Clinical trial shows implantable shock absorber Knee pain is commonly caused by osteoarthritis, a chronic condition that affects approximately 14 million Americans of all ages.

Results from a multi-center clinical trial, presented today at an orthopedic symposium in Boston, show a new implantable shock absorber can relieve pain and improve function. Dr. David Flanigan, an orthopedic surgeon at The Ohio State University Wexner Medical Center, enrolled patients in the trial at the medical center and was first in the U.S. to implant the MISHA Knee System made by Moximed.

“There really hasn’t been much to offer for knee arthritis between the more basic options like medications, therapy and injections all the way to joint replacement,” said Flanigan, who is also a professor of orthopedics at the Ohio State College of Medicine “This shock absorber could be an in between step patients need.”

The device involves a piston that anchors to the inner side of the femur and tibia bones with a small plate. Trial data showed significant reduction in pain scores and improvement in function scores for more than 90% of the 81 trial participants. The shock absorber had a success rate of 86% compared to the most common procedure, high tibial osteotomy, which has a success rate of 66% and is typically used to treat symptomatic osteoarthritis of the medial compartment of the knee.

“When you're walking, doing activities, it's going to take away about 30% of that shock or stress on the knee every time you put weight on your leg,” said Flanigan. “You see patients who are struggling just to walk and have pain on a daily basis. They have this device, go through rehabilitation and then they’re walking and getting back to activities that are really important to them.”

Chuck Stenger of New Albany, Ohio was the first person to receive the shock absorber device three years ago. Today, the retired firefighter says he’s doing exceptionally well and is grateful he had the opportunity to try the device.

“Before participating in the clinical trial, I was told I was probably a candidate for a knee replacement, and I didn't think I was quite ready for that yet,” Stenger said. “Three days after the implant procedure I was walking around, and with a little therapy I’m back to golfing, taking long walks and just living life without constant pain in my knees.”

The two-year collective clinical trial data has been submitted to the U.S. Food and Drug Administration and is under regulatory review.

 

Do sleep timing and duration affect dementia risk?

 

New research published in the Journal of the American Geriatrics Society suggests that the time people go to bed and the amount of time they sleep may affect their risk of developing dementia.

In the study of 1,982 older adults in China who were free of dementia at the start of the study, 97 participants were diagnosed with dementia during an average follow-up of 3.7 years.

Risk of dementia was 69% higher in those who slept for more than 8 hours (versus 7-8 hours) and 2-times higher for those who went to bed before 9 PM (versus 10 PM or later).

“This suggests that cognitive function should be monitored in older adults who report prolonged 102time in bed and advanced sleep timing,” the authors wrote.

A consistent lack of sleep negatively impacts immune stem cells, increasing risk of inflammatory disorders and heart disease

 

IMAGE: INSUFFICIENT SLEEP AND THE IMPACT ON IMMUNE STEM CELLS. THE LEFT SIDE OF THE FIGURE SHOWS THE SLEEP TIME OF THE HUMANS IN THE STUDY. PARTICIPANTS IN THE SLEEP RESTRICTION GROUP (THE RED DOTS) SLEPT LESS OVER THE SIX WEEKS. THE RIGHT SIDE OF THE FIGURE THE STEM CELL ANALYSIS. THE FIRST GRAPH SHOWS THAT PEOPLE IN THE SLEEP RESTRICTION GROUP (AGAIN RED DOTS) HAD MORE STEM CELLS. THE REMAINDER OF THE FIGURE REPRESENTS THE ‘DNA STRUCTURE AND RE-PROGRAMMING. THE RED AND BLUE COLORS SHOW LOCATIONS IN THE GENOME THAT WERE RE-WIRED. THE BOTTOM ‘PEAKS’ ARE SPECIFIC GENES THAT RESEARCHERS LOOKED AT AND SHOWS THE RE-WIRING AT THESE LOCATIONS. view more 

CREDIT: MOUNT SINAI HEALTH SYSTEM

Chronic, insufficient sleep can negatively affect immune cells, which may lead to inflammatory disorders and cardiovascular disease, according to a new study from the Icahn School of Medicine at Mount Sinai. More specifically, consistently losing an hour and a half of sleep a night potentially increases the risk.

