**A 2016 study found a significant increase in the risk of type 2 diabetes in those who took regular naps. Unfortunately, the authors of that study did not determine why such a link existed.**However, a more comprehensive review published in the journal _Diabetes & Metabolism _in January 2015 set out to look at how some sleep habits can not only increase the risk of developing diabetes, but also influence the severity of the disease for those who have diabetes.The effect of sleep duration on diabetes and diabetes risk The review found that sleep duration appeared to be linked to an increased risk of developing type 2 diabetes.Researchers also found that both short and long sleep durations in those already diagnosed with type 1 or type 2 diabetes had a negative effect on glycemic control and other health issues (such as high blood pressure) that could lead to organ damage.
Why does sleep duration influence diabetes?** 1. Insulin resistance**
Sleep restriction inhibits insulin secretion and promotes insulin resistance. It also can stimulate the breakdown of fats, leading to the release of fatty acids which can lead to excess fat deposits in the liver and muscles, further contributing to insulin resistance.
Sleep deprivation is also linked to higher cortisol levels, which can induce insulin resistance. Low grade inflammation (often associated with sleep restriction) also leads to insulin resistance.
2. Appetite hormonesAppetite-regulating hormones appear to be heavily influenced by the amount of sleep we get. One study found that those who got** just four hours of sleep saw leptin (a hunger inhibitor) levels decrease by 18 percennd ghrelin (a hunger stimulator) levels increase by 28 percent**.
3. More time awake
More time awake means more time available to eat. This can lead to an increase in eating and weight gain, which is a risk factor for type 2 diabetes.
Chronic sleep deprivation also leads to fatigue, which can reduce motivation to exercise, further increasing the risk for weight gain.
The effects of sleep schedules on diabetes and diabetes risk
Those who go to bed later at night were found to be more likely to have type 2 diabetes. Night owls who were already diagnosed with type 2 diabetes were found to have poorer glycemic control, too.
Sleep schedules that lead to an ever-increasing accrual of sleep debt also were found to influence diabetes risk.
Why do sleep schedules influence diabetes?** 1. The influence of the body clock**
Our body clocks do more than just regulate our sleep cycle, and the part of the brain that regulates the body clock is influenced by more than just the natural cycle of daylight and darkness. That part of the brain also is connected to a number of other regions of the brain that are influenced by environmental cues such as nutritional intake and exercise.
Our body clocks influence how much food we eat, and when. This may be a factor when it comes to explaining why there appears to be an association between sleep habits and diabetes.** 2. The influence of melatonin**
The sleep hormone melatonin also may influence how our body regulates insulin sensitivity.
A study published in 2000 matched 370 nurses with type 2 diabetes with 370 nurses without type 2 diabetes. It found that those with lower melatonin levels were far more likely to have type 2 diabetes.
As the authors of that study pointed out, as melatonin levels increase during hours of darkness and fall when we are exposed to light, diabetes risk may be influenced by short sleep duration, misaligned sleep schedules, and/or light exposure.
It's a two-way street
One study found that individuals with type 1 or type 2 diabetes were more likely to experience chronic pain, and this chronic pain was associated with more sleep disturbances.
Other studies have found that 45 percent of those with type 2 diabetes experience poor sleep, 26 percent suffer from excessive daytime sleepiness and as many as 35 percent of patients with type 1 diabetes may experience poor sleep quality.
What to do next
Getting more sleep, getting quality sleep, and following an appropriate sleep schedule may help reduce the risk of developing diabetes and mitigate the negative effects of the disease. That being said, more studies are needed to evaluate the effectiveness of such lifestyle changes.
Martin is the creator of Insomnia Land’s free sleep training for insomnia. His online course uses CBT techniques to teach participants how to fall asleep and stay asleep. More than 4,000 insomniacs have completed his course and 97 percent of graduates say they would recommend it to a friend.