Sleep Health

  • Regular napping linked to larger brain volume

    Original Article | UCL News

    Daytime napping may help to preserve brain health by slowing the rate at which our brains shrink as we age, suggests a new study led by researchers at UCL and the University of the Republic in Uruguay.

    woman napping

    The study, published in the journal Sleep Health, analysed data from people aged 40 to 69 and found a causal link between habitual napping and larger total brain volume – a marker of good brain health linked to a lower risk of dementia and other diseases.

    Senior author Dr Victoria Garfield (MRC Unit for Lifelong Health & Ageing at UCL) said: “Our findings suggest that, for some people, short daytime naps may be a part of the puzzle that could help preserve the health of the brain as we get older.”

    Previous research has shown that napping has cognitive benefits, with people who have had a short nap performing better in cognitive tests in the hours afterwards than counterparts who did not nap.

    The new study aimed to establish if there was a causal relationship between daytime napping and brain health.

    Using a technique called Mendelian randomisation, they looked at 97 snippets of DNA thought to determine people’s likelihood of habitual napping. They compared measures of brain health and cognition of people who are more genetically “programmed” to nap with counterparts who did not have these genetic variants, using data from 378,932 people from the UK Biobank study, and found that, overall, people predetermined to nap had a larger total brain volume.

    The research team estimated that the average difference in brain volume between people programmed to be habitual nappers and those who were not was equivalent to 2.6 to 6.5 years of ageing.

    But the researchers did not find a difference in how well those programmed to be habitual nappers performed on three other measures of brain health and cognitive function – hippocampal volume, reaction time and visual processing.

    Lead author and PhD candidate Valentina Paz (University of the Republic (Uruguay) and MRC Unit for Lifelong Health & Ageing at UCL) said: “This is the first study to attempt to untangle the causal relationship between habitual daytime napping and cognitive and structural brain outcomes. By looking at genes set at birth, Mendelian randomisation avoids confounding factors occurring throughout life that may influence associations between napping and health outcomes. Our study points to a causal link between habitual napping and larger total brain volume.”

    Dr Garfield added: “I hope studies such as this one showing the health benefits of short naps can help to reduce any stigma that still exists around daytime napping.”

    The genetic variants influencing our likelihood to nap were identified in an earlier study looking at data from 452,633 UK Biobank participants. The study, led by Dr Hassan Dashti (Harvard University and Massachusetts General Hospital), also an author on the new study, identified the variants on the basis of self-reported napping, and this was supported by objective measurements of physical activity recorded by a wrist-worn accelerometer.

    In the new study, researchers analysed health and cognition outcomes for people with these genetic variants as well as several different subsets of these variants, adjusted to avoid potential bias, for instance avoiding variants linked to excessive daytime sleepiness.

    Genetic data and magnetic resonance imaging (MRI) scans of the brain were available for 35,080 individuals drawn from the larger UK Biobank sample.

    In terms of study limitations, the authors noted that all of the participants were of white European ancestry, so the findings might not be immediately generalisable to other ethnicities.

    While the researchers did not have information on nap duration, earlier studies suggest that naps of 30 minutes or less provide the best short-term cognitive benefits, and napping earlier in the day is less likely to disrupt night-time sleep.

    Previous research looking at the UK and the Netherlands found that nearly a third of adults aged 65 or over had a regular nap.

    The study was supported by Diabetes UK, the British Heart Foundation and the Diabetes Research and Wellness Foundation. In Uruguay it was supported by Programa de Desarrollo de las Ciencias Básicas (PEDECIBA, MEC-UdelaR), Agencia Nacional de Investigación e Innovación (ANII), Comisión Sectorial de Investigación Científica (CSIC, UdelaR), and Comisión Académica de Posgrados (CAP, UdelaR). In the United States it was supported by the National Heart, Lung, and Blood Institute.



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  • Night owls may die earlier because they tend to drink and smoke more, study suggests.

    The heightened mortality of “night owls” compared with “early birds” may come down to heavier smoking and higher alcohol consumption among night owls, a large study of people in Finland suggests.

    Night owls have a higher risk of death than early birds, but that might come down to the overall amount of alcohol and cigarettes they use. (Image credit: FreshSplash via Getty Images)

    Night owls’ tendency to smoke more cigarettes and drink more alcohol than early birds could explain why evening people have a higher risk of early death than early risers do, a large analysis suggests.

    “This can reassure people concerned about what being a morning or evening person means for their life expectancy and health,” study co-author Jaakko Kaprio, a professor of genetic epidemiology at the University of Helsinki in Finland, told Live Science. “It’s not about the chronotype [being a morning or evening person] itself that is dangerous, but it is the associated lifestyle factors.” 

