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    A good night of sleep is important for blood glucose regulation. Nighttime hormonal release and glucose control occur at different sleep stages. Sleep is composed of rapid-eye-movement (REM) sleep and stages 1, 2, and 3 of non-REM (NREM) sleep. During the deeper stage of non-REM sleep or stage NREM 3, brain glucose utilization and sympathetic nervous activity are decreased, and parasympathetic nervous activity is increased relative to both wake and REM sleep.

    The sympathetic nervous system activates the fight or flight response during a threat or perceived danger, and the parasympathetic nervous system restores the body to a calm state. The parasympathetic nervous system is a network of nerves that relaxes your body after periods of stress or danger. The body enters a state of relaxation, and this relaxation helps recovery.

    Sleep deprivation can lead to elevated blood glucose levels and poor glycemic control in a few ways. Sleep deprivation can induce insulin resistance, which can increase blood glucose levels. Sleep loss is associated with increased levels of pro-inflammatory cytokines and low-grade inflammation, a condition that may predispose to insulin and leptin resistance (1).

    Sleep deprivation increases cortisol, a hormone released under stressful situations. Lack of sleep can also result in lower growth hormones for muscle regeneration. Growth hormone not only improves nerve regeneration but also helps with muscle growth.

    The changes in hormone patterns due to sleep loss: both increases in the secretion of catabolic hormones such as cortisol, and changes in the secretion of anabolic hormones such as testosterone, growth hormone, and insulin-like growth factor 1, may reduce protein synthesis and increase proteolysis, thereby impairing muscle recovery (2).

    Muscle tissue is constantly being repaired and rebuilt. Over long-term sleep loss, a person would lose muscles. The muscle tissue is metabolically active, and the primary tissue uses energy including glucose. Sleep deprivation would also result in slowing down the metabolism of energy in muscles. All lead to elevated blood glucose levels.

    The brain is the major tissue user of glucose. Brain glucose utilization is reduced after sleep deprivation. Sleep loss is associated with sleepiness and fatigue that may result in reduced energy expenditure through decreased physical exercise and decreases in non-exercise activity thermogenesis.

    Sleep loss also impacts hormones involved in appetite regulation, in the direction of the promotion of food intake. Leptin is a hormone secreted by adipose tissue, and its secretion is inhibited by sympathetic activity. Ghrelin (the hunger hormone) is a hormone secreted by the stomach, and its secretion is inhibited by parasympathetic activity. During deeper sleep, leptin increases, and ghrelin decreases.

    Sleep loss, especially the lack of a deeper stage of sleep, would result in a simultaneous reduction of leptin and an increase of ghrelin, both of which would promote the need for extra caloric intake (3). The changes in these hormonal concentrations following sleep restriction could contribute to the increased hedonic, rather than homeostatic, eating that may be typical of short sleepers. Sleep restriction had been shown to increase hunger and appetite, especially related to carbohydrate-rich foods (4). In addition, the increased opportunity to eat due to longer waking time, probably also plays a role in the generation of a positive energy balance in short sleepers.

    Sleep loss increases the risk of obesity and diabetes. Obesity is in itself a major risk factor for diabetes mellitus. The sleep-disordered breathing that is common in obese people is a reported independent risk factor for insulin resistance. The detrimental effects of sleep loss are likely to be exacerbated in overweight and obese individuals.

    Sleep is very critical for overall good health and well-being. It enables the body to rest and recover, and to be fit and well the next day since the body repairs and regenerates in the deeper stages of sleep. That is why we spend roughly 1/3 of the day in sleep. Get a good night's sleep for glucose control.

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References:

1. Morselli, L. et al. Role of sleep duration in the regulation of glucose metabolism and appetite. Best Pract Res Clin Endocrinol Metab. 2010; 24(5): 687–702. doi:10.1016/j.beem.2010.07.005.

2. Dattilo M, Antunes HK, Medeiros A, et al. Sleep and muscle recovery: endocrinological and molecular basis for a new and promising hypothesis. Med Hypotheses. 2011;77(2):220–222. doi: 10.1016/j.mehy.2011.04.017.

3. Van Cauter E, Spiegel K, Tasali E, et al. Metabolic consequences of sleep and sleep loss. Sleep Med. 2008;9(Suppl. 1):S23–S28. doi: 10.1016/S1389-9457(08)70013-3.

4. Spiegel K, Tasali E, Penev P, et al. Brief communication: sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Ann Intern Med. 2004;141(11):846–850. doi: 10.7326/0003-4819-141-11-200412070-00008.