Supplemental Digital Content is available in the text. Atrial fibrillation (AF) is associated with increased risk of cognitive impairment and dementia, even with no overt stroke. Hypertension has been a potentially modifiable risk factor for dementia, especially in midlife (<70 years) individuals. We aimed to investigate the associations of blood pressure (BP) and hypertension burden with dementia risk among midlife AF patients. From the Korean National Health Insurance Service database, we enrolled 171 228 incident AF patients aged 50 to 69 years with no prior dementia from 2005 to 2016. During a mean of 6.6 years of follow-up, 9909 patients received a first-time diagnosis of dementia. U-shaped relationships were noted between systolic or diastolic BP and dementia risk: A 10 mm Hg increase or decrease in systolic BP starting from 120 mm Hg was associated with 4.4% (95% CI, 2.7%–6.0%) and 4.6% (95% CI, 0.1%–8.2%) higher dementia risk, respectively. An increase or decrease in diastolic BP starting from 80 mm Hg also increased dementia risk. In subtype analyses, Alzheimer disease increases with BP decrease whereas vascular dementia increases according to BP increase. When BP changes over time were accounted for in time-updated models, BP of 120 to 129/80 to 84 mm Hg was associated with the lowest dementia risk. Increasing hypertension burden (the proportion of days with increased BP during follow-up) was associated with higher dementia risk (hazard ratio, 1.10 per 10% increase [95% CI, 1.08–1.12]). Among midlife AF patients, there were a U-shaped association of BP and a log-linear association of hypertension burden with dementia risk. Minimizing the burden of hypertension in AF patients might help to prevent dementia.

中文翻译：

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中年心房颤动患者的血压控制和痴呆风险

补充数字内容在文本中可用。心房颤动 (AF) 与认知障碍和痴呆的风险增加有关，即使没有明显的中风。高血压一直是痴呆症的潜在可改变危险因素，尤其是在中年（<70 岁）人群中。我们旨在调查血压 (BP) 和高血压负担与中年 AF 患者痴呆风险的关联。我们从韩国国民健康保险服务数据库中招募了 171228 名 50 至 69 岁的 2005 年至 2016 年既往无痴呆症的房颤患者。在平均 6.6 年的随访期间，9909 名患者首次诊断为痴呆。收缩压或舒张压与痴呆风险之间存在 U 形关系：从 120 mmHg 开始，收缩压升高或降低 10 mmHg 与痴呆风险分别增加 4.4%（95% CI，2.7%–6.0%）和 4.6%（95% CI，0.1%–8.2%）相关. 舒张压从 80 mmHg 开始升高或降低也会增加痴呆风险。在亚型分析中，阿尔茨海默病随血压降低而增加，而血管性痴呆随血压升高而增加。当在时间更新模型中考虑血压随时间的变化时，120 至 129/80 至 84 mmHg 的血压与最低的痴呆风险相关。增加的高血压负担（随访期间血压升高的天数比例）与更高的痴呆风险相关（风险比，每 10% 增加 1.10 [95% CI，1.08-1.12]）。在中年 AF 患者中，血压呈 U 型关联，高血压负担与痴呆风险呈对数线性关联。将 AF 患者的高血压负担降至最低可能有助于预防痴呆。