Wednesday, March 4, 2015

Later school start times for teenagers

School start times are a hot issue these days. Particularly, letting teenagers start school later, to match their natural pattern of sleeping in later than younger kids. This report is about a survey done at the University of Michigan where researchers asked parents how they felt about later school start times. Below is a figure from the report that shows some of the results of the survey.

Most of the parents (88%) said their teens currently have a start time before 8:30 a.m. Among these parents, 27% of parents would support a school start of 8:30 a.m. or later only if it did not impact the school budget, and 24% would support a later start time regardless of impact on the school budget. Less than one-half (49%) of the parents do not support a later school start time.

Wednesday, February 25, 2015

Sleep duration in American teens

On the heels of last week's post about new sleep duration recommendations, this post is about an article in the journal Pediatrics about the changes in sleep amounts among teens in the United States from 1991 to 2012. The participants were 270,000 8th, 10th, and 12th graders involved in a larger survey. The researchers asked the participants two questions about sleep duration. One was how often they got less 7 hours or at least 7 hours of sleep. The other question was how often the teen felt they got enough sleep per week.

Epidemiological studies show that almost a third of teens don't get enough sleep. The reasons are not known, but researchers speculate that internet, social media, and increased competitiveness of the college admissions process are contributing. And, in last week's blog, I posted a table that recommends 8-10 hrs per night for 14-17 year olds.

The results of the current study showed that self-reported sleep duration in teens has decreased over the past 20 years. The largest decrease was in 15 year olds. Although the data show that sleep duration declined across all age groups and major socio-demographic subgroups, results showed that female students, racial/ethnic minorities, and students of lower socio-economic status (SES) reported getting at least 7 hours of sleep less often than male subjects, non-Hispanic white subjects, and students of higher SES.

Wednesday, February 18, 2015

New sleep duration recommendations

Here is an article that discusses the National Sleep Foundaion's latest sleep duration recommendations. One thing that caught my attention is that sleep duration for adults is broken up into 3 categories - young adult, adult, and older adult. This makes sense to me from a physiological perspective, as older adults may not need as much sleep as 20 somethings.

Wednesday, February 11, 2015

Nasal surgery and CPAP

Most of my patients with obstructive sleep apnea (OSA) report they are "mouth breathers" at night. Because of that, they often think they should use a CPAP mask that covers their nose AND mouth...the full face mask. Full face masks often leak excessively, especially for side sleepers. I find that most of the time, my patients do well with a mask that just covers their nose or goes right in their nose (nasal pillows). But I have a small segment of patients who really struggle to breathe just through their nose. Almost all of these patients have daytime nasal stuffiness as well. Often, airflow through their nose is not improved with by-mouth medications or nasal sprays. In these cases, patients can opt to use the full face mask, or consider surgical therapy to improve nasal airflow. If the Ear, Nose and Throat (ENT) physician determines there is significant anatomical obstruction, then surgical therapy may improve nasal airflow enough to allow the patient to utilize an over-the-nose mask, instead of the full face mask.

Here is a study supporting my clinical experience. It's a meta-analysis of current literature. After examining past studies, the authors concluded that nasal surgery to relieve obstruction resulted in an average lowering of CPAP pressure by 2.66 cwp. Regardless of nasal surgery type, CPAP pressures were lower on average 1.9 cwp between preoperative and postoperative periods. The greatest difference was in those patients undergoing combined septoplasty with turbinoplasty. Finally, overall CPAP use increased after nasal surgery, possibly due to overall lowered CPAP pressures. The study did not mention changes in mask styles after surgery, such as from full face mask to nasal mask. This change alone, even without reduction in CPAP pressure may improve CPAP adherence.

Wednesday, February 4, 2015

Treating obstructive sleep apnea with medication

Obstructive sleep apnea (OSA) is currently treated with mechanical devices - air pressure from CPAP, jaw movement with oral appliance therapy, or surgical therapy. No medications have been shown to be particularly helpful in treating OSA. This article discusses NIH funding given to a team of researchers at the University of Chicago.

