Study shows that “catch up” sleep on the weekends is linked to improved insulin sensitivity
A small study of 19 young men found that catching up on sleep on the weekend was associated with improved insulin sensitivity. The men had chronic, intermittent, lifestyle-driven sleep restriction, ie they were too busy to get sufficient sleep during the week. They did catch up on sleep during the weekends. The authors of this study examined what effect “catch up” sleep had on insulin sensitivity. On weeknights the men slept an average of 6.2 hours a night and an additional 2.3 hours on the weekends. The men spent three nights over two weekends in a sleep lab where they were randomly assigned to two of three conditions: sleep for 10 hours, sleep for six hours, or sleep for 10 hours but exposed to noise that aroused them to shallow sleep without waking them. Blood glucose was measured in the morning of the fourth day. Compared to when they only got six hours of sleep, the men’s insulin sensitivity improved when they had 10 hours of uninterrupted sleep. While good insulin sensitivity reduces the risk of developing type 2 diabetes, it is a big step to go from these results to claiming that sleep could be the key to preventing type 2 diabetes, as some of the news items claim. First, this is a small study of short duration. It is not clear what the long-term results of catch up sleep might have. Second, improvements in disease markers do not always translate into reduced risk of disease. These findings were presented at a meeting, so they are preliminary and subject to change until published in a peer-reviewed journal.