Wednesday, March 22, 2017

Wearable sleep-tracking devices and apps

This article points out a trend I've seen in my practice with some of my patients. Patient, typically with insomnia, describe their sleep quality based on what their FitBit watch tells them, rather than on their own perception of their sleep quality. The problem with these wearable sleep-tracking devices is that they are not very accurate at measuring sleep - they only record movements. Those movements could be from the patient, their bedpartner, or a pet in the bed.

The article highlights 3 separate patients who put more trust in their sleep-tracking device rather than on more accurate diagnostic tools (like sleep studies) and the sleep therapist who was using validated treatments like cognitive-behavioral therapy for insomnia (CBT-I). The study authors are concerned that these sleep-tracking devices are interfering with CBT-I, reinforcing sleep-related anxiety or perfectionism for some patients. For example, they explained how all three patients were spending excessive time in bed in an attempt to increase sleep duration as measured by their sleep-tracking device. But spending excess time in bed is one of the behaviors that worsens insomnia.

The authors explained what they tell their patients about the sleep tracking devices - that the trackers measure movement and not brainwaves. Therefore, these devices cannot determine light from deep sleep. They explain that the best use of these devices is probably to monitor their sleep patterns, including how much time they are spending in bed, rather than the number of minutes spent awake or asleep.

Wednesday, March 15, 2017

Living with children may mean less sleep for women

This article discusses research presented at a the annual meeting of the American Academy of Neurology - I didn't attend this meeting. The article surveyed men and women about sleep duration and level of daytime tiredness. Researchers looked at age, race, education, marital status, number of children in the household, income, body mass index, exercise, employment, and snoring as possible factors linked to sleep deprivation. Results showed that living with children was associated with more sleep deprivation in women, but not with men. Also living with children resulted in women feeling more tired in the daytime. One thing not stated was how old the children are in these households. I would imagine that sleep deprivation and daytime tiredness would increase with younger children.

Monday, March 6, 2017

Obstructive sleep apnea without obesity

Obstructive sleep apnea (OSA) is more common in obese individuals. Less is known about OSA in non-obese persons. This study looked at characteristics of OSA in non-obese people and compared them to OSA in obese people. In the introduction, the authors mention that non-obese individuals make up at least 20% of the adult OSA population. The authors also discussed that one reason non-obese people may have OSA is due to a low respiratory arousal threshold. This means that non-obese people may wake up more easily when their breathing tube collapses. In the study, the authors used information from sleep studies to estimate respiratory arousal threshold. The results showed that 25% of their patients were non-obese. And a higher proportion of non-obese patients had a low respiratory arousal threshold. Also CPAP usage was less in non-obese patients than obese patients. The authors concluded that non-obese patients may respond less to conventional OSA therapies (like CPAP) and that research is needed to discover alternative ways of treating OSA in non-obese patients.

Friday, November 4, 2016

Common swift stays airborne for 10 months straight!

I know this article about birds isn't relative to human sleep (at least directly). I thought it was fascinating because as a sleep doctor, my first question was when do these birds sleep, if they can stay in the air for 10 months. All animals have to sleep, so they much be getting some sleep. Turns out they climb really high and then coast down for 30 minutes at least twice a day, presumably to take power naps. Scientists don't know for sure if the birds are actually sleeping, but this is their best guess, and it makes sense to me. Maybe the ornithologists need to do a portable sleep study on these birds!

Thursday, October 27, 2016

American Academy of Pediatrics Updates

Recently, the American Academy of Pediatrics released updated guidelines on two important issues related sleep. The first update concerned sudden infant death syndrome (SIDS). Here is a link to the guidelines.

The second update concerned media use in children and adolescents. The recommendations discuss sleep and other aspects of how media affects children. For younger children, here is the link. For older children and adolescents, here is the link.

Wednesday, September 7, 2016

High blood pressure medications and obstructive sleep apnea severity

Obstructive sleep apnea (OSA) is associated with high blood pressure (HTN). Studies have shown that OSA is independently associated with resistant HTN and it is believed that untreated OSA may worsen HTN. However, studies involving treatment of OSA with continuous positive airway pressure (CPAP) have demonstrated only modest improvement in daytime blood pressure in randomized control trials. some research first speculate that the relationship between OSA and HTN may be bidirectional.

With OSA, the muscles that make up the throat lose their home causing collapse of that area and reduction in airflow to the lungs. Research her as hypothesized that intensive blood pressure control may influence always say I stabilizing the upper airway. There is also evidence for the role of volume status affecting the severity of OSA. What this means is that some people have worse OSA when they have too much blood volume from conditions like heart failure or kidney failure.

This study theorized that it is at least plausible that intensive treatment of HTN may bring about improvement in the severity of OSA, either by volume control, stabilization of upper airway muscles, or perhaps because of some direct effect of blood pressure medications. The researchers conducted a systematic review and meta-analysis on this topic.

Although there were limited number of studies and the studies were not of high quality, though results revealed that there was a decrease in OSA severity after treatment with blood pressure medications. Of note, the decrease reached statistical significance but the researchers doubted if it would be clinically significant.

I wanted to blog about this study in part because because throughout my career as a sleep physician I have thought of the OSA-HTN relationship as more one way, with OSA contributing to HTN, rather than the opposite as suggested by the authors of this study. Certainly more studies will be required before any definitive conclusions can be made.

Friday, August 26, 2016

Snoring and obstructive sleep apnea

Snoring is a common problem among men and women and is one of the cardinal symptoms of obstructive sleep apnea (OSA). With the explosion of smartphones and the emphasis on in-home monitoring, sleep researchers have attempted to use measurement of snoring to determine risk of obstructive sleep apnea. It has been difficult to do this because not all people who snore have obstructive sleep apnea. In addition, sleep researchers don't agree on an objective definition of snoring or an established threshold level of loudness. The quality of snoring is determined by multiple factors including the stage of sleep, body position, use of alcohol or other sedating medications, and upper respiratory tract illnesses such as a cold. There is significant variation of snoring from night to night for no apparent reason as well. Finally, snoring can be chronic throughout the night or periodic meaning that there are periods of silence between snoring episodes. The periodic snoring may be more suggestive of obstructive sleep apnea.

This study evaluated the diagnostic value of periodic snoring sounds measured during home sleep apnea testing. Subjects that were at risk for obstructive sleep apnea were sent home with a home sleep study monitoring kit and worn while they slept. The home sleep study kit has a built-in microphone that is located on the chest to detect the snoring sounds. the results showed a strong positive correlation between the percentage of periodic snoring and obstructive sleep apnea severity (AHI). The correlation was strongest for younger subjects, females, and obese subjects. The researchers discussed that some women do not get evaluated for obstructive sleep apnea because they do not know that they snore or are embarrassed to report snoring. In my clinic, I find this to be the case as well. Therefore measuring snoring at home while the patient is asleep many help sleep physicians to recommend formal diagnostic sleep studies to accurately assess female patients without a strong history of snoring.