Thursday, June 29, 2006

Rich people get more sleep

In a study of sleep characteristics in 669 adults in Chicago who were compared by sex and race, investigators found that blacks got less sleep than whites, while men got less sleep than women.
Furthermore, the wealthier you are, the more sleep you're likely to get, Dr. Diane S. Lauderdale of the University of Chicago and her colleagues found.
"There was an expectation that people with very demanding jobs in terms of high status, high income, would be getting less sleep, and that was not true," Lauderdale told Reuters Health in an interview. The findings could help explain why blacks suffer from more health problems than whites, she added.

Monday, June 12, 2006

Short Naps are Better

Thinking about taking a nap, but not sure how much napping will help you wake up refreshed? A new study finds that ten minutes may be the magic number when it comes to napping. The study of 24 healthy, young adults who were good sleepers and not regular nappers investigated what would be most effective after a night of five hours of sleep – no nap, a five minute, ten minute, twenty minute or thirty minute nap. Participants took afternoon naps at 3 p.m., and their performance post-nap was measured for three hours. Benefits of the five-minute nap were similar to taking no nap, while twenty and thirty-minute naps offered improvements up to an hour and a half after the nap, though immediately following these naps there was a period of reduced performance, sleep inertia and sleepiness. In the end, the ten-minute nap yielded the most benefits with the least side effects. This nap triggered improvements in cognitive function, sleepiness, fatigue, vigor, etc., and the effects lasted for up to 155 minutes. Researchers believe further investigation is needed to understand what processes occur in the first ten minutes of sleep and how they may provide benefit.
From the National Sleep Foundation. Here is the actual abstract:

A Brief Afternoon Nap Following Nocturnal Sleep Restriction: Which Nap Duration is Most Recuperative?
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Amber Brooks, PhD; Leon Lack, PhD
School of Psychology, Flinders University, Adelaide, SA, Australia

Study Objectives: The purposes of this study were to compare the benefits of different length naps relative to no nap and to analyze the electroencephalographic elements that may account for the benefits. Design: A repeated-measures design included 5 experimental conditions: a no-nap control and naps of precisely 5, 10, 20, and 30 minutes of sleep. Setting: Nocturnal sleep restricted to about 5 hours in participants’ homes was followed by afternoon naps at 3:00 PM and 3 hours of postnap testing conducted in a controlled laboratory environment. Participants: Twenty-four healthy, young adults who were good sleepers and not regular nappers. Measurements and Results: The 5-minute nap produced few benefits in comparison with the no-nap control. The 10-minute nap produced immediate improvements in all outcome measures (including sleep latency, subjective sleepiness, fatigue, vigor, and cognitive performance), with some of these benefits maintained for as long as 155 minutes. The 20- minute nap was associated with improvements emerging 35 minutes after napping and lasting up to 125 minutes after napping. The 30-minute nap produced a period of impaired alertness and performance immediately after napping, indicative of sleep inertia, followed by improvements lasting up to 155 minutes after the nap. Conclusions: These findings suggest that the 10-minute nap was overall the most effective afternoon nap duration of the nap lengths examined in this study. The implications from these results also suggest a need to consider a process occurring in the first 10 minutes of sleep that may account for the benefits associated with brief naps.

Thursday, June 08, 2006

Dear Abby says to go see a Sleep Specialist

DEAR ABBY: I am a 37-year-old married woman with a problem. My mother committed suicide when I was 18, and I have never dealt with my loss. The day after she died, my father bagged up all of her possessions and gave them to charity. I tried talking to him about her, but he told me she was "gone" and I had to move on. I guess I have just put my pain on the back burner all these years.
For the last five years or so, I have been sleepwalking and having horrible nightmares about my mother's death. My husband tells me I carry on conversations with him, but that I am not really "there." I also take baths when I'm technically asleep. On one occasion, I woke up behind the wheel of my truck in my garage. I don't know if I went out driving or not, but the thought terrifies me.
I am afraid I will hurt myself, or possibly others, in my zombie-like state. Any advice you can give me would be greatly appreciated. -- OUT OF IT IN LAS VEGAS
DEAR OUT OF IT: Please accept my deepest sympathy for the tragic loss of your mother. The first thing you must do is ensure that your husband has the keys to your truck at bedtime.
Then, contact your physician and ask for a referral to a sleep disorder specialist for an evaluation. Some people experience the symptoms you have described as a side effect from certain sleep-aid medications. However, if you are not taking anything, you may have a treatable sleep disorder.
After that, ask your doctor to refer you to a licensed psychotherapist who can help you deal with the emotions you have kept buried all these years since your mother's death. Once your feelings are out in the open, you will be able to deal with them -- and discussing them with a professional will help you more quickly through the process.

