Kidney and ureteral stones. Credit: Scientific Animations CC4.0
Sometimes all it takes is a little push. That is the conclusion of a study, published recently in the Journal of Urology, in which doctors used a handheld ultrasound device to nudge patients’ kidney-stone fragments.
As many as 50% of patients who have kidney stones removed surgically still have small fragments remaining in the kidneys afterward. Of those patients, about 25% find themselves returning for another operation within five years to remove the now-larger fragments.
UW Medicine researchers found, however, that patients who underwent the stone-moving ultrasound procedure had a 70% lower risk of such a recurrence.
“I think the main takeaways of this study are removing fragments reduces relapse and using a noninvasive, hand-held ultrasound device to help clear these kidney stone fragments,” said UW Medicine urologist Dr Jonathan Harper, the study’s senior author.
The multisite, randomised and controlled trial was conducted from May 2015 to April 2024. Almost all of the 82 participants were from the UW Medicine or the VA Puget Sound health systems. All had stone fragments that had persisted in their kidneys for months, and their ureters were free of stones and fragments.
In the study, 40 underwent ultrasound treatment to encourage fragments to clear from the kidneys, while 42 control-group members received no such treatment.
With patients awake in a clinic office setting, doctors used a wand that generated ultrasonic pulses through the skin to move the fragments closer to the ureter, where they could be naturally expelled, sometimes with the next urination, Harper noted.
Harper and his co-lead author on the paper, urologist Dr Mathew Sorensen, have worked on this technology and treatment for 15 years. They also use this technology, called burst wave lithotripsy, to blast larger stones into smaller pieces; those successes were published in 2022.
The pushing and breaking technologies are used with the same ultrasound platform.
Harper expressed hope that both clinical uses of the technology would become commonplace. A company, SonoMotion, is commercialising the technology, which was developed at the University of Washington, he added.
“I see a lot of potential in this It could become as common as getting your teeth cleaned. If you have a couple of small stones which could cause future problems, you make an office appointment and in 30 minutes you’re done.
“This could really revolutionise kidney stone treatment,” Harper said.
Human breast milk regulates a baby’s mix of microbes, known as the microbiome, during the infant’s first year of life, in turn lowers the child’s risk of developing asthma, according to a new study published in Cell.
Led by researchers at NYU Langone Health and the University of Manitoba, the study results showed that breastfeeding beyond three months supports the gradual maturation of the microbiome in the infant’s digestive system and nasal cavity, the upper part of the respiratory tract. Conversely, stopping breastfeeding earlier than three months disrupts the paced development of the microbiome and was linked to a higher risk of preschool asthma.
Some components in breast milk, such as complex sugars called human milk oligosaccharides, can only be broken down with the help of certain microbes. This provides a competitive advantage to microbes capable of digesting these sugars. By contrast, infants who are weaned earlier than three months from breast milk and who then rely solely on formula feeding, become home to a different set of microbes –ones that will help the infant to digest the components in formula. While many of these microbes that thrive on formula do eventually end up in all babies, the researchers showed that their early arrival is linked to an increased risk of asthma.
“Just as a pacemaker regulates the rhythm of the heart, breastfeeding and human milk set the pace and sequence for microbial colonisation in the infant’s gut and nasal cavity, ensuring that this process occurs in an orderly and timely manner,” said study co-senior investigator and computational biologist Liat Shenhav, PhD. “Healthy microbiome development is not only about having the right microbes. They also need to arrive in the right order at the right time,” said Dr Shenhav, an assistant professor at NYU Grossman School of Medicine, its Institute for Systems Genetics, and the school’s Department of Microbiology.
For the study, Dr Shenhav, who is also an assistant professor at NYU’s Courant Institute of Mathematical Sciences, worked in collaboration with study co-senior investigator Meghan Azad, PhD, director of the Manitoba Interdisciplinary Lactation Center, and a professor of paediatrics and child health, at the University of Manitoba.
