Research

You are currently browsing the archive for the Research category.

Medical Xpress reports that women diagnosed with gestational diabetes are nearly seven times more likely to have obstructive sleep apnoea than other pregnant women, according to a recent study accepted for publication in The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM). Gestational diabetes causes glucose levels in the bloodstream to rise above normal levels. This form of diabetes occurs during pregnancy, typically in the second trimester. Between four and eight of every 100 pregnant women in the United States develop gestational diabetes.

The new study found a link between gestational diabetes and sleep apnoea, which causes brief interruptions in breathing during sleep. If sleep apnea goes untreated, it can raise the risk for stroke, cardiovascular disease and heart attacks.

“It is common for pregnant women to experience sleep disruptions, but the risk of developing obstructive sleep apnea increases substantially in women who have gestational diabetes,” said Sirimon Reutrakul, MD, who conducted the research at Rush University Medical Center in Chicago. “Nearly 75 percent of the participants in our study who had gestational diabetes also suffered from obstructive sleep apnoea.”

In a series of observational case control studies, researchers monitored 45 women for sleep apnoea and other sleep disruptions. The research examined sleep health in 15 pregnant women who had gestational diabetes, 15 pregnant women who did not have the condition and 15 women who were not pregnant and did not have diabetes.

The study found a strong association between obstructive sleep apnoea and gestational diabetes in this group of mostly overweight or obese women. Pregnant women who did not have gestational diabetes were able to get an additional hour of sleep and had less fragmented sleep than women who had gestational diabetes. Past research has shown lost sleep, fragmented sleep and shorter periods spent in deep sleep – all symptoms of sleep apnoea – are likely to raise the risk a person will develop diabetes.

“Based on these findings, women who have gestational diabetes should be considered for evaluation for obstructive sleep apnoea, especially if other risk factors such as hypertension or obesity are present, and women already diagnosed with sleep apnoea should be monitored for signs of gestational diabetes during pregnancy,” Reutrakul said.

Tags: , , , , , ,

New research published in the American Journal of Physiology – Regulatory Integrative and Comparative Physiology, suggests the estimated 12 million Americans who have obstructive sleep apnea should take better care to sleep in a very dark room. Scientists at The Ohio State University Wexner Medical Center have found exposure to dim light at night can interact with sleep apnea and lead to increased levels of depression and anxiety in mice.

“Although it is unclear at the present time whether sleep apnea causes depression, both conditions are commonly seen together in patients. Our research suggests that sleeping even with a minimum amount of light may increase symptoms of depression in those with sleep apnea,” said Dr. Ulysses Magalang, director of Ohio State’s Sleep Disorders Center and a co-author of the study.

The study involved mice that were placed in sleep apnea-like conditions that mimic the repetitive lowering of oxygen levels that sleep apnea patients experience. Half were kept in normal lighting conditions during the day and total darkness at night. The other half was exposed to dim light at night using a 40-watt light bulb in the lab. The group in dim light had higher anxiety behaviors and more depressive behaviors than the mice kept in the dark environment. Scientists also observed impaired learning and memory among both sets of mice.

“Not only were these changes observed during field and maze tests, but we also recorded physical changes, including a reduction of cell size in the hippocampus, an area of the brain important in memory and spatial navigation,” said Taryn Aubrecht, first author of the study and a neuroscience graduate student at Ohio State. “The combination of dim light exposure and sleep apnea appears to result in increased depressive and anxiety-like behaviors in mice, so limiting exposure to light at night could be a very simple strategy to help patients with sleep apnea,” Magalang said. “We’re currently exploring further human testing.”

Tags: , , ,

Science Nordic reports ona new which study reveals that children with obstructive sleep apnoea have a 6.5 times higher mortality rate than other children. Children who suffer obstructive sleep apnoea experience repetitive pauses in breathing during sleep. This interrupts their sleep, which can lead to irritability, poor concentration and slower growth. However, these children often have other and more serious ailments to deal with.

