Disrupted Sleep Increases Blood Sugar, Slows Metabolism

Altering the amount and time of sleep, as is common with shift-workers, can have effects such as increases in blood sugar and slowing of metabolism, according to a new study. These metabolic changes can lead to both obesity and diabetes. Previous studies have shown that night-shift workers and people who persistently get too little sleep have high levels of fat in their blood. Research has also shown that people with altered sleep patterns or who don’t regularly get enough sleep are more likely to be obese and develop diabetes or metabolic syndrome, which is a cluster of conditions that are associated with increased risk of heart disease. The findings of this new, small study add to the growing evidence of how important it is to maintain healthy sleep habits. For the study, researchers controlled the sleep cycles, diet and activities of 21 healthy adults who stayed in their laboratory over a six week period. The study began with an initial period of normal sleep, of about 10 hours per night.  Then, the participants underwent three weeks of restricted sleep, getting less than six hours per 24-hour period. Their body clocks, or “circadian rhythms”, were also disrupted, brought about by cycles of 28-hour days similar to that of a shift worker. The final period of the study was a recovery period, with nine days of normal sleeping.

One of the key findings of the study was that during the sleep deprivation and circadian rhythm disruption period, the participants’ resting metabolic rate decreased while their blood sugar levels increased after meals, at times even reaching a level considered pre-diabetic. This was caused by the pancreas not producing enough insulin. These changes seen in the participants were severe enough to amount to a 10 pound weight gain over the course of a year. After the recovery period, these metabolic changes returned to normal.

A recent study of more than 2000 nurses found that those who work long hours were significantly more likely to be obese. You can read about the study here.