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
January 12,2020

Washington D.C., Jan 12: Disruption in one night's sleep can lead to getting Alzheimer's disease, a recent study has stated.

The interruption in the sound sleep for a single night aggravates the level of tau protein in any young male's body, thus gives rise to the chances of developing the disease.

According to CNN, the report was published on Wednesday in neurology, the medical journal of the American Academy of Neurology.

"Our study focuses on the fact that even in young, healthy individuals, missing one night of sleep increases the level of tau in blood suggesting that over time, such sleep deprivation could possibly have detrimental effects," says study author Dr Jonathan Cedernaes, a neurologist at Uppsala University in Sweden.

As defined by the Alzheimer's Association, tau is the name of a protein that helps in stabilizing the internal structure of the brain's nerve cells. An abnormal build-up of tau protein in the body can end up in causing interior cells to fall apart and eventually developing Alzheimer's.

"When you get more of that deep sleep and you get the REM sleep in the normal amounts, that improves clearance of abnormal proteins which we think is good," said Mayo Clinic neurologist Dr Donn Dexter, not the study author but a fellow of the American Academy of Neurology.

Earlier studies have also shown that getting deprived of sleep can allow higher tau development and accumulation. Thus that poor sleep can hasten the development of cognitive issues.

Researchers caution that the study is small and inconclusive, and acknowledged they were not able to determine what the increased levels might mean.

"This study raises more questions than answers," agreed Dexter on a concluding note, sharing, "What this is telling us is that we have to dig more deeply. Despite something we do for a third of our lives, we know so little about sleep and we're learning every day, particularly when it comes to sleep and dementia."

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Agencies
June 11,2020

The World Health Organisation (WHO) Director-General Tedros Adhanom Ghebreyesus said that more research needs to be done to better understand the extent to which COVID-19 is being spread by people who don't show symptoms.

"Since early February, we have said that asymptomatic people can transmit COVID-19, but that we need more research to establish the extent of asymptomatic transmission," the WHO chief said at a virtual press conference from Geneva on Wednesday, Xinhua news agency reported.

"That research is ongoing, and we're seeing more and more research being done," he added.

Saying that the world has been achieving a lot in knowing the new virus, the WHO chief told reporters that "there's still a lot we don't

"WHO's advice will continue to evolve as new information becomes available," he said.

Tedros stressed that the most critical way to stop transmission is to find, isolate and test people with symptoms, and trace and quarantine their contacts.

"Many countries have succeeded in suppressing transmission and controlling the virus doing exactly this," Tedros said.

Meanwhile, Michael Ryan, executive director of WHO Health Emergencies Program, said Wednesday that the COVID-19 pandemic is still evolving.

"If we look at the numbers... this pandemic is still evolving. It is growing in many parts of the world," he said. "We have deep concerns that health systems of some countries are struggling, under a huge strain and require our support, our help and our solidarity."

He said "each and every country has a different combination of risks and opportunities, and it's really down to national authorities to carefully consider where they are in the pandemic."

In Europe, the risk issue now are about travels and the opening of the schools, around risk management, mass gathering, surveillance and contact tracing, said the WHO official.

In Southeast Asian countries, where to a great extent transmissions have been under control, governments are more concerned about the re-emergence of clusters, while in South America, the issue of PPE for health workers has not gone away, said Ryan.

As regards Africa, Ryan said the death rates have been very low in the past week, but the health system can be overwhelmed, as it would have to cope with other diseases such as malaria.

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News Network
February 22,2020

Feb 22: The subjective feeling of well-being experienced by many people with the practice of meditation is associated with specific changes in the brain, according to a study which may lead to better clinical recommendations of the practice.

The study, published in the journal Brain and Cognition, examined the effects of the technique known as Transcendental Meditation (TM), which consists of the silent repetition of a meaningless sound.

In the study, the researchers from the IMT School for Advanced Studies Lucca in Italy, enrolled 34 healthy young volunteers and divided them in two groups.

They said the first group practised TM 40 minutes per day in two sessions of 20 minutes each, one in the morning and the other in the evening.

The second group, the scientists said, did not change its daily routine.

Using questionnaires, they also measured the anxiety and stress levels of all the participants at the beginning of the study, as well as the subjects' ability to manage stressful situations.

According to the researchers, the participants were also subjected to a functional magnetic resonance imaging (fMRI) brain scan, in order to measure the organ's activity at rest, and changes in the excitation among different cerebral areas.

They repeated the tests after three months, at the end of the study.

According to the study, the levels of anxiety and stress perceived by the subjects who followed the meditation program were significantly reduced in comparison with those of the volunteers who did not practice TM.

"Magnetic resonance imaging also shows that the reduction of anxiety levels is associated with specific changes in the connectivity between different cerebral areas, such as precuneus, left parietal lobe and insula, which all have an important role in the modulation of emotions and inner states," said study co-author Giulia Avvenuti from the IMT School for Advanced Studies Lucca.

"In the control group, instead, none of these changes was observed. The fact that Transcendental Meditation has measurable effects on the 'dialogue' between brain structures involved in the modulation of affective states opens new perspectives for the understanding of brain-mind relationships," said Pietro Pietrini, IMT School's Director, and co-author of the study.

"It also extends the results of recent research suggesting that drugs therapies and psychotherapy leverage on the same biological mechanism," Pietrini said.

According to the researchers, even a few months of practice of TM can have positive effects which can be correlated with measurable changes in the brain.

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