Hypertension linked to increased risk of mild cognitive impairment

Last Updated: 2007-12-10 16:02:55 -0400 (Reuters Health)

NEW YORK (Reuters Health) – A history of hypertension is associated with the risk of incident mild cognitive impairment (MCI), investigators at Columbia University College of Physicians and Surgeons report in the December issue of the Archives of Neurology.

Dr. Jose A. Luchsinger and his associates conducted a prospective, longitudinal study among Medicare recipients residing in northern Manhattan. Participants were examined and underwent a neuropsychological test battery at baseline in 1992 through 1994, which was repeated up to three more times by 1999.

The 918 subjects were free of MCI and dementia at baseline. Mean age was 76.3 years, 62.8% were women, and 62.8% had hypertension. The cohort comprised 23% non-Hispanic white, 33% non-Hispanic black, and 44% Hispanic.

During 4337 person-years of follow-up, 334 cases of incident MCI were diagnosed, including 160 cases of amnestic MCI and 174 cases of nonamnestic MCI, "such as frontal-executive cognitive impairment."

Multivariate analyses adjusted for age and sex showed that hypertension was significantly associated with all-cause MCI (hazard ratio 1.40, p = 0.02) and with nonamnestic MCI (HR 1.70, p = 0.009), the New York-based research team observed. The risk of amnestic MCI was not significantly associated with hypertension.

"These associations remained stable in models additionally adjusting for years of education, ethnic group, and APOE-epsilon-4 genotype," the group reports. They add that use of antihypertensive medication had no apparent effect on the link between high blood pressure and MCI.

However, the associations were slightly attenuated after adjustment for stroke and other vascular risk factors, "indirectly suggesting that cerebrovascular disease may be mediating the relation between hypertension and nonamnestic MCI," Dr. Luchsinger and colleagues state.

They conclude: "Preventing and treating hypertension may have an important impact in lowering the risk of cognitive impairment."

Arch Neurol 2007;64:1734-1740.