- Written by Nicola Parry
A recent study has shown that long-term sleep deprivation and disruption can significantly increase blood sugar levels, putting people at a greater risk of developing obesity and diabetes. This finding could have important implications for shift workers.
The study, conducted by Orfeu M. Buxton, PhD and colleagues, from the Division of Sleep Medicine at Brigham and Women’s Hospital in Boston, MA, was published in the journal Science Translational Medicine, April 11th, 2012. The study found that during a phase of sleep restriction and disruption, study participants had a lower metabolic rate, and therefore burned fewer calories than normal. They additionally had higher blood glucose levels, but produced almost a third less insulin than when they were rested.
The researchers followed 21 healthy men and women under controlled sleep laboratory conditions for more than 5 weeks. The study involved participants of ages ranging from their 20s to 60s. They spent their time in rooms with low lighting and no windows to prevent their bodies from adjusting to shifting days and nights.
Initially, the study involved a phase of optimal sleep, and this was then followed by a three-week period of sleep restriction during which participants were kept awake for periods of 28 hours at a time, and allowed less than 6 hours of sleep in any 24-hour period. This combination caused sleep deprivation, and led to them sometimes being awake and eating during nights, and sleeping during days.
Throughout the study, the researchers monitored the resting metabolic rate of participants, their blood glucose levels before after a meal, and also their insulin levels. They found that when participants were sleep deprived and disrupted, they burned fewer calories due to a reduced metabolic rate. Blood sugar levels were also increased, yet they produced 32% less insulin than when they were rested.
These parameters did normalize, however, during the final phase of the study, when participants were allowed to recover with a regular sleep schedule.
Overall, the study demonstrates that in people who suffer long-term sleep deprivation and disruption – common in shift workers – metabolism can be significantly altered in such a way that predisposes them to obesity and diabetes.
These results pose a tough challenge for shift workers. Since the results aren’t favorable for those who work erratic schedules, creativity is needed to find ways to cope better with these situations. It can certainly help to try to choose a regular shift, instead of one that changes from day to day, since the body can better adapt to a long stretch of overnight shifts than to a constantly changing schedule.
The good news is that the metabolic changes were able to return to normal once participants returned to a regular sleep schedule at the end of the study. So, wherever possible, shift workers should try to stick with a regular schedule. They should try to eat during the day, at times as close to “normal” as possible, and avoid eating during the night when they would normally be asleep.
Although settling into some kind of schedule is not easy when you’re a shift worker, it’s important to aim for this since these results provide yet more evidence that sleep should be a priority for us.