Why Better Sleep Should Be Your Priority

A bad nights sleep can be frustrating for many reasons, but we rarely consider its impact beyond the associated fatigue or the sluggish day of work. Sleep deprivation is associated with both short and long term health concerns, and the evidence is only mounting. From a very basic standpoint, poor sleep makes us less cognitively sharp and therefore at a greater risk for careless mistakes. This is consistent with many studies finding that self-reported sleep problems, short sleep duration, fatigue and daytime sleepiness are all linked in some way to workplace injuries due to accidents.

But what about the health impact of inadequate sleep beyond injury? Well, surveys taken by insomniacs have shown impairments in physical functioning, pain measures, social functioning and emotional health. Moreover, insufficient and excess sleeping durations have been associated with an increased risk of all-cause death by as much as 12% and 30%, respectively!

How could this be? Generally speaking, it all comes back to endocrine disruption and metabolic dysregulation. Basically this means that there are alterations in hormone output and our body’s ability to break down and synthesize molecules, say, for energy production and waste excretion. In healthy sleepers, growth hormone (GH) is released at nighttime and cortisol is not. In problem sleepers, the opposite is true. Impaired blood sugar regulation, decreased insulin sensitivity, proinflammatory cytokines and low-grade inflammation are also all associated with impaired sleep.

These factors, in combination, seem to contribute to a large number and wide variety of health concerns. Given the underlying pathological process of something like inflammation in so many chronic diseases, perhaps it’s no surprise that the following health concerns that have been linked to either sleep deprivation, sleep excess or insomnia:  

Cardiovascular and Coronary Heart Disease

• When we think about cardiovascular disease (CVD), we tend to think about lack of exercise and poor diet; poor sleep habits hardly ever enter the conversation. Yet, one study found that insomnia was associated with a 45% increased risk of death and disease from CVD.
• A 2013 study in postmenopausal women found that women who slept less than 5 hours/night had a much higher number of CVD events within a 10-year period. Poor sleep quality (as opposed to duration) was predicative of CVD events, too, and sleep deprivation also comes with a greater risk for high blood pressure measurements
• These associations have not just been found in female populations; both insomnia and short sleep duration were found to be associated with a 4x greater risk of death in men according to one study

Diabetes and Obesity

• In the same large-scale study examining postmenopausal women and their risk of CVD, a significant finding was noted regarding the incidence of diabetes. Independently, a strong association between lack of and excess sleep was discovered with diabetes risk, greater body mass and greater abdominal fat measurements
• Poor sleepers tend to have blood sugar dysregulation, insulin resistance and increased inflammation while also engaging in less physical activity and watching more television than average sleepers.
• Even a single night of sleep deprivation (< 4 hours) has shown to lead to increased food consumption on the next day (on average 559 more calories; ~ 22% more daily energy consumption)
• Subjective hunger levels before dinner and breakfast have also been noted in those with acute sleep deprivation on the night prior.

Mood Disorders

• Depression and anxiety have long been associated with insomnia. Mood disorders can lead to worse sleep but poor sleeping patterns and habits also greatly increase the risk of mood disorders.
• In the case of depression, this increased risk has been found to be as much as 5 times greater with problem sleepers. Difficulty falling asleep, difficulty returning to sleep and decreased sleep duration all predicted greater depression outcomes.
• A “U-shaped” association has been found with sleep and depression (meaning too much and too little sleep increases the risk of depression).
• This greater risk for subsequent depression lasts for decades! Insomnia in young men was found to increase the risk for subsequent clinical depression and psychiatric distress for at least 30 years, leading some researchers and practitioners to suggest that sleep disturbances could be viewed as an early symptom of depression.

