Genetically predicted insomnia is a risk factor for allergic disease and asthma, according to a recent Mendelian randomization study.
Insomnia was found to have an association with allergic disease and asthma, which indicates that improving sleep quality could be a way to prevent both diseases, according to a study published in Respiratory Research. The researchers performed a Mendelian randomization (MR) study to determine the causal association between insomnia and allergic disease/asthma.
MR uses genetic variants as instrumental variables to assess the potential causal impact of exposure on results, which overcomes the limitations of observation methods, according to the authors.
The most up-to-date publicly available genome-wide association study (GWAS) data sets were used for this study. There were 248 single nucleotide polymorphisms associated with insomnia that were extracted from a large-scale GWAS. Genetic association data were also extracted from a publicly available GWAS.
GWAS data sets were used to extract genetic association data for allergic disease; summary level-statistics for asthma, adult-onset asthma, and childhood asthma; genetic associations with insomnia; and genetic associations with moderate-severe asthma. All GWAS data sets featured participants of European ancestry. Statistics were used from UK Biobank data and 23andMe data.
A bidirectional MR study used 3 models—the inverse variance weighted model, the weighted median model, and the MR-Egger regression model—to evaluate the causal relationship between insomnia and allergic disease, asthma, and the asthma subtypes.
The MR analysis identified genetically predicted insomnia as a factor that increased the risk of allergic disease (odds ratio [OR], 1.054; 95% CI, 1.031-1.078). Causal effects of genetically predicted insomnia on the risk of asthma (OR, 1.043; 95% CI, 1.010-1.077) were also observed. Finally, the analysis found causal associations between genetically predicted insomnia and moderate-severe asthma (OR, 1.168; 95% CI, 1.069-1.277) and adult-onset asthma (OR, 1.086; 95% CI, 1.037-1.138).
There was no significant causal relationship between genetically predicted insomnia and childhood asthma. There was also no evidence of potential causal effects of genetically predicted allergic disease, asthma, and moderate-severe asthma on insomnia.
There were some limitations to this study. There may have been some overlap in participants’ exposure and outcomes, which would reduce the data quality. Some diagnoses were based on self-reported conditions collected through questionnaires, which could lead to misclassification. Only populations of European ancestry were incorporated into the MR analysis, so the authors noted that all findings should be verified in other populations.
The researchers concluded that their results provided evidence that genetically predicted insomnia was associated with an increased risk of allergic disease, asthma, moderate-severe asthma, and adult-onset asthma.
Li R, Chen Y, Zhao A, et al. Exploring genetic association of insomnia with allergic disease and asthma: a bidirectional Mendelian randomization study. Respir Res. 2022;23:84. doi:10.1186/s12931-022-02009-6