It has been suggested that babies of Covid-19-infected mothers be separated from their mothers
It may, however, not be necessary as pregnant mothers with Covid-19 tend not to infect their babies
A new study, therefore, recommends normal breastfeeding, while taking a few extra precautions
In some reassuring news on the coronavirus front, a new study finds that pregnant women with Covid-19 rarely infect their newborn.
That finding suggests that it may not be necessary to separate infected mothers from their infants and that moms can continue to breastfeed, the researchers added.
“Our findings should reassure expectant mothers with Covid-19 that basic infection-control measures during and after childbirth, such as wearing a mask and engaging in breast and hand hygiene when holding or breastfeeding a baby, protected newborns from infection in this series,” said researcher Dr Cynthia Gyamfi-Bannerman. She’s a professor of women’s health in obstetrics and gynaecology at Columbia University Vagelos College of Physicians and Surgeons, in New York City.
A few extra precautions
For the study, the team looked at 101 newborns born to Covid-19-positive mothers from 13 March to 24 April, 2020.
Hospital personnel maintained basic precautions to prevent infection and kept infants in protective cribs six-feet away from the mothers’ beds. Direct breastfeeding and skin-to-skin contact with babies, however, were encouraged, as long as moms wore masks and washed hands and breasts with soap and water.
“During the pandemic, we continued to do what we normally do to promote bonding and development in healthy newborns, while taking a few extra precautions to minimise the risk of exposure to the virus,” Gyamfi-Bannerman said.
Among the infants, only two tested positive for SARS-CoV-2 and they had no symptoms. The researchers couldn’t be sure how the babies became infected.
Conflicting recommendations
Several groups have recommended that babies of Covid-19-infected mothers should be separated from their mothers, the study authors noted in a university news release.
“These recommendations were made in the absence of data on rates of mother-to-newborn SARS-CoV-2 transmission and are based on experience with mother-newborn transmission of other infectious diseases,” explained researcher Dr Dani Dumitriu, an assistant professor of paediatrics in psychiatry at Columbia.
“But some of the recommendations conflict with what we know about the developmental benefits of early breastfeeding and skin-to-skin contact,” Dumitriu added. “Our study shows that these measures may not be necessary for healthy newborns with Covid-positive moms.”
The findings were published online on 12 October in JAMA Pediatrics.
Today humans are exposed to thousands of man-made chemicals. Yet the effects on people’s health are still not fully understood.
In 2020 the number of registered chemicals reached 167 million. Every day people are exposed to them through food, water, contaminated air, drugs, cosmetics and other man-made substances. Less than 1% of these chemicals were tested for toxicity, and those that were tested demonstrate ability to disrupt almost every biological process in our body. Can we infer how cumulative exposures shape our health?
I am an environmental toxicologist studying effects of man-made chemicals on our health. I decided to develop a computational approach to objectively compare sensitivity of all genes to all chemicals and identify the most vulnerable biological processes.
Unbiased approach
For our study, my research colleagues and I used data from the Comparative Toxicogenomic Database. The Comparative Toxicogenomic Database collects information from thousands of published studies on how chemicals change the activity of genes. Genes are sections of DNA that encode proteins which perform a broad range of functions in cells, from building tissues to metabolisng nutrients. When chemicals affect genes, that results in increased or decreased production of proteins.
Modern methods of molecular biology can detect changes in activity of all genes in the genome in response to a chemical insult. I developed an approach that overlays lists of altered genes from different studies to calculate how many times each gene was affected. The resulting numbers reflect sensitivities of genes to chemicals generally.
Using 2 169 studies on mice, rats, humans and their cells, my research group ranked the sensitivity of 17 338 genes to chemical exposures. These studies tested the impact of 1 239 diverse chemicals ranging from prescription drugs to environmental pollutants.
At the next step we ran tests to ensure that this sample of over 1 000 chemicals was large enough to reliably represent all classes of man-made chemicals people are exposed to. To do so, we measured sensitivity of genes for one half of this list and then for another to test if even a smaller number of chemicals can reliably identify sensitive genes. The results were encouraging – the values of gene sensitivities were almost identical in the two trials.
This line of defense includes enzymes that eliminate toxic chemicals, alleviate oxidative stress (the accumulation of reactive radicals in cells), repair damaged DNA and proteins, and identify highly damaged cells to trigger their death and prevent them from turning cancerous.
