Tuesday, June 30, 2020

'Morning sickness' is misleading and inaccurate,

The term 'morning sickness' is misleading and should instead be described as nausea and sickness in pregnancy, argue researchers led by the University of Warwick who have demonstrated that these symptoms can occur at any time of the day

UNIVERSITY OF WARWICK

Analysis of symptom diaries kept by 256 pregnant women shows that is inaccurate to describe nausea and vomiting in pregnancy as 'morning sickness'
Team led by University of Warwick finds that symptoms can occur at any time of the day
Although likelihood of experiencing symptoms is highest in the morning, nausea was still likely to occur later in the day
First time that the symptom patterns of nausea and vomiting in pregnancy have been mapped

The researchers call for the change in a study published today (30 June) in the British Journal of General Practice which shows that, while the most likely time for pregnancy sickness symptoms to occur is in the morning, a significant number of women can experience them at any time of the day.

'Morning sickness' has long been used to describe nausea and vomiting that women often experience in the early stages of pregnancy. Although pregnant women often report experiencing nausea and sickness throughout the waking day, until now no research has described the likelihood of these symptoms occurring at different times of the day.

For this study, the researchers used data from daily symptom diaries kept by 256 pregnant women. In these diaries, the women recorded their experience of nausea and vomiting for each hour in the day, from the day they discovered they were pregnant until the 60th day of their pregnancy. The researchers then used this data to map the likelihood of experiencing nausea and experiencing vomiting in each hour of the day, broken down into weeks following last ovulation.

They found that whilst vomiting was most common between the hours of 7.00 am and 1.00 pm, nausea is highly likely throughout the whole daytime, not just the morning. Furthermore, many women still reported vomiting as a symptom even into the evening. The most common hour for participants to experience nausea and vomiting was between 9.00 am and 10.00 am with 82% experiencing nausea in this hour, and 29% experiencing vomiting.

94.2% of participants experienced at least one of these symptoms during the study, with 58% experiencing both.

In addition, by comparing occurrence of symptoms across the first 7 weeks of pregnancy, measured from last ovulation, the researchers found that the later the week, the higher the probability of experiencing symptoms. The probability of experiencing nausea is at its highest in weeks 5, 6 and 7 while for vomiting it is in week 7. As the study only examined the first seven weeks of pregnancy, the probabilities after week 7 are not known.

Professor Roger Gadsby, of Warwick Medical School, said: "Morning sickness is widely used by the general public, media and even healthcare professionals but it doesn't give an accurate description of the condition.

"If a pregnant woman experiences sickness in the afternoon she may feel that this is unusual and wrong, or if she experiences no vomiting but feels nauseated all day she might think she is not covered by the term 'morning sickness'. And those women who experience severe symptoms feel it trivialises the condition.

"Nausea and vomiting in pregnancy (NVP) can have a significant negative impact on the lives of sufferers. It can cause, feelings of depression, of being unable to look after the family, and of loss of time from paid work. Very severe NVP called hyperemesis gravidarm (HG) is the commonest cause of admission to hospital in the first trimester of pregnancy."

It is estimated that the annual costs of managing nausea and vomiting in pregnancy to the NHS in England and Wales are around £62 million.

The study authors said: "The continued use of the term 'morning sickness' could imply that symptoms only rarely occur in the afternoon and evening so that sufferers will have significant parts of the day symptom-free.

"This study shows that this is an incorrect assumption and that symptoms, particularly nausea, can occur at any time of the day."

Nearly half of Americans lack knowledge of burn injuries and treatment

Summertime means Americans are spending more time around grills, firepits, and fireworks, increasing their risk for fire-related burn injuries. While 53% of Americans say they know some or a lot about burn injuries and treatment, many mistakenly underestimate their risks with these activities, according to a new Arizona Burn Center at Valleywise Health/Ipsos survey. In fact, only 11% know that fire-flame injuries such as those from a firepit or grill are the most common types of burn injuries.

"Burn injuries increase in the summer months as more people are grilling outside, sitting around firepits, and setting off fireworks," said Kevin Foster, MD, director of Burn Services for the Arizona Burn Center at Valleywise Health. "It's important for people to be aware of not only their risk for suffering from a burn injury, but what to do if they or a loved one experience a burn."

The online survey of 1,000 adults conducted in June by Ipsos, a multinational independent market research firm, shows that a majority of Americans are unaware that applying ice to a burn is not recommended. Nearly six in 10 either think you should immediately apply ice directly to a burn (39%) or do not know whether it is okay (18%), when doing so can actually increase tissue damage.

Additionally, 40% of Americans say they are planning to use their own fireworks or sparklers this summer, activities that put a significant number of people at risk for serious burns. Children are particularly at risk because parents are more likely than the general population to report they will be around fire hazards, including fireworks (65.8% vs. 40%), and firepits or campfires (65% vs. 50%). Additionally, of those parents planning to use or be around fireworks, half (50%) say they don't know much or anything at all about burn injuries and treatments.

