Sleep Deprivation – A neglected cause of chronic diseases

By Body Satva Essentials Team                          www.bodysatva.com

Considering that we spend one-third of our life in sleep; it must be an extremely important aspect of the physiology. We shall see why it is absolutely essential to avoid sleep deprivation in order to ‘prolong youth’ and lead an ‘enlightened and balanced life’.

Sleep deprivation is a hallmark of modern society, one that is often considered harmless and efficient. The advent of artificial light has permitted the curtailment of sleep to the minimum tolerable and an increase in the time available for work and leisure. In our 24-hour-a-day society, millions work during the night and sleep during the day, a schedule that generally results in substantial sleep deprivation.[1]
Sleep deprivation can occur as a result of habitual behavior or due to the presence of a pathological condition. Here we provide evidence against the old notion that "sleep is for the mind, and not for the rest of the body."
The 2 major pathways by which sleep affects the release of hormones are the hypothalamic-pituitary axes and the autonomous nervous system. Sleep controls or modulates the secretion of hormones by the central and peripheral endocrine glands. During deep sleep, sympathetic nervous system activity is generally decreased and parasympathetic nervous system activity is increased. Sleep loss is associated with an elevation of sympathovagal balance, with higher sympathetic but lower parasympathetic tone. [1]
Most endocrine organs are sensitive to changes in sympathovagal balance. Well-documented examples are pancreatic insulin secretion and release by the fat cells of leptin, an appetite-suppressing hormone. Some of the major hormones affected are;

1.     Cortisol

The earliest effect is on Cortisol – the stress hormone. The levels of Cortisol should decrease in the evening before bedtime. Instead, sleep deprivation increases Cortisol levels. Additionally, the decline in Cortisol before sleep is 6-fold slower, if there is sleep deprivation. This leads to insulin resistance, a risk factor for diabetes and obesity.[2] 

2.     Thyroid Stimulating Hormone – TSH

The normal nocturnal thyroid-stimulating hormone (TSH) rise was strikingly decreased within 6 days of moderate sleep deprivation (4 hours a day). The overall mean TSH levels were reduced by more than 30%. Thyroid axis function was markedly altered by partial recurrent sleep restriction.[2]

3.     Growth Hormone – GH

In normal men, the majority of GH secretion occurs in a single large post sleep onset pulse that is suppressed during total sleep deprivation. During the state of sleep debt, the GH secretory pattern was biphasic, with both a pre-sleep onset "circadian" pulse and a post sleep onset pulse.[3]

4.     Leptin – Appetite suppressing hormone and satiety signal

The regulation of leptin, a hormone released by the fat cells that signals satiety to the brain and thus suppresses appetite, is markedly dependent on sleep duration. When sleep was restricted to 4 hours per night for 6 days, the plasma concentration of leptin was markedly decreased, particularly during the nighttime. The low leptin levels stimulate appetite and hunger. Chronic sleep deprivation is thus a risk factor for obesity, diabetes ad other metabolic disorders

5.     Ghrelin – Appetite stimulating hormone

Ghrelin, a peptide that is secreted by the stomach and stimulates appetite.  Within just 2 days of sleep restriction (4 hours of sleep), elevation of Ghrelin levels can be seen. Sleep deprivation was associated with reductions in leptin (the appetite suppressant) and elevations in ghrelin (the appetite stimulant) and increased hunger and appetite, especially an appetite for foods with high-carbohydrate contents. Similar findings were obtained simultaneously in a large epidemiologic study in which sleep duration and morning levels of leptin and ghrelin were measured in 1024 subjects. The study found a decrease in the satiety hormone leptin and an increase in appetite-stimulating ghrelin with short sleep.[4]
Sleep deprivation alters the ability of leptin and ghrelin to accurately signal caloric need and could lead to excessive caloric intake when food is freely available. The findings also suggest that compliance with a weight-loss diet involving caloric restriction may be adversely affected by sleep restriction.

Conclusion

In the competitive modern world sleep is the biggest casualty. Profound alterations in the neuroendocrine balance is emerging as a cause of many of major chronic disorders like obesity, diabetes, cardiac problems, premature aging and psychiatric conditions like depression and anxiety. Sleep deprivation is too serious to be ignored beyond 3-6 days. We strongly urge you to balance your activities with sufficient night time sleep. Apart from the duration of sleep, ensure better quality of sleep long-term health.

Prolong Youth by leading an ‘enlightened and balanced life’

Ref 1: Cauter E V et al, Medscape Neurology & Neurosurgery.  2005;7(1)

Ref 2: Spiegel K et al, Lancet. 1999; 354:1435-39

Ref 3: Spiegel K et al, Am J Physiol Regul Integr Comp Physiol.  2000; 279(3): R874-83

Ref 4: Taheri S et al, PLoS Med. 2004 Dec;1(3):e62.

Disclaimer

Body Satva Essentials’ Team has taken maximum care to ensure authenticity of the information provided, by sourcing from reputed medical journals and books. Body Satva Essentials’ Team urges members to seek professional advice before commencing any regimen of diet, exercise and medication.