Metabolism of lipids and carbohydrates is vulnerable
Surprisingly, we found that molecular networks involved in the regulation of cellular metabolism are most sensitive to chemical exposures. One of them is PPAR signaling. PPARs are a group of proteins that regulate energy balance and metabolism of lipids and glucose.
We also discovered that genes involved in the development of pancreatic beta cells, which secrete insulin and play a key role in glucose metabolism, are suppressed by a majority of chemicals in our list. Dysfunction of beta cells results in diabetes. Thus, cumulative chemical exposures may be a significant risk factor for diabetes.
The ability of chemicals to affect this central regulator of growth and ageing is a novel finding. What health problems may be due to the sensitivity of GH-IGF1 is yet to be uncovered.
Our analysis indicates that genes that control the immune response are also highly sensitive to chemicals.
One important question that remains unanswered is what pathways should be covered by testing to ensure that regulators do not approve chemicals that harm or disrupt critical molecular circuits. Our data suggests that we need to develop tests that cover every known molecular pathway without exception.
Our study outlines new priorities for toxicological research, including the role of chemical exposures for metabolic health, immune system, development and ageing.
According to the World Health Organization (WHO), tobacco kills up to half of its users
Teenage girls who smoke are especially vulnerable to developing breast cancer later in life
In South Africa, Protect Our Next aims to improve tobacco control legislation and educate the public on its harmful effects
The month of October is breast cancer awareness month.
It marks a special time for survivors of breast cancer, reminding them of what they have overcome. It is also a painful reminder of the dreadful effect of the disease on those who have lost loved ones as a result. Most importantly, Breast Cancer Awareness Month allows us to reflect and educate ourselves on ways in which we can lower our risk of developing cancer.
Protect Our Next is a partnership between CANSA, the National Council Against Smoking (NCAS), the South African Medical Research Council (SAMFC), and the Heart and Stroke Foundation South Africa (HSFSA). The aim of this partnership is to improve tobacco control legislation and also educate the public on the harmful effects of tobacco usage.
Lowering the risk of developing cancer
In a press release, Protect Our Next recently expressed that teenage girls who smoke are especially vulnerable to developing breast cancer later in life. The risk is even higher for those who have a family history of cancer.
While the risk for breast cancer can be due to family history, a study published in the Journal of Breast Cancer confirmed that smoking is associated with an increased risk of breast cancer. A fact sheet on the World Health Organization (WHO) website also shows that tobacco kills up to half of its users.
Controlling the consumption of tobacco, especially among the youth, is therefore a vital part of lowering the risk of developing cancer. Lorraine Govender of the Cancer Association of South Africa (CANSA) expressed, “We must ensure that we have policies in place that protect young people from these toxic, carcinogenic products. Too many lives are lost through cancers resulting from tobacco addiction, and we need to reduce every risk factor.”
Govender went on to say that implementing a new Bill that makes it harder to obtain and use tobacco-related products will be a step in the right direction.
There is a different Covid-19 phenomenon called ‘Multisystem Inflammatory Syndrome in Adults’ – or MIS-A
This is affecting patients’ heart, digestive tract and nervous systems
MIS-A might not be driven directly by the virus itself but by a post-infectious immunologic response
When the new coronavirus pandemic first began, respiratory distress immediately became the hallmark of severe Covid-19 illness. News reports focused on the inability to breathe, low oxygen saturation levels and the alarming need for ventilators.
But six months later, experts are becoming increasingly concerned about a very different Covid-19 phenomenon, one that spares the lungs only to take direct aim at the patient’s heart, digestive tract and nervous system.
Called “Multisystem Inflammatory Syndrome in Adults” – or MIS-A – the condition was first spotted last spring in children and teens.
“The symptoms are very similar among adults and children,” explained Dr Alisa Femia, director of both in-patient dermatology and autoimmune connective tissue disease at NYU Langone Dermatologic Surgery & Cosmetic Associates, in New York City.
A shock-like state
“Fever is characteristic,” Femia noted, sometimes accompanied by a rash, skin discolouration and chapping, chest pain and gastrointestinal issues.
“Some patients develop muscle pain and a general feeling of unwellness. And some experience a shock-like state, which means that blood pressure is dropping, the heart rate is up, and the patient appears very, very ill and in immediate need of hospitalisation,” she added.
Femia was part of a team that first reported on the paediatric version of the condition – known as MIS-C – back in July. To date, there have been more than 1 000 cases of MIS-C in the United States, resulting in 20 deaths.