”This is the first systematic study of mortality after children have been diagnosed [with obstructive sleep apnoea], and we were surprised to see that it was this high,” says the lead author of the study, Professor Poul Jørgen Jennum, the head of research at the Clinical Neurophysiological Research Unit at Glostrup Hospital, Denmark.

“Our study also shows that children with sleep apnoea are more prone to illness – both before and after being diagnosed.”

Sleep apnoea can occur on its own, but it is frequently described as an ‘accompanying disease’, as it is often accompanied by other serious diseases. This is one of the reasons why it is so hard to figure out why these children lose their lives. We know that sleep apnoea in itself is dangerous, but often there are other diseases too, and that may be where the explanation for the high mortality rates can be found.

“We cannot say with certainty what it is that kills these children,” says Jennum. “We know that sleep apnoea in itself is dangerous, but often there are other diseases too, and that may be where the explanation for the high mortality rates can be found.”

Obesity has become an increasingly prevalent cause of sleep apnoea. In rare cases, sleep apnoea is caused by neurological or genetic disorders, he explains. Children with sleep apnoea often experience learning difficulties and an erratic appetite as a consequence of the constant interruption of their sleep.

Since they rarely or never reach REM sleep, they do not produce sufficient amounts of growth hormones. This is why they are usually shorter, on average, than other children. The long pauses in breathing also strain the heart and may in the worst case cause brain damage. If the underlying cause of the sleep apnoea can be removed, the children will grow taller.

“Our study suggests that many children with sleep apnoea are probably not being diagnosed and treated correctly,” says Jennum.

The study is published in the journal Thorax.

Tags: , , ,

An Australian study at Royal Melbourne Hospital has found a link between epilepsy and obstructive sleep apnoea (OSA). OSA is a type of ‘sleep-disordered breathing’. It is when a person has problems breathing while they are asleep, caused by obstruction (blockage) of the airway.

Previous research has suggested that people with epilepsy have a higher risk of sleep-disordered breathing than other people. Some people also experience weight-gain as a side-effect of epilepsy medication – which can also increase this risk.

Prof Terry O’Brian and his team recruited 87 people with epilepsy and monitored their sleep patterns. In the general population, between three and seven per cent of people experience sleep-disordered breathing. Of the 87 people with epilepsy studied, 22 per cent (almost a quarter) had trouble breathing that was severe enough to need treatment.

Fortunately, treating OSA is relatively simple. The people experiencing OSA were given a continuous positive airway pressure (CPAP) device to wear during sleep. The device maintains a steady pressure that prevents disordered breathing.

Prof O’Brian said in a press release: “It is important to diagnose [OSA] in patients with epilepsy, as treatment with CPAP can improve sleep quality and seizures, and associated problems like day time drowsiness, difficulty concentrating and cardiovascular disease, often without the requirement of medication.”

The full study findings were published in an online edition of Epilepsy Research on 27 March.

Source: Epilepsy Today

Tags: , , , ,

WebMD reports on a new study published in the BMJ in which researchers took a close look at the effect of poor sleep on the chance of work-related injuries. They pooled the results of 27 studies, which included more than 268,000 working adults. Through interviews, questionnaires, and doctors’ diagnoses, the studies identified which people had sleep problems. The researchers then looked at whether workplace injuries were more likely among people with sleep difficulties than among those without these problems.

The researchers found a strong link between sleep problems and work injuries. People with sleep difficulties were around 60 percent more likely to have an injury at work than those without these problems. Overall, the researchers estimated that 13 in every 100 work injuries were related to poor sleep.

When the researchers looked at different types of sleep problems, they found that people who had sleep apnoea or took sleep medicines had the highest chance of work injuries. Perhaps surprisingly, the risk of injury related to poor sleep was lower for workers in industrial jobs and other physically demanding work (such as farming, mining, and building) than for workers overall.

