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.

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.

Obstructive sleep apnea in childhood and adolescence

There is limited study data about the natural course of obstructive sleep apnea (OSA) in children. This study looked at OSA incidence and remission from middle childhood (ages 8-11 years) through late adolescence (ages 16-19 years). It also studied if risk factors for OSA that were present in middle childhood remained in adolescence. This was a retrospective study from a larger sleep and health study.

Of note, OSA in children is typically defined as full or partial collapse of the airway at least 1 time an hour. In this study, the authors used a more conservative measure of 5 or more airway collapses per hour. The results showed OSA was present in 4.7% of middle childhood aged kids and in 4.3% of adolescents. And only 8.7% of those with OSA in middle childhood still had OSA in adolescence - meaning almost 91% of cases of OSA resolved between middle childhood and adolescence. And of those whose OSA had remitted by adolescence, only 24% had had tonsillectomy, the treatment of choice for OSA in children. So in 3 out of 4 cases, the OSA went away on it's own, without surgical intervention. Of the children without OSA, only 4% went on to be diagnosed with OSA in adolescence.

Unlike OSA, habitual snoring was much more persistent from middle childhood to adolescence. Half of the snorers in middle childhood were still snoring in adolescence, yet most of them did not go on to develop OSA as adolescents. However, when the study authors lowered the threshold for diagnosing OSA, 32% of middle childhood snorers went on to develop OSA in adolescence.

Risk factors for middle childhood OSA were African American race, preterm status, and neighborhood distress. However, these were not risk factors for OSA in adolescents. Instead, the risk factors were male sex and history of tonsillectomy or adenoidectomy. Finally, adolescents with OSA had a higher body-mass index (marker for obesity) compared to adolescents and middle childhood kids without OSA. The authors speculated that the changing risk factors may reflect the fact that upper airway changes occur from middle childhood to adolescence, especially regression of tonsils. Thus, other factors like male gender and obesity would be more important in adolescents. The authors go on to explain that the risk factor of prior tonsillectomy in adolescents with OSA may be due to other risk factors that reflect a predisposition for upper airway collapse in sleep.

The authors concluded that screening for OSA could be age specific given the different risk factors present at the different ages. Also, the cutoff values for OSA may need to be altered given the child's age - using a more liberal cutoff for younger children and a more conservative one for older children. This is already being done at many sleep centers, where the sleep physician can use adult criteria or pediatric criteria cutoff values for children aged 13 and older.

Flying with your CPAP

I get asked about this regularly by my patients. This article is about traveling with a CPAP. Since using CPAP therapy with all sleep will maximize effectiveness, you should bring your CPAP with you when you travel. Of course, don't forget to bring all of the accessories, especially the power cord. Most CPAP machines these days come with a canvas bag to carry the device. I advise my patients to carry the device on board, not checking it as luggage. This is because the CPAP may be damaged during luggage handling or transportation in the plane, or your luggage may be lost. You will need to show the TSA agent the CPAP equipment. Nowadays, they will be used to it, and you will see many other travelers with their CPAPs. You may also need to bring a letter from your physician or a specialized luggage tag that says the CPAP is a medical device that has been prescribed for you.

Some travelers, especially on overnight flights, will want to use their CPAP's on the plane. You will need to check with the airline to see if their planes have power sources and if you can sit near enough to one to plug in your CPAP. Be sure to ask what kind of power source the plane has, as you may need an adapter. Some of my patients have gotten small travel CPAPs that operate on battery power.

If you use the humidifier chamber, don't try to bring distilled water on the plane. Best to buy it at your destination, if available.