Another key study finding was that the bacterium Ruminococcus gnavus appeared much sooner in the guts of children who were weaned early from breast milk than in those of children who were exclusively breastfed. The bacterium is known to be involved in the production of molecules called short-chain fatty acids, and the formation and breakdown of the amino acid tryptophan. Both tryptophan and its metabolites have been linked to immune system regulation and disruption in previous research, including an increased risk of asthma. The study authors noted that beyond aiding in digestion, an infant’s microbiome plays a crucial role in the immune system’s development.
The study tracked the ebb and flow of microbes in the guts and noses of infants during the first year of life, as well as details on breastfeeding and the composition of their mothers’ milk. All the children and their mothers were participating in the CHILD Cohort Study, a long-term research project that has been studying the same 3500 Canadian children at different stages of life from the womb well into adolescence.
The data provided by the CHILD Cohort Study enabled researchers to detangle the impact of breastfeeding on an infant’s microbiome from a range of other environmental factors, including prenatal smoke exposure, antibiotics, and the mother’s asthma history.
Even when these factors were accounted for, they found that breastfeeding duration remained a powerful determinant for the child’s microbial makeup over time. They also used these microbial dynamics and data on milk components to train a machine learning model that accurately predicted asthma years in advance. Finally, they created a statistical model to learn causal relationships, which showed that the primary way breastfeeding reduces asthma risk is through shaping the infant’s microbiome.
“The algorithms we developed provide valuable insights into microbial dynamics during an infant’s first year of life and how these microbes interacted with the infant,” said Dr Shenhav. “These insights allowed us to move beyond identifying associations, enhancing our ability to make predictions and explore causal relationships.
“Our research highlights the profound impact of breastfeeding on the infant microbiome and breastfeeding’s essential role in supporting respiratory health. By uncovering the mechanisms behind the protective effects of breast milk, as demonstrated in this study, we aim to inform national guidelines on breastfeeding and weaning from breast milk in a data-driven manner.
“With further research, our findings could also contribute to developing strategies to prevent asthma in children who cannot be breastfed for at least three months,” she added.
Researchers discovered a drug that safely and effectively helped cancer patients when they suffered from cachexia, a common condition related to cancer that involves weight loss and muscle wasting.
The results of the randomised phase 2 clinical trial, which included 187 individuals who experienced cachexia with pancreatic (32%), colorectal (29%) or non–small-cell lung (40%) cancer, appear in the New England Journal of Medicine. Richard Dunne, MD, MS, a Wilmot Cancer Institute oncologist and cachexia expert was part of the large group of investigators who ran the nationwide clinical trial.
Cachexia involves loss of appetite and weight, muscle-wasting, fatigue, and weakness. It affects more than 50% of people who have cancer, and currently there are no FDA-approved treatments.
Scientists discovered that the monoclonal antibody ponsegromab blocks a hormone known as GDF-15 that regulates appetite and body weight. The patients in the trial had elevated levels of GDF-15, a primary driver of cachexia, and ponsegromab improved many aspects of cachexia and its symptoms.
Patients were randomised to receive ponsegromab at doses of 100mg, 200mg, or 400 mg, or to receive placebo. At 12 weeks, patients in the ponsegromab groups had significantly greater weight gain than those in the placebo group, with a median between-group difference of 1.22 kg in the 100mg group, 1.92 in the 200mg group, and 2.81 in the 400mg group. Improvements were observed across measures of appetite and cachexia symptoms, along with physical activity, in the 400mg ponsegromab group relative to placebo.
Drugmaker Pfizer supported the study, and released this news. Side effects were minimal, Dunne said, and in fact ponsegromab appeared to be safer than common appetite stimulants used by cachexia patients.
“This is super exciting,” said Dunne, an associate professor of Medicine at the University of Rochester Medical Center. “This study is an important step in providing treatment for the hundreds of thousands of patients who suffer from poor quality of life due to cachexia.”
Several academic medical centres participated in the clinical research, which was led by John D. Groarke, MB, BCh, MPH, at Pfizer. Investigators are continuing to study GDF-15 and the importance of the biomarker in several types of cancer. Other clinical trials are also testing additional cachexia treatments that do not target the GDF-15 pathway.