Lack of knowledge can be especially dangerous around grills, as they account for thousands of visits to the emergency room every year. Seventy-one percent of respondents say they are planning to grill this summer, but one in four incorrectly thinks water is the best way to put out a grill fire. Additionally, while nearly two-thirds (59%) of parents who plan to grill this summer know it is not okay to put out a grill fire with water, 41% falsely think it is okay or don't know. "Burns are one of the leading causes of injury-related death in children, so the lack of knowledge that Americans demonstrate around burn injuries is concerning," said Dr. Foster. "People need to be aware of the dangers, even with something as common as grilling, so that they are prepared to react appropriately and safely in an emergency. I encourage anyone planning to grill or use a firepit or fireworks this summer to review basic safety measures for these activities and understand what to do if someone experiences a burn."

If you plan to use or be around a grill, firepit, fireworks, or sparklers this summer, here are just a few tips to help keep you and your family safe:

When grilling, cook your food in batches to avoid overloading the grill, particularly with fatty meats that can cause a flare-up.
If you are faced with a grill fire, use a fire extinguisher to put out the flames, not water.
Keep children and pets at least three feet away from the grill area at all times.
If the flame goes out on your gas grill, turn the grill and gas off and wait at least 5 minutes before re-lighting.
Fire pits should be placed at a minimum of ten feet away from your house.
Store matches and lighters out of children's sight and reach.
Use a metal screen over wood-burning firepits to keep sparks and embers contained.
When using fireworks or sparklers, keep a supply of water or fire extinguisher at hand.
Never hold lighted fireworks in your hands and never use fireworks while impaired by alcohol.
Instead of sparklers, consider using safer alternatives, such as glow sticks, confetti poppers or colored streamers.

If you or someone with you experiences a burn, please seek immediate medical attention if the burn is larger than your palm; it covers your hands, joints, or face; if the pain progressively gets worse; or if the skin is peeling. For more information on burn safety, please visit The Arizona Burn Center's website: https://valleywisehealth.org/patient-education-resource/burn-care-patient-education/

Light drinking may protect brain function

Light to moderate drinking may preserve brain function in older age, according to a new study from the University of Georgia.

The study examined the link between alcohol consumption and changes in cognitive function over time among middle-aged and older adults in the U.S.

"We know there are some older people who believe that drinking a little wine everyday could maintain a good cognitive condition," said lead author Ruiyuan Zhang, a doctoral student at UGA's College of Public Health.

"We wanted to know if drinking a small amount of alcohol actually correlates with a good cognitive function, or is it just a kind of survivor bias."

Regular, moderate alcohol consumption has been shown to promote heart health and some research points to a similar protective benefit for brain health. However, many of these studies were not designed to isolate the effects of alcohol on cognition or did not measure effects over time.

Zhang and his team developed a way to track cognition performance over 10 years using participant data from the nationally representative Health and Retirement Study.

During the study, a total of 19,887 participants completed surveys every two years about their health and lifestyle, including questions on drinking habits. Light to moderate drinking is defined as fewer than eight drinks per week for women and 15 drinks or fewer per week among men.

These participants also had their cognitive function measured in a series of tests looking at their overall mental status, word recall and vocabulary. Their test results were combined to form a total cognitive score.

Zhang and his colleagues looked at how participants performed on these cognitive tests over the course of the study and categorized their performance as high or low trajectories, meaning their cognitive function remained high over time or began to decline.

Compared to nondrinkers, they found that those who had a drink or two a day tended to perform better on cognitive tests over time.

Even when other important factors known to impact cognition such as age, smoking or education level were controlled for, they saw a pattern of light drinking associated with high cognitive trajectories.

The optimal amount of drinks per week was between 10 and 14 drinks. But that doesn't mean those who drink less should start indulging more, says Zhang.

"It is hard to say this effect is causal," he said. "So, if some people don't drink alcoholic beverages, this study does not encourage them to drink to prevent cognitive function decline."

Also of note, the association was stronger among white participants versus African American participants, which is significant, said Zhang, and prompts further exploration into the mechanisms of alcohol's effect on cognition.

Many antibiotic substitutions for self-reported penicillin allergies likely unnecessary

Hospitalized patients who report an allergy to penicillin are often prescribed alternative antibiotics for infection that can be harmful, even though diagnostic testing or evaluations would show that the vast majority of these reported allergies could be disproven, according to researchers from Massachusetts General Hospital.

In a national study published in JAMA Internal Medicine, the team found that the 16% of hospitalized patients with a documented penicillin allergy were twice as likely to be prescribed alternative antibiotics. Given that more than 90 percent of documented penicillin allergies are unconfirmable, those antibiotic substitutions by physicians were likely unnecessary.

"Too often clinicians are making inferior antibiotic decisions based on unverified penicillin allergy histories that may date back to a patient's childhood and are no longer valid," says Kimberly Blumenthal , MD, MSc, with the Division of Rheumatology, Allergy, and Immunology, MGH, and lead author of the study.

"As a result, patients are often prescribed antibiotics other than penicillins and cephalosporins - some of our core infection fighters - that may increase the risk of adverse side effects and antibiotic resistance.

"This pattern could be changed with a little more testing or, in many cases, by simply taking the time to talk to patients in order to learn more about a reported penicillin allergy, instead of taking the penicillin allergy label at face value."

Approximately half of hospitalized patients today receive antibiotics to treat or prevent infections caused by bacteria, and more than 10 percent have a penicillin allergy documented in their medical records.

In the first study to investigate antibiotic use patterns in documented penicillin allergy on a national scale, Mass General researchers combed the records of nearly 11,000 patients at 106 hospitals.

