As awareness of pre-diabetes grows, the list of conditions that can lead to it seems to be growing. Along with obesity and a sedentary lifestyle, researchers may start listing lack of sleep as another danger signal. Two recently published studies conclude that sleep deprivation can lead to insulin resistance-a precursor for diabetes-and even increase the risk of early death.
The first study, conducted by the Leiden University Medical Center in The Netherlands, tracked glucose levels in five men and four women after they slept one night for eight-and-a-half hours and a second night for four hours. The Dutch researchers found that even one night of sleep deprivation reduced the subjects’ insulin sensitivity by 25 percent. (Read the Diabetes Health article about the study here).
Although the size of their study was small, the Dutch researchers concluded that insulin sensitivity is not fixed in people and can be affected by something as simple as hours of sleep. If so, the pattern of sleep deprivation that affects so many people in Western countries is one more large stone in the edifice of pre-diabetes.
(A 2009 U.S. study concluded that people who slept fewer than six hours per night were 450 percent more likely to develop high blood sugar readings over a six-year period than people who got more sleep.)
The second, longer-term study, conducted by the University of Warwick Medical School in the United Kingdom and the University of Naples Medical School in Italy, tracked 16 studies done over a 25-year period, involving a total of 1.3 million people. The studies were designed to show whether there is a link between too little sleep and the risk of early death. The British and Italian researchers found that people who slept fewer than six hours per night were 12 percent more likely to die prematurely than people who consistently got six to eight hours sleep per night.
The UK-Italy study, although it asserts that there is a conclusive link between sleep deprivation and early death, may have more of a chicken-or-egg component to it. Does lack of sleep lead to undesirable outcomes, or can other undesirable factors lead to sleep deprivation, thus opening the door to yet more problems?
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