Professor Glenda Gray, internationally known for her research in HIV vaccines and interventions to prevent transmission of HIV from mother to child, received the country’s highest honour, the Order of Mapungubwe, in 2013. (Photo: Biénne Huisman/Spotlight)
By Biénne Huisman
After a decade at the helm of the country’s primary health research funder, Professor Glenda Gray will focus again on doing the science. She tells Spotlight’s Biénne Huisman about her childhood, her passion for research, administering multi-million dollar grants, and a heated argument in the bathroom with an ANC bigwig.
Professor Glenda Gray, the first woman president and chief executive of South Africa’s Medical Research Council (SAMRC), has among others been described as outspoken, credible and tenacious. After a decade at the helm of the SAMRC, Gray retains her reputation for fearlessly speaking truth to power.
“Heading the SAMRC was definitely the best job of my life,” says Gray. “But I am excited about my future, it’s time for another best job. After ten years of doing science administration, it’s time to get back and do the science.”
Perhaps Gray’s fierce spirit was honed in her childhood, growing up in Boksburg on the East Rand, “on the wrong side of the tracks”. She laughs, remembering how American cable news channel ABC sub-titled her first TV interview, due to her strong “East Rand accent”.
Investing in research
From a childhood of counting cents, these days Gray administers multi-million dollar grants and passionately makes the case for greater investment in scientific research.
She says that while South Africa’s health department has competing priorities, ideally it should double or triple its allocation to research.
“We spend a lot of time trying to show the Department of Health how important science is. And so while there is commitment from them, they’re so busy worrying about services; healthcare workers, doctors, hospitals falling down, no equipment, no cancer treatment. And so, sometimes science is seen as esoteric and a luxury.”
Speaking to Spotlight during her lunch break at an SAMRC event in Cape Town, Gray adds: “Science gives you evidence to reduce morbidity and mortality. All the things that change people’s lives; like covid vaccines, ARVs, mother to child transmission interventions, typically these stem from research. And so, you can only improve outcomes if you fund research. Currently, the SAMRC gets around R750 million from government a year; in my view, around R2 to 3 billion a year is needed to really make profound investments in research.”
Supplementing the funding from the government, the SAMRC has scores of international funders and collaborators, such as the United States National Institutes for Health. One concern with such international donor funding is that local research may end up pandering to agendas set abroad.
Gray rejects this suggestion. “We [the SAMRC] always fund the ten most common causes of mortality and morbidity in South Africa. So the funders who work with us have to agree on funding what we deem our priorities.”
One of these priorities is transformation. “So I spent ten years of my life changing who we funded, where we funded, how we funded; changing the demographics of the SAMRC, creating an executive management committee that was diverse, and being able to attract a great black scientist [Professor Ntobeko Ntusi] to take over from me,” says Gray.
While having passed the public mantle onto Ntusi in July, the paediatrician and renowned HIV vaccinologist, named one of Time magazine’s 100 most influential people in 2017, will continue her HIV vaccine research. Gray is heading a major USAID funded study aimed at “galvanising African scientists, mostly women, into discovering and making an HIV vaccine.” She also holds tenure as a distinguished professor at the University of the Witwatersrand’s Infectious Diseases and Oncology Research Institute.
Give and take
Speaking to Spotlight, Gray reflects on managing the political side of the SAMRC – the intersection between politics and science: “As the president of the MRC, you have to be very brave and you have to be able to speak truth to power. Sometimes it’s hard, and sometimes it’s easy.”
This, she says, is a dance of give and take: “The relationship has to be flexible. Because, sometimes scientists are wrong and politicians are right. Sometimes politicians are wrong and scientists are right. And sometimes both are wrong, and sometimes both are right. And our egos can get in the way. You know: ‘Oh, you took me off the MAC [Ministerial Advisory Committee], now I’m not going to help you’. That’s not the right attitude to have…”
COVID-19 lockdown ruckus
Gray served on the Department of Health’s COVID-19 MAC at the height of the pandemic. In May 2020, she caused a ruckus for breaking away from the committee’s more measured counsel, turning to the press to criticise government’s lockdown regulations as “unscientific”.