Impaired Bone Health

• Healthy bones need calcium – but they also need sleep. Numerous studies have demonstrated that irregular sleep patterns may have detrimental impacts on bone health.
• One study in over 600 Chinese women found that shorter sleep duration (<6 hours/night) was associated with decreased total bone mineral density (BMD) in those over the age of 45.
• Researchers concluded that the decreased BMD discovered in those with less sleep is most likely due to the resultant elevations in cortisol during the daytime. In other words, stress can cause sleep deprivation and sleep deprivation can cause stress. This forms a viscious cycle of elevated cortisol that is capable of inhibiting bone formation.

Impaired Immune Function  

• Some very interesting research has demonstrated that the disruption of our sleep-wake cycle can lead to long-lasting compromised immune function. This is partly because our immune system is repaired while we sleep – activation and proliferation of many immune cells have been shown to exhibit the greatest activity at nighttime.
• One study recorded the sleep habits of 155 healthy individuals over 14 days before administering nasal drops of the rhinovirus (the virus most commonly responsible for the common cold). Upon follow-up, it was discovered that people who slept for an average of less than 7 hours per night were 3x more likely to develop a cold than those who slept more than 8 hours per night. Poor sleep quality led to a 5.5x increased likelihood of contracting a cold when compared to efficient sleepers.
• Sleep also enhances the formation of our immune system’s memory – meaning tonight’s sleep can affect your body’s ability to fight off an infection months from now! A very interesting study examined the effect of sleep deprivation after the hepatitis A vaccine administration. Subjects that slept regularly on the first night following vaccination showed twice the levels of Hepatitis A antibody in their blood samples 4 weeks later, as opposed to those who stayed awake for the duration of that first night. This immune boosting effect of sleep was still present at a 1-year follow-up!

The take home message here is that there are many reasons why 7 to 8 hours per night of quality sleep is recommended. As we’ve examined, poor sleep leads to a brittle-boned, depressed, overweight, injury-prone and overall sicker version of yourself. As with most things in life, moderation and consistency are healthy habits and the research supports this idea when it comes to sleep.

Speak with your Sprout Wellness practitioner about your sleep to determine what you can do to improve your rest, your energy and your long-term health prognosis!

Select References:

• Journal of Clinical Sleep Medicine. 2007; 3(S):5, S7-S10.
• Sleep 2012; 35(6)
• Semin Neurol 2005; 25:52-63.
• J Clin Psychiatry 2001; 62 Suppl 10:27-32.
• Prev Med. 2013 Oct;57(4):377-85.
• Lancet 1999;354(9188): 1435–1439.
• Sleep Med 2008;9(Suppl 1):S23–8 
• Sleep Med Rev. 2007 June; 11(3): 163–178
• European Journal of Preventive Cardiology 2012 Aug 31
• National vital statistics reports. 2011;60(3).
• Statistics Canada. (2013, October). Mortality, summary list of causes 2008.
• J Womens Health (Larchmt). 2013 Jun;22(6):477-86.
• Hypertension 2007;50(4):693–700.
• Sleep 2010;33(9)1159–1164.
• Sleep 2010;33: 739–744.
• Journal of Women’s Health 2013; 22 (6)
• Diabetes Care 2006;29(3):657–661
• Annals of the New York Academy of Sciences 2008;1129:287–304.
• Int J Obes (Lond) 2008;32(12):1825–1834
• Sleep Med 2012;13, 1138–1145.
• Sleep 2007; 30, 1085–1095.
• American Journal of Clinical Nutrition. 2010.
• Sleep 2010; 33, 289–295.
• J. Epidemiol. 2010;20, 385–390.
• Am J Epidemiol. 2010 Mar 15;171(6):709-20.
• Am J Epidemiol. 1997; 146: 105-114
• Bone 2011 Nov; 49(5):1062-6. 
• Curr Osteoporos Rep 2009;7:134–9.
• Pflugers Arch – Eur J Physiol (2012) 463:121–137
• Arch Intern Med. 2009 January 12; 169(1): 62–67
• Psychosom Med 65:831–835
• NIH, National Heart, Lung and Blood Institute 2005; 06-5271.