Thursday, September 24, 2020

Covid-19 Preys Upon The Elderly And The Obese


sciencemag | This spring, after days of flulike symptoms and fever, a man arrived at the emergency room at the University of Vermont Medical Center. He was young—in his late 30s—and adored his wife and small children. And he had been healthy, logging endless hours running his own small business, except for one thing: He had severe obesity. Now, he had tested positive for COVID-19 and was increasingly short of breath.

He was admitted directly to the intensive care unit (ICU) and was on a ventilator within hours. Two weeks later, he died.

“He was a young, healthy, hardworking guy,” recalls MaryEllen Antkowiak, a pulmonary critical care physician who is medical director of the hospital’s ICU. “His major risk factor for getting this sick was obesity.”

Since the pandemic began, dozens of studies have reported that many of the sickest COVID-19 patients have been people with obesity. In recent weeks, that link has come into sharper focus as large new population studies have cemented the association and demonstrated that even people who are merely overweight are at higher risk. For example, in the first metaanalysis of its kind, published on 26 August in Obesity Reviews, an international team of researchers pooled data from scores of peer-reviewed papers capturing 399,000 patients. They found that people with obesity who contracted SARS-CoV-2 were 113% more likely than people of healthy weight to land in the hospital, 74% more likely to be admitted to an ICU, and 48% more likely to die.

A constellation of physiological and social factors drives those grim numbers. The biology of obesity includes impaired immunity, chronic inflammation, and blood that’s prone to clot, all of which can worsen COVID-19. And because obesity is so stigmatized, people with obesity may avoid medical care.

“We didn’t understand early on what a major risk factor obesity was. … It’s not until more recently that we’ve realized the devastating impact of obesity, particularly in younger people,” says Anne Dixon, a physician-scientist who studies obesity and lung disease at the University of Vermont. That “may be one reason for the devastating impact of COVID-19 in the United States, where 40% of adults are obese.”

People with obesity are more likely than normal-weight people to have other diseases that are independent risk factors for severe COVID-19, including heart disease, lung disease, and diabetes. They are also prone to metabolic syndrome, in which blood sugar levels, fat levels, or both are unhealthy and blood pressure may be high. A recent study from Tulane University of 287 hospitalized COVID-19 patients found that metabolic syndrome itself substantially increased the risks of ICU admission, ventilation, and death.

Sunday, June 7, 2020

Sleep Essential To The Elimination Of Reactive Oxidative Species


medicalexpress |  The first signs of insufficient sleep are universally familiar. There's tiredness and fatigue, difficulty concentrating, perhaps irritability or even tired giggles. Far fewer people have experienced the effects of prolonged sleep deprivation, including disorientation, paranoia and hallucinations. 

Total, prolonged , however, can be fatal. While it has been reported in humans only anecdotally, a widely cited study in rats conducted by Chicago-based researchers in 1983 showed that a total lack of sleep inevitably leads to death. Yet, despite decades of study, a central question has remained unsolved: why do animals die when they don't sleep?

Now, Harvard Medical School neuroscientists have identified an unexpected, causal link between sleep deprivation and premature death. In a study on sleep-deprived , researchers found that death is always preceded by the accumulation of molecules known as reactive oxidative species (ROS) in the gut.

When fruit flies were given that neutralize and clear ROS from the gut, sleep-deprived flies remained active and had normal lifespans. Additional experiments in mice confirmed that ROS accumulate in the gut when sleep is insufficient.

The findings, published in Cell on June 4, suggest the possibility that animals can indeed survive without sleep under certain circumstances. The results open new avenues of study to understand the full consequences of insufficient sleep and may someday inform the design of approaches to counteract its detrimental effects in humans, the authors said.

"We took an unbiased approach and searched throughout the body for indicators of damage from sleep deprivation. We were surprised to find it was the gut that plays a key role in causing death," said senior study author Dragana Rogulja, assistant professor of neurobiology in the Blavatnik Institute at HMS.

"Even more surprising, we found that premature death could be prevented. Each morning, we would all gather around to look at the flies, with disbelief to be honest. What we saw is that every time we could neutralize ROS in the gut, we could rescue the flies," Rogulja said.

Scientists have long studied sleep, a phenomenon that appears to be fundamental for life, yet one that in many ways remains mysterious. Almost every known animal sleeps or exhibits some form of sleeplike behavior. Without enough of it, serious consequences ensue. In humans, chronic insufficient sleep is associated with , type 2 diabetes, cancer, obesity, depression and many other conditions.

Sunday, January 19, 2020

Swear to Gawd I Can Smell the Cancer and Diabetes...,


medicalexpress |  Non-communicable diseases including heart disease, cancer and lung disease are now the most common causes of death, accounting for 70 percent of deaths worldwide. These diseases are considered "non-communicable" because they are thought to be caused by a combination of genetic, lifestyle and environmental factors and can't be transmitted between people. 

A new research paper in Science by a team of fellows in CIFAR's Humans and the Microbiome program throws this long-held belief into question by providing evidence that many diseases may be transmissible between people through microbes (including bacteria, fungi, and viruses) that live in and on our bodies.

"If our hypothesis is proven correct, it will rewrite the entire book on public health" says B. Brett Finlay, CIFAR Fellow and professor of microbiology at the University of British Columbia, who is lead author on the paper.

Connecting the dots
The authors base their hypothesis on connections between three distinct lines of evidence. First, they demonstrate that people with a wide range of conditions, from obesity and inflammatory bowel disease to type 2 diabetes and cardiovascular disease, have altered microbiomes. Next, they show that altered microbiomes, when taken from diseased people and put into animal models, cause disease. Finally, they provide evidence that the microbiome is naturally transmissible, for example: Spouses who share a house have more similar microbiomes than twins who live separately.

"When you put those facts together, it points to the idea that many traditionally non-communicable diseases may be communicable after all," says Finlay.

Eran Elinav, an author on the paper, CIFAR fellow, and professor at the Weizmann Institute of Science, sees the proposed connection between these points of evidence as an argument for thinking about disease more broadly. "This may represent new opportunities for interventions in some of the world's most common and bothersome diseases," he says. "We can now think about modulating and the , not just about targeting the human host."