She said the hard lockdown was causing unemployment and unnecessary hardship and malnourishment in poor families. Later as the hard lockdown started to lift, she spoke out against government’s continuation of restrictions on school going, the sale of certain foods and clothes like open-toe footwear, and the limits on outdoor exercise. “It’s almost as if someone is sucking regulations out of their thumb and implementing rubbish, quite frankly,” she told journalists at the time.
Then health minister Dr Zweli Mkhize rebuked Gray’s claims and sidelined her in the MAC before excluding her from a newly constituted MAC in September. The acting Director-General of Health, Anban Pillay, wrote to the SAMRC board urging them to investigate Gray’s conduct. As the fray deepened, the SAMRC board failed to back Gray. The council’s boardwas was acting in a “sycophantic manner aimed at political appeasement”, lamented a guest editorial published in the South African Medical Journal.
Despite this public falling-out, the following year, in February 2021, Gray worked with Mkhize to bring vaccines to South Africa’s healthcare workers.
“So basically at that stage government didn’t have a vaccine programme, and I bailed them out,” she tells Spotlight.
In February 2021, results from a clinical trial showed that the Oxford AstraZeneca COVID-19 vaccine – then intended for rollout in South Africa – performed poorly in preventing mild to moderate illness caused by the Beta variant of SARS-CoV-2, which was dominant at the time.
Gray says she was approached by Mkhize about an alternative vaccine – to which she responded by facilitating the procurement of 500 000 doses of the Johnson & Johnson vaccine through personal connections. These were officially rolled out to healthcare workers on February 17, when President Cyril Ramaphosa received his jab at the Khayelitsha District Hospital. Spotlight previously reported in more detail on the procurement of those first 500 000 doses.
“The vaccines arrived in Johannesburg at about midnight,” Gray recalls. “Then the plane with the president’s vaccine touched down in Cape Town at 12:20pm; and we had to rush it to Khayelitsha to have him vaccinated at one o’clock”.
A bathroom row with a minister
Gray is no stranger to fighting for policies and treatments based on scientific evidence. She recalls an altercation with former health minister Nkosazana Dlamini-Zuma in a bathroom at the presidential residence in Pretoria (Mahlamba Ndlopfu) in the late 1990s – the era of AIDS-denialism under then President Thabo Mbeki.
“Thabo Mbeki had a national AIDS plan and they were about to publish it. So there was a meeting; we were presenting, and we had data that mother to child transmission interventions were affordable, or that it was actually cheaper to give ARVs to a pregnant woman, than to treat a child who is HIV positive. But they kept on saying it was unaffordable, and that they wouldn’t be doing it. And then, when I saw Dlamini-Zuma in the bathroom, I got into a fight with her and said: ‘but it is affordable!’”
Early years in Boksburg
One of six children born to a “maverick father”, whip-smart but taken to getting involved in crazy schemes, and a mother who later in life became a Baptist minister, Gray says they grew up poor.
“My parents would often run out of money in the middle of the month, having to scrounge for food, borrow milk or buy on the book (credit arrangements). So I know what it’s like to be on the other side of privilege.”
Gray relays how neighbours would drop by at her childhood home to borrow cups of sugar, to spy on their family – as, during apartheid, her father would entertain friends of colour.
Gray matriculated from Boksburg High School in 1980. The next year she enrolled for medical school at Wits, working part-time to pay her way: “I worked at an ABC shoe store, Joshua Door, selling furniture, making Irish coffees at Ster Kinekor, waitressing…”
In 1993, as HIV exploded across the country; pregnant with her first child, Gray watched her own stomach expand while treating HIV-positive expectant mothers at Chris Hani Baragwanath Hospital. “In those days, there were no ARVs for children,” she recalls. “And so women had to navigate this joy of a new life, with the fact that death was looming over them.”
Today, Gray has three children and lives in Kenilworth in Cape Town.
Commenting on her reputation for standing up to pressure, she smiles. “My tongue has gotten me into trouble. How do I feel about that? I just want to make sure that as scientists we let politicians and society know the data and the evidence. I feel passionate about translating science, I feel passionate about evidence. I feel passionate about science changing the world.”
