Three studies have concluded that obesity and depression are the two main culprits that make people excessively sleepy while awake.
Researchers at Penn State examined a random population sample of 1,741 adults and decided that obesity and emotional stress are the main causes of the current “epidemic” of sleepiness and fatigue plaguing America.
Insufficient sleep and obstructive sleep apnea also play a role; both have been linked to high blood pressure, heart disease, emotional stress, diabetes, obesity and accidents.
“The ‘epidemic’ of sleepiness parallels an ‘epidemic’ of obesity and psychosocial stress,” Alexandros Vgontzas, MD, the principal investigator for the three studies, said.
“Weight loss, depression and sleep disorders should be our priorities in terms of preventing the medical complications and public safety hazards associated with this excessive sleepiness,” Vgontzas said.
In the Penn State cohort study, 222 adults reporting excessive daytime sleepiness (EDS) were followed up 7 and a half years later.
For those whose EDS persisted, weight gain was the strongest predicting factor.
“In fact, our results showed that in individuals who lost weight, excessive sleepiness improved,” Vgontzas said.
Adults from that same cohort who developed EDS within the 7½-year span also were studied.
The results show for the first time that depression and obesity are the strongest risk factors for new-onset excessive sleepiness.
The third study, of a group of 103 research volunteers, determined once again that depression and obesity were the best predictors for EDS.
“The primary finding connecting our three studies are that depression and obesity are the main risk factors for both new-onset and persistent excessive sleepiness,” Vgontzas said.
In the Penn State cohort study, the rate of new-onset excessive sleepiness was 8 percent, and the rate of persistent daytime sleepiness was 38 percent.
Like insufficient sleep and obstructive sleep apnea, EDS also is associated with significant health risks and on-the-job accidents.