Lack of Sleep, High Blood Pressure

A March 2024 study by the American College of Cardiology said,

• “Based on the most updated data, the less you sleep—that is less than seven hours a day—the more likely you will develop high blood pressure in the future,”

• “We saw a trend between longer sleep durations and a greater occurrence of high blood pressure, but it was not statistically significant. Getting seven to eight hours of sleep, as is recommended by sleep experts, may be the best for your heart too.”

• “Getting too little sleep appears to be riskier in females,”

• “The difference is statistically significant, though we are not sure it’s clinically significant and should be further studied. What we do see is that lack of good sleep patterns may increase the risk of high blood pressure, which we know can set the stage for heart disease and stroke.”

• “Further research is required to evaluate the association between sleep duration and high blood pressure using more accurate methods like polysomnography, a method for evaluating sleep quality more precisely,” Hosseini said. “Moreover, the variations in reference sleep duration underline the need for standardized definition in sleep research to enhance the comparability and generalizability of findings across diverse studies.”

Energy Drinks and Sleep

A January 2024 study of Danish students found a link between energy drinks and poor quality sleep and insomnia saying, “Identifying modifiable risk factors for sleep problems among college and university students is vital and our results suggest that the frequency of …consumption could be a possible target for interventions.”

Snoring Signs

A January 2024 study by St James’s University Hospital, Leeds, said,

• “Up to one fifth of collisions on the road may be caused by fatigue or sleepiness. Many obstructive sleep apnoea (OSA) patients drive either for personal or for professional reasons and there is good evidence to suggest that some patients are at increased risk of collisions on the road.”

• “Doctors are often asked to make recommendations about their patient’s fitness to drive. This can be challenging as it can have major implications on a patient’s livelihood, particularly if they are a professional driver. However, there is a duty of care on doctors to discourage patients from driving if are at high risk of causing a collision.”

•  “Our research suggests that untreated OSA patients often use coping strategies that could be surrogate markers of sleepiness. Asking about these strategies in the clinic may help doctors identifying patients who are at risk of driving incidents and to advise appropriately.”

•  “Obstructive sleep apnoea is of high public health relevance due to its high prevalence, symptoms that impair quality of life and potential cardiovascular consequences. In addition to choking, fragmented sleep and unrefreshing sleep, possible symptoms include difficulty concentrating, tiredness and a tendency to fall asleep during the day. Fortunately, awareness of OSA has increased somewhat in recent years. Today, treatment recommendations are based on the different risk factors, symptom groups and cardiovascular consequences of certain OSA types. Various treatment approaches geared to different types of OSA can be offered to successfully treat the symptoms, including daytime sleepiness.”

Disrupted Sleep, Memory and Cognition

A January 2024 study the University of California, San Francisco said,

• “Given that signs of Alzheimer’s disease start to accumulate in the brain several decades before symptoms begin, understanding the connection between sleep and cognition earlier in life is critical for understanding the role of sleep problems as a risk factor for the disease,”

• “Our findings indicate that the quality rather than the quantity of sleep matters most for cognitive health in middle age.”

• “More research is needed to assess the link between sleep disturbances and cognition at different stages of life and to identify if critical life periods exist when sleep is more strongly associated with cognition,”

• “Future studies could open up new opportunities for the prevention of Alzheimer’s disease later in life.”

Sleep and Exercise

A November 2023 study by the University of Portsmouth said,

• “We know from existing research that exercise improves or maintains our cognitive performance, even when oxygen levels are reduced. But this is the first study to suggest it also improves CP after both full and partial sleep deprivation, and when combined with hypoxia.”

• “The findings significantly adds to what we know about the relationship between exercise and these stressors, and helps to reinforce the message that movement is medicine for the body and the brain.”

• “Because we were looking at exercise as a positive intervention, we decided to use a moderate intensity programme as recommended in existing literature”, added Dr Costello.

• “If the exercise was any longer or harder it may have amplified the negative results and became a stressor itself.”

• “Sleep deprivation is often experienced in combination with other stressors. For example, people who travel to high altitude are also likely to experience a disruption to their sleep pattern.

• “One potential hypothesis for why exercise improves cognitive performance is related to the  increase in cerebral blood flow and oxygenation, however, our findings suggest that even when exercise is performed in an environment with low levels of oxygen, participants were still able to perform cognitive tasks better than when at rest in the same conditions.”

