ALAD and atrial fibrillation: At the circulating protein level, both ALAD (OR 0.898, 95% CI 0.845–0.954, PPH4 = 0.67) and APOH (OR 0.896, 95% CI 0.844–0.952, PPH4 = 0.93) were associated with a lower risk of AF, and APOH was validated in the replication group.