They found that the 16 percent of inpatients with a penicillin allergy on their medical records were typically treated with β-lactam alternative antibiotics, including significantly increased use of clindamycin, linezolid, fluoroquinolones, aminoglycosides, tetracyclines, and vancomycin.

The highest risk exposure was to clindamycin, which is associated with C difficile infection. Patients with a documented penicillin allergy were five times more likely to be given clindamycin than those without such an allergy.

Another key finding involved inpatients with a documented penicillin allergy who received antibiotics as prophylaxis for an upcoming surgical procedure to prevent infections. Although a β-lactam is the recommended antibiotic for this indication in most cases, the study found that patients with a documented penicillin allergy were nine-fold less likely to receive a β-lactam, but seven-fold more likely to receive a β-lactam alternative antibiotic.

"Hospitals should especially be targeting penicillin allergy evaluations for patients with planned surgical procedures and those who are otherwise likely to be prescribed clindamycin," says Rochelle Walensky, MD, MPH, chief of Infectious Diseases at MGH, Steve and Deborah Gorlin MGH Research Scholar and senior author of the study.

"For patients who claim a penicillin allergy, those interventions could be as simple as asking the right questions and compiling a comprehensive history. Unfortunately, antibiotic decisions are often made based on limited information or without a thorough investigation. We learned from our study that antibiotic prescribing without full allergy information can ultimately do the patient more harm than good."

Blumenthal, an expert in allergy and immunology, underscores the need for hospitals across the country to more aggressively address penicillin allergy risk detection. While a diagnostic test exists to help clinicians accurately make that determination, less than half of hospitals have access to it, she points out.

"Hospitals should clearly be treating patients with the most targeted and effective antibiotic for their infection, rather than being influenced by a penicillin reaction years earlier that might have been nothing more than itching or a headache," Blumenthal declares. "That will require hospitals to become much more vigilant and proactive in penicillin allergy assessment as part of their inpatient antibiotic stewardship programs."

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The consumption of too much fructose -- particularly in a short period of time -- can overwhelm the gut

After one consumes food or a beverage containing fructose, the gastrointestinal system, or gut, helps to shield the liver from damage by breaking down the sugar before it reaches the liver, according to a new multi-center study led by researchers in the Perelman School of Medicine at the University of Pennsylvania. However, the consumption of too much fructose -- particularly in a short period of time -- can overwhelm the gut, causing fructose to "spill over" into the liver, where it wreaks havoc and causes fatty liver, researchers discovered.

The findings, in mice, help to unravel longstanding questions about how the body metabolizes fructose -- a form of sugar often found in fruits, vegetables, and honey, as well as most processed foods in the form of high fructose corn syrup. Consumption of fructose has increased 100-fold over the last century, even as studies have shown that excessive consumption, particularly sweet drinks, are linked to non-alcoholic fatty liver disease, obesity and diabetes. The findings were published in Nature Metabolism.

"What we discovered and show here is that, after you eat or drink fructose, the gut actually consumes the fructose first -- helping to protect the liver from fructose-induced damage," said the study's corresponding author Zoltan Arany, MD, PhD, a professor of Cardiovascular Medicine at Penn. "Importantly, we also show that consuming the food or beverage slowly over a long meal, rather than in one gulp, can mitigate the adverse consequences."

Studies have shown that the excessive consumption of fructose can be toxic to the liver. When large quantities of fructose reach the liver, the liver uses excess fructose to create fat, a process called lipogenesis. Eventually, people who consume too much fructose can develop nonalcoholic fatty liver disease, a condition in which too much fat is stored in the liver cells.

Until now, it hasn't been clear whether the gut's role in processing the fructose prevents or contributes to fructose-induced lipogenesis and the development of liver diseases. For this study, the team of researchers, including Princeton University's Joshua Rabinowitz, MD, PhD, studied a key enzyme, called ketohexokinase, that controls how fast fructose is consumed. They showed, by genetically engineering mice, that lowering the levels of this enzyme in the gut led to fatty livers in the mice. Conversely, the team showed that increasing the level of ketohexokinase in the gut protected from fatty liver. Thus, the researchers found the breakdown of fructose in the gut mitigates the development of extra fat in liver cells in mice. They discovered that the rate at which the intestine can clear fructose determines the rate at which fructose can be safely ingested.

In addition, the team showed the same amount of fructose is more likely to result in the development of fatty liver when its consumed via a beverage versus food. Similarly, one faces an increased likelihood of developing fatty liver when consuming fructose in a single setting compared to several doses spread over 45 minutes.

"Collectively, our findings show fructose induces lipogenesis when the intake rate exceeds the gut's capacity to process fructose and protect the liver," Arany said. "In the modern context of excessive availability and consumption of processed foods, it is easy to see how the resulting fructose spillover would drive metabolic syndrome."

Researchers noted that more work is needed to determine the extent to which these findings in mice extend to humans. Additional Penn authors include Shogo Wada, Steven Yang and Bridget Gosis.

Monday, June 29, 2020

Alternative medicine is widespread among people with MS

A new survey of more than 1,000 people with multiple sclerosis finds that an overwhelming majority use complementary and alternative medicine, with many using cannabis.

Researchers at Oregon Health & Science University conducted the survey of people in Oregon and Southwest Washington in 2018. The results were published recently in the journal Multiple Sclerosis and Related Disorders.

