High BP in late life may protect against dementia: study

January 17, 2017

Los Angeles, Jan 17: Onset of high blood pressure later in life, especially at age 80 or older, is associated with lower dementia risk after 90, a new study has found. High blood pressure and other heart health risk factors are generally thought to increase dementia risk.

bpResearchers challenge this idea and add to scientist's understanding of hypertension and dementia risk over a person's life course.

Researchers at the University of California, Irvine in the US followed 559 people for an average of 2.8 years to investigate the relationship between dementia, age of hypertension onset and blood pressure measurements. All participants are from an ongoing, long-term study of people aged 90 and older known as 'The 90+ Study'. At enrolment, participants did not have dementia, were 93 years old on average and 69 per cent female.

They received dementia assessments every six months during the study period. During the follow-up period, 224 (40 per cent) of the participants were diagnosed with dementia. The researchers found that study participants who reported hypertension onset at age 80 to 89 were 42 per cent less likely to develop dementia after age 90 compared to those who reported no history of high blood pressure.

Participants whose hypertension began at age 90 or older were at even lower risk — 63 per cent less likely to develop dementia. These associations were statistically significant and independent of whether participants were taking medications to treat hypertension. "In this first-of-its-kind study, we find that hypertension is not a risk factor for dementia in people aged 90 or over but is actually associated with reduced dementia risk," said Maria Corrada, professor at University of California.

"This relationship had not yet been examined in groups of older people in their 80s or 90s, known as the 'oldest old'," said Corrada. The researchers also measured study participants' blood pressure at enrolment. Those in the hypertensive range at baseline were at lower risk for dementia compared to those with blood pressure in the normal range.

While these results were not statistically significant, the researchers observed that dementia risk declined as hypertension severity increased - a trend consistent with the idea that, in this age group, hypertension may protect the brain from insults that lead to dementia. The researchers suggest several potential reasons for the association between hypertension and dementia risk observed in the study.

These include that blood pressure may need to reach a certain level to maintain adequate blood flow in the brain for normal cognition and that this level may change with age. Another explanation that the researchers note is less likely, but possible, is that blood pressure drops before the onset of dementia as a consequence of brain cell deterioration and thus older people who are not developing dementia will have higher blood pressure. The study was published in the journal Alzheimer's and Dementia.

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Agencies
July 21,2020

New Delhi, Jul 21: The Centre has written to all states and union territories warning against the use of N-95 masks with valved respirators by people, saying these do not prevent the virus from spreading out and are "detrimental" to the measures adopted for its containment.

The Director General of Health Services (DGHS) in the Ministry of Health, in a letter to the Principal Secretaries of health and medical education of states, said it has been observed that there is "inappropriate use" of N-95 masks, particularly those with valved respirators, by the public other than designated health workers.

The DGHS referred to the advisory on the use of homemade protective cover for face and mouth available on the website of the Ministry of Health.

"It is to bring to your knowledge that the use of valved respirator N-95 masks is detrimental to the measures adopted for preventing the spread of coronavirus as it does not prevent the virus from escaping out of the mask. In view of the above, I request you to instruct all concerned to follow the use of face/mouth cover and prevent inappropriate use of N-95 masks," DGHS Rajiv Garg said in the letter.

The government had in April issued an advisory on the use of homemade protective cover for face and mouth, asking people to wear it, particularly when they step out of their residences.

The advisory stressed such face covers must be washed and cleaned each day, as instructed, and stated that any used cotton cloth can be used to make this face cover.

The colour of the fabric does not matter but one must ensure that the fabric is washed well in boiling water for five minutes and dried well before making the face cover. Adding salt to this water is recommended, it said.

It also listed the procedures of making such homemade masks, asking to ensure it fits the face well and there are no gaps on the sides.

It urges people to wash hands thoroughly before wearing the face cover, switching to another fresh one as the face cover becomes damp or humid, and never reusing it after single use without cleaning it.

"Never share the face cover with anyone. Every member in a family should have separate face cover," the advisory stated.

India's COVID-19 case tally crossed the 11-lakh mark on Monday, while the total number of recovered patients increased to over seven lakh, according to Union health ministry data.

