Prospective associations between pulse pressure and cognitive performance in Chinese middle-aged and older population across a 5-year study period

Tingting Sha, Wenwei Cheng, Yan Yan

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.