CHICAGO—Hypertension is associated with an increased risk of mild cognitive impairment (MCI) in the elderly, according to research presented at the 60th Annual Meeting of the American Academy of Neurology. The association appeared to be stronger with nonamnestic MCI than with amnestic MCI, reported Christiane Reitz, MD, PhD, and colleagues.
“These findings suggest that prevention and treatment of hypertension may have an important impact in lowering the risk of cognitive impairment,” said Dr. Reitz, who is a postdoctoral research scientist at Columbia University in New York City.
At Risk for MCI
Dr. Reitz’s group included 918 patients ages 65 and older, who were followed up for a mean of 4.7 years, in the longitudinal, community-based cohort study. All subjects were interviewed regarding their general health and function at time of study entry and underwent a standard assessment that included medical history, physical/neurologic examination, and neuropsychologic battery. The investigators assessed multiple cognitive domains with the use of a number of tests, including the Mini-Mental State Examination, Boston Naming Test, and Controlled Word Association Test, among others.
All patients with MCI had the following criteria—memory complaint; objective impairment in one or more cognitive domains based on the average score on the neuropsychologic measures within that domain and a 1.5-SD cutoff using normative corrections for age, years of education, ethnicity, and sex; essentially preserved activities of daily living; and no dementia. Hypertension was defined as having a history of hypertension, intake of antihypertensive treatment, or blood pressure values greater than or equal to 140 mm Hg systolic blood pressure or 90 mm Hg diastolic blood pressure.
The researchers identified 334 cases of incident MCI, 160 cases of amnestic MCI, and 174 cases of nonamnestic MCI during 4,337 person-years of follow-up. Among this sample, the mean age was 76, 69% were women, and the mean years of education was 8.9. About 69% of participants had hypertension, 24% had diabetes, and 34% had heart disease. In addition, 28% of subjects had the apolipoprotein (APOE) ε4 allele, and 14% had used statins.
Association Stronger With Nonamnestic MCI
“Hypertension was associated with an increased risk of all-cause MCI (hazard ratio [HR] 1.4) that was mostly driven by an association with an increased risk of nonamnestic MCI (HR 1.7)” said Dr. Reitz. “Both associations were slightly attenuated in models additionally adjusting for stroke and other vascular risk factors. There was no association between hypertension and the risk of incident amnestic MCI (HR 1.1).
“Hypertension was related with the slope of change in an executive ability score, but not with memory or language scores,” Dr. Reitz continued. “There was no effect modification of the association between hypertension and MCI by APOE ε4 genotype or use of antihypertensive medication.”
—Colby Stong