Short sleep time; diabetes risk

A November 2023 study by Columbia University said,

• “Throughout their lifespan, women face many changes in their sleep habits due to childbearing, child-rearing, and menopause,”

• “And more women than men have the perception they aren’t getting enough sleep.” 

• “Over a longer period of time, ongoing stress on insulin-producing cells could cause them to fail, eventually leading to type 2 diabetes.”

• “The fact that we saw these results independent of any changes in body fat, which is a known risk factor for type 2 diabetes, speaks to the impact of mild sleep reduction on insulin-producing cells and metabolism,”

• “The bottom line is that getting adequate sleep each night may lead to better blood sugar control and reduced risk for type 2 diabetes, especially among postmenopausal women.” 

Chronic sleep deficiency; insulin resistance

A November 2023 study by the NIH/National Heart, Lung and Blood Institute says,

• “Women report poorer sleep than men, so understanding how sleep disturbances impact their health across the lifespan is critical, especially for postmenopausal women,”

•  “What we’re seeing is that more insulin is needed to normalize glucose levels in the women under conditions of sleep restriction, and even then, the insulin may not have been doing enough to counteract rising blood glucose levels of postmenopausal women,”

• “If that's sustained over time, it is possible that prolonged insufficient sleep among individuals with prediabetes could accelerate the progression to type 2 diabetes.”

•  “This study provides new insight into the health effects of even small sleep deficits in women across all stages of adulthood and racial and ethnic backgrounds,” said Corinne Silva, Ph.D., Program Director in the Division of Diabetes, Endocrinology, & Metabolic Diseases at NIDDK. “Researchers are planning additional studies to further understand how sleep deficiency affects metabolism in men and women, as well as explore sleep interventions as a tool in type 2 diabetes prevention efforts.”

14 Hour Fasts

A November 2023 study by Kings College London

• “This is the largest study outside of a tightly controlled clinic to show that intermittent fasting can improve your health in a real world setting. What's really exciting is that the findings show that you don’t have to be very restrictive to see positive results. A ten-hour eating window, which was manageable for most people, and improved mood, energy levels and hunger. We found for the first time that those who practised time-restricted eating, but were not consistent day to day, did not have the same positive health effects as those who were dedicated every day. ”  

• “This study adds to the growing body of evidence showing the importance of how you eat. The health impact of food is not just what you eat but the time at which you choose to consume your meals, and eating window is an important dietary behaviour that can be beneficial for health. Findings shows that we don’t need to be eating all the time. Many people will feel satiated and even lose weight if they restrict their food to a ten-hour window.” 

Sleep and cardiovascular health

An August 2023 study by Penn State found

• “Only 65% of adults in the U.S. regularly sleep the recommended seven hours per night, and there's a lot of evidence suggesting that this lack of sleep is associated with cardiovascular disease in the long term,” 

• “Our research reveals a potential mechanism for this longitudinal relationship, where enough successive hits to your cardiovascular health while you're young could make your heart more prone to cardiovascular disease in the future.”

• “Both heart rate and systolic blood pressure increased with each successive day and did not return to baseline levels by the end of the recovery period,” Reichenberger said. “So, despite having additional opportunity to rest, by the end of the weekend of the study, their cardiovascular systems still had not recovered.”

• “Sleep is a biological process, but it’s also a behavioral one and one that we often have a lot of control over,” Chang said. “Not only does sleep affect our cardiovascular health, but it also affects our weight, our mental health, our ability to focus and our ability to maintain healthy relationships with others, among many other things. As we learn more and more about the importance of sleep, and how it impacts everything in our lives, my hope is that it will become more of a focus for improving one’s health.”

Sleep, immunity, inflammation

A September 2022 study by the Icahn School of Medicine at Mount Sinai said,

• “This study begins to identify the biological mechanisms that link sleep and immunological health over the long-term. It shows that in humans and mice, disrupted sleep has a profound influence on the programming of immune cells and rate of their production, causing them to lose their protective effects and actually make infections worse—and these changes are long-lasting.  This is important because it is yet another key observation that sleep reduces inflammation and, conversely, that sleep interruption increases inflammation,” 

• “This work emphasizes the importance of adults consistently sleeping seven to eight hours a day to help prevent inflammation and disease, especially for those with underlying medical conditions."

