Causal Relationship Between Sleep Characteristics and Alopecia Areata and Other Non-Scarring Alopecia: A Two-Sample Bidirectional Mendelian Randomization Analysis

This study explored the potential causal relationships between sleep characteristics and different types of alopecia using a bidirectional Mendelian randomization analysis with sample sizes ranging from 209 to 452,633 participants. The analysis suggested possible causal links between insomnia and a higher risk of alopecia areata, alopecia areata and morningness, and non-scarring alopecia with reduced sleep duration. However, these associations did not hold after correcting for multiple testing, indicating the need for cautious interpretation. The study found no evidence of horizontal pleiotropy, but heterogeneity was noted in the analysis of scarring alopecia and daytime napping. The authors recommend further research to explore underlying mechanisms and validate these findings across diverse populations.