Adcock Ingram Critical Care, a leading manufacturer and supplier of hospital and critical care products in Southern Africa, is taking another step towards improving patient care in the region through a strategic alliance with Medline.
Medline is one of the world’s largest manufacturers and distributors of medical supplies and services, with annual global sales in excess of US$23 billion. The partnership solidifies Adcock Ingram Critical Care as the exclusive distributor of Medline’s products in Southern Africa and is a testament to its commitment to provide quality products that improve the health and lives of people in the markets they serve.
Ranked as one of Forbes largest private companies, Medline delivers world-class products, robust supply chain resources and clinical practice expertise to clients in more than 125 countries. Medline’s innovative and cutting-edge MedTech portfolio includes more than 550 000 products, serving the entire continuum of care. Its extensive reach and product range have transformed healthcare delivery worldwide, making it a key player in driving efficiency and improving patient outcomes.
By partnering with Adcock Ingram Critical Care, Medline is bringing its global expertise to South Africa, strengthening the country’s healthcare infrastructure at a time when it is most needed.
“This is another milestone in our commitment to ensure that every South African can access the care they deserve. Together with Medline, we can help to build a stronger, healthier South Africa,” says Colin Sheen, Managing Director, Adcock Ingram Critical Care.
A Strategic Alliance with National Impact
For decades, Adcock Ingram Critical Care has been delivering essential medical solutions to the nation, from Medicine Delivery in Hospital Care to Renal Care, Transfusion Therapies, Infusion Systems and most recently Wound & Stoma Care. The strategic alliance with Medline will ensure expanded and continued medical access and support healthcare providers and patients across South Africa and Southern Africa.
“The Strategic Alliance with Medline is a significant milestone for us,” says Sheen. “This partnership will provide medical professionals across the country with access to world-class medical supplies and technology, empowering them to deliver better care and improved patient outcomes.”
Beyond its business scope and as part of its larger mission, Adcock Ingram Critical Care is connecting global medical innovations with local requirements, ensuring that hospitals, clinics, and healthcare providers – even in the most remote areas – have access to the essential tools needed to save lives.
“Adcock Ingram Critical Care’s knowledge of the South African medical sector, combined with Medline’s world-class products, creates a powerful synergy,” says Salam Hadla, Medline’s Vice President for the Middle East & Africa Region. “We are excited to partner with Adcock Ingram Critical Care to help advance care standards across Southern Africa. Our shared mission is to offer healthcare providers the highest quality products, ensuring better clinical outcomes and contributing to a stronger medical care system.”
Improving Healthcare for a Stronger Nation
South Africa is one of the largest medical technology markets in Africa and the Middle East, valued at over R21 billion in 2021 and projected to grow to R29.6 billion by 2025. As the demand for access to quality healthcare services increases, strategic alliances like Adcock Ingram Critical Care and Medline are vital in ensuring that healthcare providers are equipped at providing medical services and improving access in both urban and rural clinical settings.
Sometimes you have to take a step backward to move forward. Or, in the case of patients recovering from ACL reconstruction, a hop backward may help them know if they are ready to return to the field of play.
A University of Kansas researcher is leading studies examining how single leg backward hopping can help determine recovery progress of patients who have had the anterior cruciate ligament of the knee reconstructed. Initial studies have shown backward hopping distance can tell practitioners, therapists and researchers about strength, force and recovery in the affected joint.
Research so far has shown that backwards hopping it is an effective way of measuring the strength of a person’s knee function and quadriceps strength. And unlike some commonly used measures like vertical jump, it does not take additional equipment to measure – simply a floor and tape measure.
“The goal is to help practitioners have an easy way to measure where people are after an ACL injury and during recovery,” said Yu Song, assistant professor of health, sport & exercise sciences at KU and lead author of the study. “One of the most common ways to measure recovery now is forward hopping distance. However, studies reported that the forward hopping distance masked the real knee recovery status. We want to be able to evaluate more closely with more exact measures.”