    Other scientists previously found elevated mortality rates among night owls compared with morning people, but these past analyses didn’t account for differences in participants’ alcohol consumption or smoking quantity, making it difficult to tell whether being an evening person directly increases mortality risk.

    Now, Kaprio and his colleagues have analyzed health and lifestyle data from more than 23,000 people living in Finland to tease out whether being a night owl directly affects the risk of dying within the next few decades. The findings were published Friday (June 16) in the journal Chronobiology International.

    Related: Life really is harder for night owls. Here’s why. 

    In a survey carried out in 1981, participants — who were 41 years old at the time, on average — self-reported their smoking and drinking habits. On a questionnaire, they also stated whether they were “clearly a morning person,” “to some extent a morning person,” “clearly an evening person” or “to some extent an evening person.” 

    Overall, more than 8,700 participants died during the 37-year follow-up period, which ended in 2018. By analyzing participants’ health records collected in that time, the researchers found that participants who initially said they were “clearly” evening people had a 21% higher risk of death from any cause compared with those who were “clearly” morning people.

    This initial analysis only adjusted for participants’ ages and sex, but the scientists then ran a second analysis that accounted for additional factors that could affect people’s mortality risk, such as body mass index (BMI), self-reported sleep duration, educational level, rates of chronic diseases, alcohol consumption and smoking status and quantity. After the researchers controlled for these additional factors, the night owls’ overall excess mortality risk dropped to just 9%.

    Why did night owls’ risk fall by more than half? The team found that most of their raised mortality risk was attributable to higher alcohol consumption and heavier smoking among evening people than in morning people. Supporting this idea, they found that mortality rates did not differ between evening and morning people who were light drinkers that never smoked. 


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    What’s more, an analysis that accounted for differences in age and sex found that rates of death due to alcohol-related diseases and accidental alcohol poisoning were 92% higher among “clearly” evening people compared with “clearly” morning people. And deaths due to lung and airway cancers, made more likely by smoking, were 78% higher among night owls. Both of these risks fell “substantially” when other lifestyle factors, including alcohol and smoking habits, were considered. These findings further support the idea that smoking and drinking, not staying up late, raise night owls’ risk of death, the authors concluded. 

    The remaining 9% increase in mortality rate among evening people is unlikely to be directly due to their late bedtimes, Kaprio said. 

    “We measured people’s chronotype and alcohol consumption at one time using one question, which means we don’t account for how things might have changed years later,” he said. “If we measured alcohol and drinking habits perfectly throughout the study period, I think the raised risk may be much less or absent.” 

    Kristen Knutson, a professor of neurology at Northwestern University who was not involved in the study, agreed that the remaining 9% risk isn’t necessarily linked to chronotype.The risk could be related to yet-unknown “unmeasured environmental or behavioral factors, rather than an inherent risk associated with a later internal clock,” she told Live Science. 

    It remains unclear why being an evening person is linked to heavier smoking and drinking, Kaprio said. Beyond potential differences in the social activities of evening and morning people, “one explanation would be that there are genes that predispose you to both being an evening person and also to drinking more alcohol,” he said. 

  • Sleep and Time with Pets Help People Living with Bipolar Disorder

    by University of Western Sydney | Original Article Feb 2018

    Bipolar disorder is characterized by transitions between depression and mania. Credit: Wikipedia

    New research from Western Sydney University has revealed that simple self-care strategies, such as spending time with animals and getting enough sleep, are helpful for people managing bipolar disorder symptoms.

    The research, published in Clinical Psychologist this week, involved 80 participants with bipolar disorder reviewing the frequency and perceived helpfulness of 69 self-care strategies. These strategies were diverse, and included things such as abstaining from drugs and alcohol, practising yoga and finding things that make you laugh.

    The study found that an increased engagement in self-care strategies was associated with improved quality of life, reduced the impact of the illness, and reduced depression, anxiety and stress. Getting enough sleep was the most commonly rated strategy as “very helpful,” with “spending time with pets,” also rating highly.

    Lead researcher, honours student Edward Wynter from Western Sydney University’s School of Social Sciences and Psychology, says the study provides encouraging findings about the relationship between self-care and important functional and symptomatic outcomes, i.e. the ability of these strategies to alleviate the impact of the disorder.

    “The benefits of self-care have been reported in other chronic illnesses, but bipolar disorder research has focused primarily on medication management,” Mr Wynter says.

    “This research reveals support for strategies already well known to professionals and people living with bipolar disorder, including those relating to quality and quantity of sleep, and drug and alcohol abstinence; but this study also highlights the effectiveness of several strategies yet to be explored such as spending time with pets and engaging in creative pursuits.”

