Smoking, Coffee Consumption, Alcohol Intake, and Obstructive Sleep Apnea: A Mendelian Randomization Study.

Background: Previous studies revealed that obstructive sleep apnea (OSA) and smoking, alcohol consumption, and coffee intake are closely related. This study aimed to evaluate the causal effect between these factors and OSA.

Methods: The published genome-wide association study data (GWAS) provided genetic tools. We conducted a univariable two-sample Mendelian Randomization (MR) to estimate the causal effect between smoking initiation, never smoking, alcohol consumption, coffee intake, and coffee consumption with the risk of incidence OSA. Inverse variance weighting (IVW) was used as the main method for effect evaluation, and other MR methods were used for sensitivity analysis. After adjusting for body mass index (BMI), hypertension, and diabetes respectively by multivariable MR (MVMR), we further evaluate the causal effect of these factors on OSA.

Results: Under univariable MR analysis, we observed that smoking initiation was associated with an increased risk of incidence OSA (OR 1.326, 95% CI 1.001-1.757, p =0.049). Never smoking was associated with decreased risk of OSA (OR 0.872, 95% CI 0.807-0.942, p <0.001). Coffee intake and coffee consumption was associated with an increased incidence of OSA (OR 1.405, 95% CI 1.065-1.854, p =0.016) and (OR 1.330, 95% CI 1.013-1.746, p =0.040). Further multivariate MR showed that the causal relationship between never smoking and OSA existed but not coffee consumption, after adjusting for diabetes and hypertension. However, the all results did not support causality after adjusting for BMI.

Conclusion: This two-sample MR study showed that genetically predicted smoking and higher coffee intake are causally associated with an increased risk of OSA.