The association between pulse pressure change and cognition in late life: Age and where you start matters

Introduction: Variations across studies in the association between blood pressure (BP) and cognition might be explained partly by duration of exposure to hypertension and partly by nonrandom attrition over time. Pulse pressure (PP) reflects arterial stiffness which may better reflect chronicity of hypertension. Methods: Over six annual cycles, 1954 individuals aged 65+ years from a prospective population-based cohort underwent BP measurements and cognitive evaluations. We examined the relationship of change in five cognitive domains to longitudinal PP patterns across the late-life age spectrum, before and after stratifying by baseline systolic blood pressure (SBP) and adjusting for attrition. Results: There were four longitudinal PP patterns: stable normal, stable high, increasing, and decreasing. Those with lower baseline SBP and an increasing or stable high PP had less decline in cognition, an effect that was attenuated with aging. Among those with higher baseline SBP, there were no differences across PP groups, but increasing age was consistently associated with greater cognitive decline. Discussion: The effect of PP on cognitive decline depends on age, baseline SBP, and the trajectory of PP change. Cardiovascular mechanisms underlying cognitive aging should be recognized as nuanced and dynamic processes when exploring prevention and treatment targets in the elderly, so that the optimal timing and type of intervention can be identified.