Excessive Daytime Sleepiness Linked To Obesity, Depression

Could excess body-weight ultimately influence daytime drowsiness? New findings published in the journal Sleep suggest that obesity and depression could play a role in our inability to stay awake during the day.

For the study, researchers at Penn State College of Medicine found that as much as 30 percent of the general population experienced excessive daytime sleepiness, resulting in excessive daytime drowsiness or exhaustion throughout the day.

"Excessive daytime sleepiness has huge implications for public health and policy," Julio Fernandez-Mendoza, researcher and assistant professor of psychiatry at the Sleep Research and Treatment Center at Penn State College of Medicine, said in a news release. "Fatigue and sleepiness are the most common causes of poor work productivity and fatal car crashes. In our study we were able to causally link obesity and depression - disorders of epidemic proportions - with daytime sleepiness through different mechanisms; in fact, we found that individuals who lost weight did not complain of daytime sleepiness anymore." 

For the study, they measured self-reporting of excessive daytime sleepiness at baseline and again at the average of 7.5 years later in over 1,000 men and women. Study participants were asked to complete a comprehensive sleep history and physical examination where they were evaluated one night in a sleep laboratory.

Then, researchers recorded sleep, physical and mental health problems, along with substance use and determined whether participants were being treated for physical and mental health conditions.

Findings revealed that body weight predicted excessive daytime sleepiness better than sleep apnea.

"This data is also consistent with studies showing that CPAP (continuous positive airway pressure) machines greatly reduce the number of apneas, or pauses in breathing, that a person with sleep apnea experiences during the night, but don't effectively reduce daytime sleepiness, probably because CPAP does not help reduce weight," Fernandez-Mendoza concluded.