Lower Systolic Blood Pressure Targets May Benefit Cognition in Black Patients
The researchers observed a racial disparity in decrease in cognitive scores between whites and blacks.
Among black patients treated for hypertension, a systolic blood pressure (SBP) level of ≤120 mmHg results in no significant cognitive deficits compared with SBP ≤150 mmHg, which is the recommendation of the Eighth Joint National Committee (JNC-8). In fact, it may actually be associated with improved cognition, according to findings from a study published in JAMA Neurology.
Researchers examined the long-term cognitive-related outcomes associated with various SBP levels among 1657 older adults (mean age, 73.7). Specifically, the investigators sought to determine racial differences among patients being treated for hypertension. The researchers compared the JNC-8 recommendation to bring SBP to ≤150 mmHg in patients with hypertension vs data from the Systolic Blood Pressure Intervention Trial (SPRINT), which suggests treating SBP to ≤120 mmHg.
A differential decrease occurred in the Digital Symbol Substitution Test (DSST) and Modified Mini-Mental State Examination (3MSE) scores based on SBP level, with a greater decrease seen among patients with SBP of ≥150 mmHg (6.2 for DSST and 3.7 for 3MSE, P <.001) compared with patients who had SBP of ≤120 mmHg, who had the smallest decrease in scores, with the lowest decrease seen in patients with SBP of ≤120 mmHg (5.0 for DSST and 3.0 for 3MSE, P <.001).
Compared with white patients, black patients (n=784) experienced a greater decrease in cognition between the SBP levels; differences observed between SBP levels of ≤120 mmHg and SBP levels of ≥150 mmHg were -0.07 in whites and -0.13 in blacks for DSST (P =.05) and -0.05 in whites and -0.08 in blacks for 3MSE (P =.03).
Although this study had a long-term follow-up and a large number of participants, the observational nature represents a potential limitation to the overall findings. The investigators noted that the lack of neuroimaging and the small number of cognition tests were also limitations related to the study's design.
Ultimately, the results of the present study, together with results from SPRINT, suggest that lower SBP targets may not only benefit cardiovascular outcomes, but cognitive ones too, especially in black patients. “Future recommendations for the management of hypertension and cognitive outcomes need to take this racial disparity into consideration,” they concluded.
Hajjar I, Rosenberger KJ, Kulshreshtha A, et al. Association of JNC-8 and SPRINT systolic blood pressure levels with cognitive function and related racial disparity [published online August 21, 2017]. JAMA Neurol. doi:10.1001/jamaneurol.2017.1863