The article describes the research already going on at the University that focuses on a small group of cells in the carotid artery called the carotid bodies. When levels of oxygen in the blood drop, these carotid bodies send signals to the brainstem to increase breathing, with the goal of increasing oxygen levels in the blood. The article describes that in sleep apnea, the carotid bodies may not react appropriately, and thus stop sending signals to the brain. The University of Chicago team has developed a compound that may help the carotid bodies to keep working properly during sleep apnea, and thus aid in their regulation of breathing - at least in rodents.

However, it's not clear what type of sleep apnea the researchers are working on. It sounds like central sleep apnea (CSA), which is a completely different, and less common form of sleep apnea, than OSA. In most cases of OSA, the drive to breathe is intact, but airflow is significantly reduced due to a blockage in the upper airway. In addition, not every patient with OSA has oxygen level reductions, even though airflow through the upper airway is reduced. But if a person with OSA has regular blood oxygen level reductions, perhaps a medication that helps the carotid bodies stimulate breathing may be effective, if that stimulation involves increasing the diameter of the upper airway.

Wednesday, January 28, 2015

Asthma and obstructive sleep apnea

This article is about a study showing an association between asthma and risk of obstructive sleep apnea (OSA). All participants were adults drawn from a random sample of Wisconsin state employees. Initially they were free of OSA based on overnight sleep studies done every 4 years. Results showed that the relative risk of developing OSA was 1.39 times higher in those with asthma. And this was after adjusting for sex, age, baseline and change in body mass index, and other factors. The study authors suggest that physicians who treat asthma should periodically screen those patients for OSA.

Wednesday, January 21, 2015

Sleep and screen time in children

Studies have been demonstrating that some children are getting too little sleep, and that technology is driving some of the sleep deprivation. Studies have also shown that TV in a child's bedroom has been linked to less sleep. And interactive media devices like smart phones and video games may be more disruptive to sleep. This is in contract to TV viewing, which is a passive activity. Also, interactive devices are held very close to the face, meaning that light from the screens on these devices is more likely to interrupt melatonin secretion at night, which may further disrupt sleep. Finally, these interactive devices can disrupt sleep by text messages, which is not a problem with TV viewing.

This study was a cross-sectional survey of about 2000 4th and 7th graders in Massachusettes. They asked children about their TV viewing, small screen use (like cell phone, Ipad, etc), and various sleep parameters. Results showed that 54% of kids slept near a small screen and 75% slept with a TV in the room. Not surprisingly, a higher proportion of seventh graders slept near a small screen than 4th graders.

Children who slept near a small screen reported 21 fewer minutes of sleep per weekday when compared to those who did not sleep near a small screen. This effects was independent of having a TV in the room. Children who slept in a room with a TV reported sleeping 18 fewer minutes during the weekday than those without a TV in their room. This was independent of sleeping near a small screen. The results showed that the association between the screens and sleep duration resulted from a later bedtime. Sleeping near a small screen, but not a TV in the room, was associated with a 1.39 times the prevalence of perceived insufficient sleep or rest, even after adjusting for sleep duration. Not surprisingly, longer time watching TV or playing video games was associated with shorter weekday sleep duration, again accounted for by later bedtimes. And each hour spent watching TV or playing video games was associated with a higher prevalence of perceived insufficient sleep or rest. Interestingly, physical activity reduced the association between video games and perceived insufficient rest or sleep.

The study authors concluded that the small screens affect sleep quality more than TV viewing because of the stimulating content, calls, and audible text messaging while sleeping. They also mentioned that other mechanisms may contribute. For example, consuming caffeinated beverages near bedtime, evening exposure to bright light, and increased cognitive / emotional / physiologic arousal after playing video games, interacting on social media, or watching exciting / frightening TV content.