Midnight Dr Eve Van Cauter and her team at the University of Chicago have conducted numerous experiments on sleep and type 2 diabetes. In 2004, they utilised (mean age) 22-year old subjects and for six nights only allowed them to obtain four hours of sleep2.
The subjects all started the experiment with no type 2 diabetes symptoms and blood glucose baseline measures were normal. After six nights of four hours of sleep, all the subjects had blood glucose levels in the pre-diabetic range. Findings indicated that the chronic sleep loss was associated with:
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decreased glucose tolerance (inability for the cells to take up glucose); decreased leptin levels (hormone that sends message to brain to stop eating when full); increased Ghrelin levels (increases hunger); increases in evening cortisol levels (normally decreasing at this time of day), and adverse cardiovascular effects.
It took around seven nights of catch up sleep (averaging 9.3 hours each night) to pay back the sleep debt and stabilise back to normal glucose tolerance levels. In 2007, a team also led by Dr Van Cauter, had subjects obtain eight hours of sleep for three nights in a row. However, every time a subject moved into deep sleep (as indicated by slowwave sleep signals), they were moved/shaken enough to take them out of deep sleep (but not enough to waken them). After only three nights of eight hours sleep (without deep sleep), all subjects again became pre-diabetic. Once again, it took around a week to return to normal. For years we have discussed managing or avoiding type 2 diabetes using two tools - namely, diet and exercise. The great thing about the research discussed in this article is that we now realise that there are three tools to combat type 2 diabetes. If you are in the pre-diabetes range or have already been diagnosed with type 2 diabetes, check your sleep to see if you can make improvements. For a healthy adult, you require between seven and nine hours of sleep every night. If your sleep is too short, affected by constant awakenings or if you have a sleep disorder, please see a professional to help you get better sleep.
A healthy adult should aim for between 7 & 9 hours of sleep every night. FOR A HEALTHY NIGHT’S SLEEP:
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Try to go to sleep at the same time each night. Try and keep the same wake time every morning. Your sleep time should be 8-9 hours before your alarm is due to go off. Correct any sleep disorders you or your partner may have.
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Have a dark, quiet and cool room to sleep in. Avoid taking stress or anxiety to bed. Do a brain dump and jot things down before sleep. Ensure others around you respect your sleep. Keep your bedroom as a sanctuary for sleep. No kids or pets!
Dr Nick Mabbott is the Director of Beyond Midnight Consulting and has over 22 years of experience with sleep and fatigue risk management. This includes conducting research, investigating fatigue incidents, providing fatigue risk assessments of organisations and rosters, and delivering training to well over 10,000 people. His clients range from mining and resources, to transport and logistics, construction, health, forestry, rail, education and a host of other organisations. beyondmidnight.org
Article References
1 Cappuccio, F.P., Strazzullo, P., D’Elia, L. and Miller, M.A. (2010). Quantity and Quality of Sleep and Incidence of Type 2 Diabetes. Diabetes Care, Volume 33, Number 2, February. 2 Spiegel, K., Tasali, E., Penev, P., Van Cauter, E. (2004). Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Annals of internal medicine, Vol. 141, Issue 11, pp. 846-850.
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