Thursday, June 11, 2009

SLEEP 2009 Concludes

The final sessions of the SLEEP 2009 scientific program ended at 12:15 p.m. Pacific Time at the Washington State Convention and Trade Center in Seattle, Wash.

The SLEEP 2010 24th Annual Meeting of the Associated Professional Sleep Societies is scheduled for June 5 to 9, 2010, in San Antonio, Texas.

CPAP for Mild to Moderate Sleep Apnea

A late-breaking abstract (LBA 8) that will be presented at noon Pacific Time as an oral presentation demonstrates that people with mild to moderate obstructive sleep apnea may experience a clinically relevant and statistically significant improvement in functional status at eight weeks on active continuous positive airway pressure (CPAP) therapy.

The study analyses involved 113 people who were randomized to an active CPAP therapy treatment group, and 110 people who were randomized to a sham treatment group. The adjusted group difference in mean changes from baseline to week eight of treatment was 0.95 points on the Functional Outcomes of Sleep Questionnaire total score.

You can read the abstract in the
final program.

The Genetics of Sleep Duration

A late-breaking abstract (LBA 2) that will be presented later this morning as an oral presentation identified new genes associated with variations in sleep duration. The genome-wide association study involved 2,200 people in Finland; they were characterized for sleep length per night and evaluated for depressive symptoms and variation in mood.

The researchers found several new genes and variants that showed statistically significant association with total sleep length. Analysis also showed that sleep length and seasonal changes in mood share common molecular genes and pathways. This suggests that sleep disturbances and mood disorders may share common genetic components.

You can read the abstract in the
final program.

Why Do We Sleep?

A symposium taking place until 10 a.m. and being led by chair Dr. Jerome Siegel is discussing answers to this intriguing question: “Does sleep have a universal vital function across individuals and species?”

The discussion is getting to the heart of theories about why we sleep and about possible functions of sleep. Siegel addressed the topic in the
2003 articleWhy we sleep.” He writes that “we have no comparably straightforward explanation for sleep.” But sleep research has led to numerous “reasonable proposals.”

One of the symposium faculty,
Dr. Chiara Cirelli, was the co-author of a recent essay on the subject entitled, “Is sleep essential?” They conclude that there is still no consensus for “the elusive phoenix of sleep.”

In April the Sleep Education Blog
reported that a group from Spain has proposed a more controversial perspective. In “The trivial function of sleep,” they argue that “sleep does not provide additional advantages over simple rest.”

Sleep & Hypertension

A symposium taking place until 10 a.m. and being led by chair Dr. Antonio Culebras is focusing on “Sleep and Hypertension.” Topics being discussed include the relationship between sleep, sleep disorders and high blood pressure, as well as how to manage patients with high blood pressure through the identification of these sleep disorders.

Sleep disorders that will be prominent in this discussion include
obstructive sleep apnea, periodic limb movements and insomnia. A study in the April 1 issue of the journal SLEEP reported that the risk of hypertension associated with insomnia and a short sleep duration is comparable to the risk associated with obstructive sleep apnea.

Culebras was one co-author of a
scientific statement published last summer that focused on the growing evidence linking sleep apnea to cardiovascular disease. The statement reported that about 50 percent of OSA patients are hypertensive, and an estimated 30 percent of hypertensive patients also have OSA, often undiagnosed.

Sleep & Emotional Memories

A study (#1244) that will be presented later this morning as an oral presentation suggests that sleep preserves in long-term memory only what is emotionally important and relevant to future goals.

Results show that the placement of sleep is critical for remembering the components of emotionally negative scenes, but it does not impact memory for neutral scenes. Emotional items are selectively remembered 24 hours and 4 months later, but only if sleep comes soon after learning.

Find out more about theories describing
the role of sleep in memory on the Sleep Education Blog.

You can
download the SLEEP 2009 abstract supplement as an 11 MB file in PDF format.

Sleep & Weight Gain

Two studies that will be presented later this morning as oral presentations shed light on the associations between sleep and weight gain.

One study (#0981) used data from 1,797 twins with an average age of 37 years to show that body mass index (BMI) varied as a function of habitual sleep duration. Results show that twins who slept between 7 and 8.9 hours each night had a lower mean BMI (25.0 kg/m2) compared with those who regularly slept either more (25.2 kg/m2) or less (26.4 kg/m2) per night. The findings remained significant even after careful adjustment for genetics and shared environment.

Analyzing data from the
Sleep Heart Health Study, another study (#0515) suggests that there is a positive association between the severity of obstructive sleep apnea and subsequent change in BMI over approximately five years. The study involved 3,001 people with an average age of 62 years. Compared with participants who did not have sleep apnea, individuals with baseline moderate to severe sleep apnea had a mean change in BMI of 0.52 kg/m2; those with mild sleep apnea had a BMI change of 0.22 kg/m2. The association was significant despite adjustments for age, gender and race.

You can
download the SLEEP 2009 abstract supplement as an 11 MB file in PDF format.

Final Day of SLEEP 2009 Will Start at 8 a.m. Pacific Time

The final day of the SLEEP 2009 scientific program will begin in about three hours at 8 a.m. Pacific Time.

There will be two rounds of symposia and oral presentation sessions: from 8 a.m. to 10 a.m., and then from 10:15 a.m. to 12:15 p.m.

There also will be a special session of “late-breaking abstracts” from 10:15 a.m. to 12:15 p.m.

SLEEP 2009 will conclude today at 12:15 p.m. Pacific Time.

View today’s
session schedule.