The survey found that patients are nine times more likely to talk with their neurologist about the use of alternative therapies than patients in a similar survey conducted in 2001, a sign of broader societal acceptance of treatments beyond conventional medications. In the years since the first survey, several conventional medications have become available to manage MS-related disease activity.

Even so, patients appear to be more inclined to use alternatives such as dietary supplements, despite limited evidence of their effectiveness.

"The use of these alternative supplements has remained high even though we have all these other treatment modalities," said lead author Elizabeth Silbermann, M.D., a fellow in neurology in the OHSU School of Medicine.

Key findings:

81% used dietary supplements such as vitamins, minerals and herbs, up from 65% in the same survey conducted almost two decades ago.
39% used mind-body therapies such as mindfulness and massage, up from 14% in the earlier survey.
81% used exercise to help manage their symptoms - an increase from 67% in 2001.

The use of cannabis was common among respondents in the new survey, with about 30% reporting that they've used it in a variety of forms. Although cannabis remains an illegal substance under federal law, voters in recent years legalized it in both Oregon and Washington state.

Even though traditional uses of alternative therapies such as botanical supplements dates back hundreds of years, scientific research generally has been limited. Silbermann said it's a positive sign that patients are more open to discussing their use of alternatives with their neurologist because it's important to manage interactions with conventional medications.

"There's been a change in culture between patients and providers over the past 20 years," Silbermann said. "It's less paternalistic and more of a partnership."

More research is needed so that neurologists can tell patients what does and doesn't help their MS, she said. About 85% of the respondents reported mild or moderate disability.

Senior author Rebecca Spain, M.D., M.S.P.H., associate professor of neurology in the OHSU School of Medicine, said she was gratified the survey reflected patients' comfort and openness in sharing their full experience with their doctors. She said that may be due in part to OHSU's well-established reputation as an academic health center that supports patients' use of complementary and alternative medicine, or CAM.

"Patients' openness in sharing the whole picture of what CAM they're taking has allowed us to better understand and effectively care for our patients with MS," Spain said.

Long-term use of muscle relaxants has skyrocketed since 2005

Office visits for ongoing prescribing of skeletal muscle relaxant drugs tripled from 2005 to 2016, according to a new study from researchers in the Perelman School of Medicine at the University of Pennsylvania.

Moreover, in 2016, nearly 70 percent of patients prescribed muscle relaxants were simultaneously prescribed an opioid -- a combination that has the potential to cause dangerous interactions. The researchers also found that muscle relaxants were prescribed disproportionately to older adults during this time period, despite national guidelines warning that this class of drugs should almost always be avoided in patients who are 65 and older. The results were published today in JAMA Network Open.

"There are few studies on the short-term efficacy and safety of skeletal muscle relaxants, and almost no data on their long-term effects, so it is very concerning that patients, and particularly older adults, are using these drugs for an extended period of time," said Charles E. Leonard, PharmD, MSCE, an assistant professor of Epidemiology. "Providers seem to be reaching for them despite incomplete information on their potential benefits and risks."

Skeletal muscle relaxants are drugs that were approved years ago for short-term treatment of muscle spasms and back pain, and are used today, without good evidence, to treat chronic pain and other conditions. Recommendations generally limit the use of these drugs to a maximum of three weeks, since they have not been shown to work for muscle spasms beyond that duration, and they can cause serious side effects including falls, fractures, vehicle crashes, abuse, dependence, and overdose. Due to these risks, muscle relaxants should be avoided altogether in elderly patients, according to guidelines from the American Geriatrics Society.

Despite these concerns, Leonard and his colleagues hypothesized that the growing opioid epidemic may have led clinicians to prescribe muscle relaxants as an alternative to opioids for long-term pain management.

To measure national trends in muscle relaxant prescribing, the researchers analyzed publicly-available 2005-2016 data from the National Ambulatory Medical Care Survey. NAMCS is a U.S.-based annual survey of non-federally funded office-based physicians engaged in direct patient care. The researchers examined the total number of visits per year, and stratified counts by the muscle relaxant agent, whether the drug was newly prescribed or continued therapy, as well as the race, ethnicity, and sex of the patient, and the region of the visit.

From 2005 to 2016, the number of office visits resulting in new muscle relaxant prescriptions remained stable at approximately 6 million per year, while office visits for continued muscle relaxant drug therapy tripled -- from 8.5 million in 2005 to 24.7 million in 2016. Worryingly, older adults accounted for 22.2 percent of all muscle relaxant visits in 2016, even though this group accounted for just 14.5 percent of the U.S. population. Also of concern, in 2016, 67 percent of the continued muscle relaxant visits also recorded therapy with an opioid. The U.S. Food and Drug Administration warns against use of co-prescribing of these medications, because of the risk of serious side effects, including slowed or difficult breathing, and death.

"For older adults, I think the message should be to avoid using muscle relaxants, especially when we consider the side effects and increased risk of falls and fractures, and to find alternatives for pain management," said the study's first author Samantha Soprano, MPH, a research coordinator and student in Penn's Master of Behavioral and Decision Sciences program.

Leonard added that, in addition to potential adverse effects, muscle relaxants may not be any more effective in managing pain than medications like Tylenol or Advil. Past studies examining muscle relaxants found they were more efficacious than a placebo, but they were not compared to other therapies. Further research is needed to determine more detailed information about the effects of muscle relaxants, particularly when used for longer periods of time, since their use is so widespread, Leonard said. Additionally, doctors need better, safer options for managing patients' pain.

