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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April 15,2020

Dear parents, if you want your children to have proper sleep, read this carefully. Joining a growing list of studies that tell parents to shun devices at bed-time, researchers say that children who use devices and decide what time they go to sleep, achieve less sleep and feel more sleepier the following day than their peers.

The study of children in this age-group (aged 11 to 13 years), published in the New Zealand Medical Journal, found most (72 per cent) of the 163 students interviewed by University of Otago researchers achieved recommended guidelines of an average 9 to 11 hours sleep nightly over one week.

"But that also means that almost one in four students did not achieve sleep within these guidelines, which highlights an area for improvement," said study researcher Kate Ford.

However, consistent with previous research in 15 to 17-year-old New Zealanders, the study results show less sleep on the nights where devices are used in the hour before bed.

According to the researchers, students who used devices before going to sleep were also more likely to report that they felt sleepy the following morning. Watching television before bed had no significant effect on sleep length.

There were also some interesting observations over the weekends where students went to bed later but woke later achieving similar sleep length to the school days, the researchers said.

A small group of students (six per cent) who reported less than seven hours of sleep, including a small number reporting not sleeping at all, according to the study,

Therefore, while the average across the week of 72 per cent of students reporting adequate sleep is reassuring, it is far from the goal of every child achieving sleep within the recommended guidelines," Ford said.

Dr Paul Kelly, head of the Sleep Health Service at Canterbury District Health Board, supervised the study and explained that the foundations for good health are based on proper nutrition, regular exercise and good sleep quality.

Sleep quality is often overlooked as a contributory factor to poor health.

"The study findings suggest the need for parental guidance around bedtimings and moderation of the use and availability of electronic devices before bed," Kelly said.

"Respect and protect your sleep, as good daytime functioning is reliant on adequate sleep," Kelly added.

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Agencies
April 14,2020

There is no evidence that the Bacille Calmette-Guerin (BCG) vaccine, which is primarily used against tuberculosis, protects people against infection with the novel coronavirus, the World Health Organization (WHO) said.

The WHO therefore didn't recommend BCG vaccination for the prevention of COVID-19 in the absence of evidence, according to its daily situation report on Monday, Xinhua news agency reported.

"There is experimental evidence from both animal and human studies that the BCG vaccine has non-specific effects on the immune system. These effects have not been well characterized and their clinical relevance remains unknown," WHO stated.

Two clinical trials addressing the question are underway, and WHO will evaluate the evidence when it is available, it noted.

BCG vaccination prevents severe forms of tuberculosis in children and diversion of local supplies may result in an increase of disease and deaths from the tuberculosis, it warned.

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January 25,2020

Washington D.C., Jan 25: A new study conducted by a team of researchers reveals why individuals who have a history of early life adversity (ELA) are disproportionately prone to opioid addiction.

The study conducted examined how early adversities interact with factors such as increased access to opioids to directly influence brain development and function, causing a higher potential for opioid addiction.

The study was lead by UCI researchers and was published in Molecular Psychiatry.

Tallie Z. Baram, MD, PhD, the Danette Shepard Chair in Neurological Sciences at the UCI School of Medicine and one of the senior researchers for the study, was on the take that the widely known factor genetics that plays major role in addiction vulnerability, cannot be solely held responsible for the recent rise in opioid abuse.

To further clarify, the researchers simulated ELA in rats by limiting bedding and nesting materials during a short, postnatal period of time.

In female rats, this led to striking opioid addiction-like characteristics including an increased relapse- behaviour, for example.

As observed in addicted humans, the rats were willing to work very hard (pay a very high price) to obtain the drug.

Baram said: "Ultimately, we found that conditions during sensitive developmental periods can lead to vulnerability to the addictive effects of opioid drugs, especially in females, which is consistent with the prevalence of ELA in heroin-addicted women."

These findings can be used to highlight the importance given to sex differences in future ELA-related studies on opioid addiction, and in future prevention or intervention strategies being developed to address the growing opioid crisis.

The study conducted examined how early adversities interact with factors such as increased access to opioids to directly influence brain development and function, causing a higher potential for opioid addiction.

The study was lead by UCI researchers and was published in Molecular Psychiatry.

The study found that unpredictable, fragmented early life environments may lead to abnormal maturation of certain brain circuits, which profoundly impacts brain function and persists into adolescence and adulthood.

Tallie Z. Baram, MD, PhD, the Danette Shepard Chair in Neurological Sciences at the UCI School of Medicine and one of the senior researchers for the study, was on the take that the widely known factor genetics that plays major role in addiction vulnerability, cannot be solely held responsible for the recent rise in opioid abuse.

To further clarify, the researchers implanted ELA in rats by limiting bedding and nesting materials during a short, postnatal period of time.

In female rats, this led to striking opioid addiction-like characteristics including an increased relapse- behaviour, for example.

As observed in addicted humans, the rats were willing to work very hard (pay a very high price) to obtain the drug.

Baram said: "Ultimately, we found that conditions during sensitive developmental periods can lead to vulnerability to the addictive effects of opioid drugs, especially in females, which is consistent with the prevalence of ELA in heroin-addicted women."

These findings can be used to highlight the importance given to sex differences in future ELA-related studies on opioid addiction, and in future prevention or intervention strategies being developed to address the growing opioid crisis.

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