Hypertension and obesity are known risk factors for atrial fibrillation (AF). However, it is unclear whether uncontrolled, long-standing hypertension has a particularly profound effect on AF. Because they have a similar underlying pathophysiology, hypertension and obesity could act synergistically in the context of AF. We evaluated how various stages of hypertension and body weight status affect new-onset AF. We analyzed a total of 9 797 418 participants who underwent a national health checkup. Hypertension was classified into 5 stages: nonhypertension, prehypertension, hypertension without medication, hypertension with medication <5 years, and hypertension with medication ≥5 years. The participants were also stratified based on body mass index and waist circumference. During the 80 130 161 person×years follow-up, a total of 196 136 new-onset AF cases occurred. The incidence of new-onset AF gradually increased among the 5 stages of hypertension: the adjusted hazard ratio for each group was 1 (reference), 1.145, 1.390, 1.853, and 2.344 for each stage of hypertension. A graded escalation in the risk of new-onset AF was also observed in response to increased systolic and diastolic blood pressure. The incidence of new-onset AF correlated with body mass index and waist circumference, with obese people having a higher risk than others. Hypertension and obesity acted synergistically: obese people with hypertension on medication ≥5 years had the highest risk of AF. In conclusion, the degree and duration of hypertension, as well as the presence of hypertension, were important factors for new-onset AF. Body weight status was significantly associated with new-onset AF and acted synergistically with hypertension.
Keywords: atrial fibrillation; body weight; obesity; risk factor; waist circumference.