Daytime Sleepiness Linked to Depression,&

HERSHEY, Pa., Sept. 7-Daytime sleepiness is likely to stem from depression or metabolic factors such as diabetes and obesity, rather than sleep apnea, researchers here report.

A cross-sectional study of 16,583 men and women found depression to be the strongest risk factor for excessive daytime sleepiness (P<0.0001), researchers reported in the latest issue of Journal of Clinical Endocrinology and Metabolism. A body mass index of 28 or higher and diabetes (P<0.001) were also significant and independent risk factors.

On the other hand, sleep apnea was not as significant a risk factor as once believed (P=0.266), wrote investigators led by Edward O. Bixler, Ph.D., a professor of psychiatry at Pennsylvania State University here.

"When we addressed the relative contribution of various factors for the complaint of excessive daytime sleepiness, current treatment for depression was most strongly associated," the researchers wrote. This relationship held even after controlling for antidepression medication.

Body mass index was also a significant and independent risk factor for excessive daytime sleepiness. There was a "dramatic increase" in the prevalence of excessive daytime sleepiness when BMI reached 28, the researchers reported. A BMI of 25 to 29 equals overweight; 30 or higher defines obesity.

The findings were based on telephone interviews with 12,219 women and 4,364 men ages 20 to 100. The presence of excessive daytime sleepiness was determined on the basis of a moderate or severe rating response to one of two questions: Do you feel drowsy or sleepy most of the day, but manage to stay awake? and Do you have any irresistible sleep attacks during the day?

Survey respondents were also asked whether they were being treated for depression, allergies, asthma, hypertension, or diabetes.

A total of 8.7% of this group reported excessive daytime sleepiness. Thirteen percent had diabetes and 13.3% were being treated for depression. Gender was not a factor, but age was.

Excessive daytime sleepiness was more common among those ages 30 and younger and those ages 75 and older. Depression and unmet sleep needs probably accounted for the young adults' sleepiness, while increased health problems and medical illnesses most likely affected the older respondents, the researchers wrote. Daytime fatigue showed a linear decline between ages 30 and 75.

The association between diabetes and excessive daytime sleepiness suggests "that a simple fasting blood sugar test should be considered appropriate in the presence of an excessive daytime sleepiness complaint," the researchers wrote. The biochemical relationships between these associations have not yet been made clear and warrant further study, the researchers noted.

Smoking tended to be a risk factor for excessive daytime sleepiness. However, smoking, it turned out, was not strongly associated with nocturnal sleep disturbance in this study. The researchers had no clear answers for this finding, but suggest that smokers may use nicotine to self-medicate during the day.

In the second part of the study, a sub-sample of 741 men and 1,000 women who had participated in the telephone survey were randomly selected to participate in a one-night observation at the researchers' sleep laboratory. Each participant underwent a physical examination and provided an in-depth sleep history. They were monitored for eight hours using 16-channel polygraphs.

There was a significant association between typical sleep duration and excessive daytime sleepiness (P=0.007) when compared with patients who did not have daytime sleepiness, the research team reported.

Although excessive daytime sleepiness has been associated with sleep breathing disorders in the past, such as sleep apnea, Dr. Bixler and colleagues found these breathing disorders were not the leading significant factor as previously believed.

Sleep apnea was described as having an obstructive or hypopnea index (OHI) of 15 or higher. The prevalence of excessive daytime sleepiness was 18.3% among those who had an OHI of 15 or more compared with only 10.7% for those without a breathing disorder.

"This finding may explain to some extent why continuous positive airway pressure at times fails to improve excessive daytime sleepiness in patients with sleep apnea," Dr. Bixler's team wrote.

The findings suggested that when diagnosing excessive daytime sleepiness, patients should also be screened for depression and/or diabetes, the authors concluded, "both in the presence and absence of sleep apnea."

[系统提示]:
  .::本帖子因为[奖励]值得推荐的转帖文章被神经科学论坛管理员a2s2d3实行了：+5金钱 的奖惩::.

This is another great article!

Please read it carefully!