Working at night may mess with glucose tolerance

Working the night shift may have an association with type 2 diabetes, a new study from Harvard Medical School reveals.

The research showed that glucose levels were 16 percent higher during a night of simulated work than they were in eight hours of simulated daytime work. Additionally, after meals, insulin levels jumped 40 to 50 percent higher for night workers than day workers.

"It is surprising that just a single night shift can significantly impair glucose tolerance and increase insulin levels," said author Christopher Morris, PhD, postdoctoral research fellow in the Medical Chronobiology Program of the Division of Sleep Medicine at Brigham & Women's Hospital and Harvard Medical School in Boston, Mass.

Diet doesn't make a difference

Participants in the study included 13 healthy, non-obese adults who all ate the same meals during two eight-day "work" sessions either at night or during the day. Fasting blood samples were taken before the meal and then every 10 minutes for 90 minutes.

"These findings are important because they demonstrate, under highly controlled lab conditions, that acute exposure to night work impairs glucose tolerance. Chronic impaired glucose tolerance is likely to lead to Type 2 diabetes," Morris said.

According to the study, about 8.6 million Americans work at night.

The results of the research were presented at SLEEP 2013, the 27th annual meeting of the Associated Professional Sleep Societies LLC., and can be found online in the journal Sleep.

Source: Science Daily