Health News Report

Wednesday, September 2, 2020

Asthma may not be a significant risk factor for severe COVID-19

A new research letter published online in the Annals of the American Thoracic Society examines whether asthma is a significant risk factor for developing COVID-19 that is severe enough to warrant hospitalization and intubation. According to the Centers for Disease Control and Prevention, individuals with asthma are at higher risk for hospitalization and other severe effects from COVID-19, similar to the elevated risk from such health conditions as obesity, hypertension and diabetes.

In "Asthma in COVID-19 Hospitalizations: An Overestimated Risk Factor?," Fernando Holguin, MD, MPH, and co-authors compared the prevalence of asthma among patients hospitalized for COVID-19, as reported in 15 peer-reviewed studies, with that of the corresponding population's asthma prevalence. They also correlated the study's asthma prevalence with the four-year average asthma prevalence in influenza hospitalizations in the United States. In addition, they analyzed the medical records of 436 COVID-19 patients admitted to the University of Colorado Hospital to evaluate the likelihood that patients with asthma would be intubated more often than patients without asthma.

"The CDC places people with asthma at higher risk for COVID-related hospitalization," said Dr. Holguin, professor, Asthma Clinical & Research Program, Pulmonary Division, University of Colorado Anschutz Medical Campus.

"However, many international studies show low numbers of asthmatics among hospitalized COVID-19 patients. These findings challenge the assumption about asthma as a risk factor."

The researchers performed a focused review of English-language scientific literature in order to identify studies reporting asthma prevalence among patients hospitalized for COVID-19 infection. Three independent reviewers agreed on 15 studies to include in the analysis. Using local data from hospitalized COVID-19 patients, they performed a statistical analysis to determine the relationship between asthma status and intubation, once they took into account patients' age, gender and body mass index (BMI).

The authors stated, "We found that the proportion of asthmatics among hospitalized patients with COVID-19 is relatively similar to that of each study site's population asthma prevalence. This finding is in stark contrast to influenza, in which asthmatics make up more than 20 percent of those hospitalized in the United States."

"Using data from our hospital, we also observed that among COVID-19 patients, those with asthma, which had a 12 percent prevalence rate, did not seem to be more likely to be intubated than non-asthmatics," they added. Dr. Holguin and colleagues theorize that the corticosteroid inhalers many people with asthma use make it more difficult for coronaviruses to enter their airways.

Specifically, these individuals may have lower levels of expression of ACE2, a protein that binds to SARS-CoV-2, the virus caused by COVID-19. People with asthma that is related to allergies may also have lower expression of ACE2, whether or not they use corticosteroids.

"The contribution of ACE2 receptor expression levels to COVID-19 susceptibility is still unclear, however, it should certainly be further investigated," said Dr. Holguin. Dr. Holguin adds that the asthma-COVID-intubation risk relationship should be studied further.

Evening eating is associated with higher total calorie intake and lower diet quality

A study of nearly 1200 UK adults, being presented at this year's European and International Conference on Obesity (ECOICO 2020), held online this year (1-4 September), suggests that there is a link between eating a larger proportion of one's daily energy intake during the evening, and having a higher total energy intake and lower quality of diet.

In recent decades there has been a growing interest in how the timing of our food consumption can influence metabolism and other physiological processes. Sensations of hunger follow a strong daily rhythmic pattern and are often most intense later in the day. This phenomenon could influence both the type and amount of food we eat.

The research was conducted by Judith Baird, Nutrition Innovation Centre for Food and Health (NICHE), Ulster University, Northern Ireland, UK, and colleagues. It aimed to investigate the association of energy intake (EI) during the evening on total EI and diet quality.

The team selected a group of 1177 adults aged 19-64 years from the UK National Diet and Nutrition Survey, using data covering the years 2012-2017. The Survey, which began in 2008, collects detailed information on the food consumption, nutrient intake and nutritional status of the general UK population aged 18 months and over by canvassing a representative sample of around 1000 participants each year.

Subjects were grouped into quartiles (4 equal groups of 25%) based on the proportion of their daily EI consumed after 6pm, from the lowest with under 31.4%, through to the highest whose evening consumption accounted for more than 48.6% of their EI. Diet quality was assessed by scoring the food diaries kept by participants using the Nutrient Rich Food Index, which classifies and ranks foods according to the ratio of important nutrients they contain relative to their energy content.

Across the whole sample group, eating during the evening provided an average of almost 40% (39.8%) of daily EI. The authors found a significant variation in total EI across the different quartiles, with individuals in the lowest quartile of evening EI consuming fewer calories in total over the day than those in the other three quartiles.