Femia ultimately went on to treat the first reported case of MIS-A. Now, the US Centers for Disease Control and Prevention is zeroing in on the adult version, with an analysis outlined recently in the CDC’s Morbidity and Mortality Weekly Report.
The CDC report focused on 27 MIS-A patients ranging in age from 21 to 50. Of those, 10 ended up in the intensive care unit and two of those patients died.
“The lack of respiratory symptoms at presentation represent the main distinction between patients with severe Covid-19 and MIS-A,” said Dr Sapna Bamrah Morris, lead author of the CDC report. She’s an infectious disease specialist and clinical lead of the Health Care Systems and Worker Safety Task Force for the CDC’s Covid-19 Response Team.
In fact, said Morris, in some cases, MIS-A patients “may have multiorgan dysfunction without [any] history of showing symptoms of Covid-19”.
Many patients show no ‘typical’ COVID-19 symptoms
That speaks to the bewildering nature of MIS-A, Femia said. MIS-A patients are testing positive for Covid-19 antibodies, but absent classic respiratory symptoms, many had no idea they were infected. But several weeks or even months later, they suddenly end up hospitalised with serious MIS-A symptoms. At that point, they are often no longer positive for active Covid-19.
“The timing of all of this is very difficult to establish,” Femia said. “We really don’t know how long after an infection with Covid this can happen, because antibodies can remain positive for a couple of months. I would say that, from a doctor’s perspective, our best guess is that this is likely to happen four to six weeks after infection, but it could be three to four months. We really don’t know.”
Dr David Hirschwerk is an infectious disease specialist at Northwell Health in Manhasset, New York. “The timing of all of this suggests that MIS-A is driven not directly by the virus itself but by a post-infectious immunologic response that causes damage to the body,” he said.
“We think that it is relatively rare,” Hirschwerk added. “But we are all on the lookout for it now.”
Femia acknowledged that wasn’t always the case, given that in the early days of the pandemic “hospitals were overwhelmed, and it was a new disease, and this condition just wasn’t on the radar, which means we honestly don’t really know how many adults have gotten this”.
So, who is most at risk for MIS-A? Hirschwerk pointed to the CDC finding that “the vast majority of patients with MIS-A belonged to racial or ethnic minority groups”.
More prevalent in children
But, “like many things with Covid-19, it is all very new to us,” he added. “It requires more study, more data and more time.”
Femia agreed. But she noted that some characteristics of MIS-A are becoming both clear and worrisome. For example, “this has been seen in otherwise healthy patients, as well as among patients with underlying conditions, like obesity. So, the overall suspicion is that you probably don’t need as may co-morbidities to be at risk,” she explained.
“MIS also seems to be more prevalent in children than adults,” she noted. “Why, we just don’t know.”
The good news: “It is treatable,” Femia said. Apart from anti-clotting meds and aspirin, “the most consistent treatment that’s given is IV immunoglobulins”, which are proteins that function as antibodies. “We don’t usually use that to treat acute Covid infection, but it’s borrowed from treatments for other hyper-inflammatory conditions, like Kawasaki disease,” a pediatric illness that causes blood vessel inflammation.
“There’s a lot we don’t know about this,” said Femia. “And many patients will have a very difficult hospital course before they come back to health. But in the end, the majority of patients do survive.”
In a survey, only about three-quarters of the participants said they would take a Covid-19 vaccine
A study found that vaccine hesitancy is strongly related to a lack of trust in government
Vaccine acceptance was found to be highest in China and lowest in Russia
When scientists finish developing a Covid-19 vaccine, will people be willing to take it?
An international research team analysed data from 19 countries hit hard by the new coronavirus and found that when confidence in government was low, hesitancy to accept a Covid-19 vaccine was higher.
Based on a previous survey of more than 13 400 people, researchers found that about 72% were likely to take a vaccine. About 14% would refuse and a similar percentage would hesitate, the survey showed.
Vaccine hesitancy a key obstacle
“The problem of vaccine hesitancy is strongly related with a lack of trust in government. Vaccine confidence was invariably higher in countries where trust was higher,” said study co-leader Jeffrey Lazarus, of the Barcelona Institute for Global Health (ISGlobal) in Spain.
Study co-leader Ayman El-Mohandes said health leaders need to increase confidence and improve the public’s understanding of how they can help control the spread of Covid-19. El-Mohandes is dean of the School of Public Health at the City University of New York (CUNY).
