Cognition Improves With Lower SBP Targets in Some Patients

Systolic blood pressure (SBP) targets of 120 mm Hg or lower are associated with better cognitive outcomes among older adults with hypertension, especially among blacks, according to a recent study.

Although the Eighth Joint National Committee (JNC-8) has recommended lowering SBP to below 150 mm Hg in older adults, data from the Systolic Blood Pressure Intervention Trial (SPRINT) has indicated that an SBP level of 120 mm Hg or lower can also effectively decrease the rate of cardiovascular events. Furthermore, target SBP guidelines have not yet addressed the greater risk of morbidity, mortality, and cognitive decline in black patients with hypertension.
__________________________________________________________________________________________________________________________

RELATED CONTENT
Cholesterol-Lowering Drug Does Not Cause Cognitive Decline
Can Cognitive Decline Be Predicted 10 Years Before Parkinson Onset?
__________________________________________________________________________________________________________________________

To better understand the association between these discordant SBP targets, cognitive outcomes, and racial disparities, the researchers assessed 1657 cognitively intact older adults who had been treated for hypertension in the Health Aging and Body Composition study from 1997 to 2007. Patients were a mean age of 73.7 years. A total of 908 patients were women, and 784 were black.

The Modified Mini-Mental State Examination (3MSE) was used 4 times and the Digit Symbol Substitution Test (DSST) 5 times to assess cognition. Participants were categorized according to SBP levels at each visit based on the mean SBP level of 2 seated readings: 120 mm Hg or lower, 121 to 139 mm Hg, 140 to 149 mm Hg, or 150 mm Hg or higher. The association of SBP levels with 10-year cognitive trajectories was evaluated via mixed models, and the impact of race was studied with a race interaction term.

After adjustment, results indicated that patients had experienced differential decreases in cognitive scores based on SBP levels. Patients with SBP levels of 150 mm Hg or higher had experienced the greatest decrease in 3MSE (3.7) and DSST (6.2) scores, while patients with SBP levels of 120 mm Hg or lower had experienced the lowest decrease in 3MSE (3.0) and DSST (5.0) scores.

Ultimately, the researchers found that black patients had a greater difference between the higher and lower SBP levels in the decrease in cognition, compared with white patients. Following adjustment, the differences in scores between patients with 150 mm Hg or higher and patients with levels of 120 mm Hg or lower were -0.05 in white patients and -0.08 in black patients for 3MSE and -0.07 in white patients and -0.13 in black patients for DSST.

“For patients 70 years of age or older receiving treatment for hypertension, a SPRINT SBP level of 120 mm Hg or lower was not associated with worsening cognitive outcome and may be superior to the JNC-8 target for cognition,” the researchers concluded. “Lower SBP treatment levels may result in improved cognition in black patients.”

—Christina Vogt

Reference:

Hajjar I, Rosenberger KJ, Kulshreshtha A, Ayonayon HN, Yaffe K, Goldstein FC. 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.