Department of Epidemiology and Medical Statistics, Xiangya School of Public Health, Central South University, Xiangya Road 110, Changsha, Hunan, 410078, China.
Alzheimers Res Ther. 2018 Mar 12;10(1):29. doi: 10.1186/s13195-018-0355-1.
Substantial evidence indicates that the relationship between blood pressure (BP) measures and cognitive functioning is inconsistent, complex, and age-related. Pulse pressure (PP), which can not only reflect arterial stiffness and but also represent the chronic effects of hypertension other than BP itself, has been considered as a better predictor of cognitive impairment. However, evidence on the association of cognitive function with PP has not been investigated extensively. We examined this relationship in a longitudinal study based on the latent growth model (LGM).
This study was based on a nationally representative sample of Chinese middle-aged and older participants from the China Health and Retirement Longitudinal Study (CHARLS), a prospective observational study conducted from 2011 to 2016. Cognitive performance was assessed on the basis of three measures of cognition. The PP was calculated as the difference of the average values of three systolic and diastolic BP readings. A series of potential confounders were collected in this research. The LGM was used to examine the effects of PP on cognitive performance at three time points. To test the independent effects of PP on the initial level and the subsequent development of cognition, unconditional and conditional models were compared sequentially.
After excluding respondents with missing key variables, we ultimately included 9750 participants in the analysis. Cognitive performance scores and PP showed significant differences across time. After adjustment for the confounders, the standardized coefficients of PP in the LGM indicated negative effects on cognitive performance in elderly Chinese participants at wave 2 and wave 3 (P < 0.01). The initial level of PP in the unconditional model was negatively associated with the initial level (β = - 0.25) and the slope (β = - 0.16) of cognition, whereas these effects were attenuated and the association between intercept of PP and slope of cognition became nonsignificant after controlling for the confounders.
The implications of these results demonstrate that a higher PP lowers the cognitive performance of middle-aged and elderly persons independent of a comprehensive set of covariates, but it is not a contributor to the rate of change in cognition.
大量证据表明，血压（BP）测量值与认知功能之间的关系不一致、复杂且与年龄相关。脉压（PP）不仅可以反映动脉僵硬，而且可以代表除 BP 本身以外的高血压的慢性影响，已被认为是认知障碍的更好预测指标。然而，关于认知功能与 PP 之间关联的证据尚未得到广泛研究。我们基于潜在增长模型（LGM）在一项纵向研究中检验了这种关系。
本研究基于中国健康与退休纵向研究（CHARLS）的全国代表性中年和老年参与者样本，这是一项从 2011 年至 2016 年进行的前瞻性观察研究。认知表现是基于三个认知测量来评估的。PP 是通过平均三次收缩压和舒张压读数的差值计算得出的。本研究收集了一系列潜在的混杂因素。LGM 用于检验 PP 在三个时间点对认知表现的影响。为了检验 PP 对认知初始水平和随后发展的独立影响，我们依次比较了无条件和条件模型。
在排除了关键变量缺失的受访者后，我们最终对 9750 名参与者进行了分析。认知表现得分和 PP 在不同时间显示出显著差异。在调整混杂因素后，LGM 中 PP 的标准化系数表明其对中国老年参与者的认知在波 2 和波 3 时存在负面影响（P < 0.01）。无条件模型中 PP 的初始水平与认知的初始水平（β=-0.25）和斜率（β=-0.16）呈负相关，而在控制混杂因素后，这些效应减弱，PP 截距与认知斜率之间的关联变得不显著。
这些结果表明，较高的 PP 独立于综合混杂因素降低了中年和老年人的认知表现，但它不是认知变化率的一个促成因素。