The research, published September 21 in the Journal of Experimental Medicine, is the first to show that sleep alters the structure of DNA inside the immune stem cells that produce white blood cells—also known as immune cells—and this can have a long-lasting impact on inflammation and contribute to inflammatory diseases. Immune cells fight infection, but if the number of these cells gets too high, they overreact and cause inflammation. The study is also the first to show that catching up on sleep doesn’t reverse the effects of sleep disruption.

“This study begins to identify the biological mechanisms that link sleep and immunological health over the long-term. It shows that in humans and mice, disrupted sleep has a profound influence on the programming of immune cells and rate of their production, causing them to lose their protective effects and actually make infections worse—and these changes are long-lasting.  This is important because it is yet another key observation that sleep reduces inflammation and, conversely, that sleep interruption increases inflammation,” says lead author Filip Swirski, PhD, Director of the Cardiovascular Research Institute at Icahn Mount Sinai. “This work emphasizes the importance of adults consistently sleeping seven to eight hours a day to help prevent inflammation and disease, especially for those with underlying medical conditions."

A team of investigators analyzed 14 healthy adults who regularly sleep eight hours a night. First, researchers monitored them sleeping at least eight hours a night for six weeks. They drew their blood and analyzed their immune cells. Then, the same group of adults reduced their sleep time by 90 minutes every night for six weeks, and had their blood and immune cells reanalyzed. At the end of the study researchers compared the blood and cell samples from the full night’s sleep and restricted sleep periods. All participants had significant changes in their immune cells (also known as hematopoietic cells) due to a lack of sleep—there were more of them, and the DNA structure was altered. After six weeks of sleep restriction, they had an increased number of immune cells.

Researchers also analyzed sleep in mouse models. Groups of mice were either allowed to sleep undisturbed, or had sleep fragmentation, where they were awakened throughout the night for 16 weeks. Then, mice with sleep fragmentation went through uninterrupted sleep recovery for ten weeks. Investigators took immune stem cells and immune cells from mice during these undisturbed, fragmented, and sleep recovery phases, analyzed them and compared them at the end of the experiment. Results in mice were consistent with results in humans. They showed that all mice with fragmented sleep had significant changes to their immune stem cells, producing an increased number of immune cells, and also showed evidence of rewiring and reprogramming. A notable finding from the mouse group was that even after sleep recovery, the immune stem cells retained this rewiring structure, and they continued to produce additional white blood cells, making the mice susceptible to inflammation and disease.

“Our findings suggest that sleep recovery is not able to fully reverse the effects of poor-quality sleep. We can detect a molecular imprint of insufficient sleep in immune stem cells, even after weeks of recovery sleep. This molecular imprint can cause the cells to respond in inappropriate ways leading to inflammation and disease,” says co-lead investigator Cameron McAlpine, PhD, Assistant Professor of Medicine (Cardiology) at Icahn Mount Sinai. “It was surprising to find that not all clusters of stem cells responded to insufficient sleep in the same way. There were some stem cell clusters that proliferated and grew in number, while other clusters became smaller. This reduction in overall diversity and aging of the immune stem cell population is an important contributor to inflammatory diseases and cardiovascular disease.”

Simple 20-20-20 screen rule really does help with eye strain, research shows

It’s long been recommended as a way of easing eye strain while working at a computer screen. Now the 20-20-20 rule – taking a break of at least 20 seconds, every 20 minutes, to look at least 20 feet away - has been confirmed by scientists at Aston University to help ease some of the symptoms of prolonged computer use.

It’s estimated that at least half of people using computers in their regular work have some form of digital eye strain, resulting in eye surface problems including irritation and dryness, or vision issues such as headaches or blurred vision. Humans normally blink around 15 times each minute. When staring at screens, this number decreases generally to half that rate or less. That can lead to dry, irritated, and tired eyes, but twenty seconds focusing elsewhere is long enough for the eyes to relax enough to reduce the strain.

