An article in the December issue of the Sleep Journal has received media attention, so I thought I would summarize it here.
Metabolic syndrome is defined as having three or more of the following: elevated blood glucose, increased waist circumference, high blood pressure, increased triglycerides, and low HDL (the good cholesterol). It is estimated that 20% of us have the metabolic syndrome.
The authors of this study assessed over 800 people ages 45 to 74 over a three year period to see if they developed the metabolic syndrome and if it was associated with any sleep symptoms. They used a subjective questionnaire to assess insomnia symptoms, loud snoring, gasping at night, and/or nighttime choking. Sleep duration was not assessed. Almost 300 of the study participants volunteered to have a home sleep study (Resmed's ApneaLink) at the end of the three years.
Over the three year span of time, 14% developed the metabolic syndrome. The sleep symptoms that were statistically related to metabolic syndrome were difficulty falling asleep, unrefreshing sleep, loud snoring, and elevated score on the ApneaLink home sleep study. There was no interaction with race of gender. Loud snoring was most predictive, more than doubling the risk of developing metabolic syndrome. As expected, insomnia syndrome did not raise the risk of metabolic syndrome.
The study authors were not able to tell if the patients who claimed loud snoring also had the elevated sleep apnea severity as measured by the ApneaLink. This would have been helpful because the authors concluded that loud snoring by itself is a risk factor in developing metabolic syndrome. I'm not convinced that loud snoring without sleep apnea is physically dangerous to patients.
It was interesting that difficulty staying asleep did not significantly raise the metabolic syndrome risk, but difficulty falling asleep did. This goes against my clinical experience of how many sleep apnea patients sleep - most fall asleep easily, but just can not stay asleep. The authors suggested that the difficulty falling asleep could be due to emotional and/or physiologic hyperarousal, which could be due to increase nervous system activity and elevated cortisol levels. These have been linked to insulin resistance and the metabolic syndrome.
For me, the conclusion from this study is that you should seek a sleep evaluation from your doctor if you have loud snoring and/or difficulty falling asleep.
Monday, December 20, 2010
Monday, December 13, 2010
Snoring and Obstructive Sleep Apnea
In the October (yes, I am behind) edition of the Journal of Clinical Sleep Medicine, there is an article about how snoring correlates with the severity of obstructive sleep apnea (OSA). Snoring occurs in 25% of women and 45% of men, and is the most common symptom of OSA. Snoring is considered a "cosmetic" issue and is not associated with other illnesses like high blood pressure, cardiovascular disease, stroke, or metabolic syndrome, the way OSA is.
This study was the first one to use an objective measurement of snoring intensity in a large (>1600) group of patients to determine the relationship between OSA and snoring loudness. They measued snoring during a sleep study with a digital sound meter. In this study, there were more males than females. Men were older, heavier, and had larger neck circumferences than women.
The results showed that men had louder snoring than women (big surprise, huh?), and this was consistent across all sleep stages, body positions, and weight. Snoring was louder among those that were heavier, had larger neck sizes, and when sleeping on the back, regardless of gender. Snoring was more common in non-dream (NREM) than dream (REM) sleep. As expected, snoring got louder as the OSA got more severe. I've told patients about this observation in my clinical practice, and now there is objective proof.
This study was the first one to use an objective measurement of snoring intensity in a large (>1600) group of patients to determine the relationship between OSA and snoring loudness. They measued snoring during a sleep study with a digital sound meter. In this study, there were more males than females. Men were older, heavier, and had larger neck circumferences than women.
The results showed that men had louder snoring than women (big surprise, huh?), and this was consistent across all sleep stages, body positions, and weight. Snoring was louder among those that were heavier, had larger neck sizes, and when sleeping on the back, regardless of gender. Snoring was more common in non-dream (NREM) than dream (REM) sleep. As expected, snoring got louder as the OSA got more severe. I've told patients about this observation in my clinical practice, and now there is objective proof.
Monday, December 6, 2010
Geneitc Link and Sleep Disorders
There is an article in the October 26th issue of Neurology where researchers studied normal sleep and sleep-deprivation, and determined if participants had a certain gene variant (DQB1*0602). Patients with that gene variant were sleepier and more fatigued while sleep-deprived or even while fully rested. These individuals also woke up more often at night and spent less time in deep sleep than those without the gene variant. However, there was no difference on tests of memory and attention, or in their ability to resist sleep during the day.
The authors explained that their findings mean there might be a genetic biomarker to predict how people will respond to sleep deprivation. This has significant health consequences and affects millions around the world. It may be particularly important in those work night shift, travel frequently across multiple time zones, or just don't sleep enough due to multiple work and family obligations.
This gene variant has already been implicated in narcolepsy, a sleep disorder characterized by excessive sleepiness, despite adequate amounts of sleep at night.
The authors explained that their findings mean there might be a genetic biomarker to predict how people will respond to sleep deprivation. This has significant health consequences and affects millions around the world. It may be particularly important in those work night shift, travel frequently across multiple time zones, or just don't sleep enough due to multiple work and family obligations.
