By: Laurie Edwards for Diabetes1
In an age of constant Internet access, cable news, cell phones and endless supplies of caffeine, it’s no surprise that many Americans aren’t getting enough sleep. While we all know that persistent lack of sleep can wreak havoc on our moods, research is beginning to uncover the effects our decreased sleep has on our bodies: A heightened risk for major illnesses like cancer, heart disease and obesity.
|Sleep for Your Health
Lack of sleep can do more than make us cranky and irritable – less than five or six hours a night increases our risk of developing major health problems like obesity, heart disease and diabetes.
It’s about the appetite: When we don’t get enough sleep, the normal balance of hormones that keeps our cravings in check is disrupted.
Given the growing obesity epidemic in our country and the close association between obesity and Type 2 diabetes, this emerging body of research indicates that an overall healthy lifestyle isn’t just about what we eat but how much we rest.
In terms of developing diabetes, the link between how much we sleep has an even more interesting relationship: Too little sleep or too much sleep can increase the risk.
“We’re shifting to a 24-hour-a-day, seven-day-a-week society, and as a result we’re increasingly not sleeping like we used to. We’re really only now starting to understand how that is affecting health, and it appears to be significant,” said Najib T. Ayas of the University of British Columbia.
An emergence of new research examining sleep and physical health points to the idea that America’s growing obesity epidemic is at least partly caused by a shift in our attitudes towards sleeping. The effects of not enough sleep include changes in metabolic and endocrine function – including decreased carbohydrate tolerance – insulin resistance and lower levels of leptin, a hormone that helps lead to obesity.
Studies have shown that sleep deficit causes the body to be in a state of alert, which increases the production of stress hormones and levels of substances in the blood that point to increased inflammation and are risk factors for heart disease and stroke.
Researchers have discovered that even slight sleep disturbances disrupt normal levels of leptin and ghrelin, both of which regulate appetite. These findings correspond to the theory that humans might be wired genetically so that we need to be awake at night only when we need to search for food or ward off danger.
In terms of developing diabetes, it seems as though there’s a “magic” number of hours slept per night. According to a recent study published in Diabetes Care, seven hours is considered ideal in terms of minimizing the risk of developing diabetes. The study followed more than 1,100 middle-aged and elderly men enrolled in the Massachusetts Male Aging Study living in the Boston area. Starting in the 1980s, the men provided blood samples and answered questions about their health. Researchers followed up with the men in the mid-1990s and from 2002-2004.
The study found that the diabetes risk was twice as high for men who slept less than five or six hours. For men who slept more than eight hours per night, their risk of developing diabetes was three times higher than it was for men who slept seven hours.
“These elevated risks remained after adjustment for age, hypertension, smoking status, self-related health status and education,” said lead author Dr. H. Klar Yaggi of Yale University’s Department of Internal Medicine.
It’s important to realize that this study does not mean sleep habits either directly cause or prevent diabetes. For instance, men who reported seven hours of sleep per night tended to be younger with better education, better overall health status and higher levels of testosterone.
The study also highlights a connection between testosterone and diabetes in terms of body fat distribution and insulin resistance.
Not everyone is convinced that the link between sleep patterns and health issues couldn’t be just as easily explained by other factors.
“There are Chicken Little people running around saying that the sky is falling because people are not sleeping enough. But everyone knows that people are getting healthier. Life expectancy has been increasing, and people are healthier today than they were generations ago,” said Daniel F. Kripke of the University of California at San Diego.