Quality of diet also differed across the quartiles with participants who consumed the largest proportion of their EI in the evening having a significantly worse score on the Nutrient Rich Food Index than those in the rest of the sample groups.

The authors say: "Our results suggest that consuming a lower proportion of EI in the evening may be associated with a lower daily energy intake, while consuming a greater proportion of energy intake in the evening may be associated with a lower diet quality score."

They conclude: "Timing of energy intake may be an important modifiable behaviour to consider in future nutritional interventions. Further analysis is now needed to examine whether the distribution of energy intake and/or the types of food consumed in the evening are associated with measures of body composition and cardiometabolic health."

Tuesday, September 1, 2020

The heart risks and benefits of today's most popular fad diets

Researchers examine claims associated with keto and intermittent fasting

MEDIASOURCE

IMAGE: ANDREW M. FREEMAN, MD, IS A CARDIOLOGIST AT NATIONAL JEWISH HEALTH. DR. FREEMAN IS IN THE DIVISION OF CARDIOLOGY AND DEPARTMENT OF MEDICINE. view more

CREDIT: NATIONAL JEWISH HEALTH

In a review of existing scientific studies on trendy ketogenic and intermittent fasting diets, researchers at National Jewish Health concluded that these diets do seem to help people lose weight in the short-term, and modest evidence suggests they may contribute to cardiovascular health. However, these diets also allow consumption of foods that are known to increase cardiovascular risk and are unlikely to be as effective at preventing heart disease as well-established nutritional guidelines currently recommended by health experts.

"With diets like keto and intermittent fasting, social and popular media has been flooded with claims, promises and warnings that are at best unverified and at worst harmful to your health," said Andrew Freeman, MD, director of cardiovascular prevention and wellness at National Jewish Health and co-author of the study. "Diets recommended by health experts, such as plant-based and Mediterranean diets, have been extensively studied for safety and efficacy, and demonstrated conclusively to improve cardiovascular health."

Keto is a very low carbohydrate dietary approach that sends the body into ketosis, a metabolic state in which it has reduced access to glucose and is instead mostly fueled by fat. While the limited study of the keto diet shows those who follow it initially lose weight, it tends not to be sustainable according to 12-month data. It is also unclear whether the weight loss is caused by ketosis or simply by calorie restriction.

Researchers also have concerns about the type and amount of fat consumed by those following a keto diet. While existing studies strictly controlled the type of fat and foods participants consumed, many who try keto consume high amounts of unhealthy saturated fat, which is associated with an increased risk of heart disease and high lipid levels in the blood. There is also evidence that eating a keto diet for an extended period of time may lead to stiffening of the arteries, and several studies found that those who eat a keto diet have a greater risk of death.

Keto does, however, show promise as a potential treatment for diabetes, with studies showing improved glucose levels as well as lower fasting glucose and insulin levels in mice fed a keto diet. Further research is needed to confirm these benefits and assess risk before keto is clinically recommended.

Researchers are also optimistic about potential health benefits of intermittent fasting, but are concerned about possible pitfalls. There are a wide range of practices being called "intermittent fasting", with some fasting without food an entire day and others restricting meals to certain hours of the day. Experts also worry that the hunger induced by fasting causes many people to overeat when it is time for meals, or make unhealthy choices that have adverse effects on their cardiovascular health.

A majority of the current evidence regarding the potential benefits of intermittent fasting come from animal studies, which have shown increased longevity, weight loss, decreased blood pressure, improved glucose tolerance and controlled lipid levels.

"The potential risks of intermittent fasting that require further study include effects of starvation and how it may impact organ function," Dr. Freeman said. "It is particularly important for diabetics to speak with their doctor before trying intermittent fasting to discuss how to control their disease and the risk of hypoglycemia that may come with skipping regular meals."

While there is modest evidence regarding favorable effects of both dietary approaches, neither the keto nor intermittent fasting is recommended for the treatment or prevention of any condition until large, long-term studies can more definitively examine their impact. Instead, experts recommend diets that have been extensively studied and scientifically proven to prevent or even reverse cardiovascular issues, which include the mediterranean diet, a whole food plant-based diet and the National Institutes of Health's Dietary Approaches to Stop Hypertension (DASH). All of these share a common foundation that includes fruits, vegetables, legumes, nuts and whole grains.