For the study, researchers recruited participants who have not suffered ACL injuries in order to initiate the first step of using backward hopping to measure the knee function and quadriceps strength deficits. To simulate a reconstructed ACL, participants performed single leg backwards hops both before and after their quadriceps muscle were fatigued through exercise on one leg. Those in the study stood on a force plate, a device that can measure the amount of force exerted, when performing the hops.
Hip, knee and ankle mechanics were measured in all three movements. Knee mechanics showed significant decrease in all three after fatigue, only in the fatigued leg. Backward hopping distances showed the most significant change, as participants were only able to hop at about 84% of their pre-fatigue force and distance. Subjects were able to perform at more than 90% of their pre-fatigue measures in other hops.
“The knee contribution is very small, especially compared to the hip in forward hops,” Song said. “That is not the case in backward hopping, the knee work is significantly greater (two times) in that motion.”
Single leg backward hopping recorded the greatest peak knee torque, peak knee power and knee work compared to forward and vertical hopping. The fact that backward hopping showed such stark difference in the knee indicates that it could likely be at least an equal, if not superior, method of measuring quadriceps strength deficiency in people recovering from ACL reconstruction, Song said.
The results warrant further study with individuals who are recovering from ACL construction. Work is underway to recruit patients doing rehabilitation from the injury to take part in further studies. That research could help further validate single leg backward hopping as a measure of where they are at in recovery and ultimately, help patients and medical practitioners partner for better recovery and a quicker, safe return to the field of play.
And while hopping from one leg backward may not sound intuitive, it could indeed be the key to a step forward.
“People may not think of knee function or hopping backward as a natural part of movement, but people do use backward direction, such as walking backwards regularly in rehab,” Song said. “Single-leg hopping is something we want to better understand and have found it can significantly and accurately tell us about knee strength.”
Ischaemic and haemorrhagic stroke. Credit: Scientific Animations CC4.0
People who have had a stroke may be more likely to sleep too much or too little compared to those without prior stroke, according to a study published in Neurology®, the medical journal of the American Academy of Neurology. The study does not prove that stroke causes abnormal sleep; it only shows an association.
“Sleeping the right amount is considered essential for ideal brain and heart health,” said study author Sara Hassani, MD, of Duke University School of Medicine in Durham, North Carolina, and member of the American Academy of Neurology. “We know that abnormally long or short sleep after stroke can affect recovery and deteriorate quality of life, so these results should prompt us to screen for these issues and look at how we can help people improve their sleep habits.”
The study involved 39 559 participants, of whom 1572 had a stroke and 37 987 without stroke history. Every two years, participants were asked how much sleep they usually get at night on weekdays or workdays. Sleep duration was divided into three categories: short, less than six hours; normal, six to eight hours; and long, eight or more hours of sleep.
Researchers looked at how often participants had normal sleep, defined as six to eight hours. Normal sleep duration was less common for people who had a stroke than for those with no prior stroke for all age groups with 32% vs 54% for people age 18-44; 47% vs 55% for people age 45-64; and 45% vs. 54% for people over age 65.
After adjusting for factors that could affect sleep such as age, weight and high blood pressure, researchers found people who had a stroke were 54% more likely to report more than eight hours of sleep per night compared to those without stroke. Those with stroke were 50% more likely to get less than six hours of sleep per night when compared to those without stroke.
“In previous research, stroke has been linked to abnormal sleep, in particular sleep apnea,” said Hassani. “Conditions like insomnia and excessive sleepiness are common in stroke patients and may occur as a direct or indirect consequence of stroke itself. Future research should explore the links between stroke and duration of sleep and determine the effect of sleep duration on outcomes after stroke.”
One limitation of the study was that hours of sleep were self-reported, so participants may not have remembered accurately how much they slept.
Those mesmerising blue and orange hues in the sky at the start and end of a sunny day might have an essential role in setting humans’ internal clocks. In new research from the University of Washington in Seattle, a novel LED light that emits alternating wavelengths of orange and blue outpaced two other light devices in advancing melatonin levels in a small group of study participants.
Published in the Journal of Biological Rhythms, the finding appears to establish a new benchmark in humans’ ability to influence their circadian rhythms, and reflects an effective new approach to counteract seasonal affective disorder (SAD).
