A genetic analysis by researchers at the Yale School of Public Health and the Norwegian University of Science and Technology (NTNU) has found new evidence that insomnia may heighten the risk of sepsis.
Recent observational studies have documented multiple adverse health effects attributed to insomnia including inflammation, a weakened immune response, and an increased risk of bloodstream infection – a condition closely linked to sepsis.
But other factors strongly linked to insomnia – such as body mass index and smoking – are also potential causes of sepsis. This makes it difficult for scientists to accurately assess whether the association of insomnia with the risk of sepsis is due to insomnia itself or those other factors.
In the present study, researchers took a novel approach, analyzing genetic data from more than 2 million people of European ancestry to uncover new evidence supporting the link between insomnia and sepsis.
Importantly, the analysis was performed using a Mendelian randomization approach to determine whether genetically predicted insomnia is associated with sepsis risk.
“Mendelian randomization mimics a randomized controlled trial by utilizing the principle of random allocation of genetic variations. Because it is random whether you have a high or low genetic risk of insomnia, the association between genetically predicted insomnia and risk of sepsis is much less likely to be biased by common causes of insomnia and sepsis compared with what is often seen in traditional observational studies,” said Yale School of Public Health Assistant Professor of Epidemiology Dr. Tormod Rogne, MD, the study’s senior author. Dr. Marianne S. Thorkildsen, MD, is first author on the study and will be visiting Yale University as a Fulbright Scholar this fall.
“The majority of the association between insomnia and sepsis risk was not explained by these factors [body mass index, type 2 diabetes, cardiovascular diseases, and smoking], indicating that insomnia may have a substantial direct influence on sepsis risk,” the researchers reported. The findings, the researchers said, “are in line with previous research and results from observational data reporting that insomnia increases the risk of altered immune response and bloodstream infection.”
The findings also confirm that insomnia is a potentially preventable risk factor of sepsis that should be further investigated, the researchers said.
Sepsis is a serious medical condition that occurs due to an overwhelming immune response to an infection and can lead to organ failure and sometimes death.
Interestingly, the researchers also found in their analysis that insomnia presents a stronger risk for sepsis in women than in men. That may be because sleep deprivation affects women’s immune systems more than it does in men, the researchers said.
There is an important limitation to the study. The genetic data used in the analysis was limited to people of European ancestry. The researchers cautioned that the findings may differ when genetic datasets of different ancestry groups are analyzed.
The findings appear online Aug. 9 in JAMA Psychiatry.