Tag: 18/8/25

Categories : Cardiovascular DiseaseTags :

Why Common Blood Pressure Readings May Be Misleading – and How to Fix Them

On By ModernMedia

Researchers have found why common cuff-based blood pressure readings are inaccurate and how they might be improved, which could improve health outcomes for patients.

Photo by CDC on Unsplash

High blood pressure, or hypertension, is the top risk factor for premature death, associated with heart disease, strokes and heart attacks. However, inaccuracies in the most common form of blood pressure measurement mean that as many as 30% of cases of high blood pressure could be missed.

The researchers, from the University of Cambridge, built an experimental model that explained the physics behind these inaccuracies and provided a better understanding of the mechanics of cuff-based blood pressure readings.

The researchers say that some straightforward changes, which don’t necessarily involve replacing standard cuff-based measurement, could lead to more accurate blood pressure readings and better results for patients. Their results are reported in the journal PNAS Nexus.

Anyone who has ever had their blood pressure taken will be familiar with the cuff-based method. This type of measurement, also known as the auscultatory method, relies on inflating a cuff around the upper arm to the point where it cuts off blood flow to the lower arm, and then a clinician listens for tapping sounds in the arm through a stethoscope while the cuff is slowly deflated.

Blood pressure is inferred from readings taken from a pressure gauge attached to the deflating cuff. Blood pressure is given as two separate numbers: a maximum (systolic) and a minimum (diastolic) pressure. A blood pressure reading of 120/80 is considered ‘ideal’.

“The auscultatory method is the gold standard, but it overestimates diastolic pressure, while systolic pressure is underestimated,” said co-author Kate Bassil from Cambridge’s Department of Engineering. “We have a good understanding of why diastolic pressure is overestimated, but why systolic pressure is underestimated has been a bit of a mystery.”

“Pretty much every clinician knows blood pressure readings are sometimes wrong, but no one could explain why they are being underestimated — there’s a real gap in understanding,” said co-author Professor Anurag Agarwal, also from Cambridge’s Department of Engineering.

Previous non-clinical studies into measurement inaccuracy used rubber tubes that did not fully replicate how arteries collapse under cuff pressure, which masked the underestimation effect.

The researchers built a simplified physical model to isolate and study the effects of downstream blood pressure — the blood pressure in the part of the arm below the cuff. When the cuff is inflated and blood flow to the lower arm is cut off, it creates a very low downstream pressure. By reproducing this condition in their experimental rig, they determined this pressure difference causes the artery to stay closed for longer while the cuff deflates, delaying the reopening and leading to an underestimation of blood pressure.

This physical mechanism — the delayed reopening due to low downstream pressure — is the likely cause of underestimation, a previously unidentified factor. “We are currently not adjusting for this error when diagnosing or prescribing treatments, which has been estimated to lead to as many as 30% of cases of systolic hypertension being missed,” said Bassil.

Instead of the rubber tubes used in earlier physical models of arteries, the Cambridge researchers used tubes that lay flat when deflated and fully close when the cuff pressure is inflated, the key condition for reproducing the low downstream pressure observed in the body.

The researchers say that there are a range of potential solutions to this underestimation, which include raising the arm in advance of measurement, potentially producing a predictable downstream pressure and therefore predictable underestimation. This change doesn’t require new devices, just a modified protocol.

“You might not even need new devices, just changing how the measurement is done could make it more accurate,” said Agarwal.

However, if new devices for monitoring blood pressure are developed, they might ask for additional inputs which correlate with downstream pressure, to adjust what the ‘ideal’ readings might be for each individual. These may include age, BMI, or tissue characteristics.

The researchers hope to secure funding for clinical trials to test their findings in patients, and are looking for industrial or research partners to help refine their calibration models and validate the effect in diverse populations. Collaboration with clinicians will also be essential to implement changes to clinical practice.

The research was supported by the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation (UKRI). Anurag Agarwal is a Fellow of Emmanuel College, Cambridge. 

Reference:
Kate Bassil and Anurag Agarwal. ‘Underestimation of systolic pressure in cuff-based blood pressure measurement.’ PNAS Nexus (2025). DOI: 10.1093/pnasnexus/pgaf222.

Republished from University of Cambridge under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Read the original article.