The death toll due to the disease rose to 27,497 with 681 fatalities reported in one day.

The ministry data updated at 8 am on Monday showed that a record single-day jump of 40,425 COVID-19 cases had taken the total number of cases to 11,18,043.

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International New York Times
July 7,2020

The coronavirus can stay aloft for hours in tiny droplets in stagnant air, infecting people as they inhale, mounting scientific evidence suggests.

This risk is highest in crowded indoor spaces with poor ventilation, and may help explain superspreading events reported in meatpacking plants, churches and restaurants.

It’s unclear how often the virus is spread via these tiny droplets, or aerosols, compared with larger droplets that are expelled when a sick person coughs or sneezes, or transmitted through contact with contaminated surfaces, said Linsey Marr, an aerosol expert at Virginia Tech.

Follow latest updates on the Covid-19 pandemic here

Aerosols are released even when a person without symptoms exhales, talks or sings, according to Marr and more than 200 other experts, who have outlined the evidence in an open letter to the World Health Organization.

What is clear, they said, is that people should consider minimizing time indoors with people outside their families. Schools, nursing homes and businesses should consider adding powerful new air filters and ultraviolet lights that can kill airborne viruses.

What does it mean for a virus to be airborne?

For a virus to be airborne means that it can be carried through the air in a viable form. For most pathogens, this is a yes-no scenario. HIV, too delicate to survive outside the body, is not airborne. Measles is airborne, and dangerously so: It can survive in the air for up to two hours.

For the coronavirus, the definition has been more complicated. Experts agree that the virus does not travel long distances or remain viable outdoors. But evidence suggests it can traverse the length of a room and, in one set of experimental conditions, remain viable for perhaps three hours.

How are aerosols different from droplets?

Aerosols are droplets, droplets are aerosols — they do not differ except in size. Scientists sometimes refer to droplets fewer than 5 microns in diameter as aerosols. (By comparison, a red blood cell is about 5 microns in diameter; a human hair is about 50 microns wide.)

From the start of the pandemic, the WHO and other public health organizations have focused on the virus’s ability to spread through large droplets that are expelled when a symptomatic person coughs or sneezes.

These droplets are heavy, relatively speaking, and fall quickly to the floor or onto a surface that others might touch. This is why public health agencies have recommended maintaining a distance of at least 6 feet from others, and frequent hand washing.

But some experts have said for months that infected people also are releasing aerosols when they cough and sneeze. More important, they expel aerosols even when they breathe, talk or sing, especially with some exertion.

Scientists know now that people can spread the virus even in the absence of symptoms — without coughing or sneezing — and aerosols might explain that phenomenon.

Because aerosols are smaller, they contain much less virus than droplets do. But because they are lighter, they can linger in the air for hours, especially in the absence of fresh air. In a crowded indoor space, a single infected person can release enough aerosolized virus over time to infect many people, perhaps seeding a superspreader event.

For droplets to be responsible for that kind of spread, a single person would have to be within a few feet of all the other people, or to have contaminated an object that everyone else touched. All that seems unlikely to many experts: “I have to do too many mental gymnastics to explain those other routes of transmission compared to aerosol transmission, which is much simpler,” Marr said.

Can I stop worrying about physical distancing and washing my hands?

Physical distancing is still very important. The closer you are to an infected person, the more aerosols and droplets you may be exposed to. Washing your hands often is still a good idea.

What’s new is that those two things may not be enough. “We should be placing as much emphasis on masks and ventilation as we do with hand washing,” Marr said. “As far as we can tell, this is equally important, if not more important.”

Should I begin wearing a hospital-grade mask indoors? And how long is too long to stay indoors?

Health care workers may all need to wear N95 masks, which filter out most aerosols. At the moment, they are advised to do so only when engaged in certain medical procedures that are thought to produce aerosols.

For the rest of us, cloth face masks will still greatly reduce risk, as long as most people wear them. At home, when you’re with your own family or with roommates you know to be careful, masks are still not necessary. But it is a good idea to wear them in other indoor spaces, experts said.

As for how long is safe, that is frustratingly tough to answer. A lot depends on whether the room is too crowded to allow for a safe distance from others and whether there is fresh air circulating through the room.

