CONCLUSION
We found that obesity, SDB, and sleep quality were consistently associated with asthma in observational, MR, and prospective survival analysis models. After a series of complementary analyses to further strengthen the causal inference, poor sleep quality and SDB emerged as the most plausible causal risk factor, followed by obesity. Hence, lifestyle interventions aimed at promoting high-quality sleep and reducing SDB symptoms, such as weight management, might effectively reduce asthma risk.