"Muscle relaxants' place in therapy is really limited. Based on most guidelines, they're normally reserved as second- or third-line therapies," Leonard said. "Our findings suggest that prescribers may be reaching for these drugs sooner than that."

Gas cooker exposure can lower blood pressure,

A study, published recently in Circulation Research and led by a team from King's College London, has investigated how nitrogen dioxide can impact the cardiovascular system.

The study examined the blood chemistry and cardiovascular changes of 12 healthy volunteers. They sat next to a domestic gas cooker for ninety minutes followed by ninety minutes with normal background nitrogen levels. On another occasion, the volunteers were exposed to normal background nitrogen dioxide levels for three hours.

The period next to a gas cooker increased nitrogen dioxide levels in the air 10-fold and subsequently lowered blood pressure by 5 mm Hg from 45 minutes onwards. The study also found that blood levels of the substance nitrite increased by 15% after 15 minutes.

Previous studies have shown nitrite, which can be converted from dietary nitrate following the ingestion of green leafy vegetables and beetroot, can lower blood pressure. This study suggests nitrite can also be made when the body processes nitrogen dioxide and makes a link between previous research focusing on dietary nitrate and studies of inhalation of nitrogen dioxide for the first time.

Air pollution contributes to illness and death in the general population, but it is a complex mixture of airborne particles and gases, including nitrogen dioxide. Working out the individual effects of each is challenging and there has been a running debate about how to distinguish between the independent effects of nitrogen dioxide and respirable particles in the air.

While the evidence linking nitrogen dioxide to a worsening of symptoms in respiratory disease is well established, its short-term impact on the heart and circulation is less clear. Notably, people with domestic gas appliances or people working in kitchens with gas cookers may be exposed to higher levels of nitrogen dioxide, but with less particulate matter, than that found on the street.

This unique study helps to shed light on some of the rapid effects of nitrogen dioxide on the heart and circulation. Looking at previous air pollution studies, it had been unclear whether the nitrite in the blood came from nitrogen dioxide or from particulate matter causing inflammation and generation of nitric oxide, which is converted to nitrite. This study suggests that it is the nitrogen dioxide that causes nitrite to be formed in the blood.

Crucially, while this effect of short-term exposure to nitrogen dioxide in healthy volunteers may be beneficial, there are other studies of adverse effects of long-term exposure to nitrogen dioxide, and on adverse effects of short-term exposure in asthmatics.

Further research will confirm these findings in larger studies and examine the effects on a more varied cohort.

Dr Andrew Webb, Clinical Senior Lecturer at King's College London, said: "High blood pressure is the biggest single contributor to deaths around the world. Therefore, if exposure to nitrogen dioxide from gas cookers contributes to lowering blood pressure, this could be beneficial per se, and in the context of general air pollution may partially offset the adverse cardiovascular effects of short-term exposures to elevated particulate matter concentrations.

"The mechanism by which nitrogen dioxide lowers blood pressure appears to be through linking into the same pathway as dietary nitrate (found in green leafy vegetables and beetroot): both result in an increase in blood nitrite levels. Therefore, it is not just what you eat, but how you cook it that matters."

Evaluating the impact of long-term exposure to fine particulate matter on mortality among the elderly

A new analysis of 16 years of publicly accessible health data on 68.5 million Medicare enrollees provides broad evidence that long-term exposure to fine particles in the air - even at levels below current EPA standards - leads to increased mortality rates among the elderly. Based on the results of five complementary statistical models, including three causal inference methods, the researchers estimate that if the EPA had lowered the air quality standard for fine particle concentration from 12 μg/m3 down to the WHO guideline of 10 μg/m3, more than 140,000 lives might have been saved within one decade. "Our findings provide the strongest evidence to date that current national air quality standards aren't sufficiently protective of Americans' health," said corresponding author Francesca Dominici. "Now, in the middle of a pandemic that attacks our lungs and makes us unable to breathe, it is irresponsible to roll back environmental policies," she added. The new study is likely to inform national discussions around updating air quality standards, for example, the National Ambient Air Quality Standards by the EPA.

A number of studies have documented a strong correlation between long-term exposure to fine particulate and greater human mortality, but some concern has remained about the causal nature of the evidence, and whether it is sufficient to inform revisions to air quality standards. Some scientists argue that modern causal inference methods can provide such evidence, using the right data. "Causal inference can quantify and visualize how close our data are to approximating a randomized controlled study, the gold standard for assessing causation," said the study's lead author Xiao Wu. Analyzing a massive dataset through five distinct approaches, including two traditional statistical methods and three causal inference methods, Wu and colleagues derived broad evidence consistent with a causal link between long-term particulate exposure and mortality. Modeling a 10 μg/m3 decrease of fine particle concentration between 2000 and 2016 resulted in a 6% to 7% decrease in mortality risk. Based on their model results, the researchers estimated that more than 140,000 lives might have been saved if the current U.S. standard for fine particle concentration had been lowered to 10 μg/m3 between 2007 and 2016. The authors emphasize the urgent need to modify particulate concentration levels to help protect elderly individuals with respiratory diseases living in polluted areas.