Fungi in gut linked to higher Alzheimer's risk can be reduced through ketogenic diet

WAKE FOREST BAPTIST MEDICAL CENTER

WINSTON-SALEM, N. C. - August 31, 2020 - Specific fungi in the gut associated with a higher risk of Alzheimer's disease and found in people with mild cognitive impairment (MCI) can be altered in a beneficial manner by eating a modified Mediterranean diet, researchers at Wake Forest School of Medicine have found.

The small study is published in the current online edition of the journal EBioMedicine.

"Our study reveals that unique fungi co-living with bacteria in the gut of patients with MCI can be modulated through a Mediterranean ketogenic diet," said principal investigator Hariom Yadav, assistant professor of molecular medicine at Wake Forest School of Medicine, part of Wake Forest Baptist Health.

In the single-center, randomized, double-blind crossover pilot study, Yadav's team identified the organisms in the gut microbiome by sequencing the fungal rRNA ITS1 gene in 17 older adults (11 with diagnosed MCI and six with normal cognition) before and after a six-week intervention of a modified Mediterranean ketogenic diet or the American Heart Association Diet to determine its correlation with Alzheimer's markers in cerebrospinal fluid and gut bacteria.

"Although we do not fully understand how these fungi contribute to Alzheimer's disease, this is the first study of its kind to reveal their role in our mental health, which we hope will ignite thinking in the scientific community to develop better understanding of them in relation to Alzheimer's disease," Yadav said. "It also indicates that dietary habits such as eating a ketogenic diet can reduce harmful fungi in the gut which might help in reducing Alzheimer's disease processes in the brain."

First treatment identified for fainting

EUROPEAN SOCIETY OF CARDIOLOGY

Research News

Sophia Antipolis, France - 1 Sept 2020: Fainting affects one in two people during their lifetime. Those with recurrent episodes are often afraid to socialise or go to work. Today researchers report the first effective therapy. The late breaking research is presented at ESC Congress 2020.1

Fainting is caused by a fall in blood pressure and/or number of heart beats. In some patients, a trigger is identified - for example emotional stress, standing in a hot, crowded space or sitting up too quickly - and they have warning signs such as weakness, nausea, and dizziness. But in many others, especially older adults, no trigger is found and there are no warning signs.

"This unpredictability raises the risk of falls and even serious trauma and people end up in the emergency room," said principal investigator Professor Michele Brignole of the Faint and Fall Programme, Istituto Auxologico, Milan, Italy. "If it happens repeatedly, it has a major impact on quality of life - at the same magnitude as a chronic disease."

Currently there is no specific therapy and patients usually receive only generic advice on prevention, such as keeping hydrated, avoiding hot crowded environments, tensing the muscles, and lying down. But prevention is particularly difficult if there are no warning signs.

The BIOSync CLS study examined whether a pacemaker could prevent unpredictable fainting caused by missed heart beats. Patients with this particular cause of fainting were identified using tilt testing. This involves lying on a table that is slowly tilted upward to simulate standing up. Blood pressure and heart rate are monitored during the examination.

The study included 128 patients aged 40 and above who had fainted at least twice in the previous year with no warning signs. A tilt test showed that fainting was caused by missed heart beats.

All study participants received a pacemaker - but they were randomly allocated to having the pacemaker switched on (pacing group) or switched off (control group). They were then followed-up for fainting episodes.

During a median follow-up of 11.2 months, more than half of patients (53%) in the control group fainted compared to just 16% in the pacing group. This translated into a 77% lower risk of fainting in the pacing group.

The researchers estimated that at two years, two-thirds (68%) of the control group would have a fainting episode compared to one-fifth (22%) of the pacing group. A pacemaker would provide a 77% relative risk reduction of fainting over two years and a 46% absolute risk reduction.

Just over two patients (2.2) would need to receive a pacemaker to prevent fainting. Put another way, if 11 patients received a pacemaker, fainting could be avoided in five patients.

Implanting the pacemaker caused minor adverse events in five patients (4%) such as lead-related complications.

Professor Brignole said: "Our study shows that pacing can be an effective treatment for selected people with unpredictable fainting episodes. Tilt testing is a simple and non-invasive way to identify people who could benefit. We hope this new treatment option will enable these patients to resume a normal life without fear of blackouts."

Blood pressure-lowering is even more beneficial than previously thought

BPLTTC trial presented in a Hot Line Session today at ESC Congress 2020

EUROPEAN SOCIETY OF CARDIOLOGY

Research News

Sophia Antipolis, France - 31 Aug 2020: Blood pressure medication can prevent heart attacks and strokes - even in people with normal blood pressure. That's the finding of late breaking research presented in a Hot Line session today at ESC Congress 2020.1

"Greater drops in blood pressure with medication lead to greater reductions in the risk of heart attacks and strokes," said principal investigator Professor Kazem Rahimi of the University of Oxford, UK. "This holds true regardless of the starting blood pressure level, in people who previously had a heart attack or stroke, and in people who have never had heart disease."