Vaccine hesitancy will be a key obstacle for public health officials, in addition to the already challenging tasks of developing, producing and equitably distributing a vaccine. More than 90 Covid-19 vaccines are in development around the world, and about half are in human trials.
Vaccine acceptance varied by country, with the highest percentage of positive responses, 87%, coming from respondents in China. The lowest number of positives, 55%, was from Russia.
In the United States, 76% of survey respondents gave positive responses. About 11% were negative; 13% of respondents had no opinion.
Robust and sustained effort
Respondents who were older and those with higher incomes were more likely to accept a vaccine. People who had been sick with Covid-19 or whose relatives had been sick were not more likely to respond positively.
“It will be tragic if we develop safe and effective vaccines and people refuse to take them,” said study co-author Scott Ratzan, a lecturer at CUNY.
“We need to develop a robust and sustained effort to address vaccine hesitancy and rebuild public confidence in the personal, family and community benefits of immunisations,” he said in a CUNY news release.
Ratzan noted that the results were consistent with recent surveys in the United States, which point to diminished public trust in a Covid-19 vaccine.
The findings were published recently in the journal Nature Medicine.
After Massachusetts healthcare workers were required to wear masks, Covid-19 infections among them sharply decreased
At the same time, infections in the community continued to rise
This serves as a clear indication that wearing masks helps to prevent infection
Here’s more proof that masking up reduces transmission of Covid-19: A new Massachusetts study found that wearing face coverings resulted in a decrease in coronavirus cases among healthcare workers as infections were increasing in the surrounding community.
“We found clear benefits to universal masking for preventing infectious spread within the work environment,” researcher Dr Stefanos Kales said. He’s division chief of occupational and environmental medicine at the Cambridge Health Alliance (a Harvard-affiliated community health system) and a professor at Harvard Medical School.
Universal masking implemented and maintained
For the study, the researchers compared the rate of Covid-19 cases between the Cambridge Health Alliance (CHA) and Massachusetts residents from 17 March to 6 May. The CHA started requiring masks on 26 March.
The universal masking was done during a time of rising infections in both the healthcare system and the community. After the policy was instituted, infections among healthcare workers sharply decreased, while community infections continued to rise until their peak on April 20. Before the mask mandate, infection rates increased almost identically in the healthcare system and the state’s population, the study found.
“Our findings suggest that universal masking policy should be implemented and maintained in healthcare settings as well as within indoor businesses when physical distancing and ventilation may be inadequate,” Kales added in a CHA news release.
Dementia has tremendous costs in terms of treatment and caregiving.
Preventing dementia, therefore, is of great importance
The findings of a new study suggest that socialising could benefit older adults’ brain health
Older adults who get together with friends, volunteer or go to classes have healthier brains, which could help them ward off dementia, according to a new study.
Researchers who used brain imaging to examine brain areas involved in mental decline found that greater social engagement made a difference in brain health.
Being socially engaged – even moderately – with at least one relative or friend activates parts of the brain needed to recognise familiar faces and emotions, make decisions and feel rewarded, the study found.
No cure for dementia
“We need to do more research on the details, but that’s the beauty of this – social engagement costs hardly anything, and we do not have to worry about side effects,” said lead author Dr Cynthia Felix, a geriatrician and postdoctoral associate at the University of Pittsburgh Graduate School of Public Health.
“There is no cure for dementia, which has tremendous costs in terms of treatment and caregiving. Preventing dementia, therefore, has to be the focus. It’s the ‘use it or lose it’ philosophy when it comes to the brain,” she said in a university news release.
The researchers drew on information from nearly 300 community-dwelling seniors (average age 83) who had a sensitive brain scan to gauge the integrity of brain cells used for social engagement.
Once brain cells die, dementia typically follows. Researchers said it’s not yet clear whether social engagement keeps brains healthy or if having a healthy brain leads to more socialising.
Either way, the findings suggest that “prescribing” socialisation could benefit older adults’ brain health – similar to the way prescribing physical activity can help prevent diabetes or heart disease. Existing programmes that provide group physical activities would be a good starting point, Felix said.
Social engagement crucial during pandemic
“Our data were collected before the Covid-19 pandemic, but I believe our findings are particularly important right now, since a one-size-fits-all social isolation of all older adults may place them at risk for conditions such as dementia,” she said.
“Older adults should know it is important for their brain health that they still seek out social engagement in safe and balanced ways during the pandemic,” Felix advised.
The findings were reported on 19 October in the Journal of Gerontology: Psychological Sciences.