• “Our findings suggest that sleep recovery is not able to fully reverse the effects of poor-quality sleep. We can detect a molecular imprint of insufficient sleep in immune stem cells, even after weeks of recovery sleep. This molecular imprint can cause the cells to respond in inappropriate ways leading to inflammation and disease,” 

• “It was surprising to find that not all clusters of stem cells responded to insufficient sleep in the same way. There were some stem cell clusters that proliferated and grew in number, while other clusters became smaller. This reduction in overall diversity and aging of the immune stem cell population is an important contributor to inflammatory diseases and cardiovascular disease.”

Weighted blankets and melatonin

An October 2022 study by Uppsala University said,

• "Using a weighted blanket increased melatonin concentrations in saliva by about 30 percent. However, no differences in oxytocin, cortisol, and the activity of the sympathetic nervous system were observed between the weighted and light blanket conditions,”

• "Our study may offer a mechanism explaining why weighted blankets may exert some therapeutic benefits, such as improved sleep. However, our findings rely on a small sample and investigated only the acute effects of a weighted blanket. Thus, larger trials are needed, including an investigation of whether the observed effects of a weighted blanket on melatonin are sustained over longer periods," 

Five hours’ sleep

An October 2022 study by UCL Institute of Epidemiology & Health, and Inserm, Université Paris Cité said, 

• “Multimorbidity is on the rise in high income countries and more than half of older adults now have at least two chronic diseases. This is proving to be a major challenge for public health, as multimorbidity is associated with high healthcare service use, hospitalisations and disability.

• “As people get older, their sleep habits and sleep structure change. However, it is recommended to sleep for 7 to 8 hours a night - as sleep durations above or below this have previously been associated with individual chronic diseases.

• “Our findings show that short sleep duration is also associated with multimorbidity.

• “To ensure a better night’s sleep, it is important to promote good sleep hygiene, such as making sure the bedroom is quiet, dark and a comfortable temperature before sleeping. It’s also advised to remove electronic devices and avoid large meals before bedtime. Physical activity and exposure to light during the day might also promote good sleep.”

• “Getting enough sleep allows your body to rest. There are a host of other ways that poor sleep could increase the risk of heart disease or stroke, including by increasing inflammation and increasing blood pressure.”

• “This research adds to a growing body of research that highlights the importance of getting a good night’s sleep.”

Quality of sleep link to fatty liver disease

A July 2022 study by the Guangdong Provincial Key Laboratory of Food, Nutrition and Health and Sun Yat-sen University in Guangzhou, China said,  “People with poor nighttime sleep and prolonged daytime napping have the highest risk for developing fatty liver disease,”  and “Our study found a moderate improvement in sleep quality was related to a 29% reduction in the risk for fatty liver disease.”

Poor “sleep hygiene” included

• late bedtime

• snoring

• daytime napping for over 30 minutes

“Our study provides evidence that even a moderate improvement in sleep quality is sufficient to reduce the risk for fatty liver disease, especially in those with unhealthy lifestyles,” 

“Given that large proportions of subjects suffering from poor sleep quality are underdiagnosed and undertreated, our study calls for more research into this field and strategies to improve sleep quality.”

Depression: Waking earlier

A May 2021 study at the University of Colorado Boulder and the Broad Institute of MIT and Harvard said, 

• "We have known for some time that there is a relationship between sleep timing and mood, but a question we often hear from clinicians is: How much earlier do we need to shift people to see a benefit?" 

• "We found that even one-hour earlier sleep timing is associated with significantly lower risk of depression."

• "Our genetics are set at birth so some of the biases that affect other kinds of epidemiological research tend not to affect genetic studies,"

• "We live in a society that is designed for morning people, and evening people often feel as if they are in a constant state of misalignment with that societal clock,"

• "Keep your days bright and your nights dark,”

• "Have your morning coffee on the porch. Walk or ride your bike to work if you can, and dim those electronics in the evening."

Older men and sleep

A May 2021 study by the Florey Adelaide Male Ageing Study said,

"Less deep sleep and more light sleep is related to slower responses on cognitive function tests,".

"While obstructive sleep apnoea itself is not directly related to cognitive function in all men studied, we did note that in men aged 65 and older, more light sleep was related to worse attention and processing speed."