Excessive sugar intake linked with unhealthy fat deposits

Sugar consumption is linked with larger fat deposits around the heart and in the abdomen, which are risky for health. That's the finding of a study published today in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).1

"When we consume too much sugar the excess is converted to fat and stored," said study author Ms. So Yun Yi, a PhD student at the University of Minnesota School of Public Health. "This fat tissue located around the heart and in the abdomen releases chemicals into the body which can be harmful to health. Our results support limiting added sugar intake."

Excess sugar consumption is a worldwide problem. The six countries with the highest sales of sugary drinks per capita are Chile, Mexico, Argentina, Peru, the US, and Saudi Arabia. The demand for sugar is expected to increase in Asia, Africa, and Russia.

This observational study examined both sugar-sweetened beverages (such as soft drinks, fruit drinks, energy drinks) and sugar added to foods and beverages for sweetness (for example when cooking or in processed foods). The researchers analysed the association between long-term sugar consumption and fat stores around the heart and other organs.

Data were obtained from Coronary Artery Risk Development in Young Adults (CARDIA), an ongoing cohort study in the US that includes centres in Alabama, California, Illinois, and Minnesota. A total of 3,070 healthy participants aged 18 to 30 were included in this study.

Food and beverage intakes were measured three times over a 20-year period (1985 to 2005). After 25 years (in 2010) computed tomography (CT) scans of the chest and abdomen were performed to measure fat volumes in the abdomen and around the heart.

The researchers found that sugar intake over the 20-year period was related to fat volumes later in life. Higher intakes of both sugar-sweetened beverages and added sugar were related to greater fat stores around organs in a stepwise fashion.

"Our findings provide more evidence that consuming too much added sugar and sugary drinks is related to a higher amount of fat tissue," said study author Dr. Lyn Steffen of the University of Minnesota School of Public Health. "And, we know that fat deposits are connected with higher risks of heart disease and diabetes."

She advised reducing the amount of added sugar consumed each day. "Have water instead of sugary drinks and choose healthier snacks over foods rich in added sugar like cakes," she said. "Read food labels to check the amount of added sugar in what you are buying. Look for ingredients like syrups, glucose, fructose, sucrose, and maltose. Being more aware of hidden sugar will help you cut back."

Dr. Steffen said: "On top of our individual efforts, governments, food manufacturers, restaurants, schools, and workplaces have a role to play in increasing consumer awareness of the sugar content in foods and beverages and offering healthier alternatives."

Lifting weights makes your nervous system stronger, too

IMAGE: THE WEIGHT TRAINING SETUP (LEFT) AND THE WEIGHT PROGRESSION FOR EACH MONKEY (RIGHT). view more

CREDIT: GLOVER AND BAKER, JNEUROSCI 2020

Gym-goers may get frustrated when they don't see results from weightlifting right away, but their efforts are not in vain: the first few weeks of training strengthen the nervous system, not muscles. New research published in JNeurosci reveals how.

The brain orchestrates movement via two major neural highways descending to the spinal cord: the corticospinal tract (CST) and reticulospinal tract (RST). The CST is thought to be the dominant pathway, with the RST controlling posture. However, the CST does not change during strength training, so increased strength must stem from the more primitive RST.

Glover and Baker trained monkeys to pull a weighted handle using one arm, with the weight gradually increasing over twelve weeks. Each day, the scientists stimulated the motor cortex and the two motor tracts, measuring the resulting electrical activity in the arm muscles. Over the course of the training regimen, the electrical response from stimulating the cortex and RST increased -- a sign of strengthened signaling. After three more months of strength training, stimulating the RST elicited a greater response in the side of the spinal cord connected to the trained arm. Outputs from the reticulospinal tract become more powerful during weight training and could be the driving force behind increases in strength.

Exercise increases benefits of breast milk for babies

A new study led by researchers at The Ohio State University Wexner Medical Center and College of Medicine finds even moderate exercise during pregnancy increases a compound in breast milk that reduces a baby's lifelong risks of serious health issues such as diabetes, obesity and heart disease.

Findings from the study published online today in the journal Nature Metabolism.

"We've done studies in the past that have shown that maternal exercise improves the health of offspring, but in this study, we wanted to begin to answer the question of why," said Kristin Stanford, a researcher at The Ohio State Wexner Medical Center's Diabetes and Metabolism Research Center and lead author of the study. "Because there is evidence that breast milk plays a major role, we wanted to isolate the effects of breast milk on offspring health."

To do that, Stanford and her team - including researchers at the University of California, San Diego, Arkansas Children's Nutrition Center, and the Joslin Diabetes Center - studied mice born from sedentary mothers and fed them milk from mothers who were active throughout pregnancy. They found that the health benefits from fit moms transferred to the pups, proving that they were, in fact, passed through breast milk and not simply inherited genetic traits.

Researchers also followed about 150 pregnant and postpartum women using activity trackers and found that those who had more steps per day had an increased amount of a compound known as 3SL in their breast milk, which they believe is responsible for these health benefits.

"The increase in 3SL were not necessarily related to exercise intensity, so even moderate exercise like a daily walk is enough to reap the benefits," said Stanford, an associate professor of physiology and cell biology at Ohio State's Dorothy M. Davis Heart and Lung Research Institute. "Exercise is also great for your overall health during and after pregnancy, so anything you can do to get moving is going to benefit both you and your baby."