There was a significant decrease in the average number of asthma hospitalisations during the first part of 2020
A possible explanation is that better hygiene as a result of Covid-19 reduced exposure to asthma triggers
Enhanced precautions and preventative asthma medications could also have had an effect
Measures enacted to slow the spread of the new coronavirus also appeared to reduce hospitalisations for asthma, a new study finds.
Researchers compared weekly data on hospitalisations at 272 hospitals in Japan in the first five months of 2020 to the same period in 2017, 2018 and 2019.
Asthma hospitalisations in 2017–19 and 2020 showed similar trends until week eight, but in 2020 hospitalisations began to decline in week nine, the study found.
Hospitalisations for Covid-19 were first recorded during week seven of 2020. Further analysis found a significant decrease in the average number of asthma hospitalisations during weeks nine to 22 of this year compared to 2017–19.
Enhanced precautions
The findings were published on 13 October in The Journal of Allergy and Clinical Immunology: In Practice.
“Asthma hospitalisations usually indicate that an individual’s asthma is not currently under control,” corresponding author Dr Atsushi Miyawaki, of the University of Tokyo, said in a journal news release. “This would suggest that asthma control improved during the pandemic. It illustrates the importance of environmental factors when it comes to treating and managing patients with asthma.”
One possible explanation is that increased hygiene to prevent Covid-19 would also reduce exposure to asthma triggers, according to the researchers. Enhanced precautions – such as frequent cleaning and reduced smoking – by people concerned that Covid-19 may trigger asthma may also have helped reduce triggers.
Other possible explanations include people being more likely to use preventative asthma medications, and community Covid-19 prevention measures helping reduce other respiratory infections, which can cause worse asthma.
As the Covid-19 pandemic continues, obesity has been one of the top triggers for severe cases. Outside of the disease, obesity has always had a detrimental effect on health through chronic inflammation, a higher risk of heart disease and a weakened response to viral infections.
But how much does it matter in relation to other conditions, age, sex and race when it comes to contracting a severe coronavirus infection?
To answer this question, Brazilian researchers conducted a meta-analysis of nine studies from five countries on severe Covid-19, which included more than 6 500 patients. More than half were male and had comorbidities such as hypertension (51.51%), diabetes (30.3%), cardiovascular disease (16.66%), lung disease (15.99%), renal disease (7.49%), cancer (5.07%), and immunosuppression (1.8%). A high proportion of patients were smokers and suffered from dyslipidemia – a condition involving high levels of cholesterol or fat in the blood.
They wanted to investigate the prevalence of obesity as a contributing factor in severe Covid-19 cases that required admission to ICU. They also looked at the best treatments that helped obese patients recover from the virus.
The studies they analysed included case studies and series, clinical trials and randomised controlled trials that mentioned obesity. They found that in more than half of severe cases, people suffered from obesity. In terms of other comorbidities, just less than half had hypertension, while type 2 diabetes, lung disease, smokers, cardiovascular disease were each around the 20% mark.
Not only is obesity a major factor for severe Covid-19, the condition also indicates that these patients are also more likely to be infected with the coronavirus in the first place.
A 51-year-old patient ended up with a snapped coronavirus test swab inside her lung after it was inserted into a breathing tube in her neck, a BMJ case report revealed.
The woman was undergoing brain surgery in a UK hospital to remove a fragment of her skull. As part of her treatment, a tracheostomy tube – placed into the windpipe to assist with breathing – was fitted.
After the operation, medical staff at the University Hospitals of Leicester NHS (National Health Service) Trust sent the patient to undergo a coronavirus test as part of normal protocol before discharging her to a nursing home.
Since the patient had been breathing through the hole in her neck and could have potentially become infected with the virus through this airway, medical staff took a swab through her tracheostomy tube.
However, a nurse carrying out the test felt the swab snap during the procedure, and part of it ended up in the patient’s windpipe.
The test swab is designed to snap into a test tube to be sent to the lab.
Understanding the features of SARS-CoV-2, the virus that causes Covid-19, is crucial for predicting the future, and in a recent study, scientists may have come one step closer.
According to Duke University (DU) researchers, a number of “silent” mutations in the roughly 30 000 letters of the virus’s genetic code may have given it an advantage and caused it to thrive in the human population after crossing over from bats and other wild animals.
“We’re trying to figure out what made this virus so unique,” said lead author Alejandro Berrio, a postdoctoral associate in biologist Greg Wray’s lab at DU.