This is the first time that the 20-20-20 guidance rule has been properly validated.  

Researchers at Aston University’s College of Health and Life Sciences set up their study with the help of 29 participants who suffer from symptoms of eye strain. Special software downloaded onto the participants’ own laptop computers used the built-in laptop camera both to check if a user was sitting at the screen and to monitor their gaze direction every few seconds. After 20 minutes of continuous screen viewing, the programme flashed up a message, asking users to rest for 20 seconds while looking at any distant target around 20 feet away, such as out of the window or across a room. The message couldn’t be removed until the task was performed correctly, as measured by the app.

Participants’ digital eye strain symptoms were measured before and after two weeks of using the reminders, and one week after completing the study. Results showed a marked  decrease in symptoms including dryness, sensitivity and discomfort.

Professor James Wolffsohn, Professor of Optometry at Aston University, who led the research in collaboration with the University of Valencia, Spain, said: “The one previous study merely asked people to carry out the suggestions; but here the access control on the software meant we could be sure that participants really had looked away every 20 minutes. We saw a consequent improvement in the symptoms of the group as a whole.”

Researchers noted that after the study, the participants’ eye symptoms returned to what they had been before the intervention. Professor Wolffsohn says: “We are planning to conduct longer term studies to see whether we can teach eyelid muscle memory impulses to blink more often during digital viewing, to help mitigate this chronic issue without long term use of reminders.”

The findings confirm that people should try and take breaks from their screens. He added: “Although we used sophisticated software, it’s easy for others to replicate the effect by setting a timer on their phone, or downloading a reminder app. It’s a simple way of reminding yourself to take regular breaks for the good of your eyes.”

Stain-resistant school uniforms could expose children to harmful chemicals

 Children who wear stain-resistant school uniforms may be exposed to potentially harmful levels of chemicals, according to a new study by researchers in the Paul H. O'Neill School of Public and Environmental Affairs at Indiana University and colleagues from the University of Toronto, the University of Notre Dame and the Green Science Policy Institute.

About a quarter of U.S. children wear school uniforms, according to a survey from Statista. One-fifth of U.S. public schools require uniforms, with the greatest prevalence in elementary and low-income schools. They are even more common in Catholic and other private schools in the United States and Canada.

The study, published in Environmental Science & Technology, found that millions of schoolchildren in the U.S. and Canada are exposed to potentially harmful levels of per- and polyfluoroalkyl substances, or PFAS, through their uniforms. The researchers detected PFAS in all of the stain-resistant school uniforms they tested from nine popular brands. Most products had concentrations as high as those in outdoor clothing.

"PFAS don't belong in any clothing, but their use in school uniforms is particularly concerning," said Marta Venier, senior author and professor at Indiana University. "School uniforms are worn directly on the skin for up to eight hours per day by children, who are particularly vulnerable to harm."

Some PFAS have been associated with a wide variety of serious health issues, such as cancer, obesity and more severe COVID-19 outcomes. They've also been found to contaminate the drinking water for millions of citizens. Only a small fraction of the thousands of PFAS have been tested for toxicity, and all PFAS are either extremely persistent in the environment or break down into extremely persistent PFAS. Additionally, some newer PFAS first claimed to be safe have later been determined to be harmful to human health.

PFAS in treated uniforms may end up harming children through skin absorption, as well as from eating with unwashed hands, other hand-to-mouth behaviors and mouthing of clothing by younger children. The fluorotelomer alcohols, which were the primary type of PFAS found in the uniforms, also pose an inhalation risk. Further, PFAS-treated uniforms are a source of PFAS contamination in the environment when they are worn, laundered, and discarded or recycled.

"I don't know any parent who values stain repellency over their child's health," said Miriam Diamond, co-author and professor at the University of Toronto.

The findings come as legislation to phase out PFAS in textiles, which would include school uniforms, moves forward in New York and California. New York's Senate Bill S6291A and California's Assembly Bill 1817, known as the Safer Clothes and Textiles Act, have both passed their legislatures and are expected to be signed by their respective governors soon. 