Caffeine and sleep

A May 2021 study by Michigan State University found, 

• "that sleep deprivation impaired performance on both types of tasks and that having caffeine helped people successfully achieve the easier task. However, it had little effect on performance on the placekeeping task for most participants," 

• "Caffeine may improve the ability to stay awake and attend to a task, but it doesn't do much to prevent the sort of procedural errors that can cause things like medical mistakes and car accidents."

• "Caffeine increases energy, reduces sleepiness and can even improve mood, but it absolutely does not replace a full night of sleep … Although people may feel as if they can combat sleep deprivation with caffeine, their performance on higher-level tasks will likely still be impaired. This is one of the reasons why sleep deprivation can be so dangerous."

• "If we had found that caffeine significantly reduced procedural errors under conditions of sleep deprivation, this would have broad implications for individuals who must perform high stakes procedures with insufficient sleep, like surgeons, pilots and police officers," 

•  "Instead, our findings underscore the importance of prioritizing sleep."

Sleep Disorder: Crash risk for night-shift drivers

A May 2021 study found that,

“People who work nontraditional work hours, such as 11 p.m.-7 a.m., or the "graveyard" shift, are more likely than people with traditional daytime work schedules to develop a chronic medical condition -- shift work sleep disorder -- that disrupts their sleep. According to researchers at the University of Missouri, people who develop this condition are also three times more likely to be involved in a vehicle accident.”

Children - sleep -v- exercise

An April 2021 study by the University of South Australia said,

"There are many competing time demands in modern families ¬- whether it's after school soccer, music lessons, or simply walking the family dog, finding the time to fit everything into a single day, can be a challenge," 

"International guidelines suggest that children need 9-11 hours' sleep, 60 minutes of physical exercise, and no more than two hours of recreational screen time per day, yet only seven percent of children are regularly meeting these goals.”

"With so many competing priorities and commitments, it's helpful to know which activities deliver the greatest 'bang for your buck’."

"In this research we calculated how much sleep, sedentary time, light exercise, and moderate-to-vigorous exercise was associated with the same improvements in mental health, physical health and academic achievement.”

"For families with very little available time, small increases in moderate-to-vigorous exercise could be an option to improve children's health and wellbeing; alternatively an earlier night could equally deliver the same health benefits - importantly, it's the flexibility that these findings offer that make them so valuable.”

"Exploring trade-offs between children's activities is a promising way for families to make healthy choices that suit their regular family schedule."

The Heart Foundation's Director of Physical Activity said

"This study confirms that physical activity is the quickest and most effective way to deliver benefits for children's physical health and mental wellbeing. But the findings also offer some flexibility for families,"

"Helping young people make healthy choices and helping families create an environment that supports them in these choices can improve their quality of life in the future, as well as reducing their risk of chronic diseases, such as heart disease."

Shift working and Heart Health

An April 2021 study by the University of Lisbon said,

"Our study found that for each hour the work schedule was out of sync with an employee's body clock, the risk of heart disease got worse," 

"We all have an internal biological clock which ranges from morning types (larks), who feel alert and productive in the early morning and sleepy in the evening, to late types (owls), for whom the opposite is true - with most of the population falling in between. Circadian misalignment occurs when there is a mismatch between what your body wants (e.g. to fall asleep at 10pm) and what your social obligations impose on you (e.g. work until midnight)."

"These results add to the growing evidence that circadian misalignment may explain, at least in part, the association found between shift work and detrimental health outcomes. The findings suggest that staff with atypical work schedules may need closer monitoring for heart health. Longitudinal studies are needed to investigate whether late chronotypes cope better with late/night shifts and earlier chronotypes to early morning schedules, both psychologically and physiologically."

Men, Women, the Impact of Shiftwork

An April 2021 report by the University of Waterloo said, 

"Because our immune system is affected by the circadian clock, our ability to mount an immune response changes during the day," 

"How likely are you to fight off an infection that occurs in the morning than midday? The answer depends on whether you are a man or a woman, and whether you are among quarter of the modern-day labour force that has an irregular work schedule."

"Shift work likely affects men and women differently," 

"Compared to females, the immune system in males is more prone to over-activation, which can increase their chances of sepsis following an ill-timed infection."