The relationship between insomnia and multiple gastrointestinal disorders: a Mendelian randomization study.

Area of Science:

• Genetics
• Gastroenterology
• Sleep Medicine

Background:

• Observational studies suggest a link between insomnia and gastrointestinal (GI) disorders.
• Confounding factors and reverse causation complicate determining the true relationship.
• Mendelian randomization (MR) offers a method to explore genetic-level causal associations.

Purpose of the Study:

• To investigate the bidirectional causal relationship between insomnia and nine GI disorders using a two-sample, two-way MR approach.
• To leverage genetic variants as instrumental variables for robust causal inference.
• To identify specific GI conditions causally influenced by insomnia and vice versa.

Main Methods:

• Utilized two-sample, two-way Mendelian randomization (MR).
• Extracted genetic variants from genome-wide association study (GWAS) data.
• Employed inverse variance weighted (IVW), weighted median (WM), and MR-Egger for causal effect estimation.
• Assessed pleiotropy using MR-PRESSO and MR-Egger regression.
• Evaluated heterogeneity and sensitivity with Cochran's Q and leave-one-out analyses.

Main Results:

• Insomnia showed a significant causal effect on gastroesophageal reflux disease (GERD) and irritable bowel syndrome (IBS).
• Reverse MR analysis indicated a protective effect of chronic gastritis against insomnia.
• Acute gastritis was found to have a risk-enhancing effect on insomnia development.
• No significant causal associations were found for the remaining five GI conditions.

Conclusions:

• Provided genetic evidence for a causal link between insomnia and four GI conditions: GERD, IBS, chronic gastritis, and acute gastritis.
• Highlights the complex bidirectional relationship between sleep disturbances and digestive health.
• Supports the role of insomnia as a potential risk factor for specific GI disorders.