"To protect our children and future generations, the whole class of PFAS should be eliminated from school uniforms and all other products where they are not essential," said Arlene Blum, co-author and executive director of the Green Science Policy Institute. "Manufacturers can prevent harm by moving away from PFAS as soon as possible."

The researchers recommend that parents check labels to see if their children's' uniforms are marketed as stain resistant. If so, they say there is some evidence to suggest that multiple washes can reduce PFAS concentration. They also say that used clothes or hand-me-down clothes are better options, because the levels of PFAS might decline with laundering.

Other authors of the study include Chunjie Xia of the O'Neill School at IU; Graham Peaslee, Heather Whitehead and Megan Green from the University of Notre Dame; Zhanyun Wang of the Swiss Federal Laboratories for Materials Science and Technology; and Hui Peng, Anna Shalin, Heather Schwartz-Narbonne and Diwen Yang of the University of Toronto.

---

JOURNAL

Environmental Science & Technology

DOI

10.1021/acs.est.2c02111 

People who are ‘night owls’ could have greater risk of type 2 diabetes and heart disease than those who are ‘early birds’

Are you an early bird or a night owl? Our activity patterns and sleep cycles could influence our risk of diseases, such as type 2 diabetes and heart disease. New research published in Experimental Physiology found wake/sleep cycles cause metabolic differences and alter our body’s preference for energy sources. The researchers found that those who stay up later have a reduced ability to use fat for energy, meaning fats may build-up in the body and increase risk for type 2 diabetes and cardiovascular disease.

The metabolic differences relate to how well each group can use insulin to promote glucose uptake by the cells for storage and energy use. People who are ‘early birds’ (individuals who prefer to be active in the morning) rely more on fat as an energy source and are more active during the day with higher levels of aerobic fitness than ‘night owls’. On the other hand, ‘night owls’ (people who prefer to be active later in the day and night) use less fat for energy at rest and during exercise.

Researchers from Rutgers University, New Jersey, USA classified participants (n=51) into two groups (early and late) based on their ‘chronotype’ – our natural propensity to seek activity and sleep at different times. They used advanced imaging to assess body mass and body composition, as well as insulin sensitivity and breath samples to measure fat and carbohydrate metabolism.

Participants were monitored for a week to assess their activity patterns across the day. They ate a calorie and nutrition-controlled diet and had to fast overnight to minimise dietary impact on the results. To study fuel preference, they were tested while at rest before completing two 15-minute bouts of exercise: one moderate and one high intensity session on a treadmill. Aerobic fitness levels were tested through an incline challenge where the incline was raised 2.5% every two minutes until the participant reached a point of exhaustion.

Researchers found that early birds use more fat for energy at both rest and during exercise than night owls. Early birds were also more insulin sensitive. Night owls, on the other hand, are insulin resistant, meaning their bodies require more insulin to lower blood glucose levels, and their bodies favoured carbohydrates as an energy source over fats. This group’s impaired ability to respond to insulin to promote fuel use can be harmful as it indicates a greater risk of type 2 diabetes and/or heart disease. The cause for this shift in metabolic preference between early birds and night owls is yet unknown and needs further investigation.

Senior author Professor Steven Malin, Rutgers University, New Jersey, USA said:

“The differences in fat metabolism between ‘early birds’ and ‘night owls’ shows that our body’s circadian rhythm (wake/sleep cycle) could affect how our bodies use insulin. A sensitive or impaired ability to respond to the insulin hormone has major implications for our health. This observation advances our understanding of how our body’s circadian rhythms impact our health. Because chronotype appears to impact our metabolism and hormone action, we suggest that chronotype could be used as a factor to predict an individual’s disease risk.”

“We also found that early birds are more physically active and have higher fitness levels than night owls who are more sedentary throughout the day. Further research is needed to examine the link between chronotype, exercise and metabolic adaptation to identify whether exercising earlier in the day has greater health benefits.”

---

JOURNAL

Experimental Physiology

DOI

10.1113/EP090613 

Many heart-related emergencies are due to uncontrolled blood pressure

 The top cardiovascular (CVD) diagnoses from U.S. emergency departments suggest that many cardiovascular emergencies are due to poorly controlled high blood pressure, according to a study of more than 20 million emergency department visits published Sept. 8 in the Journal of the American Heart Association, an open access, peer-reviewed journal of the American Heart Association.

