Exact mechanisms of action unknown
Hélène Girouard, PhD, assistant professor of pharmacology and physiology at the University of Montreal, said in an interview that the findings are “of considerable importance, knowing that brain alterations could begin as much as 30 years before manifestation of dementia.”
Dr. Hélène Girouard
Since 2003, Dr. Girouard has been studying the cognitive effects of antihypertensive medications. She noted that previous studies involving rodents “have shown beneficial effects [of BBB-crossing antihypertensive drugs] on cognition independent of their effects on blood pressure.”
The drugs’ exact mechanisms of action, however, remain elusive, according to Dr. Girouard, who offered several possible explanations, including amelioration of BBB disruption, brain inflammation, cerebral blood flow dysregulation, cholinergic dysfunction, and neurologic deficits. “Whether these mechanisms may explain Ho and colleagues’ observations remains to be established,” she added.
Andrea L. Schneider, MD, PhD, assistant professor of neurology at the University of Pennsylvania, Philadelphia, applauded the study, but ultimately suggested that more research is needed to impact clinical decision-making.
“The results of this important and well-done study suggest that further investigation into targeted mechanism-based approaches to selecting hypertension treatment agents, with a specific focus on cognitive outcomes, is warranted,” Dr. Schneider said in an interview. “Before changing clinical practice, further work is necessary to disentangle contributions of medication mechanism, comorbid vascular risk factors, and achieved blood pressure reduction, among others.”
The investigators disclosed support from the National Institutes of Health, the Alzheimer’s Association, the Waksman Foundation of Japan, and others. The interviewees reported no relevant conflicts of interest.