October 25, 2019
By Will Boggs MD
NEW YORK (Reuters Health) - Higher blood pressure variability is associated with greater cognitive and functional deterioration in Alzheimer disease (AD), according to a post hoc analysis of findings from the NILVAD trial.
Previous studies have found increased risks of future dementia and cognitive decline among patients with high visit-to-visit and day-to-day blood pressure variability.
Dr. Jurgen A. H. R. Claasen of Radboud University Medical Center, in Nijmegen, the Netherlands, and colleagues used data from the NILVAD randomized trial of nilvadipine in mild to moderate Alzheimer disease to investigate possible associations between blood pressure variability and progression of clinical Alzheimer disease.
Based on data for 460 patients (mean age, 72), a higher visit-to-visit variability in both systolic and diastolic blood pressure was associated with greater cognitive deterioration at one year. Only diastolic blood pressure variability remained a significant predictor after 1.5 years, however.
Similarly, patients in the highest quartiles of diastolic and systolic blood pressure variability had signficantly worse cognitive scores after one and 1.5 years, compared with patients in the lowest quartiles.
Visit-to-visit blood pressure variability was not associated with functional deterioration, the researchers report in Hypertension, online September 23.
In contrast, higher day-to-day systolic and diastolic blood pressure variability was associated with significantly greater functional deterioration after one year, but not after 1.5 years.
Higher day-to-day systolic blood pressure variability was also tied to significantly greater cognitive deterioration after one year.
"This study indicates that fluctuations in BP, and not BP levels per se, may be a risk factor for the progression of AD," the authors conclude. "Future research should confirm this and determine whether stabilizing BP might be a target to slow decline in this group."
"Given the worldwide burden of AD, even minor modifiable risk factors will have a large impact on a societal level," they note. "Also, on an individual level, reducing blood pressure variability (BPV) might have a substantial impact, as shown by the difference we observed between the highest and lowest quartile of BPV."
Dr. Simona Lattanzi of Marche Polytechnic University, in Ancona, Italy, who recently reviewed the association between visit-to-visit blood pressure variability and AD, told Reuters Health by email, "As currently there are no effective therapeutic strategies to slow or prevent AD development and progression, the identification of risk factors related to the disease course that may be potentially targeted and controlled represents a potentially important step toward the control of the disease burden."
"As antihypertensive agents have different effects on blood pressure variability, it would be really interesting to explore whether they are associated with different rates of AD progression," said Dr. Lattanzi, who was not involved in the study.
Dr. Tan Lai Zhou of Maastricht University Medical Center, in the Netherlands, recently reported that greater blood pressure variability is associated with lower cognitive performance. He told Reuters Health by email, "In the future, it is conceivable that clinicians will not only treat high blood pressure, but also treat high blood pressure variability. However, it is currently unclear how blood pressure variability could and should be treated."
Dr. Zhou, who also was not involved in the new study, noted that several post hoc trial analyses "suggest that long-acting calcium-channel blockers may be the agent of first choice," but more research is needed.
He added, "Blood pressure variability is becoming an increasingly important topic in the vascular research fields, but the use of blood pressure variability is still difficult to incorporate in daily clinical practice: how should it be measured, when is it 'too high', how do we treat it? These questions should be answered before it can be translated to an additional tool in cardiovascular risk management for physicians."
Dr. Claasen did not respond to a request for comments.
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