    Mr Wynter says he hopes this research leads to further exploration of self-care strategies used by people living with bipolar disorder, and their relationship with long-term quality of life.

    “I hope that knowledge of effective strategies can inspire proactive therapeutic engagement and empower people living with bipolar disorder to improve their health and wellbeing,” he says.

  • Link Between Sleep Apnea and Depression

    New research has explored the link between sleep apnea and depression and suggests that the former may be one reason that depression treatments fail.

    Around 20–30%Trusted Source of people with depression and other mood disorders do not get the help they need from existing therapies.

    Depression is the “leading cause of disabilityTrusted Source worldwide.”

    For this reason, coming up with effective therapies is paramount.

    New research points to obstructive sleep apnea (OSA) as a potential culprit for treatment resistant depression and suggests that screening for and treating the sleep condition may alleviate symptoms of depression.

    Dr. William V. McCall — chair of the Department of Psychiatry and Health Behavior at the Medical College of Georgia at Augusta University — is the first and corresponding author of the study.

    He says, “No one is talking about evaluating for [OSA] as a potential cause of treatment resistant depression, which occurs in about 50% of [people] with major depressive disorder.”

    He hopes that the team’s new paper — appearing in The Journal of Psychiatric Research — will remedy this.

    14% of those with depression had OSA

    Dr. McCall and team examined the rate of undiagnosed OSA in a randomized clinical trial of people with major depressive disorder and suicidal tendencies.

    They recruited 125 people with depression, originally for the purpose of determining if treating their insomnia would improve their depression symptoms.

    The original trial excluded people at risk of OSA, such as those taking sleeping pills, or people with obesity or restless legs syndrome.

    The scientists tested the participants with a sleep study and found that 17 out of the 125 (nearly 14%) had OSA.

    Dr. McCall and colleagues note that people who had OSA did not present with the usual indicators of OSA severity, such as daytime sleepiness. Also, 6 of the 17 people were non-obese women.

    This is contrast with the demographic group usually at risk of OSA: overweight men.

    “We were completely caught by surprise,” says Dr. McCall, “that people did not fit the picture of what [OSA] is supposed to look like.”

    Also, 52 of the 125 participants had treatment resistant depression; 8 of those with treatment resistant depression also had OSA.

    Future treatment options

    The researchers point out that underlying conditions — such as hypothyroidismcancer, and carotid artery disease — may often be the cause of treatment resistant depression.

    Therefore, many people with depression undergo a series of invasive and costly tests in an attempt to figure out the cause of depression treatment failure.

    Such tests may include an MRI scan or even a spinal tap — but Dr. McCall and team urge for sleep tests first. “I am thinking before we do a spinal tap for treatment resistant depression, we might need to do a sleep test first,” he says.

    “We know that [people] with sleep apnea talk about depression symptoms,” he goes on. “We know that if you have [OSA], you are not going to respond well to an antidepressant.”

    “We know that if you have sleep apnea and get [a CPAP machine], it gets better and now we know that there are hidden cases of sleep apnea in people who are depressed and [have] suicidal [tendencies].”

    Dr. William V. McCall

    However, the study authors also acknowledge that other factors — such as the side effects of other medications, including beta-blockers and corticosteroids — may cause treatment resistant depression.

    They also point out that suicidal tendencies are also a key factor, and the researchers suggest that a further area of investigation should be the question of whether or not treating sleep apnea will also reduce suicide ideation.

    In the United States, suicide is the 10th leading cause of deathTrusted Source among people of all ages.

  • Have trouble grinding your teeth? Here’s how to control it.

    By Sally Wadyka | June 20, 2022 featured in Washington Post

    Dr. Vicki Cohn was interviewed for her professional insight regarding the issues with grinding your teeth at night. Below is the article including Dr Cohn’s input.

    Dentists reported a 69 percent jump in patients who clench or grind their teeth during the pandemic, according to the American Dental Association (ADA). And most of these people are probably unaware that they’re doing it. “It’s an almost completely unconscious behavior,” says Vicki Cohn, chair of the American Academy of Sleep Medicine’s Dental Assembly.

    The condition, called bruxism, can apply up to 200 pounds of force to the teeth. “The bite strength of grinding can be up to six times greater than normal chewing,” says Ada Cooper, a dentist and a spokesperson for the American Dental Association. So it’s no surprise that it can wear down or even break teeth. And for older adults — whose teeth may be more fragile — bruxism may be especially troubling.

    Wearing a mouth guard can help protect teeth from grinding at night.

