Day: November 6, 2024

Standing on One Leg is a Good Indicator of Ageing

Photo by RDNE Stock project

How long a person can stand on one leg is a more tell-tale measure of ageing than changes in strength or gait, according to new Mayo Clinic research published in the journal PLOS ONE.

Good balance, muscle strength and an efficient gait contribute to people’s independence and well-being as they age. How these factors change, and at what rate, can help clinicians develop programs to ensure healthy aging. Individually, people can train their balance without special equipment and work on maintaining it over time.

In this study, 40 healthy, independent people over 50 underwent walking, balance, grip strength and knee strength tests. Half of the participants were under 65; the other half were 65 and older.

In the balance tests, participants stood on force plates in different situations: on both feet with eyes open, on both feet with eyes closed, on the non-dominant leg with eyes open, and on the dominant leg with eyes open. In the one-legged tests, participants could hold the leg they weren’t standing on where they wanted. The tests were 30 seconds each.

Standing on one leg, specifically the nondominant leg, showed the highest rate of decline with age.

“Balance is an important measure because, in addition to muscle strength, it requires input from vision, the vestibular system and the somatosensory systems,” says Kenton Kaufman, PhD, senior author of the study and director of the Motion Analysis Laboratory at Mayo Clinic. “Changes in balance are noteworthy. If you have poor balance, you’re at risk of falling, whether or not you’re moving. Falls are a severe health risk with serious consequences.”

Unintentional falls are the leading cause of injuries among adults who are 65 and older. Most falls among older adults result from a loss of balance.

In the other tests:

  • Researchers used a custom-made device to measure participants’ grip. For the knee strength test, participants were in a seated position and instructed to extend their knee as forcefully as possible. Both the grip and knee strength tests were on the dominant side. Grip and knee strength showed significant declines by decade but not as much as balance. Grip strength decreased at a faster rate than knee strength, making it better at predicting aging than other strength measures.
  • For the gait test, participants walked back and forth on an 8-metre, level walkway at their own pace and speed. Gait parameters didn’t change with age. This was not a surprising result since participants were walking at their normal pace, not their maximum pace, Dr Kaufman says.
  • There were no age-related declines in the strength tests that were specific to sex. This indicates that participants’ grip and knee strength declined at a similar rate. Researchers did not identify sex differences in the gait and balance tests, which suggests that male and female subjects were equally affected by age.

Dr Kaufman says that people can take steps to train their balance. For example, by standing on one leg, you can train yourself to coordinate your muscle and vestibular responses to maintain correct balance. If you can stand on one leg for 30 seconds, you are doing well, he says.

“If you don’t use it, you lose it. If you use it, you maintain it,” Dr Kaufman says. “It’s easy to do. It doesn’t require special equipment, and you can do it every day.”

Source: Mayo Clinic

New Anti-cancer Agent Works Without Oxygen

Human colon cancer cells. Credit: National Cancer Institute

Tumours often contain areas of oxygen-deficient tissue that frequently withstand conventional therapies. This is because the drugs applied in tumours require oxygen to be effective. An international research team has developed a novel mechanism of action that works without oxygen: polymeric incorporated nanocatalysts target the tumour tissue selectively and switch off the glutathione that the cells need to survive. The team published their findings in the journal Nature Communications.

Why tumours shrink but don’t disappear

Study leader Dr Johannes Karges from Ruhr University Bochum, Germany, explained: “As tumours grow very quickly, consume a lot of oxygen and their vascular growth can’t necessarily keep pace, they often contain areas that are poorly supplied with oxygen.” These areas, often in the centre of the tumour, frequently survive treatment with conventional drugs, so that the tumour initially shrinks but doesn’t disappear completely. This is because the therapeutic agents require oxygen to be effective. 

The mechanism of action developed by Karges’ team works without oxygen. “It’s a catalyst based on the element ruthenium, which oxidises the naturally present glutathione in the cancer cells and switches it off,” explains Karges. Glutathione is essential for the survival of cells and protects them from a wide range of different factors. If it ceases to be effective, the cell deteriorates. 

Compound accumulates in tumour tissue

All cells of the body need and contain glutathione. However, the catalyst has a selective effect on cancer cells as it is packaged in polymeric nanoparticles that accumulate specifically in the tumour tissue. Experiments on cancer cells and on mice with human tumours, that were considered incurable, proved successful. “These are encouraging results that need to be confirmed in further studies,” concludes Johannes Karges. “Still, there’s a lot of research work to be done before it can be used in humans.”

Source: Ruhr-University Bochum

Researchers Find Persistent Problems with AI-assisted Genomic Studies

Photo by Sangharsh Lohakare on Unsplash

In a paper published in Nature Genetics, researchers are warning that artificial intelligence tools gaining popularity in the fields of genetics and medicine can lead to flawed conclusions about the connection between genes and physical characteristics, including risk factors for diseases like diabetes.