"The fact that the relative effects are similar for everyone does not mean that everyone should be treated," he added. "This decision will depend on an individual's likelihood of suffering cardiovascular disease in the future - there are a number of risk calculators health professionals can use. Other factors to consider are the potential for side effects and the cost of treatment."

There has been controversy about whether pharmacological blood pressure lowering is equally beneficial in people with versus without a prior heart attack or stroke, and when blood pressure is below the threshold for hypertension (typically 140/90 mmHg). Evidence from previous studies has been inconclusive, leading to contradictory treatment recommendations around the world.

This was the largest - and most detailed - study ever conducted to examine these questions. The researchers combined data on individuals who had participated in a randomised clinical trial and conducted a meta-analysis. The study included 348,854 participants from 48 trials.

Participants were divided into two groups: those with a prior diagnosis of cardiovascular disease and those without. Each group was divided into seven subgroups based on systolic blood pressure at study entry (less than 120, 120-129, 130-139, 140-149, 150-159, 160-169, 170 and above mmHg).

Over an average four years of follow-up, each 5 mmHg reduction in systolic blood pressure lowered the relative risk of major cardiovascular events by about 10%. The risks for stroke, ischaemic heart disease, heart failure and death from cardiovascular disease were reduced by 13%, 7% and 14% and 5%, respectively.

Neither the presence of cardiovascular disease nor the level of blood pressure at study entry modified the effect of treatment.

Professor Rahimi said: "The decision to prescribe blood pressure medication should not be based simply on a prior diagnosis of cardiovascular disease or an individual's current blood pressure. Rather, blood pressure medication should be viewed as an effective tool for reducing cardiovascular risk when an individual's probability of having a heart attack or stroke is elevated."

Elderly people protected against respiratory infections by BCG vaccine

However, the effect of the vaccine specifically against COVID-19 has not been demonstrated

RADBOUD UNIVERSITY MEDICAL CENTER

Research News

The BCG vaccine has a broad, stimulating effect on the immune system. This gives it an effective preventive action against various infections - possibly also against COVID-19. New studies are investigating that. BCG is frequently given to children, but a double-blind randomized clinical study, a collaboration between Radboud university medical center and the National and Kapodistrian University of Athens shows that elderly people also benefit from it. The results are published in Cell.

At Radboudumc, Professor of Experimental Internal Medicine Mihai Netea is conducting research into this protective effect against various infections by the BCG vaccine, an effect called "trained immunity". Prof. Mihai Netea: "Two years ago we started the ACTIVATE study, with the aim of showing whether BCG vaccination could protect against infections in vulnerable elderly people. Patients over 65 years of age who were admitted to hospital were randomized to receive BCG or placebo vaccination at their discharge. We followed them for a year to see if BCG could protect them against a broad range of infections."

Study started before the pandemic

The ACTIVATE study had already started before the corona pandemic. 198 elderly people were given either a placebo or a BCG vaccine upon discharge from the hospital. The last follow-up was scheduled for August 2020, but due to the arrival of COVID-19, the researchers looked at the preliminary results, published today in Cell.

Protective effect

There was a noticeable difference: in the placebo group, 42.3% of the elderly developed an infection, while this was the case in only 25% of the BCG group. It also took longer: the BCG-vaccinated participants had their first infection on average 16 weeks after vaccination, compared to 11 weeks for the placebo group. There was no difference in side effects.

Prof. Evangelos J. Giamarellos-Bourboulis, co-coordinator of the study at the 4th Department of Internal Medicine at ATTIKON University Hospital: "In addition to the clear effect of BCG vaccination on infections in general, the most important observation was that BCG could mainly protect against respiratory infections: BCG-vaccinated elderly people had 75% fewer respiratory infections than the elderly who received placebo."

It is unclear whether it works against the coronavirus

Although most protection seems to have been against respiratory infections of (probably) viral origin, whether or not BCG also works against COVID-19 has not yet been demonstrated, due to the low prevalence of COVID-19 in this study. The study does show that the BCG vaccination is safe to give to the elderly, and that it can protect them against various infections. Several studies are underway that look specifically at the effects of BCG on COVID-19. Only these follow-up studies can provide clarity as to whether BCG vaccination can also protect against infections with the new coronavirus.