Welcome back to short sleep and obesity: Part 2! In the first post on sleep I covered how not getting adequate sleep can affect your appetite, and today I will explain how it can mess with your blood sugar. Before you tell me that you do not have diabetes and you don’t have to worry about that… just keep reading. Short sleep contributes to mechanism that impair glucose tolerance (leading to high blood sugars) which increases risk of type 2 diabetes mellitus.1 Remember we are also in the game of prevention, not just treating disease so let’s keep that diabetes at bay.
Diabetes has increased dramatically in prevalence at the same time periods that U. S. adults report less sleep.2 Glucose tolerance, or the ability to metabolize glucose and return to a normal blood sugar, varies throughout the day. Glucose tolerance peaks in the morning (meaning the body is most efficient at absorbing sugar) and it is at its minimum in the middle of the night. Overnight glucose metabolism is slower, as to maintain a stable glucose level during the extended overnight fast (because we are sleeping, not eating). Two prospective studies conducted with nurses found that the risk of type two diabetes was increased after extended periods of rotating night shift work. Women with greater than 20 years of shift work had a 44% increased risk of developing type 2 diabetes after adjusting for BMI.3 So are you getting the message? Sleep not only affects our energy level and appetite, it impacts our total health and the development of different diseases down the road. Now let’s get into the science!
Researchers investigating short sleep found that blood glucose concentrations did not significantly differ throughout the day, but insulin secretion was decreased in the morning and increased in the afternoon as compared to a night of normal sleep. After eating a meal the insulin secretions changed significantly after fragmented (or broken up) versus non-fragmented sleep nights.4 Increased insulin secretion implies a vulnerable condition for increased food and energy intake in the form of snacks due to partial sleep deprivation. High insulin secretions over time may also cascade into type 2 diabetes mellitus as cells become desensitized to the high insulin levels and glucose remains in the blood stream.
Whew! I know that is some heavy science! However, I really want you to better understand why I am harping about sleep and why us health professionals worry about it anyways. Sleep is so important! That’s it for today and be on the lookout for part 3!
- Benedict C, Hallschmid M, Lassen A, Mahnke C, Schultes B, Schioth HB, Born J, Lange T. Acute sleep deprivation reduces energy expenditure in healthy men. American Journal of Clinical Nutrition. 2011; 93(6): 1229-1236.
- 7. Knutson KL, Spiegel K, Peney P, and Van Cauter E. The Metabolic Consequences of Sleep Deprivation. Sleep Med Reviews. 2007; 11(3): 163-178. doi: 10.1016/j.smrv.2007.01.002
- Pan A, Schernhammer ES, Sun Q, Hu FB. Rotating night shift work and risk of type 2 diabetes: Two prospective cohort studies in women. PLoS Medicine. 2011 (8);12:doi:10.1371/journal.pmed.1001141.
- Gonnissen HK, Hursel R, Rutters F, Martens EA, Westerterp-Plantenga MS. Effects of sleep fragmentation on appetite and related hormone concentrations. British Journal of Nutrition. 2013. 109(4): 748-756. doi: 10.1017/S0007114512001894