The faulty predictions are linked to researchers’ use of AI to assist genome-wide association studies, according to the University of Wisconsin–Madison researchers. Such studies scan through hundreds of thousands of genetic variations across many people to hunt for links between genes and physical traits. Of particular interest are possible connections between genetic variations and certain diseases.

Genetics’ link to disease not always straightforward

Genetics play a role in the development of many health conditions. While changes in some individual genes are directly connected to an increased risk for diseases like cystic fibrosis, the relationship between genetics and physical traits is often more complicated.

Genome-wide association studies have helped to untangle some of these complexities, often using large databases of individuals’ genetic profiles and health characteristics, such as the National Institutes of Health’s All of Us project and the UK Biobank. However, these databases are often missing data about health conditions that researchers are trying to study.

“Some characteristics are either very expensive or labour-intensive to measure, so you simply don’t have enough samples to make meaningful statistical conclusions about their association with genetics,” says Qiongshi Lu, an associate professor in the UW–Madison Department of Biostatistics and Medical Informatics and an expert on genome-wide association studies.

The risks of bridging data gaps with AI

Researchers are increasingly attempting to work around this problem by bridging data gaps with ever more sophisticated AI tools.

“It has become very popular in recent years to leverage advances in machine learning, so we now have these advanced machine-learning AI models that researchers use to predict complex traits and disease risks with even limited data,” Lu says.

Now, Lu and his colleagues have demonstrated the peril of relying on these models without also guarding against biases they may introduce. In their paper, they show that a common type of machine learning algorithm employed in genome-wide association studies can mistakenly link several genetic variations with an individual’s risk for developing Type 2 diabetes.

“The problem is if you trust the machine learning-predicted diabetes risk as the actual risk, you would think all those genetic variations are correlated with actual diabetes even though they aren’t,” says Lu.

These “false positives” are not limited to these specific variations and diabetes risk, Lu adds, but are a pervasive bias in AI-assisted studies.

New statistical method can reduce false positives

In addition to identifying the problem with overreliance on AI tools, Lu and his colleagues propose a statistical method that researchers can use to guarantee the reliability of their AI-assisted genome-wide association studies. The method helps remove bias that machine learning algorithms can introduce when they’re making inferences based on incomplete information.

“This new strategy is statistically optimal,” Lu says, noting that the team used it to better pinpoint genetic associations with individuals’ bone mineral density.

AI not the only problem with some genome-wide association studies

While the group’s proposed statistical method could help improve the accuracy of AI-assisted studies, Lu and his colleagues also recently identified problems with similar studies that fill data gaps with proxy information rather than algorithms.

In another recently published paper appearing in Nature Genetics, the researchers sound the alarm about studies that over-rely on proxy information in an attempt to establish connections between genetics and certain diseases.

For instance, large health databases like the UK Biobank have a ton of genetic information about large populations, but they don’t have very much data regarding the incidence of diseases that tend to crop up later in life, like most neurodegenerative diseases.

For Alzheimer’s disease specifically, some researchers have attempted to bridge that gap with proxy data gathered through family health history surveys, where individuals can report a parent’s Alzheimer’s diagnosis.

The UW–Madison team found that such proxy-information studies can produce “highly misleading genetic correlation” between Alzheimer’s risk and higher cognitive abilities.

“These days, genomic scientists routinely work with biobank datasets that have hundreds of thousands of individuals; however, as statistical power goes up, biases and the probability of errors are also amplified in these massive datasets,” says Lu. “Our group’s recent studies provide humbling examples and highlight the importance of statistical rigor in biobank-scale research studies.”

Source: University of Wisconsin-Madison

Study Suggests that High-intensity Exercise Suppresses Appetite – Especially in Women

Photo by Ketut Subiyanto on Unsplash

A vigorous workout does more to suppress hunger levels in healthy adults than does moderate exercise, and females may be especially susceptible to this response, according to a small study published in the Journal of the Endocrine Society.

The study examines the effects of exercise intensity on ghrelin levels and appetite between men and women. Ghrelin is known as the “hunger hormone” and is associated with perceptions of hunger.

“We found that high intensity exercise suppressed ghrelin levels more than moderate intensity exercise,” said lead author Kara Anderson, PhD, of the University of Virginia. “In addition, we found that individuals felt ‘less hungry’ after high intensity exercise compared to moderate intensity exercise.”

Ghrelin circulates in acylated (AG) and deacylated (DAG) forms, which are known to affect appetite. Data on the impact of exercise intensity on AG and DAG levels, and their effects on appetite, is sparse and primarily limited to males, the study noted.

To address this shortfall, the study examined eight males and six females. Participants fasted overnight and then completed exercises of varying intensity levels, determined by measurements of blood lactate, followed by self-reported measurements of appetite.

