new research shows.
Investigators found that use of any antihypertensive was associated with an 18% decrease in Alzheimer’s disease neuropathology, a 22% decrease in Lewy bodies, and a 40% decrease in TAR DNA-binding protein 43 (TDP-43), a protein relevant to several neurodegenerative diseases. Diuretics in particular appear to be driving the association.
Although diuretics might be a better option for preventing brain neuropathology, it’s too early to make firm recommendations solely on the basis of these results as to what blood pressure–lowering agent to prescribe a particular patient, said study investigator Ahmad Sajjadi, MD, assistant professor of neurology, University of California, Irvine.
“This is early stages and preliminary results,” said Dr. Sajjadi, “but it’s food for thought.”
The findings were presented at the 2021 annual meeting of the American Neurological Association.
Autopsy data
The study included 3,315 individuals who had donated their brains to research. The National Alzheimer’s Coordinating Center maintains a database that includes data from 32 Alzheimer’s disease research centers in the United States. Participants in the study must have visited one of these centers within 4 years of death. Each person whose brain was included in the study underwent two or more BP measurements on at least 50% of visits.
The mean age at death was 81.7 years, and the mean time between last visit and death was 13.1 months. About 44.4% of participants were women, 57.0% had at least a college degree, and 84.7% had cognitive impairment.
Researchers defined hypertension as systolic BP of at least 130 mm Hg, diastolic BP of at least 80 mm Hg, mean arterial pressure of at least 100 mm Hg, and pulse pressure of at least 60 mm Hg.
Antihypertensive medications that were evaluated included antiadrenergic agents, ACE inhibitors, angiotensin II receptor blockers, beta blockers, calcium channel blockers, diuretics, vasodilators, and combination therapies.
The investigators assessed the number of neuropathologies. In addition to Alzheimer’s disease neuropathology, which included amyloid-beta, tau, Lewy bodies, and TDP-43, they also assessed for atherosclerosis, arteriolosclerosis, cerebral amyloid angiopathy, frontotemporal lobar degeneration, and hippocampal sclerosis.
Results showed that use of any antihypertensive was associated with a lower likelihood of Alzheimer’s disease neuropathology (odds ratio, 0.822), Lewy bodies (OR, 0.786), and TDP 43 (OR, 0.597). Use of antihypertensives was also associated with increased odds of atherosclerosis (OR, 1.217) (all P < .5.)
The study showed that hypertensive systolic BP was associated with higher odds of Alzheimer’s disease neuropathology (OR, 1.28; P < .5).