Educational attainment could be a protective factor against obstructive sleep apnea: a study based on Mendelian randomization

BACKGROUND: Causality between education and obstructive sleep apnea (OSA) is not known. METHODS: Genetic variants, as instrumental variables for years of education, were derived from the Social Science Genetic Association Consortium. The outcome datasets related to OSA were from the FinnGen research project (www.finngen.fi/en/). Inverse variance-weighted, weighted-median, and Mendelian randomization–Egger analysis were used to estimate causal effects. To assess the robustness and horizontal pleiotropy of significant results, leave-one-out sensitivity analysis and Mendelian randomization–Egger regression analysis were conducted. The inverse variance-weighted method was undertaken to estimate the association between years of education and other known risk factors for OSA. Analyses were conducted using the Two Sample Mendelian Randomization package of R 4·0·3. RESULTS: Genetic predisposition towards 4.2 years of additional education was associated with a 27.8% lower risk of OSA [odds ratio (OR) =0.722, 95% confidence interval (CI): 0.566–0.921; P=0.009]. Sensitivity analyses were consistent with a causal interpretation in which a major bias from genetic pleiotropy was unlikely. The Mendelian randomization assumptions did not seem to be violated. Genetic predisposition towards longer education was associated with a lower body mass index, fewer cigarettes smoked per day, and greater alcohol intake per week. CONCLUSIONS: Our data indicated that education could be a protective factor against OSA. Potential mechanisms could include body mass index, tobacco smoking, and alcohol intake.