Oishi Emi, Ohara Tomoyuki, Sakata Satoko, Fukuhara Masayo, Hata Jun, Yoshida Daigo, Shibata Mao, Ohtsubo Toshio, Kitazono Takanari, Kiyohara Yutaka, Ninomiya Toshiharu
From Department of Epidemiology and Public Health (E.O., T. Ohara, S.S., J.H., D.Y., M.S., T.N.), Department of Medicine and Clinical Science (E.O., S.S., J.H., T. Ohtsubo, T.K.), Department of Neuropsychiatry (T. Ohara), and Department of Center for Cohort Studies (J.H., D.Y., T.K., T.N.), Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; Department of Division of General Internal Medicine, Kyushu Dental University, Kitakyushu, Japan (M.F.); and Hisayama Research Institute for Lifestyle Diseases, Fukuoka, Japan (Y.K.).
Circulation. 2017 Aug 8;136(6):516-525. doi: 10.1161/CIRCULATIONAHA.116.025667.
Several observational studies have reported that higher visit-to-visit blood pressure variability is a risk factor for cognitive impairment and dementia. However, no studies have investigated the association of day-to-day blood pressure variability assessed by home blood pressure measurement with the development of dementia.
A total of 1674 community-dwelling Japanese elderly without dementia, ≥60 years of age, were followed up for 5 years (2007-2012). Home blood pressure was measured 3 times every morning for a median of 28 days. Day-to-day systolic (SBP) and diastolic blood pressure variabilities, calculated as coefficients of variation (CoV) of home SBP and diastolic blood pressure, were categorized into quartiles. The hazard ratios and their 95% confidence intervals of the CoV levels of home blood pressure on the development of all-cause dementia, vascular dementia (VaD), and Alzheimer disease (AD) were computed with a Cox proportional hazards model.
During the follow-up, 194 subjects developed all-cause dementia; of these, 47 had VaD and 134 had AD. The age- and sex-adjusted incidences of all-cause dementia, VaD, and AD increased significantly with increasing CoV levels of home SBP (all for trend <0.05). These associations remained unchanged after adjustment for potential confounding factors, including home SBP. Compared with subjects in the first quartile of CoV levels of home SBP, the risks of the development of all-cause dementia, VaD, and AD were significantly higher in those in the fourth quartile (hazard ratio=2.27, 95% confidence interval=1.45-3.55, <0.001 for all-cause dementia; hazard ratio=2.79, 95% confidence interval=1.04-7.51, =0.03 for VaD; hazard ratio=2.22, 95% confidence interval=1.31-3.75, <0.001 for AD). Similar associations were observed for CoV levels of home diastolic blood pressure. Meanwhile, home SBP levels were significantly associated with the risk of VaD but not with the risks of all-cause dementia and AD. There was no interaction between home SBP levels and CoV levels of home SBP on the risk of each subtype of dementia.
Our findings suggest that increased day-to-day blood pressure variability is, independently of average home blood pressure, a significant risk factor for the development of all-cause dementia, VaD, and AD in the general elderly Japanese population.
多项观察性研究报告称，就诊间血压变异性增加是认知障碍和痴呆的一个危险因素。然而，尚无研究调查通过家庭血压测量评估的日常血压变异性与痴呆发生之间的关联。
共有1674名年龄≥60岁、居住在社区且无痴呆的日本老年人接受了5年（2007 - 2012年）的随访。每天早晨测量3次家庭血压，持续28天（中位数）。将日常收缩压（SBP）和舒张压变异性计算为家庭SBP和舒张压的变异系数（CoV），并分为四分位数。采用Cox比例风险模型计算家庭血压CoV水平对全因痴呆、血管性痴呆（VaD）和阿尔茨海默病（AD）发生的风险比及其95%置信区间。
在随访期间，194名受试者发生了全因痴呆；其中，47例患有VaD，134例患有AD。随着家庭SBP的CoV水平升高，全因痴呆、VaD和AD的年龄和性别调整发病率显著增加（所有趋势P<0.05）。在调整包括家庭SBP在内的潜在混杂因素后，这些关联保持不变。与家庭SBP的CoV水平处于第一四分位数的受试者相比，处于第四四分位数的受试者发生全因痴呆、VaD和AD的风险显著更高（全因痴呆的风险比 = 2.27，95%置信区间 = 1.45 - 3.55，P<0.001；VaD的风险比 = 2.79，95%置信区间 = 1.04 - 7.51，P = 0.03；AD的风险比 = 2.22，95%置信区间 = 1.31 - 3.75，P<0.001）。家庭舒张压的CoV水平也观察到类似的关联。同时，家庭SBP水平与VaD风险显著相关，但与全因痴呆和AD风险无关。家庭SBP水平与家庭SBP的CoV水平在各痴呆亚型风险上无交互作用。
我们的研究结果表明，在日本普通老年人群中，日常血压变异性增加是全因痴呆、VaD和AD发生的一个重要危险因素，独立于家庭平均血压。