What does airborne transmission mean for reopening schools and colleges?

This is a matter of intense debate. Many schools are poorly ventilated and are too poorly funded to invest in new filtration systems. “There is a huge vulnerability to infection transmission via aerosols in schools,” said Don Milton, an aerosol expert at the University of Maryland.

Most children younger than 12 seem to have only mild symptoms, if any, so elementary schools may get by. “So far, we don’t have evidence that elementary schools will be a problem, but the upper grades, I think, would be more likely to be a problem,” Milton said.

College dorms and classrooms are also cause for concern.

Milton said the government should think of long-term solutions for these problems. Having public schools closed “clogs up the whole economy, and it’s a major vulnerability,” he said.

“Until we understand how this is part of our national defense, and fund it appropriately, we’re going to remain extremely vulnerable to these kinds of biological threats.”

What are some things I can do to minimize the risks?

Do as much as you can outdoors. Despite the many photos of people at beaches, even a somewhat crowded beach, especially on a breezy day, is likely to be safer than a pub or an indoor restaurant with recycled air.

But even outdoors, wear a mask if you are likely to be close to others for an extended period.

When indoors, one simple thing people can do is to “open their windows and doors whenever possible,” Marr said. You can also upgrade the filters in your home air-conditioning systems, or adjust the settings to use more outdoor air rather than recirculated air.

Public buildings and businesses may want to invest in air purifiers and ultraviolet lights that can kill the virus. Despite their reputation, elevators may not be a big risk, Milton said, compared with public bathrooms or offices with stagnant air where you may spend a long time.

If none of those things are possible, try to minimize the time you spend in an indoor space, especially without a mask. The longer you spend inside, the greater the dose of virus you might inhale.

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Agencies
May 6,2020

Washington D.C., May 5: Working from home has become the new normal ever since the outbreak of coronavirus and in today's time the work duties can be easily dealt with by means of mobile devices at home.

However, this easy use of technology, mobile devices for that matter, has the potential to blur the fine line between work and the other daily life routines.

But, contrary to the belief, a study at the University of Jyvaskyla reveals that the mixing of work and other daily life routines may have more benefits than previously assumed, and points to the importance of boundary-spanning communication.

A smartphone enables phone calls, email, and file transfers from the comfort of home. The study shows that there may be more effective ways to maximise the benefits of smartphone use, without diminishing employees' flexibility and the use of these technologies.

"People often forget to talk about positive effects, such as autonomy and freedom the employees gain when they have the flexibility to schedule their work," said Postdoctoral Researcher Ward van Zoonen from JYU, who with his colleagues examined the use of smartphones for work matters outside working hours.

The study paid special attention to the benefits of talking about domestic matters with the immediate supervisor outside the working hours given to an employee.

"This reduces the conflict between work and other life," van Zoonen said.

"If people in an organisation strive for more dialogue between employees' different life domains, it is possible to create a functional environment where people can talk about different matters."

The research findings show that when employees communicate across boundaries and talk at work about their life in other respects, they can receive new kinds of support and understanding from their immediate supervisor.

"This kind of communication creates a low threshold for contacting one's supervisor, which helps employees build a balance between the different domains of their lives and strengthens their organisational identification," said Professor Anu Sivunen describing the findings.

This means that tight working time restrictions to protect employees might not be beneficial after all, if they hinder reaching the positive results indicated in this research.

For the study, a survey was taken of 367 employees who were asked questions such as -- how much they talk about their work with their family, and how much they talk about their family with their immediate supervisor.

"Both supervisors and their employees answered the surveys, and the study actually focused on their mutual communication," Sivunen said.

"Usually people at workplaces are interested in how communication within the work community is succeeding. It is often forgotten how an immediate supervisor can take an employer's other life into account and thereby help the employee gain work-related benefits."

"Communication with one's immediate supervisor during flexible working hours, also on matters other than work, could ease the daily lives of many employees if they could share the possible challenges of their family life or free time with their supervisor in these settings," Sivunen added.

According to the study, such a practice could make the supervisor aware of the employee's situation as he/she works from home and the related impacts on their work performances.

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