Because many women are unable to breastfeed or experience complications that require bed rest, researchers are examining if they can isolate this beneficial compound found in the breast milk of active moms and add it to infant formula.

"This human milk oligosaccharide had a significant impact on offspring healthy. Being able to add this into formula could provide benefits for babies when women aren't able to breastfeed," Stanford said.

Raw milk may do more harm than good

Raw or unpasteurized cows' milk from U.S. retail stores can hold a huge amount of antimicrobial-resistant genes if left at room temperature, according to a new study from researchers at the University of California, Davis. The study also found bacteria that harbored antimicrobial-resistant genes can transfer them to other bacteria, potentially spreading resistance if consumed. The study was published in the journal Microbiome.

"We don't want to scare people, we want to educate them. If you want to keep drinking raw milk, keep it in your refrigerator to minimize the risk of it developing bacteria with antibiotic-resistant genes," said lead author Jinxin Liu, a postdoctoral researcher in the Department of Food Science and Technology at UC Davis.

LACKING IN PROBIOTICS

An estimated 3 percent of the U.S. population consumes unpasteurized, or raw, milk, which has not been heated to kill pathogens and extend shelf life. Raw milk is often touted to consumers as having an abundant supply of probiotics, or healthy bacteria, compared with pasteurized milk. UC Davis researchers did not find that to be the case.

"Two things surprised us," said Liu. "We didn't find large quantities of beneficial bacteria in the raw milk samples, and if you leave raw milk at room temperature, it creates dramatically more antimicrobial-resistant genes than pasteurized milk."

Bacteria with antimicrobial-resistant genes, if passed to a pathogen, have the potential to become "superbugs," so that pharmaceuticals to treat infection or disease no longer work. Each year, almost 3 million people get an antibiotic-resistant infection, and more than 35,000 people die, according to the Centers for Disease Control.

THE LONGER IT SITS, THE WORSE IT GETS

UC Davis researchers analyzed more than 2,000 retail milk samples from five states, including raw milk and milk pasteurized in different ways. The study found raw milk had the highest prevalence of antibiotic-resistant microbes when left at room temperature.

"Our study shows that with any temperature abuse in raw milk, whether intentional or not, it can grow these bacteria with antimicrobial resistance genes," said co-author Michele Jay-Russell, research microbiologist and manager with the UC Davis Western Center for Food Safety. "It's not just going to spoil. It's really high risk if not handled correctly."

Some consumers are intentionally letting raw milk sit outside of the refrigerator at room temperature to ferment, in order to make what's known as clabber. Co-author and Peter J. Shields Chair of Dairy Food Science David Mills said if consumers eat raw milk clabber, they are likely adding a high number of antimicrobial-resistant genes to their gut.

"You could just be flooding your gastrointestinal tract with these genes," said Mills. "We don't live in an antibiotic-free world anymore. These genes are everywhere, and we need to do everything we can to stop that flow into our bodies."

While more work is needed to fully understand whether antibiotic-resistant genes in raw milk translate into health risks for humans, Mills suggests that consumers instead use a starter culture if they want to ferment raw milk, which carries specific strains of bacteria to inoculate the milk.

Fish Oil and Vitamin D Fail in Knee OA

— No role in treatment, say researchers

Fish oil and vitamin D softgels arranged in a grid on a pink background

Dietary supplementation with vitamin D or fish oil failed to alleviate chronic knee pain in older adults, a secondary analysis of data from the large randomized VITAL trial found.

At baseline, pain scores on the 100-point Western Ontario and McMaster Universities (WOMAC) Arthritis Index were 35.4 among patients receiving vitamin D and 36.5 for those given placebo. At the time of last follow-up, after more than 5 years, mean WOMAC pain scores in the two groups were 32.7 and 34.6, respectively, and at no time throughout the trial was there a statistically significant difference in pain scores between the vitamin D and placebo groups, reported Lindsey Adair MacFarlane, MD, of Brigham and Women's Hospital in Boston, and colleagues.

As shown in their study online in Arthritis & Rheumatology, among patients randomized to receive marine omega-3 fatty acids or placebo, WOMAC pain scores at baseline were 36.5 and 35.4. At the final follow-up visit, pain scores were 33.6 in the fish oil group and 33.7 in the placebo group, and once again, there were no significant differences in pain scores between the two groups at any time point.

"Over the mean of 5.3 years of follow-up, a small decrease in reported knee pain was observed, but this occurred in both the treatment and placebo groups and may reflect regression to the mean and some loss of participants to total knee replacement," the researchers wrote.

An estimated one-quarter of older adults experience knee pain, usually related to osteoarthritis, but current management options include only exercise, weight loss, and analgesics that often are associated with adverse effects, MacFarlane and co-authors explained. "Identifying safe and inexpensive therapies that reduce pain could vastly improve management of chronic knee pain."

Two promising candidates have been vitamin D, because of its anti-inflammatory effects and role in muscle strength and bone resorption, and fish oils, which also have anti-inflammatory properties and protect against cartilage loss. Previous studies, however, have shown conflicting and confusing results.

For example, in one 2-year study of patients with symptomatic knee osteoarthritis and low vitamin D levels, there was no difference between vitamin D supplementation or placebo on WOMAC pain scores, but a post-hoc analysis found benefits on the WOMAC function subscale.

