued to have shorter eyes and less myopia at the end of BLINK2. Children who were switched to high-add multifocal contact lenses for the first time during BLINK2 did not catch up to those who had worn high-add lenses since the start of the BLINK Study when they were 7 to 11 years of age.
By contrast, studies of other myopia treatments, such as atropine drops and orthokeratology lenses that are designed to temporarily reshape the eye’s outermost corneal layer, showed a rebound effect (faster than age-normal eye growth) after treatment was discontinued.
“Our findings suggest that it’s a reasonable strategy to fit children with multifocal contact lenses for myopia control at a younger age and continue treatment until the late teenage years when myopia progression has slowed,” said Berntsen.
Sickle cell disease. Credit: National Institutes of Health
Individuals with sickle cell disease are at a higher risk for stroke and resulting cognitive disability. But even in the absence of stroke, many such patients struggle with remembering, focusing, learning and problem solving, among other cognitive problems, with many facing challenges in school and in the workplace.
Now a multidisciplinary team of researchers and physicians at Washington University School of Medicine in St. Louis has published a study that helps explain how the illness might affect cognitive performance in sickle cell patients without a history of stroke. The study, appearing in JAMA Network Open, found such participants had brains that appeared older than expected for their age. Individuals experiencing economic deprivation, who struggle to meet basic needs, even in the absence of sickle cell disease, had more-aged appearing brains, the team also found.
“Our study explains how a chronic illness and low socioeconomic status can cause cognitive problems,” said Andria Ford, MD, a professor of neurology and chief of the section of stroke and cerebrovascular diseases at WashU Medicine and corresponding author on the study. “We found that such factors could impact brain development and/or aging, which ultimately affects the mental processes involved in thinking, remembering and problem solving, among others. Understanding the influence that sickle cell disease and economic deprivation have on brain structure may lead to treatments and preventive measures that potentially could preserve cognitive function.”
More than 200 young, Black adults with and without sickle cell disease, living in St. Louis and the surrounding region in eastern Missouri and southwestern Illinois, participated in brain MRI scans and cognitive tests. The researchers – including Yasheng Chen, DSc, an associate professor of neurology at WashU Medicine and senior author on the study – calculated each person’s brain age using a brain-age prediction tool that was developed using MRI brain scans from a diverse group of more than 14 000 healthy people of known ages. The estimated brain age was compared with the individual’s actual age.
The researchers found that participants with sickle cell disease had brains that appeared an average of 14 years older than their actual age. Sickle cell participants with older-looking brains also scored lower on cognitive tests.
The study also found that socioeconomic status correlates with brain age. On average, a seven-year gap was found between the brain age and the participants’ actual age in healthy individuals experiencing poverty. The more severe the economic deprivation, the older the brains of such study subjects appeared.
Healthy brains shrink as people age, while premature shrinking is characteristic of neurological illnesses such as Alzheimer’s disease. But a smaller brain that appears older can also result from stunted growth early in life. Sickle cell disease is congenital, chronically depriving the developing brain of oxygen and possibly affecting its growth from birth. Also, children exposed to long-term economic deprivation and poverty experience cognitive challenges that affect their academic performance, Ford explained.
As a part of the same study, the researchers are again performing cognitive tests and scanning the brains of the same healthy and sickle cell participants three years after their first scan to investigate if the older-looking brains aged prematurely, or if their development was stunted.
“A single brain scan helps measure the participants’ brain age only in that moment,” said Ford, who treats patients at Barnes-Jewish Hospital. “But multiple time points can help us understand if the brain is stable, initially capturing differences that were present since childhood, or prematurely aging and able to predict the trajectory of someone’s cognitive decline. Identifying who is at greatest risk for future cognitive disability with a single MRI scan can be a powerful tool for helping patients with neurological conditions.”
People with psoriasis often have invisible inflammation in the small intestine with an increased propensity for ‘leaky gut’, according to new research at Uppsala University. These changes in the gut could explain why psoriasis sufferers often have gastrointestinal problems and are more prone to developing Crohn’s disease. The study is published in Biochimica et Biophysica Acta (BBA) – Molecular Basis of Disease.
Psoriasis is a hereditary, chronic skin condition that can also result in inflammation of the joints. Chronic inflammatory bowel diseases (IBD), especially Crohn’s disease, are more common in patients with psoriasis than in the rest of the population.
“Previous research has also shown that people with psoriasis have more gastrointestinal problems than the general population. However we didn’t know much about why this is the case. With our study, we can now show that people with psoriasis often have invisible inflammation in their small intestines, with an increased risk of what’s called leaky gut,” says Maria Lampinen, researcher at Uppsala University.
Pro-inflammatory activity in the gut
The study involved 18 patients with psoriasis and 15 healthy controls as subjects. None of the participants had been diagnosed with gastrointestinal diseases. Samples were taken from both their small and large bowel. The researchers then studied different types of immune cells in the mucous membrane.
“It turned out that psoriasis sufferers had higher numbers of certain types of immune cells in their small intestine, and the cells showed signs of pro-inflammatory activity. Interestingly, we found the same type of immune cells in skin flare-ups from psoriasis patients, suggesting that the inflammation of the skin may have an impact on the gut, or vice versa.
Increased propensity for leaky gut
Normally, the intestinal mucosa act as a protective barrier that also allows nutrients and water to pass through it. In some autoimmune diseases, the intestinal barrier may function poorly. This is called having a leaky gut, and leads to bacteria and harmful substances leaking through the intestinal barrier and causing inflammation. This can also cause more widespread inflammation when these substances are spread via the bloodstream.
Half of the psoriasis patients in the study had increased intestinal barrier permeability or leaky gut. These same patients also reported more gastrointestinal symptoms such as abdominal pain and bloating than patients with a normal intestinal barrier. They also had elevated levels of inflammatory substances in their intestines.
“Given that the psoriasis patients in our study had relatively mild skin disease and showed no visible intestinal inflammation in a gastroscopy, they had surprisingly clear changes in their small intestine compared to healthy controls. These changes could explain why psoriasis sufferers often have gastrointestinal problems, and an increased risk of developing Crohn’s disease.
