Low Diastolic BP Does Not Increase Risk of Cognitive Impairment with Intensive Blood Pressure Lowering

A posthoc analysis of data from the SPRINT MIND trial is providing clinicians with further evidence of the safety of intensive blood pressure lowering in patients with hypertension.

Using data from the study, investigators determined, although those with lower diastolic blood pressure experienced a greater incidence rate, intensive blood pressure lowering was associated with a lower incidence rate of probable dementia or mild cognitive impairment, regardless of whether or not a patient had low or high diastolic blood pressure at baseline.

“To the best of our knowledge, this was the first study focusing directly on the safety and efficacy of intensive SBP lowering (<120 mmHg) on cognitive outcomes and [cerebral blood flow] in patients with low baseline [diastolic blood pressure],” wrote investigators.

Although hypertension stands as one of the single greatest risks to public health across the globe, which has made blood pressure-lowering therapy a cornerstone of preventive algorithms, debate exists surrounding the effects of intensive blood pressure lowering on cognition in aging populations. A randomized, controlled, open-label trial assessing the effects of intensive and standard blood pressure control in nearly 10,000 patients aged 50-75 years, the SPRINT trial concluded a lower blood pressure target could reduce risk of cardiovascular events by 25% relative to the standard approach.

In the current study, which was led by investigators from the Beijing Anzhen Hospital, investigators sought to assess the potential benefits of intensive blood pressure control on cognitive function and cerebral blood flow based across baseline diastolic blood pressure quartiles. A post hoc analysis, the current study included 4278 randomized to an intensive blood pressure target and 4385 randomized to a standard blood pressure target.

Upon analysis, results suggested those randomized to intensive blood pressure lowering had a lower incidence rate of probable dementia or mild cognitive impairment than those in the standard group, regardless off diastolic blood pressure quartiles. Among those in the lowest diastolic blood pressure quartile the risk of probable dementia or mild cognitive impairment was 9% lower with an intensive blood pressure lowering target compared to a standard target (HR, 0.91 [95% CI, 0.73 to 1.12]). Among those in the highest diastolic blood pressure quartile, the risk of probable dementia or mild cognitive impairment was 30% lower among those with an intensive blood pressure lowering target compared to a standard target (HR, 0.70 [95% CI, 0.48 to 1.02]) (P for interaction=.24).

Further analysis indicated similar results were seen for probable dementia (P for interaction=.06) and mild cognitive impairment (P for interaction=.80). Results of the investigators’ additional analyses suggested the effect of intensive treatment on cerebral blood flow was not modified by baseline diastolic pressure (P for interaction=.25) and randomized to the intensive target was associated with an ind4sing trend of annualized change in cerebral blood flow, even among those in the lowest quartile of diastolic blood pressure (+0.26 [95% CI, -0.72 to 1.24] mL/[100g/min]).

“In this post hoc analysis of the SPRINT MIND study, participants with lower [diastolic blood pressure] had higher incidences of probable dementia or [mild cognitive impairment],” investigators concluded. “However, intensive [blood pressure] lowering did not appear to increase the risks of cognitive outcomes in patients with low baseline [diastolic blood pressure]. Moreover, there was no evidence that intensive versus standard [blood pressure] lowering had negative effects on [cerebral blood flow] in these patients.”

This study, “Diastolic Blood Pressure and Intensive Blood Pressure Control on Cognitive Outcomes: Insights From the SPRINT MIND Trial,” was published in Hypertension