A University of Washington-led team of researchers studying monozygotic (identical) twins has found that chronic sleep deprivation suppresses immune system. The research is published in the journal Sleep.
The study, which looked at 11 pairs of identical twins from Washington State, was headed by Dr. Nathaniel Watson, co-director of the University of Washington Medicine Sleep Center.
“Habitual short sleep duration is associated with adverse metabolic, cardiovascular, and inflammatory effects. Co-twin study methodologies account for familial (eg. genetics and shared environmental) confounding, allowing assessment of subtle environmental effects, such as the effect of habitual short sleep duration on gene expression,” Dr. Watson and co-authors said.
“Therefore, we investigated gene expression in monozygotic twins discordant for actigraphically phenotyped habitual sleep duration.”
The scientists took blood samples from pairs of twins with different sleep patterns and discovered that the twin with shorter sleep duration had a depressed immune system, compared with his/her sibling.
“We compared gene expression profiles of peripheral blood leukocytes between sleep duration discordant monozygotic twins to identify differentially activated transcriptional programs in these circulating immune cells and gain potential mechanistic insights linking habitual short sleep with poor outcomes,” they explained.
“By measuring sleep duration in the natural environment we provided ecologically valid results allowing insights into the impact of ‘real world’ chronic sleep curtailment on human health.”
“The mean 24-hour sleep duration of the total sample was 439.2 minutes. Mean within-pair sleep duration difference per 24 hours was 64.4 minutes,” the researchers said.
The twin cohort displayed distinctive pathway enrichment based on sleep duration differences.
Habitual short sleep was associated with up-regulation of genes involved in transcription, ribosome, translation, and oxidative phosphorylation.
Unexpectedly, genes down-regulated in short sleep twins were highly enriched in immuno-inflammatory pathways such as interleukin signaling and leukocyte activation, as well as developmental programs, coagulation cascade, and cell adhesion.
“What we show is that the immune system functions best when it gets enough sleep. Seven or more hours of sleep is recommended for optimal health,” Dr. Watson said.
“A lot of existing data shows that curtailing sleep – for a limited time in the laboratory setting – can increase inflammatory markers and activate immune cells,” added co-author Dr. Sina Gharib, director of University of Washington Medicine’s Computational Medicine Core at the Center for Lung Biology.
“Little is known, though, about the effects of longstanding short sleep duration under natural conditions.”
“This study employed ‘real world’ conditions and showed for the first time that chronic short sleep shuts down programs involved in immune response of circulating white blood cells.”
“The results are consistent with studies that show when sleep deprived people are given a vaccine, there is a lower antibody response and if you expose sleep deprived people to a rhinovirus they are more likely to get the virus,” Dr. Watson said.
“This study provides further evidence of sleep to overall health and well-being particularly to immune health.”
N.F. Watson et al. 2017. Transcriptional Signatures of Sleep Duration Discordance in Monozygotic Twins. Sleep 40 (1): zsw019; doi: 10.1093/sleep/zsw019