Sleep Loss May Significantly Affect Insulin Sensitivity

One night of sleep deprivation may impair insulin sensitivity to the same degree as 6 months on a high-fat diet, according to recent data.

“Getting adequate sleep may be as important as diet and exercise in keeping people healthy and [is] much easier to do. It is shocking that in our study we saw that 1 night of total sleep deprivation could be as detrimental to insulin sensitivity as a high-fat diet,” said study investigator Josiane Broussard, PhD, who is an assistant research professor in the department of integrative physiology at the University of Colorado in Boulder.

These findings demonstrate the importance of adequate sleep in maintaining blood sugar levels and reducing the risk for metabolic diseases such as obesity and diabetes, she noted.

Previous studies have suggested that sleep deficiency and a high-fat diet both lead to impaired insulin sensitivity. However, it is unclear which leads to more severe insulin resistance.  

Dr Broussard, who presented the study results at ObesityWeek 2015, and colleagues at Cedars-Sinai Medical Center in Los Angeles used a canine model to examine whether sleep deprivation and a high-fat diet affect insulin sensitivity in similar ways.  

For this investigation, the researchers measured insulin sensitivity in 8 male dogs before and after diet-induced obesity. Prior to the high-fat feeding, researchers used an intravenous glucose tolerance test to measure insulin sensitivity in dogs that had 1 night of sleep deprivation and compared the results with dogs that had a normal night’s sleep.

The dogs were then fed a high-fat diet for 6 months and retested. Prior to the high-fat diet, 1 night of sleep deprivation reduced insulin sensitivity by 33%. This reduction was similar to the reduction caused by a high-fat diet alone (21%).

Interestingly, once the dogs had impaired insulin sensitivity from the high-fat diet, 1 night of sleep deprivation did not further impair the insulin sensitivity.  

“The importance of sleep is particularly important to endocrinologists and their patients since they may often recommend diet and weight loss to improve metabolism and blood glucose,” Dr Broussard told Endocrinology Advisor.

“The take-home message is that sleep is not a luxury. Adequate sleep is necessary to maintain whole body health.”

Dr Broussard said the findings suggest that both insufficient sleep and a high-fat diet may induce insulin resistance through a similar mechanism. It may also be possible that after high-fat feeding, insulin sensitivity cannot be reduced further by sleep loss.

Caroline Apovian, MD, who is a spokesperson for The Obesity Society (TOS) and the director of the Nutrition and Weight Management Center at Boston Medical Center, said it is critical for health practitioners to emphasize the importance of sleep to their patients. Many patients understand the importance of a balanced diet, but they might not have a clear idea of how critical sleep is to maintaining equilibrium in the body, she explained.

“There are many human studies that show that short sleep which is 6 hours or less per night increase hunger hormones and decrease satiety hormones and also increase levels of cortisol. So, the dog model is confirming what we have seen in humans for the detrimental effects of sleep,” Dr Apovian told Endocrinology Advisor.

“I think Dr Broussard’s study emphasizes how critical sleep is, comparing 1 night of no sleep as being as detrimental as 6 months of high-fat feeding on insulin sensitivity. This is a very dramatic outcome that should be corroborated on humans certainly, but the prior human studies support it.”

Reference

1. Broussard J, Bediako I, Paszkiewicz R, Kolka C, Bergman R. Abstract T-P-3275. Sleep Deprivation and Fat Feeding May Reduce Insulin Action by Similar Mechanistic Pathways. Presented at ObesityWeek; November 2-6, 2015; Los Angeles, CA.