Categories : New Compounds and TreatmentsTags :

Small Molecule Could Alleviate Paracetamol-induced Liver Injury

On By ModernMedia
Human liver. Credit: NIH

Paracetamol (acetaminophen) is one of the most common painkillers and is found in hundreds of different medications. While safe at recommended doses, paracetamol overdose is the leading cause of acute liver injury in the U.S. Now, researchers propose that a new molecule has the potential to treat acetaminophen-induced liver injury (AILI) and other inflammatory conditions. They conducted a small-scale mouse trial and found that the new compound decreased AILI-caused liver inflammation and prevented liver damage. 

Jannatun Nayem Namme, a graduate student at Virginia Commonwealth University, will present her team’s results at the fall meeting of the American Chemical Society (ACS). ACS Fall 2025 is being held Aug. 17-21; it features about 9000 presentations on a range of science topics.  

Most acetaminophen overdoses are accidental, often due to people unintentionally consuming multiple products containing the painkiller or misinterpreting dosage. After taking a recommended amount of paracetamol, a person’s liver converts a small percentage of it into a toxic molecule called N-acetyl-p-benzoquinone imine (NAPQI). Normally, the liver can quickly metabolise NAPQI into a non-toxic form. But if a person takes too much acetaminophen, NAPQI builds up and causes irreversible cell damage, leading to liver injury or death. Currently, N-acetylcysteine is the only drug available to treat AILI, and it must be administered within eight hours of overdose. 

To develop novel treatments for inflammatory conditions, such as AILI, and neurodegenerative conditions, Namme and her colleagues previously focused on small molecules that reduce the activity of inflammation-causing proteins, known as inflammasomes. Inflammasomes are also involved in pyroptosis, a type of cellular death associated with AILI. While developing inflammasome inhibitors, the researchers noticed that some of the compounds they created could target a specific inflammatory protein called gasdermin D (GSDMD). GSDMD is involved in pyroptosis. 

Namme and the team synthesised several different GSDMD-inhibiting compounds and tested them for their ability to bind to GSDMD. They discovered that one small molecule, which they labelled YM81, selectively binds to and inhibits GSDMD from initiating pyroptosis.  

Next, the researchers treated five mice with AILI using YM81 and compared them to 10 mice given a placebo. They monitored the extent of liver damage in the animals 17 hours after the acetaminophen overdose. Compared to the placebo group, mice treated with YM81 had significantly lower levels of alanine transaminase and aspartate transaminase, two liver injury biomarkers. These results indicate that the YM81 treatment helped decrease liver inflammation by inhibiting GSDMD. 

Shijun Zhang, the study’s principal investigator, says that YM81 is in the early stages of drug development. “In the future, we will focus on optimising YM81 to increase its potency, safety and stability, in addition to exploring its therapeutic potential in additional animal models,” he says. 

Namme adds that GSDMD inhibitors like YM81 have the potential to treat other inflammatory conditions. “GSDMD is a common protein involved in multiple inflammatory and neurodegenerative diseases, such as arthritis, sepsis and gout,” she says. “Targeting GSDMD could offer a therapeutic strategy to reduce the inflammation and damage from multiple diseases and causes.”

Source: American Chemical Society

Categories : Mental Health Substance UseTags :

Cannabis Potency May Be Driving a Rise in Schizophrenia

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Photo by Harrison Haines on Pexels

A new article published in the Canadian Medical Association Journal warns of the mental health dangers stemming from the increasing potency of cannabis. In Ontario, there has been a more than 14-fold increase in risk for visiting the emergency department for cannabis-related schizophrenic disorders. After a cannabis-induced psychotic episode, cessation of cannabis use is necessary to reduce the risk of relapse, and in severe cases, antipsychotics may be needed.

“Cannabis from the 2000s is not the same as in 2025,” said coauthor Dr Nicholas Fabiano, MD, resident and researcher with the Department of Psychiatry, University of Ottawa, Ottawa, Ontario. “THC content has increased by 5 times. This is likely a significant driver in the increasing link between cannabis use and schizophrenia.”

