Losing sleep speeds up the ageing process

Sleep deprivation research usually focuses on what it does to the mind.

Now, new evidence suggests that lack of sleep may also be devastating for the body and may possibly help to bring on diabetes.

In a recent US study, researchers found that just one week of sleep deprivation altered subjects' hormone levels and their capacity to metabolise carbohydrates. During sleep deprivation, the blood sugar levels of the men who participated in the study took 40 per cent longer to drop following a high carbohydrate meal during sleep deprivation compared with during the sleep recovery period.

In addition, when deprived of sleep, the men's ability to secrete and respond to insulin dropped by 30 per cent. The men also had higher night time levels of cortisol, which helps to regulate blood sugar and to lower levels of thyroid stimulating hormone.

Each of these biological responses to sleep deprivation places an individual at greater risk of developing type II or adultonset diabetes.

The good news, according to the researchers, was that the sleep debt could be made up by spending longer than the normal eight hours in bed, which helped to return the body's chemical balance to normal (Lancet, 1999; 354: 1435-9).