Another study compared high-dose versus low-dose fish oil for symptomatic knee osteoarthritis over 24 months and found improvements on WOMAC pain and function scores for the low-dose group, but the fish oil supplement used also contained sunola oil, potentially confounding the results.

Therefore, to more fully address the question of the potential utility of these treatments, MacFarlane's group analyzed data from VITAL (VITamin D and OmegA-3 Trial), which was a large population-based trial that evaluated the effects of vitamin D and omega-3 fatty acids in the primary prevention of cancer and cardiovascular disease.

Within the larger cohort was a subgroup of 1,398 participants who reported frequent, chronic knee pain at baseline and were considered "highly likely" to have knee osteoarthritis and who filled out a knee pain questionnaire at baseline and annually thereafter.

In addition to pain scores, participants also rated stiffness and function on those WOMAC subscales and reported on the type and frequency of medications used.

At baseline, participants' mean age was 68, two-thirds were women, and mean body mass index (BMI) was 31.8. The majority reported daily knee pain, unilateral symptoms, and daily or occasional use of nonsteroidal anti-inflammatory drugs (NSAIDs). About 15% also occasionally or daily used analgesics, including opioids.

As with the pain scores, no differences were seen throughout follow-up on WOMAC stiffness or function scores for either vitamin D or fish oil. Moreover, on a secondary outcome of incident total knee replacement, suggesting severe and progressive osteoarthritis, the hazard ratios compared with placebo were 0.97 (95% CI 0.78-1.22) for vitamin D and 0.99 (95% CI 0.79-1.24) for fish oil. There also was no change in analgesic or NSAID use throughout the study.

Subgroup analyses by baseline vitamin D level and omega-3 fatty acid index did not influence the effect of either treatment on knee pain, nor did race, BMI, or baseline fish consumption.

This analysis suggests "that supplementation with vitamin D or omega-3 fatty acids does not have a role in the management of symptomatic knee pain due to osteoarthritis," the authors concluded.

Wednesday, June 24, 2020

Obesity linked to higher dementia risk

UNIVERSITY COLLEGE LONDON

Obesity is associated with a higher risk of dementia up to 15 years later, finds a new UCL study suggesting that weight management could play a significant role in reducing risk.

The findings, published in the International Journal of Epidemiology, suggest that people who are obese in late adulthood face a 31% increased risk of dementia than those whose body mass index (BMI) is within the 'normal' range. The risk may be particularly high for women.

Dr Dorina Cadar (UCL Institute of Epidemiology & Health Care), the senior author, said: "These findings provide new evidence that obesity may have important implications in terms of dementia risk.

"Both BMI and waist circumference status should be monitored to avoid metabolic dysregulations. Hence, reducing weight to optimal levels is recommended by adopting healthy and balanced patterns of eating, such as the Mediterranean diet, appropriate physical exercise and reduced alcohol consumption throughout the course of the entire adult life span."

Current clinical guidelines suggest that obesity is an important modifiable risk factor linked to individual lifestyle behaviours. But the association has remained somewhat unclear due to conflicting findings from different studies, with some suggestions that obesity could even be considered a protective health factor among older adults.

For the latest study, the research team collected data from 6,582 people in a nationally representative sample of the English population aged 50 years and over, from the English Longitudinal Study of Ageing. Three different sources were used to ascertain dementia: doctor diagnosis, informant reports and hospital episode statistics.

They found that people whose BMI was 30 or higher (at obese level) at the start of the study period had a 31% greater risk of dementia, at an average follow-up of 11 years, than those with BMIs from 18.5-24.9 (normal level).

There was also a significant gender difference in the risk of dementia associated with obesity. Women with abdominal obesity (based on waist circumference) had a 39% increased risk of dementia compared to those with a normal level. This was independent of their age, education, marital status, smoking behaviour, genetics (APOE ε4 gene), diabetes and hypertension - and yet this association was not found among the male participants.

When BMI and waist circumference were viewed in combination, obese study participants of either gender showed a 28% greater risk of dementia compared to those in the normal range.

Prior evidence suggests that obesity might cause an increased risk of dementia via its direct influence on cytokines (cell signalling proteins) and hormones derived from fat cells, or indirectly through an adverse effect on vascular risk factors. Some researchers have also suggested that excess body fat may increase dementia risk through metabolic and vascular pathways that contribute to the accumulation of amyloid proteins or lesions in the brain.

MSc student Yuxian Ma (UCL Institute of Epidemiology & Health Care), the first author of the study, said: "It is possible that the association between obesity and dementia might be potentially mediated by other conditions, such as hypertension or anticholinergic treatments. While not explored in this study, the research question of whether there an interactive effect between obesity and other midlife risk factors, such as hypertension, diabetes and APOE ε4 carrier status, in relation to dementia will be investigated in upcoming work."

Co-author Professor Andrew Steptoe (UCL Institute of Epidemiology & Health Care and Director of the English Longitudinal Study of Ageing) said: "Dementia is one of the major health challenges of the 21st century that could threaten successful ageing of the population. Our findings suggest that rising obesity rates will compound the issue.

"By identifying factors that may raise dementia risk that are influenced by lifestyle factors, we hope that a substantial portion, but admittedly not all, of dementia cases can be prevented through public health interventions."

Health News Report