  1. Cannabis potency is increasing — The concentration of tetrahydrocannabinol (THC) has increased fivefold in the last 20 years in Canada from about 4% to 20% in most legal dried cannabis.
  2. High-potency and regular cannabis use is linked to increased risk of psychosis — The risk of psychosis is increased in people using high-potency THC (more than 10% THC), people using it frequently, and those who are younger and male. A history of mental disorders (depression, anxiety, etc) also appears to increase the risk.
  3. Cannabis-induced psychosis and cannabis use disorder increase the risk of schizophrenia — A recent study of 9.8 million people in Ontario found a 14.3-fold higher risk of developing a schizophrenia-spectrum disorder in people visiting the emergency department for cannabis use and a 241.6-fold higher risk from visits for cannabis-induced psychosis.
  4. Treatment requires stopping cannabis and taking medication — Continued use of cannabis after a first episode of cannabis-induced psychosis is linked to greater risk of returning symptoms. Antipsychotic medication can help people with severe and prolonged symptoms.
  5. Behavioural options may help with cannabis cessation — Motivational interviewing or cognitive behavioural therapy by a physician or psychologist can help build skills to resist cravings and follow treatment recommendations.

Source: EurekAlert!

Categories : Ageing Expert OpinionTags :

From Lifespan to Healthspan: Why Preventive Healthcare Matters Now More Than Ever

On By ModernMedia
Photo by Barbara Olsen on Pexels

South Africa is facing a major health transition. While the average life expectancy has nearly doubled over the past century, the quality of those additional years, commonly referred to as one’s ‘healthspan,’ remains under threat from non-communicable diseases (NCDs). This threat calls for a renewed national focus on prevention and early intervention to address the rapidly growing challenge.

The Healthspan Imperative

According to health data presented at the 2025 Momentum Healthcare Insights Summit, NCDs such as heart disease, cancer, diabetes and neurodegenerative disorders now account for 51% of all deaths in South Africa. In contrast, communicable diseases make up around 40% and non-natural causes (like accidents and violence) account for a mere 9%. This shift reflects a global trend, although some challenges remain; infectious diseases become more manageable, while chronic conditions associated with lifestyle and ageing take centre stage.

Damian McHugh, Chief Marketing Officer at Momentum Health

“Medical advances have added years to our lives, but not necessarily life to our years. More and more, there is growing evidence to support the fact that prevention offers the greatest potential to reduce the burden as well as cost of chronic disease and improve quality of life,” says Damian McHugh, Chief Marketing Officer at Momentum Health.

Prevention Outperforms Treatment

The summit highlighted compelling evidence that prevention is more effective than treatment for advanced disease. For example, research from the American Cancer Society shows that tobacco control measures, such as smoking bans and taxes, have prevented 3.8 million lung cancer deaths in the United States since 1970. The most effective way to save lives from late-stage lung cancer has not been through treatment, but through reducing or eliminating smoking altogether.

The same principle applies to other chronic diseases. Managing risk factors such as high blood pressure, obesity, high blood glucose, and abnormal cholesterol can actively prevent or delay the onset of disease. These factors are strongly influenced by behaviours such as a lack of physical activity, poor nutrition, unmanaged stress levels, and even excessive alcohol use or smoking.

Investing in regular health check-ups and preventative care can mitigate the risk of serious health problems, ultimately reducing the incidence of costly, advanced illnesses. Simple lifestyle changes, such as prioritising rest and recovery, making time to connect with loved ones, maintaining balanced nutrition, practicing mindfulness, and engaging in regular exercise not only promotes physical and mental health, but can also translate into significant long-term savings in healthcare costs.

“Making quality healthcare more accessible, while enabling and rewarding healthy, preventative habits can lead to complete physical and mental health and wellbeing. Investing in access and wellbeing is a powerful pathway to realising more wealth and more health for more South Africans,” says McHugh.

Measuring and Managing Healthspan within the South African Context

Momentum Health’s data reveals that many South Africans are living longer, but the average age of medical scheme beneficiaries has increased by nearly three years over the past decade, and the proportion of pensioners in medical schemes is rising. Without proactive measures, our nation’s ailing healthcare system will face increasing claims and costs as the population ages and chronic diseases become more prevalent.

Momentum Health believes that the solution lies in taking measures to improve access to both quality medical care and reliable health information and empowering individuals to take responsibility for their own health.

South Africa’s rising NCD burden is not inevitable. With early detection, healthy lifestyle choices, and consistent engagement with preventative healthcare, individuals can not only extend their lifespan but also improve the years lived in good health.

“Prevention isn’t just a personal choice; it’s a public health imperative. By investing in wellness now, we can reduce the future burden on our healthcare system and help more South Africans enjoy longer, healthier lives,” concludes McHugh.