Night Shift Workers at Greater Risk of Diabetes

Night Shift Workers at Greater Risk of Diabetes

Altering natural circadian rhythms can lead to a decrease in insulin

Working the night shift doesn't just put you out of touch with the majority of the world. Staying awake to work while most people are peacefully asleep might be an alienating and lonely experience, but scientists have recently discovered that it can have more concrete negative effects on your health, too. Namely, workers assigned to the graveyard shift have a much higher risk of diabetes than people who get to work during daylight hours. 

Researchers at Harvard Medical School slowly weaned test subjects off a normal night's sleep by shifting their sleep periods forward four hours at a time. By the time they got them sleeping during the day and staying awake all night, they were able to monitor their hormone levels to discover something surprising. Participants had much lower levels of insulin than normal after just three weeks in the lab. Their glucose levels began to rise. Three of the 21 subjects had blood sugar levels high enough to qualify them as pre-diabetic. Their pancreases just weren't working as they were supposed to.

It turns out the body stops functioning properly once it's deprived of daylight. Even those test subjects who were severely sleep deprived, but were allowed to sleep at night, had insulin levels that were closer to normal. It was the daysleepers who demonstrated dangerously low levels of insulin. These results explain the higher rates of diabetes and obesity that run rampant in night shift workers--and may help to explain the host of other medical problems that have been categorized under the term "shift work disorder."

It looks like the body has a pretty good idea of when it's supposed to sleep and when it's not--and it doesn't take kindly to adjustments in its inborn programming. Human circadian rhythms can't really be changed to fit the needs of people who must work at night. For janitors, bartenders, and other moonlight laborers, the health risks are just an irreversible part of the job. There's not a whole lot they can do to improve their condition short of seeking another line of employment. 

For those of us who have the privilege of controlling our sleep cycles somewhat, we can likely benefit from making sure we get sufficient darkness and light in our daily routine. Getting some sun in our eyes and on our skin can actually be good for us, while keeping things dark at night can help us sleep when we're supposed to. Everyone who can should maintain good sleep hygiene in order to keep those insulin levels where they should be.