Long-Term Consequences of Sleep Deprivation

Roughly one-third of U.S. adults sleep fewer than the recommended seven hours per day.¹ The physical and cognitive effects of sleep deprivation can be immediately detrimental: for example, about 20 percent of serious injuries resulting from motor vehicle accidents are associated with driver sleepiness.² Long-term consequences of chronic sleep deprivation, while less readily apparent, can be just as severe. While a person rests, the autonomic nervous system remains “awake,” involuntarily regulating numerous bodily systems to optimize their functioning. Therefore, cardiovascular, endocrine, immune, digestive, and neurologic activities are all impacted when the body does not sleep.

As stated in a literature review by Mullington et al., chronic sleep deprivation plausibly leads to increased inflammation (a response to stress), which is associated with a number of health conditions. One of these is blood coagulation, which can prime healthy individuals for the development of atherosclerosis or other forms of cardiovascular disease.³ In 2015, a meta-analysis of 15 studies documented an increased risk of cardio-cerebral vascular events (such as heart attacks and strokes) among those with insomnia symptoms.⁴ Sleep shortages can also put strain on the heart when hormones that help control blood pressure are dysregulated. One study found that those sleeping less than six hours a day had a 66 percent higher risk of having hypertension compared to those who sleep between seven and eight hours per night.³

A lack of sleep may also increase individuals’ risks of type 2 diabetes and weight gain. Researchers have hypothesized that sleep deficits may heighten risks for these conditions through a number of pathways. Sleep loss has been shown to be associated with impairments to glucose metabolism. One cause of this dysregulation could be elevated cortisol levels, which might reduce insulin activity. Appetite may also be upregulated through decreased leptin and increased ghrelin levels, which have been observed in conjunction with sleep restriction. The dysregulation of these hormones may contribute to decreased energy expenditure overall.⁵

Sleep and mental health are also intimately tied. Melatonin not only helps coordinate sleep cycles but also is linked to mood regulation, and lower levels of melatonin are often found in people suffering from depression. Those battling an extended lack of sleep have also been shown to have a lower tolerance for stressors, which can increase anxiety. Overall, the causal direction between sleep shortages and mental health challenges remains complex, with each likely exacerbating the other.⁶

Researchers are continuing to unveil ways in which neurological conditions may be associated with sleep shortages. For instance, recent findings from an analysis of nearly 3,000 people partaking in the National Health and Aging Trends Study found that dementia risks were two times higher among participants who reported getting less than five hours of sleep compared to those who reported seven to eight hours of sleep per night. Sleep disturbance and sleep deficiency was also associated with increased overall mortality.⁷

Further studies are needed to elucidate the underlying mechanisms by which a lack of sleep worsens health outcomes. The reversibility of these changes through sleep extension is also a topic of future study.³ Critically, further research on sleep deprivation will need to consider how biomedical risk factors intersect with racial and socioeconomic disparities. The CDC reports that sleep deprivation is more common in people of color than in white individuals: roughly 46 percent of Black adults sleep less than seven hours per night, compared to 33 percent of white adults.¹ Thus, research, interventions, and policy measures designed to promote sleep and mediate the consequences of sleep loss must be made accessible to populations across the social spectrum.

References 

1. Sleep and Sleep Disorders: Data and Statistics. Centers for Disease Control and Prevention. Published March 5, 2019. https://www.cdc.gov/sleep/data_statistics.html 

2. Medic G, Wille M, Hemels ME. Short- and long-term health consequences of sleep disruption. Nat Sci Sleep. 2017;9:151-161. 

3. Mullington JM, Haack M, Toth M, Serrador JM, Meier-Ewert HK. Cardiovascular, inflammatory, and metabolic consequences of sleep deprivation. Prog Cardiovasc Dis. 2009;51(4):294-302. 

4. He Q, Zhang P, Li G, Dai H, Shi J. The association between insomnia symptoms and risk of cardio-cerebral vascular events: A meta-analysis of prospective cohort studies. Eur J Prev Cardiol. 2017;24(10):1071-1082. 

5. Knutson KL, Spiegel K, Penev P, Van Cauter E. The metabolic consequences of sleep deprivation. Sleep Med Rev. 2007;11(3):163-178. 

6. Rosenberg C. Sleep deprivation: 10 long-term effects. Sleep Health Solutions. Published April 18, 2019. https://www.sleephealthsolutionsohio.com/blog/10-effects-of-long-term-sleep-deprivation/ 

7. Robbins R, Quan SF, Weaver MD, Bormes G, Barger LK, Czeisler CA. Examining sleep deficiency and disturbance and their risk for incident dementia and all-cause mortality in older adults across 5 years in the United States. Aging (Albany NY). 2021;13(3):3254-3268.