Scientists decode how COVID-19 disease kills people

Agencies
May 14, 2020

COVID-19 mostly kills through an overreaction of the immune system, whose function is precisely to fight infections, say scientists who have decoded the mechanisms, symptoms, and diagnosis of the disease caused by the SARS-Cov-2 coronavirus.

In a study published in the journal Frontiers in Public Health, the researchers explained step-by-step how the virus infects the airways, multiplies inside cells, and in severe cases causes the immune defences to overshoot with a "cytokine storm".

This storm is an over-activation of white blood cells, which release too-great amounts of cytokines -- inflammation-stimulating molecules --into the blood, they said.

"Similar to what happens after infection with SARS and MERS, data show that patients with severe COVID-19 may have a cytokine storm syndrome," said study author Daishun Liu, Professor at Zunyi Medical University in China.

"The rapidly increased cytokines attract an excess of immune cells such as lymphocytes and neutrophils, resulting in an infiltration of these cells into lung tissue and thus cause lung injury," Liu said.

The researchers explained that the cytokine storm ultimately causes high fever, excessive leakiness of blood vessels, and blood clotting inside the body.

It also causes extremely low blood pressure, lack of oxygen and excess acidity of the blood, and build-up of fluids in the lungs, they said.

The researchers noted that white blood cells are misdirected to attack and inflame even healthy tissue, leading to failure of the lungs, heart, liver, intestines, kidneys, and genitals.

This multiple organ dysfunction syndrome (MODS) may worsen and shutdown the lungs, a condition called acute respiratory distress syndrome, (ARDS), they said.

This, the researchers explained, happens due to the formation of a so-called hyaline membrane -- composed of debris of proteins and dead cells -- lining the lungs, which makes absorption of oxygen difficult.

Most deaths due to COVID-19 are therefore due to respiratory failure, they said.

The researchers explained that in the absence of a specific antiviral cure for COVID-19, the goal of treatment must be to the fight the symptoms, and lowering the mortality rate through intensive maintenance of organ function.

For example, an artificial liver blood purification system or renal replacement therapy can be used to filter the blood through mechanical means, they said.

The team noted that especially important are methods to supplement or replace lung function, for example with non-invasive mechanical ventilation through a mask, ventilation through a tube into the windpipe, the administration of heated and humidified oxygen via a tube in the nose, or a heart-lung bypass.

The researchers stressed the importance of preventing secondary infections.

They noted that SARS-Cov-2 also invades the intestines, where it causes inflammation and leakiness of the gut lining, allowing the opportunistic entry of other disease-causing microorganisms.

The researchers advocate that this should be prevented with nutritional support, for example with probiotics -- beneficial bacteria that protect against the establishment of harmful ones -- and nutrients and amino acids to improve the immune defences and function of the intestine.

"Because treatment for now relies on aggressive treatment of symptoms, preventative protection against secondary infections, such as bacteria and fungi, is particularly important to support organ function, especially in the heart, kidneys, and liver, to try and avoid further deterioration of their condition," Liu added.

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Agencies
February 27,2020

Washington D.C, Feb 27: New research shows that adults who have low fruit and vegetable intake are more likely to be diagnosed with an anxiety disorder.

"For those who consumed less than 3 sources of fruits and vegetables daily, there was at least at 24% higher odds of anxiety disorder diagnosis," says the lead author of the Canadian Longitudinal Study, Karen Davison, who is a health science faculty member, nutrition informatics lab director at Kwantlen Polytechnic University, (KPU) and North American Primary Care Research Group Fellow.

"This may also partly explain the findings associated with body composition measures. As levels of total body fat increased beyond 36%, the likelihood of anxiety disorder was increased by more than 70%," states co-author Jose Mora-Almanza, a Mitacs Globalink intern who worked with the study at KPU.

"Increased body fat may be linked to greater inflammation. Emerging research suggests that some anxiety disorders can be linked to inflammation," says Davison.

In addition to diet and body composition measures, the prevalence of anxiety disorders also differed by gender, marital status, income, immigrant status and several health issues.

An important limitation of the study was that the assessment of anxiety disorders was mostly based upon self-reporting of a medical diagnosis.

"It is estimated that 10% of the global population will suffer from anxiety disorders which are a leading cause of disability," says Karen Davison

"Our findings suggest that comprehensive approaches that target health behaviours, including diet, as well as social factors, such as economic status, may help to minimize the burden of anxiety disorders among middle-aged and older adults, including immigrants," she concluded.

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Agencies
June 12,2020

Global poverty could rise to over one billion people due to the COVID-19 pandemic and more than half of the 395 million additional extreme poor would be located in South Asia, which would be the hardest-hit region in the world, according to a new report.

Researchers from King's College London and Australian National University published the new paper with the United Nations University World Institute for Development Economics Research (UNU-WIDER) said that poverty is likely to increase dramatically in middle-income developing countries and there could be a significant change in the distribution of global poverty.

The location of global poverty could shift back towards developing countries in South Asia and East Asia, the report said.

The paper, 'Precarity and the Pandemic: COVID-19 and Poverty Incidence, Intensity and Severity in Developing Countries,' finds that extreme poverty could rise to over one billion people globally as a result of the crisis.

The cost of the crisis in lost income could reach USD 500 million per day for the world's poorest people, and the intensity and severity of poverty are likely to be exacerbated dramatically.

The report said that based on the USD 1.90 a day poverty line and a 20 per cent contraction, more than half of the 395 million additional extreme poor would be located in South Asia, which would become the hardest hit region in the world mainly driven by the weight of populous India followed by sub-Saharan Africa which would comprise 30 per cent, or 119 million, of the additional poor.

