Older patients who have been treated with beta-blockers alone show fewer signs of dementia than those treated with beta-blockers combined with other medications and those not treated with beta-blockers, a new study shows. The reduction in dementia is not simply the result of the drugs reducing their blood pressure.
The study findings will be presented at the American Academy of Neurology’s 65th Annual Meeting, to be held March 16-23, 2013, in San Diego.
This initial phase involved 2285 patients in the prospective, community-based Honolulu-Asia Aging Study (HAAS) of Japanese-American men. The patients, aged 71 to 93 years at baseline, had hypertension without dementia when they entered; cognitive impairment and cognitive decline developed in 854 and 1199 of the men, respectively. The researchers examined the brains of 774 men at autopsy; of them, 610 had been treated with antihypertensives and 40 with beta-blockers alone.
In the post-mortem analysis of brains from the HAAS, the patients who were treated with beta-blockers alone showed fewer microinfarcts, less brain atrophy, and fewer brain lesions of the type linked to Alzheimer disease after adjusting for age, diabetes mellitus, apolipoprotein E status, cognitive test scores, baseline blood pressure, and midlife hypertension and treatment.
Although the patients treated with beta-blockers combined with other medications had fewer abnormalities than those not treated with beta-blockers, the use of beta-blockers alone was consistently associated with a lower risk of cognitive impairment during the final years of life.
The HAAS study was the first to identify beta-blockers specifically as superior to other antihypertensives at counteracting cognitive decline, although the results were based on brain lesions found at autopsy rather than clinical assessment of the men while alive, the lead author noted. He suggested that might be because beta-blockers may reduce stress on small blood vessels, reducing the risk of microinfarcts.
The results will be important for “hypothesis generation” about how beta-blockers might influence Alzheimer neuropathology and therefore cognition in later life, according to an expert commentator.
The study, Autopsied Brains Show Seniors on Beta Blockers Had Fewer Signs of Dementia, was published in the March 7, 2013, issue of Neurology Today. It was funded by the National Institute on Aging; the National Heart, Lung, and Blood Institute; and the Office of Research and Development, Medical Research Service, of the Department of Veterans Affairs.