Adults in poor cardiovascular health were more likely to develop cognitive problems such as learning and memory impairment, compared with healthier peers, according to a large prospective study published online June 11 in the Journal of the American Heart Association.
But top scorers on the cardiovascular health (CVH) measure used in the study were not more protected against incident mental impairment than were intermediate scorers, reported Evan Thacker, Ph.D., of Brigham Young University in Provo, Utah, and his associates.
Dr. Evan Thacker
"This pattern suggests that even intermediate levels of CVH are preferable to low levels of CVH," the investigators said. "This is an encouraging message for population health promotion, because intermediate CVH is a more realistic target than ideal CVH for many individuals."
The investigators used the American Heart Association Life’s Simple 7 score to classify the cardiovascular health of 17,761 black and white adults in the United States aged 45 years and older (J. Am. Heart Assoc. 2014 June 11 [doi: 10.1161/JAHA.113.000635]). Individuals were participants in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study. The Six-Item Screener was used assess baseline global cognitive status; and a three-test measure of verbal learning, memory, and fluency was used to assess mental function at subsequent 2-year intervals. In all, 56% of individuals resided in "stroke belt" states, including Arkansas, Alabama, Louisiana, Georgia, Mississippi, North and South Carolina, and Tennessee, the investigators said. All study participants had normal cognitive function and no stroke history at the outset.
After adjustment for age, sex, race, and education, 4.6% of individuals with the worst CVH scores developed cognitive impairment after baseline (95% confidence interval, 4.0%-5.2%), compared with only 2.7% of those with intermediate scores (95% CI, 2.3%-3.1%) and 2.6% of those with the best scores (95% CI, 2.1%-3.1%), Dr. Thacker and his associates reported. Therefore, the odds of incident cognitive impairment were 35%-37% lower in the intermediate- and high-CVH groups than in the low-CVH group, the researchers added (odds ratios, 0.65 and 0.63; 95% CIs, 0.52-0.81 and 0.51-0.79, respectively).
"Rather than a dose-response pattern across the range of Life’s Simple 7 scores, we observed that associations with [incident clinical impairment] were the same for the highest tertile of Life’s Simple 7 score and the middle tertile, relative to the lowest tertile," the researchers wrote. "Based on these findings, we hypothesize that the AHA’s strategic efforts to improve CVH from poor to intermediate or higher levels could lead to reductions in cognitive decline, and we believe further research addressing this hypothesis is warranted."
The National Institute of Neurological Disorders and Stroke funded the study. The authors reported no conflicts of interest.