This gene variant has already been implicated in narcolepsy, a sleep disorder characterized by excessive sleepiness, despite adequate amounts of sleep at night.
Friday, November 26, 2010
Power Naps at Work
I loved the show Seinfeld. In the episode called "The Nap", George has a carpenter make some adjustments on his desk at work so that he can take secret naps and not be caught by his boss (George Steinbrenner at the time).
There is an article about napping at work from US News and World Report. Apparently, more companies are allowing employees to nap at work, usually on their work break. Employers say it increases the nappers well-being and their mood.
One employee keeps a "nap mat" in her office. Perhaps it looks like this?
Some companies offer reclining chairs and "renewal rooms." Another company offers a cot in a Zen-like room with smoothing earth tones or a beach-themed room inside an "energy pod." Finally, some companies will pay for their employees to go to a company that charges for naps - customers can take power naps in private rooms with aromatherapy, music, or nature sounds.
The article also mentions keeping the naps brief to avoid post-nap grogginess. I suggest to people that if they need to nap, keep it less than 30 minutes (by using an alarm) and take the nap before 3 pm to avoid making it tough to fall asleep that night.
There is an article about napping at work from US News and World Report. Apparently, more companies are allowing employees to nap at work, usually on their work break. Employers say it increases the nappers well-being and their mood.
One employee keeps a "nap mat" in her office. Perhaps it looks like this?
Some companies offer reclining chairs and "renewal rooms." Another company offers a cot in a Zen-like room with smoothing earth tones or a beach-themed room inside an "energy pod." Finally, some companies will pay for their employees to go to a company that charges for naps - customers can take power naps in private rooms with aromatherapy, music, or nature sounds.
The article also mentions keeping the naps brief to avoid post-nap grogginess. I suggest to people that if they need to nap, keep it less than 30 minutes (by using an alarm) and take the nap before 3 pm to avoid making it tough to fall asleep that night.
Saturday, November 20, 2010
Sleep Duration and Stroke Risk
A study was presented at the American Heart Association meeting where almost 70,000 female nurses were asked how long they slept on average over a 20 year span of time. The researchers than recorded which women had a stroke and analyzed if a certain number of hours of sleep increased the risk of stroke relative to the baseline average of seven hours per night.
The researchers found that women who slept 10 or more hours had a 63% increase risk of stroke. Those women that slept less than 7 or 8-9 hours per night had an insignificant increase in stroke risk. Of note, the researchers adjusted the risk for other factors like alcohol intake, fruit and vegetable consumption, physical activity, and smoking status. Body mass index and the presence of diabetes and high blood pressure were recorded as potential influential factors.
The researchers were unable to determine any underlying biological mechanism that could cause the increased risk of stroke in longer sleepers.
I wonder if some of the women have untreated sleep apnea, which can cause longer sleep durations, in an attempt to get more rest. Untreated sleep apnea does increase the risk of stroke.
Longer sleep durations could mean that these women have brains that function differently or are structurally different, and perhaps those differences could account for the increased stroke risk.
The researchers found that women who slept 10 or more hours had a 63% increase risk of stroke. Those women that slept less than 7 or 8-9 hours per night had an insignificant increase in stroke risk. Of note, the researchers adjusted the risk for other factors like alcohol intake, fruit and vegetable consumption, physical activity, and smoking status. Body mass index and the presence of diabetes and high blood pressure were recorded as potential influential factors.
The researchers were unable to determine any underlying biological mechanism that could cause the increased risk of stroke in longer sleepers.
I wonder if some of the women have untreated sleep apnea, which can cause longer sleep durations, in an attempt to get more rest. Untreated sleep apnea does increase the risk of stroke.
Longer sleep durations could mean that these women have brains that function differently or are structurally different, and perhaps those differences could account for the increased stroke risk.
Wednesday, November 10, 2010
Foods that promote sleep?
There is an article on Foxnews health about five foods that supposedly promote sleep. My immediate reaction to such a title is skepticism, as such "treatments" for insomnia rarely provide any lasting relief.
The first food is cottage cheese. The author says it helps sleep because it is a source of tryptophan, the same sleep-inducing amino acid in turkey. Unfortunately, consuming tryptophan is not likely to help most people who are struggling to sleep.
The next food mentioned is oatmeal. The author states that oatmeal is a slow-digesting carbohydrate that promotes serotonin release, the "feel good" neurotransmitter. He then says that serotonin is the sleep hormone - factually inaccurate on two counts - serotonin is not a hormone, it's a neurotransmitter, and many other neurotransmitters are thought to affect sleep.
Next is peanuts or peanut butter, which is a source of niacin. The author claims that niacin can promote serotonin - see above comment regarding oatmeal.
Warm milk is next and the author claims it has tryptophan - see cottage cheese. Also, the calcium in milk can help with melatonin production, so milk will help with sleep! If only it was that easy.
Finally, the author recommends grapes, which supposedly are the only food that contains melatonin. In my opinion, melatonin production is not the problem with most insomniacs.
Eating these foods most likely will not help chronic insomniacs. It could help someone who is just recently suffering from mild difficulty sleeping. This effect most likely would be due to a placebo response.