A raft of health and mood problems have been attributed to out-of-sync circadian rhythms. Such asynchrony is encouraged by seasonal changes, a lack of exposure to natural light, graveyard-shift jobs and flights across multiple time zones.
“Our internal clock tells us how our body’s supposed to act during different times of day, but the clock has to be set, and if our brain is not synced to the time of day, then it’s not going to work right,” said Jay Neitz, a coauthor on the paper and a professor of ophthalmology at the UW School of Medicine.
Circadian rhythms are trained and reset every day by the 24-hour solar cycles of light and dark, which stimulate circuits in the eyes that communicate to the brain. With that information, the brain produces melatonin, a hormone that helps organisms become sleepy in sync with the solar night.
People who spend many daily hours in artificial light often have circadian rhythms whose melatonin production lags that of people more exposed to natural light. Many commercial lighting products are designed to offset or counteract these lags.
Most of these products, Neitz said, emphasise blue wavelength because it is known to affect melanopsin, a photopigment in the eyes that communicates with the brain and is most sensitive to blue.
By contrast, “the light we developed does not involve the melanopsin photopigment,” Neitz explained. “It has alternating blue and orange wavelengths that stimulate a blue-yellow opponent circuit that operates through the cone photoreceptors in the retina. This circuit is much more sensitive than melanopsin, and it is what our brains use to reset our internal clocks.”
The paper’s lead author was James Kuchenbecker, a research assistant professor of ophthalmology at the UW School of Medicine. He sought to compare different artificial lights’ effects on the production of melatonin.
He and colleagues devised and conducted a test of three devices:
a white light of 500 lux (a brightness appropriate for general office spaces)
a short-wavelength blue LED designed to trigger melanopsin
the newly developed LED of blue and orange wavelengths, which alternate 19 times a second to generate a soft white glow
The goal was to see what lighting approach was most effective at advancing the phase of melatonin production among six study participants. All participants underwent the following regimen with exposure to each of the three test lights:
The first evening, multiple saliva samples were taken to discern the baseline onset and peak of the participants’ melatonin production. For each subject, the onset of this phase dictated when they were exposed to the test light for two hours in the morning. That evening, saliva samples were again taken to see whether subjects’ melatonin phase had started earlier relative to their individual baselines.
During each test, exposure to other light sources was controlled. The three test spans were spaced such that subjects could return to their normal baseline phases before starting a new device.
In terms of shifting the melatonin-production phase, the alternating blue-orange LED device worked best, with a phase advance of 1 hour, 20 minutes. The blue light produced a phase advance of 40 minutes. The white, 500-lux light elicited an advance of just 2.8 minutes.
Gesturing toward the light that his team developed, Neitz explained.
“Even though our light looks like white to the naked eye, we think your brain recognizes the alternating blue and orange wavelengths as the colours in the sky. The circuit that produced the biggest shift in melatonin wants to see orange and blue.”
Consuming moderate amounts of coffee and caffeine regularly may offer a protective effect against developing multiple cardiometabolic diseases, including type 2 diabetes, coronary heart disease and stroke, according to new research published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism.
Researchers found that regular coffee or caffeine intake, especially at moderate levels, was associated with a lower risk of new-onset cardiometabolic multimorbidity (CM), which refers to the coexistence of at least two cardiometabolic diseases.
The prevalence of individuals with multiple cardiometabolic diseases, or CM, is becoming an increasing public health concern as populations age around the world, notes the study.
Coffee and caffeine consumption could play an important protective role in almost all phases of CM development, researchers found.
“Consuming three cups of coffee, or 200-300 mg caffeine, per day might help to reduce the risk of developing cardiometabolic multimorbidity in individuals without any cardiometabolic disease,” said lead author Chaofu Ke, MD, PhD, at Suzhou Medical College of Soochow University, in Suzhou, China.
The study found that compared with non-consumers or consumers of less than 100mg caffeine per day, consumers of moderate amount of coffee (3 drinks per day) or caffeine (200-300 mg per day) had a 48.1% or 40.7% reduced risk for new-onset CM.
