Evaluation of blood pressure and cognitive function using individual participant data meta‐analysis: The Life‐Course Blood Pressure Cognition (LCBP‐COG) study

AbstractBackgroundThe prognostic significance of various blood pressure (BP) indices (i.e. systolic BP [SBP], diastolic BP [DBP], pulse pressure [PP] and mean arterial pressure [MAP]) on cardio‐ and cerebrovascular health vary across age groups. We examined the association between baseline BP indices in mid‐ and late‐life and cognitive function over a 9‐15 year period.MethodWe performed pooled analyses of data from 3 longitudinal cohort studies. The Personality and Total Health (PATH) Through Life study of adults initially aged 40‐44 and 60‐64 years in Australia, and Victoria Longitudinal Study (VLS) of adults initially aged 55‐85 years in Canada, included four waves of data collection every 4‐5 years. The Gothenburg H70 Birth cohort study of adults initially aged 70 years included three waves of data collection every 4‐5 years. The association between baseline BP and cognitive decline on the Mini‐Mental State Examination (MMSE) was categorized using the reliable change index (Duff K. 2012) and analyzed using logistic regression adjusted for age, sex, and study. Additional analyses examined relationships between baseline BP and repeated cognitive measures of memory, attention and processing speed, and executive function, using linear mixed models (PATH and H70). Only participants with complete BP and cognitive measures were included.ResultData from 2912 participants (mean baseline age 54.3 years, range 40 to 83 years, 1395 (47.9%) male) were included. Examining baseline BP and age, we observed SBP increasing with age until a small decrease at around 80 years. DBP and MAP also showed an increase with age until early late‐life (around 60 years) and were lower at older ages, PP consistently increased (Figure 1). There were no relationships between baseline BP measures and MMSE. For PATH only, higher SBP (P=0.002), DBP (P=0.0007) and MAP (P=0.0006) at age 40 years, and higher DBP (P=0.004) at 60 years, were associated with greater annual deterioration in attention and processing speed (symbol‐digit‐modalities test) over the subsequent decade (Figure 2).ConclusionHigher BP in midlife and DBP in early late‐life, were associated with a greater decline in measures of attention and processing speed. We observed no associations between BP and MMSE decline.