Relying on things external to our own body, whether it is food, pills, a special blanket, or whatever, probably won't work in the long term and can set up someone to become psychologically dependent on that thing to sleep. In other words, over time, the thing used to help sleep might be paired enough times with actual sleep so that if the thing is not available, the person will not be able to sleep.
Insomnia usually responds better to behavioral therapy, rather than relying on gimmicks like certain foods or other external things.
The first food is cottage cheese. The author says it helps sleep because it is a source of tryptophan, the same sleep-inducing amino acid in turkey. Unfortunately, consuming tryptophan is not likely to help most people who are struggling to sleep.
The next food mentioned is oatmeal. The author states that oatmeal is a slow-digesting carbohydrate that promotes serotonin release, the "feel good" neurotransmitter. He then says that serotonin is the sleep hormone - factually inaccurate on two counts - serotonin is not a hormone, it's a neurotransmitter, and many other neurotransmitters are thought to affect sleep.
Next is peanuts or peanut butter, which is a source of niacin. The author claims that niacin can promote serotonin - see above comment regarding oatmeal.
Warm milk is next and the author claims it has tryptophan - see cottage cheese. Also, the calcium in milk can help with melatonin production, so milk will help with sleep! If only it was that easy.
Finally, the author recommends grapes, which supposedly are the only food that contains melatonin. In my opinion, melatonin production is not the problem with most insomniacs.
Eating these foods most likely will not help chronic insomniacs. It could help someone who is just recently suffering from mild difficulty sleeping. This effect most likely would be due to a placebo response.
Relying on things external to our own body, whether it is food, pills, a special blanket, or whatever, probably won't work in the long term and can set up someone to become psychologically dependent on that thing to sleep. In other words, over time, the thing used to help sleep might be paired enough times with actual sleep so that if the thing is not available, the person will not be able to sleep.
Insomnia usually responds better to behavioral therapy, rather than relying on gimmicks like certain foods or other external things.
Tuesday, November 2, 2010
CPAP and Facial Structure
In young children, who are still growing, using CPAP can alter the way their face grows because of the pressure of the mask on their face every night. Therefore, using CPAP in young children can be challenging.
In adults, their faces are done growing, so using CPAP shouldn't alter their facial structure...or so we thought.
A study was done in Japan on Japanese adults with obstructive sleep apnea who used CPAP. There were 46 patients who used CPAP with a nasal mask (one that fits over the nose like this) for at least 4 hours per day for at least five days a week for between 25 and 46 months. Facial structure was measured with special x-rays.
The researchers concluded that there was a statistically significant change in the upper jaw of these CPAP using patients. Specifically, the change was a slight pushing in of the front teeth and upper jaw. None of the patients noticed any of the changes in their face or jaw. It was only seen on the special x-rays. Also, there was no clinical significance (like difficulty eating) with the facial changes. Finally, this is a small study and from the report, I can't tell if the masks were all the same brand or how tight they were. These are important variables that affect the significance of these findings.
I think the spokesperson, Harry L. Legan, for the American Association for Orthodontics sums up what's going on with this study. Dr. Legan says "the sharp sleep doctor will consider having the patient evaluated by an orthodontist to see if they should wear an intraoral device to prevent untoward movements of the teeth while using nCPAP."
In other words, despite having no clinical significance or asthetic change from using CPAP, the orthodontists want us sleep doctors to have our patients see them for an oral appliance. That's what it boils down to. Orthodontists can't knock CPAP for it's far superior efficacy, so they have to drum up some very minor facial changes as the reason to use an oral appliance instead. I'm not buying it. I'll stick with what works - CPAP.
In adults, their faces are done growing, so using CPAP shouldn't alter their facial structure...or so we thought.
A study was done in Japan on Japanese adults with obstructive sleep apnea who used CPAP. There were 46 patients who used CPAP with a nasal mask (one that fits over the nose like this) for at least 4 hours per day for at least five days a week for between 25 and 46 months. Facial structure was measured with special x-rays.
The researchers concluded that there was a statistically significant change in the upper jaw of these CPAP using patients. Specifically, the change was a slight pushing in of the front teeth and upper jaw. None of the patients noticed any of the changes in their face or jaw. It was only seen on the special x-rays. Also, there was no clinical significance (like difficulty eating) with the facial changes. Finally, this is a small study and from the report, I can't tell if the masks were all the same brand or how tight they were. These are important variables that affect the significance of these findings.
I think the spokesperson, Harry L. Legan, for the American Association for Orthodontics sums up what's going on with this study. Dr. Legan says "the sharp sleep doctor will consider having the patient evaluated by an orthodontist to see if they should wear an intraoral device to prevent untoward movements of the teeth while using nCPAP."
In other words, despite having no clinical significance or asthetic change from using CPAP, the orthodontists want us sleep doctors to have our patients see them for an oral appliance. That's what it boils down to. Orthodontists can't knock CPAP for it's far superior efficacy, so they have to drum up some very minor facial changes as the reason to use an oral appliance instead. I'm not buying it. I'll stick with what works - CPAP.
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