This was a well-conducted review of studies, and it should provide a reliable summary of what the current research tells us about sleep problems and work injuries. However, it’s worth noting that the review didn’t include studies looking at poor sleep and driving-related work injuries. If these studies were included, the overall risk of work injuries related to poor sleep could be even higher.

Tags: , , , , ,

Health 24 reports that sleep apnoea raises the risk of sudden cardiac death, according to a long-term study that strengthens a link doctors have suspected. The new research is published online June 11 in the Journal of the American College of Cardiology.

“The presence and severity of sleep apnoea are associated with a significantly increased risk of sudden cardiac death,” said study leader Dr. Apoor Gami, a cardiac electrophysiologist at Midwest Heart Specialists-Advocate Medical Group in Elmhurst, Ill.

Sudden cardiac death kills 450,000 people a year in the United States, according to study background information. It occurs when the heart unexpectedly and suddenly stops beating due to problems with the heart’s electrical system. Those problems cause irregular heartbeats. The condition must be treated within minutes if the person is to survive.

In earlier research, Gami and his team had found that patients with sleep apnoea who suffered sudden cardiac death often did so at night, a completely opposite pattern than found in others without sleep apnea who had sudden cardiac death. In the new study, the researchers tracked more than 10,000 men and women, average age 53, who were referred for sleep studies at the Mayo Clinic Sleep Disorders Center, mostly due to suspected sleep apnoea, from 1987 through 2003. After sleep tests, 78 percent were found to have sleep apnoea. During the follow-up of up to 15 years, they found that 142 had sudden cardiac arrest, either fatal or resuscitated.

Three measures strongly predicted the risk of sudden cardiac death, Gami said. These include being 60 or older, having 20 apnoea episodes an hour or having low blood levels of oxygen. This “oxygen saturation” drops when air doesn’t flow into the lungs. “If the lowest oxygen saturation was 78 percent, or less, their risk of [sudden cardiac death] increased by 80 percent,” Gami said. In a healthy person, 95 percent to 100 percent is normal. Having 20 events an hour would be termed moderate sleep apnea, Gami said.

Gami found a link, not a cause-and-effect relationship, between sleep apnea and sudden cardiac death. He can’t explain the connection with certainty, but said there are several possible explanations. For example, sleep apnea is related to the type of heart rhythm problem that causes sudden cardiac death, he said. The study findings should be taken seriously by those who have sleep apnea or suspect they do, said Dr. Neil Sanghvi, an electrophysiologist at Lenox Hill Hospital, in New York City, who reviewed the findings.

People with sleep apnea are often but not always obese, and many have other heart risk factors such as heart failure or heart disease. Having these other risk factors already puts a person at risk of sudden cardiac death, Sanghvi said. “The sleep apnea may be the tipping point. Each of these factors adds a level of risk. When you add sleep apnea, you could have a worse outcome.”

Anyone who suspects they have sleep apnea should ask their doctor about a sleep test, Sanghvi said. Daytime sleepiness and fatigue are frequent symptoms. Another tipoff is a bed partner who complains of snoring. The study didn’t address whether those who used sleep apnea treatments — such as the CPAP machine (continuous positive airway pressure) prescribed during sleep to help breathing — would reduce risk. “It would be fair to say we suspect it would,” Gami said.

 

 

Tags: , , , , , ,

The American Academy of Sleep Medicine (AASM) is advising anyone with Type 2 diabetes or hypertension to be evaluated for sleep apnea by a board-certified sleep medicine physician. The recommendation comes as the group of international clinicians and researchers meets in Baltimore for SLEEP 2013, the foremost gathering of sleep experts annually.

Overwhelming clinical evidence has shown that patients suffering from two very common illnesses – Type 2 diabetes and hypertension – are at much higher risk for obstructive sleep apnea (OSA), a dangerous condition characterized by episodes of complete or partial airway obstruction during sleep. Research also has shown that treating sleep apnea can help in the management of these two disorders.

