The effect of blood pressure on domain‐specific cognitive changes in older Black Americans: findings from the Baltimore Study of Aging – Patterns of Cognitive Aging

Abstract

AbstractBackgroundPrevious research suggests that hypertension shape cognitive health outcomes in older Blacks (Whitfield 2008). However, few studies have explored the relation between objective and subjective blood pressure (BP) measures and cognitive decline. This study examined whether systolic, diastolic, and self‐reported BP were associated with changes in cognition.MethodData are drawn from the Baltimore Study of Black Aging—Patterns of Cognitive Aging. At baseline, 602 Black participants (48‐95 years) were enrolled. At follow‐up, approximately 3 years later, 450 participants were re‐interviewed. Cognition included 5 domains: working memory, processing speed, verbal memory, vocabulary, and inductive reasoning. Using an oscillometer automated device (A&D model UA‐ 767), three readings of orthostatic BP were collected and mean systolic (SBP; range = 82‐230.3 mmHg) and diastolic BP (DBP; range = 51‐136.7 mmHg) values were calculated for each participant. BP was treated as a continuous variable. Participants were also asked “Have you ever been told by a doctor or nurse that you have high blood pressure? (yes/no response)” Data were analyzed using multiple linear regression, controlling for sociodemographic and health conditions.ResultMajority of the sample was female (25.4% male) and had at least a high school education (57.1%). Systolic BP was inversely associated with inductive reasoning at follow‐up (b = ‐0.208, p = 0.023; see Table 1), but was not related to any other cognitive domains, after adjusting for age, sex, education, depressive symptoms, comorbidities, diastolic BP, and baseline cognition. Diastolic BP and self‐reported hypertensive status were both unrelated to changes in each of the five cognitive domains (all models, p> 0.05).ConclusionThe present study adds to our understanding of cognitive aging among older Black Americans. Results support previous research, pointing to an independent effect of BP on domain‐specific cognitive changes (Buford 2016), but also extend the literature by highlighting a more pronounced negative effect of systolic BP. These findings suggest that the pathway to cognitive dysfunction is contributed to by BP. Several key mechanisms – including increased risk for stroke and “vascular dementia” (age‐ and hypertension‐related cerebral vasculature changes) – may explain the influence of hypertension on cognitive decline that warrant further study in Black Americans.