In their paper, they explain how the subtle changes, or mutations, influenced how the virus unfolded its RNA molecules within human cells.
The study was published in the journal PeerJ.
For their study, the researchers wanted to identify adaptive changes that occurred in the SARS-CoV-2 genome in humans, but not in closely related coronaviruses found in bats and pangolins.
The first case of sudden hearing loss due to Covid-19 infection was reported in the United Kingdom and doctors are urging people to become aware of the symptom because prompt treatment could completely or at least partially reverse it.
While the report states that the condition is uncommon, doctors warned that if the condition remains undetected, and subsequently untreated, the damage is likely to be irreversible.
The case study was published in BMJ Case Reports and details how a 45-year-old patient, who suffers from asthma, was admitted to hospital following 10 days of Covid-19 symptoms.
In hospital, the patient needed to be intubated and was transferred to the intensive care unit (ICU).
He remained intubated for 30 days and his stay in hospital was further complicated because of a number of other conditions, including pneumonia and anaemia. After going through several courses of medication, including remdesivir, intravenous steroids and plasma exchange (to treat Covid-19), he was extubated and transferred out of the ICU.
A week after leaving the ICU, the patient noticed a ringing in his left ear and a sudden loss of hearing. The patient was officially diagnosed with sudden onset sensorineural hearing loss (SSNHL).
People with certain common personality traits are less likely to remain at home when government policies are less restrictive, a global survey done during the first wave of the Covid-19 pandemic has found.
The study researchers investigated the so-called Big Five personality traits: conscientiousness, neuroticism, agreeableness, extraversion and openness and its association with complying with lockdown measures.
“The pandemic led us to revisit one of psychology’s most fundamental and most basic questions in a high-stakes context: What determines human behaviour?” the authors wrote.
Their findings were published by the American Psychological Association.
For their study, the research team used data from the “Measuring Worldwide Covid-19 Attitudes and Beliefs” project – a global survey that aimed to assess people’s behaviours and perceptions of others’ behaviours during the pandemic.
The team analysed responses from more than 101 000 participants in 55 countries.
Late on Sunday night, positive cases worldwide were more than 42.77 million, while deaths were more than 1.51 million.
The United States had the most cases in the world – more than 8.58 million, as well as the most deaths – almost 225 000.
HEALTH TIPS (as recommended by the NICD and WHO)
• Maintain physical distancing – stay at least one metre away from somebody who is coughing or sneezing
• Practise frequent hand-washing, especially after direct contact with ill people or their environment
• Avoid touching your eyes, nose and mouth, as your hands touch many surfaces and could potentially transfer the virus
• Practise respiratory hygiene – cover your mouth with your bent elbow or tissue when you cough or sneeze. Remember to dispose the tissue immediately after use.
Some people have a higher genetic risk for Alzheimer’s disease
People with Alzheimer’s often report depression and various sleep problems, like insomnia
Researchers, however, found no evidence that sleep-related characteristics or depression cause Alzheimer’s
Disturbed sleep doesn’t cause Alzheimer’s disease, but some sleep patterns may be more common in people who have a high genetic risk for it, a new study reports.
Those patterns include being a morning person, having shorter sleep duration and being less likely to have insomnia, according to findings published in the August online issue of the journal Neurology.
“We know that people with Alzheimer’s disease often report depression and various sleep problems, like insomnia,” said study author Dr Abbas Dehghan, of the faculty of medicine at Imperial College London in the UK “We wanted to find out if there are causal relationships between different sleep patterns and depression and Alzheimer’s.”
Risk based on genetic studies
His team analysed a number of genetic studies. One compared nearly 22 000 people with Alzheimer’s to nearly 42 000 others. Another compared more than 9 200 people with major depression to more than 9 500 without it. Another assessed sleep-related characteristics of more than 446 000 people.
Alzheimer’s risk was determined based on genetic studies where the disease was diagnosed by autopsy or clinical examination.
Researchers found no evidence that sleep-related characteristics caused Alzheimer’s. They also found no evidence of cause and effect between major depression and Alzheimer’s.
The study did find some small associations between sleep habits and Alzheimer’s. Specifically, people with twice the genetic risk for Alzheimer’s were 1% more likely than others to be morning people, and people with twice the genetic risk of Alzheimer’s had a 1% lower risk of insomnia.
Researchers emphasised that these associations are small and do not prove cause and effect.
They also noted that most of the people in the study were of European ancestry, so the results may not apply to other racial/ethnic groups.
