Black individuals had faster declines in global cognition than white individuals (-0.03 points/year; P=0.004), which was attenuated after adjusting for cumulative systolic blood pressure (P=0.56).
Cohort (n=19,378)
Yes
Does cumulative blood pressure explain racial differences in cognitive decline between Black and White individuals?
Higher cumulative systolic blood pressure levels in Black individuals appear to explain a significant portion of the racial disparity in later-life global cognitive decline.
Mean Difference: -0.03 (95% CI -0.05–-0.01)
p-value: p=.004
Importance: Black individuals are more likely than white individuals to develop dementia. Whether higher blood pressure (BP) levels in black individuals explain differences between black and white individuals in dementia risk is uncertain. Objective: To determine whether cumulative BP levels explain racial differences in cognitive decline. Design, Setting, and Participants: Individual participant data from 5 cohorts (January 1971 to December 2017) were pooled from the Atherosclerosis Risk in Communities Study, Coronary Artery Risk Development in Young Adults Study, Cardiovascular Health Study, Framingham Offspring Study, and Northern Manhattan Study. Outcomes were standardized as t scores (mean SD, 50 10); a 1-point difference represented a 0.1-SD difference in cognition. The median (interquartile range) follow-up was 12.4 (5.9-21.0) years. Analysis began September 2018. Main Outcomes and Measures: The primary outcome was change in global cognition, and secondary outcomes were change in memory and executive function. Exposures: Race (black vs white). Results: Among 34 349 participants, 19 378 individuals who were free of stroke and dementia and had longitudinal BP, cognitive, and covariate data were included in the analysis. The mean (SD) age at first cognitive assessment was 59.8 (10.4) years and ranged from 5 to 95 years. Of 19 378 individuals, 10 724 (55.3%) were female and 15 526 (80.1%) were white. Compared with white individuals, black individuals had significantly faster declines in global cognition (-0.03 points per year faster 95% CI, -0.05 to -0.01; P = .004) and memory (-0.08 points per year faster 95% CI, -0.11 to -0.06; P < .001) but significantly slower declines in executive function (0.09 points per year slower 95% CI, 0.08-0.10; P < .001). Time-dependent cumulative mean systolic BP level was associated with significantly faster declines in global cognition (-0.018 points per year faster per each 10-mm Hg increase 95% CI, -0.023 to -0.014; P < .001), memory (-0.028 points per year faster per each 10-mm Hg increase 95% CI, -0.035 to -0.021; P < .001), and executive function (-0.01 points per year faster per each 10-mm Hg increase 95% CI, -0.014 to -0.007; P < .001). After adjusting for cumulative mean systolic BP, differences between black and white individuals in cognitive slopes were attenuated for global cognition (-0.01 points per year 95% CI, -0.03 to 0.01; P = .56) and memory (-0.06 points per year 95% CI, -0.08 to -0.03; P < .001) but not executive function (0.10 points per year 95% CI, 0.09-0.11; P < .001). Conclusions and Relevance: These results suggest that black individuals' higher cumulative BP levels may contribute to racial differences in later-life cognitive decline.
Levine et al. (Mon,) conducted a cohort in Cognitive decline (n=19,378). Black race vs. White race was evaluated on change in global cognition (MD -0.03 points per year, 95% CI -0.05 to -0.01, p=.004). Black individuals had faster declines in global cognition than white individuals (-0.03 points/year; P=0.004), which was attenuated after adjusting for cumulative systolic blood pressure (P=0.56).