Lack of Sleep May Raise Risk of Diabetes

Your mother was right: regular bedtimes and a good night's sleep are good for you - or at least, researchers reported, irregular bedtimes and not enough sleep are bad for you.

In a 39-day experiment with healthy volunteers, shortened sleep time and varying bedtimes - meant to mimic shift work - led to impaired glucose regulation and metabolism, according to Orfeu Buxton, PhD, of Brigham and Women's Hospital in Boston, and colleagues.

Over time, the observed changes could increase the risk of obesity and diabetes, Buxton and colleagues reported online in Science Translational Medicine.

The findings support epidemiological studies linking disrupted sleep with an increased risk of metabolic syndrome and diabetes, the researchers noted - especially in workers on the night shift.

"Since night workers often have a hard time sleeping during the day, they can face both circadian disruption working at night and insufficient sleep during the day," Buxton said in a statement. "The evidence is clear that getting enough sleep is important for health, and that sleep should be at night for best effect."

Most research on the issue has been observational in nature, Buxton and colleagues noted. To help fill the gap, they analyzed what happened when 21 healthy volunteers had their sleep patterns disrupted in the lab.

According to the National Sleep Foundation’s 2007 Sleep in America poll, the amount you sleep can also contribute to your overall health. Women who responded to the poll that they were in “poor health” also experienced daytime sleepiness a few days a week, have missed work due to sleepiness, and are more likely to have used a sleep aid than those who categorized themselves as in “excellent health.” This trend can do more than make us grumpy and groggy - not getting enough sleep can contribute to the risk of developing diabetes. A study published in the Archives of Internal Medicine found that women who slept only five hours a night were 2 ½ times more likely to have diabetes as those who slept seven or eight hours. One explanation for this link is that sleep-deprivation increases insulin resistance, which contributes to diabetes. Another study found that, when healthy young men slept only 4 hours a night for 6 nights in a row, their insulin and blood sugar levels mimicked those seen in people who were developing diabetes. If you already have diabetes, a pattern of sleep-deprivation only further contributes to a flux in blood sugars.

The current epidemic of diabetes and obesity also appears to be related, at least in part, to chronically getting inadequate sleep. Even though regular exercise and a healthy diet is very important, evidence is growing that sleep is a powerful regulator of appetite, energy use, and weight control. During sleep, the body’s production of the appetite suppressor leptin increases, and the appetite stimulant grehlin decreases. Studies find that the less people sleep, the more likely they are to be overweight or obese and prefer eating foods that are higher in calories and carbohydrates. Feeling sleepy can cause you to eat more “comfort foods.” People who report an average total sleep time of 5 hours a night, for example, are much more likely to become obese compared to people who sleep 7–8 hours a night. A number of hormones released during sleep also control the body’s use of energy. A distinct rise and fall of blood sugar levels during sleep appears to be linked to sleep stage. Not getting enough sleep overall or enough of each stage of sleep disrupts this pattern.