The researchers found that 13% of all heart-related emergency department diagnoses, representing more than 2.7 million people, were for “essential” hypertension, which is high blood pressure not caused by other diseases. Most cases of high blood pressure are essential hypertension.

“These visits resulted in hospital admission less than 3% of the time and with very few deaths - less than 0.1%. This suggests that these visits were mostly related to the management of hypertension,” said lead author Mamas A. Mamas, M.D., a professor of cardiology at Keele University in Stoke-on-Trent, and a consultant cardiologist at University Hospitals of North Midlands NHS Trust, both in the UK.

For the 15 CVD conditions detailed in the study, about 30% were hypertension-related diagnoses.

The study analyzed cardiovascular diagnoses made during emergency department visits that were part of the Nationwide Emergency Department Sample from 2016-2018. The sample was 48.7% women, and the average age was 67 years. The majority were Medicare or Medicaid participants. Men in the sample were more likely to have other diseases in addition to cardiovascular disease, such as diabetes, while women had higher rates of obesity, high blood pressure and medical conditions that affect blood vessels in the brain.

The most common heart- or stroke-related diagnoses for women seen in the emergency department were high blood pressure (16% of visits), high blood pressure-related heart or kidney disease (14.1%) and atrial fibrillation (10.2%). The most common diagnoses for men were high blood pressure-related heart or kidney disease (14.7%), high blood pressure (10.8%) and heart attack (10.7%).

“Previous studies have shown sex differences in patterns of CVD among hospitalized patients,” Mamas said. “However, examining CVD encounters in the emergency department provides a more complete picture of the cardiovascular health care needs of men and women, as it captures encounters prior to hospitalization.” He also points out that previous studies of CVD emergency visits are limited to suspected heart attack visits. “Therefore, this analysis of 15 CVD conditions helps to better understand the full spectrum of acute CVD needs, including sex disparities in hospitalization and risk of death.”

The study found that outcomes from the emergency CVD visits were slightly different for men and women. Overall, women were less likely to die (3.3% of women vs 4.3% of men) or be hospitalized (49.1% of women vs 52.3% of men) after an emergency department visit for CVD. The difference may be due to women’s generally lower risk diagnoses, said Mamas, but there could be an underestimation of deaths in women.

“We did not track deaths outside of the hospital setting,” said Mamas. “Given past evidence that women are more likely to be inappropriately discharged from the emergency department, and strong evidence for the systemic undertreatment of women, further study is warranted to track outcomes beyond the emergency department visit.”

An additional limitation of the data includes potential misdiagnosis errors in cases where the final diagnosis did not match the emergency diagnosis, particularly after a hospitalization and additional bloodwork and other health information could be obtained. Furthermore, the data is limited in that it does not capture information related to severity of disease, which may make comparisons around mortality differences between different patient groups challenging.

“Our work with this large, nationally representative sample of cardiovascular emergency visits highlights differences in health care needs of men and women, which may be useful to inform planning and provision of health care services,” said Mamas. “We also encourage further research into understanding the underlying factors driving the differences in CVD patterns and outcomes between men and women.”

Studies published in the American Heart Association’s scientific journals are peer-reviewed. The statements and conclusions in each manuscript are solely those of the study authors and do not necessarily reflect the Association’s policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. The Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and biotech companies, device manufacturers and health insurance providers and the Association’s overall financial information are available here. 

Additional Resources:

• Available multimedia is on right column of release link https://newsroom.heart.org/news/many-heart-related-emergencies-are-due-to-uncontrolled-blood-pressure
• View the manuscript online.
• AHA news release: Women and Black adults waited longer in ER for chest pain evaluation (May 2022)
• AHA news release: Investment, action urged to improve access, quality and equity in women’s heart health (May 2022)
• Follow AHA/ASA news on Twitter @HeartNews
• Follow news from the Journal of the American Heart Association @JAHA_AHA