Tuesday, June 06, 2006

The difference between CPAP, BiPAP, and auto-CPAP

A reader asks "I've been on a CPAP for years, but my sleep specialist is putting me on an AutoPAP. In the meantime, my DME has me on a loaner BiPAP and I feel a lot better even after one night's sleep.Also, does the difference in machines do anything in reducing long term complications"

CPAP, continuous positive airway pressure, delivers a single continuous level of pressure. CPAP is usually effective in treating obstructive sleep apnea. BiPAP delivers a higher pressure while breathing in, and a lower pressure while breathing out. BiPAP can be used to treat obstructive sleep apnea and is sometimes effective in treating central sleep apnea. I t can also be used to assist ventilation in various pulmonary and neurological disorders. Auto-CPAP can be used in 2 different manners: 1) to vary pressure during sleep for a person who has varying pressure requirements (for example, needing a higher pressure during REM sleep) and 2) can be used on a temporary basis to do a CPAP titration. In cases in which patients have had a CPAP titration in the sleep lab but I'm still not quite sure of the exact optimal pressure, I sometimes send them home with an auto-CPAP machine for a few nights. The machine generates a computerized printout that helps me pick the right pressure.
In OSA, the differences in the machines make no difference in reducing complications as long as the patient is compliant with treatment and receiving an effective pressure(s).

Sunday, June 04, 2006

Measuring Sleepiness in Children

Clinical Psychiatry News has a good article about the use of the Multiple Sleep Latency Test in pediatric patients:
Although a simple clinical evaluation can provide a fairly good indication as to whether the child has daytime sleepiness, it's often difficult to estimate how severe the problem is. “The multiple sleep latency test (MSLT) can help answer that question in an objective way that's been standardized and well validated,” said Dr. Hoban of the sleep disorders center at the University of Michigan, Ann Arbor.
Unlike certain questionnaire-based assessments, the MSLT has been validated in children, and provides reliable results as long as the child is at least 6 or 7 years old. However, the test is expensive and time consuming to perform and must be conducted in a sleep lab. The MSLT may be useful when a child has excessive daytime sleepiness but the clinical history, examination, and polysomnography reveal no specific cause. Dr. Hoban recommended judicious use of the MSLT in evaluations of sleep-disordered breathing, circadian rhythm disorders, narcolepsy, and other disorders of excessive sleepiness.
Developed initially at Stanford (Calif.) University in the 1970s, the MSLT has a simple premise: People who are sleepy will fall asleep faster than those who are not.
After a night of polysomnography to screen for some sleep disrupters and to ensure that the patient has had a good night's sleep, the child is given four or five chances to nap in a dark, quiet environment, with each nap separated by about 2 hours. If the child fails to fall asleep (as measured by EEG tracings) within 20 minutes, the nap opportunity ends. Otherwise the child is allowed to sleep for 15 minutes following the first epoch of sleep.
In addition to the latency of sleep, the MSLT records the presence of sleep-onset REM periods (SOREMPs). The presence of SOREMPs correlates strongly with the presence of narcolepsy. Narcoleptic patients also typically have a sleep latency of 5 minutes or less.

The article goes on to give normative data for interpreting the MSLT in pediatric patients:
Normal adults have a sleep latency of about 15 minutes, but normal latencies in children can be much longer. Detailed studies have correlated mean sleep latencies with Tanner stage. Children in Tanner stage 1 take an average of 19 minutes to fall asleep, whereas those in stage 5 take about 16.6 minutes; older adolescents take a mean 15.7 minutes to fall asleep.
“The net result of this is that in preadolescent children you can have a sleep latency of 14 or 15 minutes that would be considered solidly normal by adult standards but substantially abnormal for a child,” Dr. Hoban said.

For moreinformation about the use of the MSLT in the diagnosis of narcolepsy, see here.