Females had higher levels of total ghrelin at baseline compared with males, the study noted. But only females demonstrated “significantly reduced AG” following the intense exercise, according to the findings.

“We found that moderate intensity either did not change ghrelin levels or led to a net increase,” the study noted. These findings suggest that exercise above the lactate threshold “may be necessary to elicit a suppression in ghrelin.”

Researchers also acknowledged that more work is needed to determine the extent to which the effects of exercise differ by sex. Ghrelin has been shown to have wide-ranging biological effects in areas including energy balance, appetite, glucose homeostasis, immune function, sleep, and memory.

“Exercise should be thought of as a ‘drug,’ where the ‘dose’ should be customised based on an individual’s personal goals,” Anderson said. “Our research suggests that high-intensity exercise may be important for appetite suppression, which can be particularly useful as part of a weight loss program.”

Source: The Endocrine Society

Building a Patient-centric Healthcare Ecosystem in SA: A Bold New Vision

Bada Pharasi, CEO of The Innovative Pharmaceutical Association of South Africa (IPASA)

Imagine a healthcare system which ensures that every patient’s voice helps shape their treatment, where barriers to life-saving care are dismantled, and where innovation is driven by meaningful collaboration. In South Africa, this vision is no longer a distant aspiration; it’s an urgent mission to create a system that truly serves its people, writes Bada Pharasi, CEO of the Innovative Pharmaceutical Association of South Africa.

South Africa’s healthcare system stands at a critical crossroads. Despite remarkable medical advancements, countless patients remain on the sidelines, hindered by financial, regulatory, and logistical barriers. Today, there’s an opportunity to reshape this reality by building a patient-centred healthcare model that expands access, amplifies patient voices, and creates strategic partnerships.

Empowering patient voices

In a truly inclusive healthcare system, patients aren’t just recipients of care; they are active contributors. By integrating patient perspectives into decision-making, healthcare becomes more responsive to those it serves. 

Through collaborations with patient advocacy groups, educational campaigns, and year-round initiatives, there’s a growing movement to create an environment in which patients feel heard and empowered to influence the care they receive. While events such as World Patient Safety Day help highlight the importance of prioritising patient needs, the goal is to make this a constant focus, not just an annual observance.

Key prerequisites for achieving this are efficient regulatory frameworks, impactful public-private partnerships, rare disease management, and a true commitment to innovation. 

Streamlined regulatory partnerships

Timely access to groundbreaking treatments depends on efficient regulatory frameworks. Collaborating closely with regulatory authorities such as the South African Health Products Regulatory Authority (SAHPRA) is pivotal in expediting access to new therapies. 

Such partnerships ensure that treatments meet rigorous safety standards while streamlining approval processes so that life-changing therapies reach patients without unnecessary delays. Maintaining high standards for post-market safety also strengthens public trust and reinforces the resilience of the healthcare system.

Public-private partnerships: Catalysts for innovation

Expanding access to quality healthcare in South Africa demands strong public-private partnerships (PPPs) that leverage both public resources and private sector innovation. 

Collaborative efforts with the Department of Health and other key stakeholders maximise impact by ensuring that resources are effectively allocated and that patients benefit from the latest treatments. These alliances are vital for achieving universal health coverage (UHC) under the National Health Insurance (NHI) framework, helping to ensure that equitable, high-quality healthcare becomes a reality for all.

Closing gaps in rare disease management

For patients with rare diseases, access to treatment is often riddled with obstacles, from limited therapies and high costs to a lack of awareness. Multi-stakeholder collaborations, including advisory boards initiated by organisations such as Rare Diseases South Africa, bring together patients, healthcare professionals, and industry experts to advocate for better support and access to treatments. 

This prioritisation of open communication and patient-centred outcomes offers hope to rare disease patients who, through these partnerships, gain better access to essential treatments and the support they deserve.

Breaking down barriers to innovation

The drive for a more accessible healthcare system also requires addressing policy barriers. Streamlined processes, simpler registration pathways for new drugs, and patient-centred reimbursement policies ensure that patients receive the right treatment at the right time. 

Working alongside policymakers, healthcare providers, and civil society, a concerted effort is being made to create a system in which innovation and equity go hand-in-hand to provide better outcomes and quality of life for all South Africans.

Shaping the future of healthcare

The future of South Africa’s healthcare lies in a system that prioritises patients, breaks down barriers, and capitalises on partnerships to make innovation accessible. 

The call to action is clear: build a healthcare ecosystem that is dynamic, inclusive, and adaptable to ensure that every South African has access to the care they need. By promoting patient voices and ensuring collaboration across sectors, we can transform South Africa’s healthcare system to be more responsive, resilient, and equitable – a system that truly serves its people.