A research group at the University of Helsinki has discovered new biological links between sleep loss and the immune system.The results provide at least a partial explanation of why sleep deprivation increases the risk of cardiovascular disease and type 2 diabetes.
Population-level studies have indicated that insufficient sleep increases the risk of cardiovascular diseases and type 2 diabetes. These diseases are known to be linked to inflammatory responses in the body.
The study titled “Partial Sleep Restriction Activates Immune Response-Related Gene Expression Pathways Experimental and Epidemiological Studies in Humans” was published in PLOS ONE
Conducted at the sleep laboratory of the Finnish Institute of Occupational Health, the study restricted the amount of sleep of a group of healthy young men to four hours per night for five days, imitating the schedule of a normal working week. Blood samples were taken before and after the sleep deprivation test.
White blood cells were isolated from the samples, and the expression of all genes at the time of the sampling was examined using microarrays. The results were compared with samples from healthy men of comparable age who had been sleeping eight hours per night for the week.
The expression of many genes and gene pathways related to the functions of the immune system was increased during the sleep deprivation. There was an increase in activity of B cells which are responsible for producing antigens that contribute to the body’s defensive reactions, but also to allergic reactions and asthma.
The amount of certain interleukins, or signalling molecules which promote inflammation, increased, as did the amount of associated receptors. CRP level was also elevated, indicating inflammation.