“Type 2 diabetics and people with hypertension are much more likely to have obstructive sleep apnea than other people, and as a result should immediately discuss their risk for sleep apnea with a sleep specialist,” said M. Safwan Badr, MD, president of AASM. “Diagnosis and treatment of sleep apnea from a board-certified sleep medicine physician will promote improvement in these conditions – including improved insulin sensitivity, blood pressure and cholesterol.”

Type 2 Diabetes and Obstructive Sleep Apnea
According to the Centers for Disease Control and Prevention, 25.6 million Americans aged 20 years or older suffer from diabetes, and Type 2 diabetes accounts for about 90 to 95 percent of all diagnosed cases. Seven in 10 people with Type 2 diabetes also have obstructive sleep apnea, and the severity of the sleep disorder directly impacts diabetes symptoms; the more severe a diabetic’s untreated sleep apnea, the poorer their glucose control.

“Treating sleep apnea in diabetics improves nighttime glucose levels and insulin sensitivity,” said Badr. “Treatment also will provide benefits of improved sleep unrelated to diabetes – including increased alertness during the day and improved memory and cognitive function.”

A recent study from the University of Chicago shows that continuous positive airway pressure (CPAP) treatment of sleep apnea may have as much of an effect as prescribed oral diabetes medications.

“In our study, one week of optimal CPAP use lowered average 24-hour glucose levels and improved post-breakfast glucose response in Type 2 diabetics with obstructive sleep apnea,” said Esra Tasali, MD, lead author of the study and assistant professor of medicine, pulmonary and critical care medicine at the University of Chicago Department of Medicine. “The dawn phenomenon, an early-morning increase in blood sugar in people who have Type 2 diabetes, also was reduced by 45 percent as a result of CPAP therapy.”

Hypertension and Obstructive Sleep Apnea
High blood pressure, known as hypertension, is the most important risk factor for cardiovascular disease and is not limited to diabetes sufferers. A staggering 67 million Americans have high blood pressure, which is about one in every three adults. Between 30 and 40 percent of adults with high blood pressure also have sleep apnea, which is even more prevalent in those with resistant hypertension. Approximately 80 percent of patients that do not respond to hypertensive medications have sleep apnea. Seeking and adhering to sleep apnea treatment is a proven means of decreasing blood pressure.

“Evidence shows that sleep apnea treatment lowers nighttime and daytime blood pressure, with the greatest improvement in patients seeking treatment for moderate to severe sleep apnea,” said Badr. “The higher your blood pressure, the greater your risk of suffering a heart attack or stroke. Reducing your blood pressure lowers your risk of cardiovascular disease and improves your overall health.”

Source: AASM

Tags: , , , ,

Participants in the Wisconsin Sleep Cohort who self-identified as having asthma at the start of the research in 1988 had a 41% incident obstructive sleep apnea rate, compared with an obstructive sleep apnea incident rate of 29% among participants who did not report asthma at the beginning of the study, said Mihaela Teodorescu, MD, of the University of Wisconsin in Madison.

Of the 205 individuals who reported a history of asthma, 84 developed obstructive sleep apnea during the 8-year interval sleep studies, she reported at the annual meeting of the American Thoracic Society. Of the 1,278 individuals who entered the study without a self-report of asthma, 369 had developed incident obstructive sleep apnea after 8 years.

“There has been a body of evidence published suggesting that there is a relationship between obstructive sleep apnea and asthma,” Teodorescu told MedPage Today. “Each disorder makes the other worse, so understanding what starts this vicious cycle is very important. We asked the question of whether asthma promotes the development of obstructive sleep apnea.”

“In this cohort we found that having asthma at baseline predicted an increased incidence of obstructive sleep apnea 8 years later,” she said. “Overall, having any asthma at baseline predicted about a 72% higher likelihood of developing obstructive sleep apnea 8 years later.”

“Interestingly, when stratifying by the age of diagnosis, childhood onset of asthma was a higher predictor for development of obstructive sleep apnea, with an odds ratio of about 2.1,” she said in a press briefing following her poster presentation. “For each 5 years increment in duration of asthma, the likelihood of developing obstructive sleep apnea increased by 12%,” she said.