Ke and his colleagues based their findings on data from the UK Biobank, a large and detailed longitudinal dietary study with over 500 000 participants aged 37-73 years. The study excluded individuals who had ambiguous information on caffeine intake. The resulting pool of participants included a total of 172 315 individuals who were free of any cardiometabolic diseases at baseline for the analyses of caffeine, and a corresponding 188 091 individuals for the analyses of coffee and tea consumption.
The participants’ cardiometabolic diseases outcomes were identified from self-reported medical conditions, primary care data, linked inpatient hospital data and death registry records linked to the UK Biobank.
Coffee and caffeine intake at all levels were inversely associated with the risk of new-onset CM in participants without cardiometabolic diseases. Those who reported moderate coffee or caffeine intake had the lowest risk, the study found. Moderate coffee or caffeine intake was inversely associated with almost all developmental stages of CM.
“The findings highlight that promoting moderate amounts of coffee or caffeine intake as a dietary habit to healthy people might have far-reaching benefits for the prevention of CM,” Ke said.
Addressing a research gap
Numerous epidemiological studies have revealed the protective effects of coffee, tea and caffeine consumption on morbidity of single cardiometabolic diseases. However, the potential effects of these beverages on the development of CM were largely unknown.
The authors reviewed the available research on this topic and found people with single cardiometabolic disease may have a two-fold higher all-cause mortality risk than those free of any cardiometabolic diseases. By contrast, the researchers found individuals with CM may have an almost 4 to 7 times higher risk of all-cause mortality. The researchers also noted that CM may present higher risks of loss of physical function and mental stress than those with single diseases.
A class of drugs for diabetes may be associated with a lower risk of dementia and Parkinson’s disease, according to a study published in Neurology®, the medical journal of the American Academy of Neurology. The study looked at sodium-glucose cotransporter-2 (SGLT2) inhibitors, which are also known as gliflozins. They lower blood sugar by causing the kidneys to remove sugar from the body through urine.
“We know that these neurodegenerative diseases like dementia and Parkinson’s disease are common and the number of cases is growing as the population ages, and people with diabetes are at increased risk of cognitive impairment, so it’s encouraging to see that this class of drugs may provide some protection against dementia and Parkinson’s disease,” said study author Minyoung Lee, MD, PhD, of Yonsei University College of Medicine in Seoul, South Korea.
The retrospective study looked at people with type 2 diabetes who started diabetes medication from 2014 to 2019 in South Korea. People taking SGLT2 inhibitors were matched with people taking other oral diabetes drugs, so the two groups had people with similar ages, other health conditions and complications from diabetes.
Then researchers followed the participants to see whether they developed dementia or Parkinson’s disease. Those taking the SGLT2 inhibitors were followed for an average of two years and those taking the other drugs were followed for an average of four years.
Among the 358 862 participants with an average age of 58, a total of 6837 people developed dementia or Parkinson’s disease during the study. For Alzheimer’s disease, the incidence rate for people taking SGLT2 inhibitors was 39.7 cases per 10 000 person-years, compared to 63.7 cases for those taking other diabetes drugs. Person-years represent both the number of people in the study and the amount of time each person spends in the study.
For vascular dementia, which is dementia caused by vascular disease, the incidence rate for people taking the SGLT2 drugs was 10.6 cases per 10 000, compared to 18.7 for those taking the other drugs. For Parkinson’s disease, the incidence rate for those taking the SGLT2 drugs was 9.3 cases per 10 000, compared to 13.7 for those taking the other drugs.
After researchers adjusted for other factors that could affect the risk of dementia or Parkinson’s disease, such as complications from diabetes and medications, they found that SGLT2 inhibitor use was associated with a 20% reduced risk of Alzheimer’s disease and a 20% reduced risk of Parkinson’s disease. Those taking the drugs had a 30% reduced risk of developing vascular dementia.
“The results are generally consistent even after adjusting for factors like blood pressure, glucose, cholesterol and kidney function,” Lee said. “More research is needed to validate the long-term validity of these findings.” Lee said that since participants were followed for less than five years at the most, it’s possible that some participants would later develop dementia or Parkinson’s disease.