    In these trying times, dentists are seeing more people with teeth-grinding and jaw-clenching — a.k.a. bruxism

    A host of causes

    Bruxism can occur during the day or at night. Stress can be a significant factor, either in moments of acute tension or during sleep, when elevated levels of stress hormones may still circulate after a difficult day, Cohn says. Habits such as alcohol and tobacco use hike the likelihood, too. “Smokers are about twice as likely to grind their teeth as nonsmokers,” Cooper says. Certain medications — such as some antidepressants and antipsychotics — can also increase the risk.

    Conditions that affect the central nervous system, such as dementia, Parkinson’s disease or stroke, can cause or exacerbate bruxism. And it often goes hand in hand with temporomandibular joint disorders, which cause pain around the jaw. Finally, there’s obstructive sleep apnea (OSA), where the upper airway becomes repeatedly blocked during sleep, leading to numerous breathing pauses at night. This can cause people with OSA to “unconsciously overcompensate and grind their teeth as they thrust their jaw forward to open the airway,” says Manar Abdelrahim, a dentist at Cleveland Clinic. (If you’re told you have OSA, ask about being evaluated for bruxism.)

    Untreated sleep apnea may worsen markers of heart health and diabetes

    Spotting the signs

    A cracked tooth, crown or filling may be a clear signal something is amiss, but there are less dramatic signs to watch for. People with sleep bruxism, for instance, may wake up with a sore jaw or neck, a headache, a stiff jaw, ringing in the ears, or marks around the edge of the tongue where it pressed against clenched teeth. If you notice these, see your dentist, who will check for tooth wear, fractures and gum recession. But “if the only evidence is wear on your teeth, you might not have active bruxism,” Cohn says. Chronic severe heartburn is a common cause of tooth wear in older adults.


    A video recording in a sleep lab or electromyography can definitively diagnose sleep bruxism. For the latter, electrodes attached to the skin check for repetitive jaw muscle movements.

    Need a quick stress-reliever? Try one of these surprising science-based strategies.

    Treatments to consider

    While bruxism can be hard to remedy, the following may help:

    • A plastic mouth guard: “Wearing a guard at night is usually the number one line of defense,” Abdelrahim says. “A guard puts space between the upper and lower teeth to protect them and allows the jaw muscles to relax.” A guard customized for you ($324 to $788) is usually more effective than an over-the-counter product, and is sometimes covered by insurance. Neither breaks the habit but will prevent further tooth damage.
    • Botox: Botulinum toxin injections into the jaw muscles that control chewing may reduce the pressure you exert on teeth.
    • Stress reduction: Relaxing activities (such as yoga and meditation) may help. So can increasing your awareness of the behavior. A tip: “If, during a stressful moment, you feel your teeth touching, gently allow your jaw to open and the teeth to float away from each other,” Cooper says.
    • Physical therapy: A physical therapist trained to treat bruxism can teach you exercises to stretch, strengthen and relax neck and jaw muscles, which can reduce the muscle tension that may lead to clenching and grinding.
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  • Sleep Disturbances Common in Patients Who Recovered from COVID

    Original Article | Jun 6, 2022 | Sleep Review Magazine

    Nearly all patients who recovered from COVID-19 report lingering fatigue, while half experience sleep disturbances, according to a recent analysis from Cleveland Clinic. Researchers found that race, obesity, and mood disorders are contributors. 

    Investigators analyzed data from 962 patients from the Cleveland Clinic ReCOVer Clinic between February 2021 and April 2022. The patients were recovered from COVID-19 and completed the sleep disturbance and fatigue questionnaires of the Patient-Reported Outcomes Measurement Information System. More than two-thirds of patients (67.2%) reported at least moderate fatigue, while 21.8% reported severe fatigue. Eight percent of patients reported severe sleep disturbances, and 41.3% reported at least moderate sleep disturbances.  

    “Sleep difficulties are highly prevalent and debilitating symptoms reported in patients with post-acute sequealae of COVID-19,” says Cinthya Pena Orbea, MD, a sleep specialist at Cleveland Clinic, in a release. “Our study suggests that the prevalence of moderate to severe sleep disturbances is high and that Black race confers increased odds to suffer from moderate to severe sleep disturbances highlighting the importance to further understand race-specific determinants of sleep disturbances in order to develop race-specific interventions.” 

    Patients with moderate-to-severe compared with normal-to-mild sleep disturbances had higher body mass indices, were more likely to be Black, and had worse general anxiety disorder.  

    After adjusting for demographics, Black patients were three times more likely to experience moderate-to-severe sleep disturbances. 

    The research abstract was published recently in an online supplement of the journal Sleep and will be presented June 6 and 7 during SLEEP 2022.

    Photo 188719463 © Robert Knesc