We aimed to investigate the association between visit-to-visit blood pressure variability (BPV) and future cognitive dysfunction in an elderly population.Design and Method:
The Cardiovascular Disease Risk Factors two-Township study (CVDFACTS) was a longitudinal cohort study and the first wave survey was established during 1989–1991 and four waves of survey were carried out between 1992 and 2002. The on-going sixth wave survey was started in 2015. A total of 320 seniors aged more than 60 years participated in the sixth wave survey and received the Mini-Mental State Examination (MMSE) to evaluate the global cognitive function in 2015. All seniors had participated in at least three waves of survey during 1989 to 2002. The visit-to-visit BPV was calculated as the standard deviation of measurements of brachial SBP and diastolic blood pressure (DBP) from each wave of survey. The first quartiles of SBP and DBP BPV were defined as the high variability group and others as the normal variability group. The general linear regression and the logistic regression were used to evaluate the associations between visit-to-visit BPV and MMSE and cognitive dysfunction (MMSE < 24), respectively.Results:
Both SBP and DBP BPV were significantly negatively associated with cognitive function. The correlation coefficients between BPV and MMSE were -0.132 (p-value = 0.0182) for SBP and -0.158 (p-value = 0.0047) for DBP. However, the association BPV and MMSE remained significant only for DBP (r = 0.39, p-value <0.01) but not for SBP (r = −0.09, p-value = 0.135) when age and sex were accounted for. DBP BPV remained significantly associated with MMSE and cognitive dysfunction in the multivariate models with adjustment for DBP, history of stroke and other confounders in the linear regression (beta = −0.11, p-value = 0.0347) and the logistic regression (odds ratio = 1.17, 95% CI = 1.03–1.32). Subjects with high visit-to-visit DBP BPV had significantly lower MMSE and higher prevalence of cognitive dysfunction.Conclusions:
High visit-to-visit DBP BPV was associated with future cognitive dysfunction.