Tags: , , , ,

Sleep deprivation is a significant hidden factor in lowering the achievement of school pupils, according to researchers carrying out international education tests.

It is a particular problem in more affluent countries, with sleep experts linking it to the use of mobile phones and computers in bedrooms late at night. Sleep deprivation is such a serious disruption that lessons have to be pitched at a lower level to accommodate sleep-starved learners, the study found.

The international comparison, carried out by Boston College, found the United States to have the highest number of sleep-deprived students, with 73% of 9 and 10-year-olds and 80% of 13 and 14-year-olds identified by their teachers as being adversely affected. In literacy tests there were 76% of 9 and 10-year-olds lacking sleep.

This was much higher than the international average of 47% of primary pupils needing more sleep and 57% among the secondary age group. Other countries with the most sleep-deprived youngsters were New Zealand, Saudi Arabia, Australia, England, Ireland and France. High-performing Finland is also among the most lacking in sleep. Countries with the best records for getting enough sleep include Azerbaijan, Kazakhstan, Portugal, the Czech Republic, Japan and Malta.

The analysis was part of the huge data-gathering process for global education rankings – the Trends in International Mathematics and Science Study (TIMSS) and Progress in International Reading Literacy Study (PIRLS).

Read the full BBC story

 

Tags: , , , , , , , , ,

The widening American waistline may be feeding an epidemic of sleep apnoea, potentially robbing millions of people of a good night’s rest, a new study suggests.

The research didn’t definitively link the rise in obesity to sleep apnoea, and it only looked at 1 520 people, almost all white, in Wisconsin. But study author Paul Peppard believes the findings show a big spike in sleep apnoea cases over the past two decades – as much as 55% – and may translate to the entire United States.

“There are probably 4 million to 5 million people who are more likely to have sleep apnoea due to the obesity epidemic,” estimated Peppard, an assistant professor of population health sciences at the University of Wisconsin-Madison. “It’s certainly an uncalculated cost of the obesity epidemic, an epidemic of its own.”

The researchers looked at adults aged 30 to 70 who were monitored as they slept. About 600 to 700 underwent sleep tests between 1988 and 1994, with some continuing to take part along with hundreds of new participants from 2007 to 2010. The study considered the participants to have moderate-to-severe breathing problems if they had trouble breathing 15 or more times an hour while sleeping.

Sleep apnea is the main cause of breathing problems during sleep. People with the condition often have trouble staying in deep sleep because their throats close, blocking their airways and requiring them to partially awaken to start breathing properly. They don’t realise they’re waking up and may become very sleepy during the day. Besides sleepiness, sleep apnea can contribute to heart and other health problems if untreated and increase the risk of work- and driving-related accidents, according to the US National Heart, Lung, and Blood Institute.

The researchers extrapolated their findings to the entire United States and estimated that 10% of men aged 30 to 49 currently have symptoms of sleep apnoea. The study estimates the number is 17% of men aged 50 to 70. For women, the estimate is 3% among those aged 30 to 49 and 9% among women aged 50 to 70. Among all groups, heavier people were much more likely than thinner people to suffer from the symptoms.

The study estimates that these numbers have gone up by 14% to 55% from 1988-1994 to 2007-2010. Peppard estimated that 80% to 90% of the increase in symptoms is due to the growth in obesity. But it’s hard to know for sure how much of a role that obesity plays in causing more symptoms. While obesity is “almost certainly the biggest factor” in causing sleep apnoea, Peppard said, “there’s long list of things that cause sleep apnea or are related to sleep apnea, like being older, being male, having a narrower upper airway, having a genetic predisposition to it…”

Although the study tied obesity to higher risk of having sleep apnoea, it did not establish a cause-and-effect relationship.

Tags: , , , , , ,

« Older entries § Newer entries »