The causal relationship between sleep traits and the risk of schizophrenia: a two-sample bidirectional Mendelian randomization study

Abstract

Background Observational studies suggest that sleep disturbances are commonly associated with schizophrenia. However, it is uncertain whether this relationship is causal. To investigate the bidirectional causal relation between sleep traits and schizophrenia, we performed a two-sample bidirectional Mendelian randomization (MR) study with the fixed effects inverse-variance weighted (IVW) method. Methods As genetic variants for sleep traits, we selected variants from each meta-analysis of genome-wide association studies (GWASs) conducted using data from the UK Biobank (UKB). Results We found that morning diurnal preference was associated with a lower risk of schizophrenia, while long sleep duration and daytime napping were associated with a higher risk of schizophrenia. Multivariable MR analysis also showed that sleep duration was associated with a higher risk of schizophrenia after adjusting for other sleep traits. Furthermore, genetically predicted schizophrenia was negatively associated with morning diurnal preference and short sleep duration and was positively associated with daytime napping and long sleep duration. Conclusions Therefore, sleep traits were identified as a potential treatment target for patients with schizophrenia.

Genetic insights into the relationship between immune cell characteristics and ischemic stroke: A bidirectional Mendelian randomization study

“…In accordance with the foundational assumptions of MR, and drawing on recent literature, our study set the significance threshold for each immune trait's instrumental variables at 5 × 10–6 [20, 21]. The linkage disequilibrium (LD) among SNPs was calculated using the genomes of 1000 individuals from a European population as a reference.…”

The causal effects of immune cells on pancreatic cancer: A 2‑sample Mendelian randomization study

“…[9] These immunophenotypes were categorized into 4 primary feature types: absolute cell (AC) count ( n = 118), median fluorescence intensity (MFI) which reflects the level of surface antigen expression ( n = 389), morphological parameter (MP) ( n = 32), and relative cell (RC) count ( n = 192). [10]…”

“…[9] These immunophenotypes were categorized into 4 primary feature types: absolute cell (AC) count (n = 118), median fluorescence intensity (MFI) which reflects the level of surface antigen expression (n = 389), morphological parameter (MP) (n = 32), and relative cell (RC) count (n = 192). [10] Specifically, the MFI, AC, and RC features included data on various cell types such as B cells, CDCs, T-cell maturation stages, monocytes, myeloid cells, TBNK (T-cell, B-cell, natural killer cell) cells, and Treg cells. In contrast, the MP feature was focused on CDC and TBNK cell types.…”

Causal role of immune cells in inflammatory bowel disease: A Mendelian randomization study

“…The significance level of the IV for each immune signature was set to 1 × 10 –5 , according to recent studies. [32,34,35] These SNPs (linkage disequilibrium r 2 threshold <0.1 within 500 kb distance) were trimmed using the clump function in the R package TwoSampleMR, [36] where linkage disequilibrium r 2 was a control calculated according to the 1000 Genomes Project as a reference plate. For IBD, the data were screened and analyzed to enhance the reliability of the results ( P < 5 × 10 –8 ) by referring to multiple publications and developing stricter criteria.…”