Sleep deprivation leads to increase insulin resistance.

Sleeping at work

Sleep is a vital part of a healthy lifestyle.  Ever noticed how staying up late almost always makes you just a bit off your game? Lack of sleep has long been touted as hindering your performance and making us grumpy.  Outside of performance and behavioral health, we have long suspected that leads to snacking and a sweet tooth, but we also have a decent amount of proof that going without less sleep puts your body at a chemical disadvantage that no amount of resolve can overcome.  

So what proof do we have?  Lower amounts of sleep cause a bump in your stress hormone (cortisol)  and increase your insulin resistance.  Since both will cause truncal obesity and metabolic syndrome, there is no doubt how a lack of sleep causes obesity.  The basics are that cortisol packs on the pounds in the central abdominal area which make insulin resistance worse and inches to your waistline and insulin resistance causes you to need more insulin to regulate your blood sugar.  Insulin increase hunger and fat storage.  I am sure you get the point: both worsen obesity so if less sleep causes either or both then less sleep will compound obesity.  

So, on to the research:  

1. 

   Insomnia

   A study from 2010 looked at insulin sensitivity after a single night of loss of sleep[1].  The researchers looked at nine subjects who were tested with a normal night of sleep and one that was restricted to 4 hours of total sleep.  Sleep restriction resulted in increased endogenous glucose production during the hyperinsulinemic clamp study compared to the unrestricted night.   Sleep restriction decreased the glucose disposal rate which reflects decreased peripheral insulin sensitivity.   

3. In another study 1997, researchers looked at effects of sleep deprivation on serum cortisol levels[1].  The researchers found that the elevation continued into the day following the deprivation.  The sustained elevation could indicate a sustained development of metabolic and cognitive consequences of glucocorticoid excess, but it definitely indicated why the lack of sleep is stressful and could increase the obesity risk.  

The bottom line: Partial sleep deprivation during only a single night induces insulin resistance and cortisol release.  Both increases would contribute to an increase in central obesity.  This physiological observation may be of clinical relevance for both obesity and type 2 diabetes.