A recent study published in the Annals of Internal Medicine took a small group of young healthy patients and subjected them to only 4 1/2 hours of sleep over 4 days. They were then brought back a month later and allowed to sleep for 8 hours a night. After each 4 day period, a biopsy of belly fat was taken from each individual. The question was weather sleep depravation would have any effect on how fat cells and the body as a whole responds to insulin.
Fat cells store lipids, however when the cells fail to respond to insulin correctly, they will spill lipids into the surrounding tissues. This can lead to an insulin resistance phenomenon called “ metabolic syndrome”. This is the precursor to Type 2 or adult-onset diabetes. Interestingly, when the individuals in the study were only allowed 41/2 hours of sleep a night, their fat cells were 30% less responsive to insulin. Moreover, they also underwent a “glucose tolerance” test showing a 16% whole body reduction in insulin sensitivity.
This new information, albeit a very small study, challenges the long held traditional views that sleep is mainly needed for the restorative effects it provides for the Central Nervous System (CNS). Most adults need 7-9 hours of sleep a night. If we don’t get that amount of sleep, many studies have shown a decrease in our attention span, slower reaction times and impaired learning. This study adds an increased risk of developing adult-onset diabetes and obesity to that list.
Since this study took healthy, young people and made them worse, the question is can we take older, obese people with sleep apnea and reverse their fat cells resistance by improving their sleep. Continued more in depth studies are needed to see if resolving sleep apnea will reverse the health concerns facing the population today.