(dailyRx News) Why is it so hard for some people to get a good night's sleep? The causes are complex, but new data suggests weight gain and clinical depression worsen daytime sleepiness.
Three unpublished studies presented at a Sleep research conference in June associate being seriously overweight or clinically depressed with the problem of daytime sleepiness.
While many people feel a bit drowsy during the day, more serious lack of sleep can compromise work and other responsibilities.
Sleep disorders can negatively affect work and productivity, distressing individuals and costing billions of dollars to the economy.
Overall, sleep quality seems to be affected by a number of neurological, emotional, behavioral and environmental factors. Lighting levels, stress, alcohol, caffeine intake and genetics likely play some role.
In recent years increasing attention has been given to additional factors influencing sleep quality. By researching the sleep life of 1,741 adults, teams led by Alexandros Vgontzas, MD, found noteworthy associations between body fat levels and daytime sleepiness. They also found significant associations between incidence of clinical depression and poor quality sleep.
Of particular note was the strength of the associations between clinical depression and Excessive Daytime Sleepiness (EDS), expressed as "odds ratios". The odds ratio that clinical depression is associated with daytime sleepiness was 2.9, while obesity was 2.0.
Thus, compared to baseline, the odds that a person with depression would also have a problem with daytime sleepiness is almost three times as great, and twice as much with depression.
How would body fat level make it harder to get a good night's sleep? Why should a certain intensity of prolonged sadness negatively affect restorative slumber?
These are unknown currently.
Sleep is a mysterious phenomenon, only very partially understood by psychologists, neurologists and doctors. Scientists do not have a good grasp on the particular means by which poor sleep quality might be affected by adipose tissue (fat) and clinical depression.
While the biological and psychological connections between sleep, obesity, and depression remain elusive, the dangers of poor sleep quality are hardly a secret.
There is evidence from multiple studies that a lack of restorative sleep and/or sleep apnea, where sleeping stops abruptly or where breathing is abnormally low, has negative effects on blood pressure, cardiovascular disease, metabolic processing and other aspects of health.
Excessive daytime sleepiness has multiple causes, and in turn contributes to a number of important medical problems. To the extent that being seriously overweight or depressed can influence poor sleep quality and drowsiness, people with either condition should seek help in making changes.
The studies were presented June 13 at the 26th annual meeting of the Associated Professional Sleep Societies in Boston.
Because the studies are not yet published in a peer-reviewed journal, their results should be regarded as provisional and needing analysis by subject-matter experts.
The research was funded by the National Institutes of Health. No conflicts of interest were noted.