Chronic sleep debt is becoming increasingly common and affects millions of people in more-developed countries. Until now sleep debt was believed to have no adverse effect on health. Recently, however, clinical studies discovered that not getting enough sleep may hasten aging and facilitate the development of obesity, diabetes, and hypertension.

Sleep debt leads to higher concentrations of the adrenal stress hormone cortisol, which raises blood sugar, leading to a tendency to put on weight, develop hardening of the arteries and cause memory loss. In fact, the effects are the same as those seen with rapid aging. So, to stay feeling and looking young, make sure you get plenty of deep restful sleep.

Researchers from the University of Chicago, Department of Medicine, examined the difference between healthy young men who had been restricted to 4 hours sleep per night for six nights, compared to 12 hours of sleep per night. The state of sleep debt was associated with elevated adrenal cortisol levels that cause blood sugar elevations and a blunted response to insulin. These actions lead to overeating and a tendency toward diabetes. If this state persists, the high blood sugar level could eventually damage the arteries, leading to hardening of the arteries and thus hypertension

For unknown reasons, the higher concentrations of cortisol produced by sleep deprivations also leads to memory loss, immune system suppression, and a depression.

Additionally, the sleep deprived state leads to an increase in the activity of the sympathetic nervous system. Sleep dept seems to cause the same effects as stress on the body: stimulating the "fight or flight" mechanism In fact, one can cause the other: too much stress can cause poor sleep, and too little sleep can cause additional stress, which can make you feel nervous, anxious, irritable and weak.

Source: Lancet 1999 Oct 23;354(9188):1435-9.