The report added that as the value of the poverty line increases, a larger share of the additional poor will be concentrated in regions where the corresponding poverty line is more relevant given the average income level.

For instance, the regional distribution of the world's poor changes drastically when looking at the USD 5.50 a day poverty line the median poverty line among upper-middle-income countries.

At this level, almost 41 per cent of the additional half a billion poor under a 20 per cent contraction scenario would live in East Asia and the Pacific, chiefly China; a fourth would still reside in South Asia; and a combined 18 per cent would live in the Middle East and North Africa (MENA) and in Latin America and the Caribbean (LAC), whose individual shares are close to that recorded for sub-Saharan Africa.

India plays a significant role in driving the potential increases in global extreme poverty documented previously, comprising almost half the estimated additional poor regardless of the contraction scenario, the report said.

Nonetheless, there are other populous, low and lower-middle- income countries in South Asia, sub-Saharan Africa, and East Asia and the Pacific accounting for a sizeable share of the estimates: Nigeria, Ethiopia, Bangladesh, and Indonesia come next, in that order, concentrating a total of 18 19 per cent of the new poor, whereas the Democratic Republic of Congo, Tanzania, Pakistan, Kenya, Uganda, and the Philippines could jointly add 11 12 per cent.

Taken together, these figures imply that three quarters of the additional extreme poor globally could be living in just ten populous countries.

The report added that this high concentration of the additional extreme poor is staggering , although not necessarily unexpected given the size of each country's population.

On one hand, data shows that three of these ten countries (Ethiopia, India, and Nigeria) were among the top ten by number of extreme poor people in 1990 and remained within the ranks of that group until 2018.

Despite this crude fact, two of these countries have managed to achieve a sustained reduction in their incidence of poverty since the early 1990s, namely Ethiopia and India, reaching their lowest poverty headcount ratio ever recorded at about 22 and 13 per cent, respectively. Nonetheless, the potential contraction in per capita income/consumption imposed by the pandemic's economic effects could erase some of this progress.

The researchers are now calling for urgent global leadership from the G7, G20, and the multilateral system, and propose a three-point plan to address the impact of the COVID-19 on global poverty quickly.

Professor of International Development at King's College London and a Senior Non-Resident Research Fellow at UNU-WIDER Andy Sumner said the COVID-19 crisis could take extreme poverty back over one billion people because millions of people live just above poverty.

Millions of people live in a precarious position one shock away from poverty. And the current crisis could be that shock that pushes them into poverty.

Professor Kunal Sen, Director of UNU-WIDER said the new estimates about the level of poverty in the world and the cost of the COVID-19 pandemic to the world's poor are sobering.

We cannot stand by and see the hard work and effort of so many be eradicated. We will know what the real impact is in time, but the necessary action to ensure we achieve the Sustainable Development Goals by 2030 needs to be planned now, Sen said.

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Agencies
January 26,2020

High-protein diets may help people lose weight and build muscle, but there is a downside to it --a greater heart attack risk. Researchers now report that high-protein diets boost artery-clogging plaque.

The research in mice showed that high-protein diets spur unstable plaque -- the kind most prone to rupturing and causing blocked arteries.

More plaque buildup in the arteries, particularly if it's unstable, increases the risk of heart attack.

"There are clear weight-loss benefits to high-protein diets, which has boosted their popularity in recent years," said senior author Babak Razani, associate professor at Washington University School of Medicine in St. Louis, Missouri.

"But animal studies and some large epidemiological studies in people have linked high dietary protein to cardiovascular problems. We decided to take a look at whether there is truly a causal link between high dietary protein and poorer cardiovascular health," Razani added.

The researchers studied mice who were fed a high-fat diet to deliberately induce atherosclerosis, or plaque buildup in the arteries.

Some of the mice received a high-fat diet that was also high in protein. And others were fed a high-fat, low-protein diet for comparison.

The mice on the high-fat, high-protein diet developed worse atherosclerosis -- about 30 per cent more plaque in the arteries -- than mice on the high-fat, normal-protein diet, despite the fact that the mice eating more protein did not gain weight, unlike the mice on the high-fat, normal-protein diet.

"A couple of a scoop of protein powder in a milkshake or smoothie adds something like 40 grams of protein -- almost equivalent to the daily recommended intake," Razani said.

"To see if protein has an effect on cardiovascular health, we tripled the amount of protein that the mice receive in the high-fat, high-protein diet -- keeping the fat constant. Protein went from 15 per cent to 46 per cent of calories for these mice".

Plaque contains a mix of fat, cholesterol, calcium deposits and dead cells. Past work by Razani's team and other groups has shown that immune cells called macrophages work to clean up plaque in the arteries.

But the environment inside plaque can overwhelm these cells, and when such cells die, they make the problem worse, contributing to plaque buildup and increasing plaque complexity.

"In mice on the high-protein diet, their plaques were a macrophage graveyard," Razani informed.

To understand how high dietary protein might increase plaque complexity, Razani and his colleagues also studied the path protein takes after it has been digested -- broken down into its original building blocks, called amino acids.

"This study is not the first to show a telltale increase in plaque with high-protein diets, but it offers a deeper understanding of the impact of high protein with the detailed analysis of the plaques," said Razani.

"This work not only defines the critical processes underlying the cardiovascular risks of dietary protein but also lays the groundwork for targeting these pathways in treating heart disease," he added.

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