Regularly catching only a few hours of sleep can hinder metabolism and hormone production in a way that is similar to the effects of aging and the early stages of diabetes. Chronic sleep loss may speed the onset or increase the severity of age-related conditions such as type 2 diabetes, high blood pressure, obesity, and memory loss. The researchers showed that just one week of sleep deprivation altered subject?s hormone levels and their capacity to metabolize carbohydrates. People who trade sleep for work or play may get used to it and feel less fatigued.
During sleep-deprivation, the researchers found, the men's blood sugar levels took 40% longer to drop following a high-carbohydrate meal, compared with the sleep-recovery period. Their ability to secrete and respond to the hormone insulin, which helps regulate blood sugar, dropped by 30%. These changes echo the effects of insulin resistance, a precursor to type 2 diabetes. In addition, the sleep-deprived men had higher nighttime concentrations of the hormone cortisol, which also helps regulate blood sugar, and lower levels of thyroid-stimulating hormone. These raised cortisol levels mimic levels that are often seen in older people, and may be involved in age-related insulin resistance and memory loss.
Sleep debts are sort of like stress. Most sleep-deprivation research has focused on what it does to the brain, but it is likely that sleep has many functions.? In the study, subjects' blood sugar and hormone concentrations were restored after the sleep-recovery period. Earlier research has shown that in developed countries, the average night's sleep has grown shorter since the beginning of the century, from 9 hours to 7.5 hours. Many people give up sleep to make room for work and leisure. An adequate amount of sleep is as important as an adequate amount of exercise. Sleeping is not a sin.
The Lancet October 23, 1999;354:1435-1439.
Dr. Mercola's Comment:
This topic is particularly important as we prepare for the clock shift next weekend. This is a very important study published out of my hometown at the University of Chicago right down the block from where I went to medical school.
I think most of us do not fully appreciate the value of a full night?s sleep. This article nicely demonstrates the incredible disruption of our finely balanced hormones that results when we get less sleep than we were designed to. I believe that seven hours is an absolute minimum for most all of us, and most of us would benefit from closer to 9 hours.
The researchers did find that sleep debt could be made up by spending longer than the normal eight hours in bed, which seemed to return the body?s chemical balance to normal. Another sleep hygiene principle is that you should be in bed by 10PM. I think in the winter months 9 PM is more likely to be a better time if you have to wake up early to go to work.
I have been experimenting with 9 PM as a bedtime and find it to provide a great deal of rest and I wake up feeling far more refreshed. I will attempt to keep this pattern as I usually get up at 4:30 and I believe 7 1/2 is the bare minimum amount of sleep one should get.